tag:theconversation.com,2011:/us/topics/south-africa-drought-22536/articlesSouth Africa drought – The Conversation2019-02-05T13:44:02Ztag:theconversation.com,2011:article/1095132019-02-05T13:44:02Z2019-02-05T13:44:02ZScientists split on South Africa’s winter and summer rainfall zones<figure><img src="https://images.theconversation.com/files/252854/original/file-20190108-32142-167z35w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There needs to be a more systematic approach to classifying rainfall seasonality in South Africa.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>South Africa is among a handful of countries that experience winter rainfall in some areas and summer rainfall in others. The southwestern tip of the country has a Mediterranean climate, with hot dry summers and cool wet winters. This is because mid-latitude cyclones migrate further north during winter, allowing the edge of the cold front arm to sweep across the southern most part of the country. </p>
<p>The interior is dry and cold in winter, with subsiding air from strong high pressure systems. In summer this high pressure moves south, causing the dry conditions in the Western Cape and allowing convective storms in the interior. </p>
<p>All this is well documented. What is unclear is where exactly the boundary between the winter and summer rainfall zones exists. There is consensus that Cape Town is in the winter rainfall zone, and Johannesburg is in the summer rainfall zone, but these cities are separated by a 1,400km distance. What about the zone in between? </p>
<p>As it turns out, not even climate scientists are sure. We discovered this in <a href="https://www.tandfonline.com/eprint/jWgJEN7s2yrQ6bPUu5Ze/full?target=10.1080%2F03736245.2019.1573151&">research</a> we did to try and pin down where the line might be drawn. We geo-referenced all the existing rainfall seasonality maps, using Geographic Information System software to determine the areas of overlap between the maps. We found that there was no agreement in the position of this line. This is a problem for farmers, tourists, and even high school geography students who need to accurately classify the rainfall seasonality of a particular town.</p>
<h2>Interrogating historical maps</h2>
<p>We explored 60 South African rainfall seasonality maps that published between 1938 to present. Although some of these maps are direct republishing of an original map, each unique map has used a different climatological or statistical approach, and each has a slightly different location of the boundary of the winter rainfall zone. </p>
<p>A large area of the country has an agreement in rainfall zone classification of 75% or more. However, the region between the winter and summer rainfall zones is highly contested. A large band is classified by half of the scientists as winter rainfall zone, and half as summer rainfall zone. A smaller area, including the town of Sutherland, is completely disputed with researchers classifying it as summer, winter and year-round rainfall zones. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252811/original/file-20190108-32130-1adcq2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">South Africa’s rainfall zone.</span>
<span class="attribution"><span class="source">Provided by authors.</span></span>
</figcaption>
</figure>
<p>This problem is largely unique to South Africa. Much of the Mediterranean, which experiences a similar climatic transition, comprises small countries and thus each has a relatively coherent rainfall regime. Other countries that have changes in rainfall zone have a density of rainfall stations which means they don’t face the same problem. That said, this is one of the first papers to explore disagreements in rainfall zone mapping.</p>
<p>To complicate matters, boundaries appear to be shifting under climate change. In South Africa the winter rainfall zone extended as far north as Lesotho and the Free State during the Last Glacial Maximum, 24,000 years ago. It has progressively migrated south over the past <a href="https://journals.ametsoc.org/doi/pdf/10.1175/1520-0450%282002%29041%3C0046%3AEIOCVI%3E2.0.CO%3B2">20,000 years</a>. </p>
<p>Recent <a href="http://iopscience.iop.org/article/10.1088/1748-9326/aaebc7/meta">research</a> suggests that a continued southward migration under climate change may have been responsible for the severe 2015-2017 drought in Cape Town. This southward migration in the westerlies (winds blowing from the west toward the east) has been <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007GL031200">reported</a> for the entire southern hemisphere. Similar impacts of a weakened westerly system has also been implicated in the <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.710.5155&rep=rep1&type=pdf">California drought</a> of 2013-2014.</p>
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Read more:
<a href="https://theconversation.com/global-warming-has-already-raised-the-risk-of-more-severe-droughts-in-cape-town-107625">Global warming has already raised the risk of more severe droughts in Cape Town</a>
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<h2>Why it matters</h2>
<p>The classification of rainfall seasonality is important beyond academic debate. Tourism marketing relies heavily on providing potential visitors with an <a href="https://link.springer.com/article/10.1007/s00484-018-1617-0">accurate picture</a> of the weather that they can expect so that they can choose their destination to visit, plan the timing of their vacation and pack appropriate clothing. </p>
<p>Agriculture also relies on accurate and well documented <a href="https://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-4307">climate information</a> allowing farmers to sow their crops at the correct time of the year, select appropriate crops for the area, and manage pest and plant invasions effectively. </p>
<p>Even sectors such as transport and shipping and manufacturing <a href="https://journals.ametsoc.org/doi/pdf/10.1175/1520-0450%282002%29041%3C0046%3AEIOCVI%3E2.0.CO%3B2">benefit</a> from accurate climate information. Pilots, for example, need accurate climate information to determine flight paths.</p>
<h2>Better measures needed</h2>
<p>Our study highlights that there needs to be a more systematic approach to classifying rainfall seasonality in South Africa. The country needs to decide on the most appropriate measure of seasonality, and apply it to all of the available rainfall stations in the country. Farmers, tourists and climatologists will all need to keep a particularly close eye on these shifting zones over the next few years.</p><img src="https://counter.theconversation.com/content/109513/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jennifer Fitchett receives funding from the DST-NRF Centre of Excellence in Palaeosciences and the Society of South African Geographers. </span></em></p><p class="fine-print"><em><span>Chris Curtis receives funding from the NRF.</span></em></p><p class="fine-print"><em><span>Sarah Roffe receives funding from the National Research Foundation.</span></em></p>There are regions in South Africa where it hasn’t been established if the rainy season is in summer or winter.Jennifer Fitchett, Associate Professor of Physical Geography, University of the WitwatersrandChris Curtis, Professor of Geography, University of the WitwatersrandSarah Roffe, Postdoctoral Researcher Climatology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/985352018-06-18T19:59:51Z2018-06-18T19:59:51Z‘Day Zero’: From Cape Town to São Paulo, large cities are facing water shortages<p><strong>Will South Africa’s second largest city dry up on August 19 of this year? By launching an official countdown, Cape Town City Council wished to highlight the impending cuts to domestic water supply for its more than 3.7 million inhabitants.</strong></p>
<p>The BBC then upped the ante, with an online list of 11 cities that may sooner or later suffer the same fate. Since then, a tide of alarmism has swept through the media. It is as if we are suddenly realizing that water doesn’t flow from the tap by magic!</p>
<h2>What is happening in Cape Town?</h2>
<p>Located on the southern tip of Africa, Cape Town has a distinctly Mediterranean climate. This is why grapes grow so well there. But despite being a boon for winegrowers, that climate is characterized by formidable summer droughts. And with winter ending in the northern hemisphere and summer drawing to a close in the southern hemisphere, now is the time of year when the water reservoirs of Cape Town are typically at their lowest.</p>
<p>The city has a total of six reservoir dams to store water from rivers running down from the Cape Fold mountains, east of the city. Their total storage capacity is around 900 million cubic meters (for comparison, the storage capacity of the Grands Lacs de Seine reservoirs, upstream of Paris, is 810 million cubic meters).</p>
<p>But Cape Town’s current problems are far more serious than a simple seasonal slump: a prolonged drought raging since 2015 means that reservoirs have not been able to recover their reserves over the last three winters (2015, 2016 and 2017), leading to a steady decline in water storage rates (see graph below). Only a significantly premature and rainy winter could now prevent a general water shutdown; even then, it is unlikely that water storage rates will rise to secure levels over the course of one season.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216135/original/file-20180424-57607-4w27b0.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changes in water storage levels at Theewaterskloof dam, the largest of the reservoirs supplying Cape Town with water.</span>
<span class="attribution"><a class="source" href="http://niwis.dws.gov.za/niwis2/SurfaceWaterStorage">South African Department of Water and Sanitation</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Climate impact</h2>
<p>This extraordinary crisis is clearly due to climatic causes (an uninterrupted succession of dry years), with aggravating factors, such as high sustained urban population growth (+80% between 1995 and 2018) and water sharing between the city and agricultural land.</p>
<p>As a matter of fact, the water stored in Cape Town’s water supply reservoirs is not only used for drinking water: a third of its volume is used to irrigate the approximately 37,000 acres of vines and orchards that surround the city.</p>
<p>At the turn of the century, the council implemented an active policy for controlling water consumption, stabilizing it at the level reached in 1999, in spite of a significant rise in population (see graph below). The loss rate through leakage in the water distribution network is low (around 15%) and waste water is increasingly being re-used, in particular to water parks and golf courses.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216136/original/file-20180424-57611-u920uq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changes to Cape Town’s water consumption over time.</span>
<span class="attribution"><a class="source" href="https://www.greencape.co.za/assets/Water-Sector-Desk-Content/CoCT-WCWDM-presentation-Z-Basholo-Western-Cape-Water-Forum-160204-2016.pdf">Ville du Cap</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The City has already made plans for a general shutdown, which is now a very serious possibility. Water would be distributed from 200 sites, where inhabitants would be able to collect 25 litres per day, under the surveillance of the army and police.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1067&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1067&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216137/original/file-20180424-57588-yzqt4o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1067&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How to live with only 50 litres (13 US gallons) of water a day.</span>
<span class="attribution"><a class="source" href="http://resource.capetown.gov.za/documentcentre/Documents/Graphics%20and%20educational%20material/50%20Litre%20Life%20Poster-colour.pdf">Ville du Cap</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Local or global crisis?</h2>
<p>Looking beyond South Africa’s current troubles, we can wonder whether this crisis is local, or global.</p>
<p>The BBC published a list of eleven cities with recurring water supply problems; other organizations, such as the World Bank and various scientific journals, have published similar lists.</p>
<p>Numerous regions worldwide have experienced water supply crises in recent years. In 2008, Barcelona was forced to ship in water on tankers and, in 2009-10, Melbourne residents lived under the threat of water cuts following an extraordinarily long drought (1998-2010). The same drought also forced Sydney to implement water restrictions, reducing consumption by 20%.</p>
<p>In France, the island of Mayotte nearly had to call in the tankers in 2017, following a very late start to the rainy season.</p>
<p>While Cape Town’s extraordinary drought may well be considered a local phenomenon, UN demographic predictions for large cities provide little cause for optimism: current rates of population growth in Africa, Asia and North and South America are such that it is clear that water supply will be a major challenge for big cities in the 21st century (see graph below).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216143/original/file-20180424-57614-1io7dh7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Projected population growth rates for the world’s large cities (2014-2030).</span>
<span class="attribution"><a class="source" href="https://esa.un.org/unpd/wup/Maps/CityGrowth/2014_2030GrowthRate.pdf">United Nations</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>There are solutions</h2>
<p>Fortunately, there is nowadays a wide variety of long-term solutions to avoid city water supply crises. These range from reducing water consumption to increasing water storage and improving the management of existing resources.</p>
<p><strong>Change consumption habits</strong>: Changing city dwellers’ consumption habits is the surest way of avoiding water crises. But sociologist Rémi Barbier stresses that this is no easy task. Over the last decade, the French biodiversity agency has launched a number of studies opening up options to reduce water use.</p>
<p><strong>Improve water use management in agriculture</strong>: Better irrigation efficiency worldwide is a major step towards water savings. If we reduced the amount of water used for agriculture by just 10%, we could double the drinking water supply. For many years, efforts concentrated on improved irrigation techniques (such as trickle or drip irrigation, which is slowly replacing surface irrigation, where water floods the field). Today, work is being conducted on recycling urban waste water for irrigation.</p>
<p><strong>Improve distribution efficiency</strong>: We can save large volumes by reducing water losses in water transport and distribution networks. In France, an average of 25% of drinking water is lost to leaks in the network (this reaches up to 40% in places). While this figure is very high, it should be considered in the context of the size of distribution networks (nearly 850,000 km). Locating and repairing leaks is therefore a lot trickier than it sounds and we cannot hope to eliminate them all. It is however possible to reduce their impact by reducing network pressure at night, for instance, so as to limit losses from existing leaks.</p>
<p><strong>Improve natural flow predictions</strong>: In order to optimize the use of surface water, better anticipation of water flows is necessary. Forecasts – in the short-term for high water levels and in the medium- to long term (from a few days to a few weeks or months) for average to low flows – would enable us to better plan water releases and save water. Meteorological and hydrological models are the main tools that will help us better predict these phenomena. In France, a research program on predicting low water levels (Premhyce) will soon lead to an operational forecasting system.</p>
<p><strong>Better manage underground water sources</strong>: For large cities that rely on underground water, the main threat to supply is overuse. This is difficult to control, especially because ground water is accessible to a large number of local occupants, who do not always understand the resource they are using. Water management solutions should be adopted collectively: we must control consumption, allocate usage rights and, above all, make sure these rules are upheld by installing meters on wells.</p>
<h2>What about desalination?</h2>
<p>One of the solutions often proffered for water shortages is industrial production of fresh water by desalinating seawater (or brackish underground water).</p>
<p>Desalination is on the rise in various Near- and Middle Eastern countries, and in Maghreb. In Mediterranean Europe, it is being developed in Spain (Barcelona, the Canary Islands), Cyprus, and Malta. In France, it remains very rare, but the islands of Sein and Houat (in Brittany) have small desalination plants, as does Mayotte.</p>
<p>But desalination remains a very costly solution (around €0.50 per cubic meter for very large plants) and consumes a great deal of energy (from 3.5 to 18kWh per cubic meter, depending on the technique used).</p>
<p>Melbourne provides an instructive example: the Victorian State government built a seawater desalination plant to supply the city with drinking water. Construction began in 2009, during a drought, when water levels in the reservoirs had fallen to a historical low, but the plant did not become operational until 2012, when the drought had already broken. It did not receive its first order for water until 2017.</p>
<p>The current crisis in Cape Town reminds us that water does not automatically flow from our taps. This modern privilege is under threat from climate hazards and the remarkable growth of cities worldwide. Cities will have to seek out water further afield, and will no doubt come into competition with traditional users, such as farmers.</p>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
</figcaption>
</figure>
<p><em>Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the AXA Research Fund has been supporting nearly 600 projects around the world conducted by researchers from 54 countries. To learn more about this author’s research, visit his <a href="https://www.axa-research.org/en/project/vazken-andreassian">dedicated page</a> on the AXA Research Fund website. This article was co-written with Jean Margat, a hydrogeology expert.</em></p>
<p><em>Translated from the French by Alice Heathwood for <a href="http://www.fastforword.fr/en/">Fast for Word</a>.</em></p><img src="https://counter.theconversation.com/content/98535/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vazken Andréassian received funding from the Axa Research Fund. </span></em></p>In South Africa, Cape Town fears “Day Zero”, when the city will have to ration water drastically. The phenomenon threatens other cities as well but solutions exist.Vazken Andréassian, Ingénieur en chef des ponts, eaux & forêts, directeur d'unité de recherche, InraeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/920552018-02-20T10:00:51Z2018-02-20T10:00:51ZDay Zero is meant to cut Cape Town’s water use: what is it, and is it working?<figure><img src="https://images.theconversation.com/files/207069/original/file-20180220-116327-17xa2vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If Cape Town reaches Day Zero, taps will be closed and people will have to go to collection points for 25 litres of water.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The City of Cape Town has introduced the idea of Day Zero to focus everyone’s attention on managing water consumption as tightly as possible by cajoling water consumers into reducing usage. Day Zero is when most of the city’s taps <a href="https://www.iol.co.za/news/south-africa/western-cape/7-things-you-need-to-know-about-dayzero-12801609">will be switched off</a> – literally. </p>
<p>The consequences of reaching this point will be far reaching. For one, it will mean residents will have to stand in line to collect 25 litres of water per person per day. The water will be sourced from the remaining supplies that are left in the dams. </p>
<p>Day Zero isn’t a fixed target. The city moved it out from <a href="http://ewn.co.za/2018/02/20/day-zero-pushed-back-to-9-july">April 12 to July 9</a>. The reason for this is that a number of factors affect the date. These include how much residents are reducing their demand. There are already signs that water users are saving more. The goal is to achieve an average daily demand of less than 450 million litres which equates to about 50 litres per person per day. The city isn’t there yet, but for the first time figures are consistently closer <a href="https://www.news24.com/SouthAfrica/News/cape-town-isues-first-tender-to-produce-extra-500ml-of-water-20170817">to 500 million litre per day</a>.</p>
<p>The City of Cape Town describes Day Zero as the point at which the <a href="http://www.capetown.gov.za/departments/Disaster%20Risk%20Management%20Centre">Disaster Risk Management Centre</a> introduces phase 2 of its plan. Phase 2 will be triggered when the city’s big six dams supplying Cape Town reach a storage level of 13.5%. This leaves just enough water to supply critical services. This will include sufficient water to distribute to collection sites across the city. </p>
<p>Day Zero is being used in a desperate bid to avoid the final crisis stage – Phase 3 – when there is no longer any surface water available to supply the city. At that point, bottled water that’s been collected from groundwater, springs, and from whatever desalination plants can contribute will be distributed. Phase 3 will mark the point of complete failure.</p>
<h2>What happens on Day Zero</h2>
<p>Day Zero will be the start of active water rationing. As far as possible, drinking water will continue to be supplied to some critical areas. These will include strategic commercial areas, high-density areas with significant risk of increased waterborne disease such as informal settlements, and critical services like hospitals.</p>
<p>But water will be cut off to residential taps and large numbers of households and businesses will be unable to access drinking water in their homes and places of work. People will be forced to go to collection sites across the city to fetch water. </p>
<p>Meanwhile, city authorities intend to maintain sewerage systems with minimal flow by injecting water into the pipelines. It also means that a portion of water collected from the distribution points will have to be used, for example, to flush toilets.</p>
<p>In Phase 2 the plan is to roll out distribution points across the city. This will be impractical and hugely challenging at the very least. Site selection is unlikely to be evenly distributed across the city because distribution sites will depend on existing water pipelines.</p>
<h2>Avoiding Day Zero</h2>
<p>Cape Town is using a relatively simple model to manage water in an effort to move circumstances from a critical zone, and potential failure, to a position where the risk of running out of water is greatly reduced. </p>
<p>Each week the city updates its model to show progress <a href="http://resource.capetown.gov.za/documentcentre/Documents/City%20research%20reports%20and%20review/damlevels.pdf">in avoiding Day Zero</a>. </p>
<p>Tough water restrictions, plus punitive tariffs, will drive down water demand, helping to postpone Day Zero – or even leading to it being cancelled. Reduced demand is one way of postponing Day Zero. But there are other factors too.</p>
<p>The agricultural sector is already using 60% less water than what’s usually allocated to it. Some irrigation boards have closed off their water supply and farmers are reducing the amount they draw from the <a href="https://memeburn.com/2018/02/cape-town-dams-agriculture-usage/">Western Cape Water Supply System</a>.</p>
<p>Another factor is rainfall. But that’s unpredictable. In April 2005 a thunderstorm broke the drought and <a href="https://www.news24.com/SouthAfrica/News/analysis-this-water-crisis-wont-be-cape-towns-last-20170218">provided some relief</a>. </p>
<p>A final factor is that new projects will also bring additional water from tapping into the aquifers and from desalination. </p>
<h2>Painful months ahead</h2>
<p>There are some painful months ahead for Capetonians. For now, Day Zero remains a useful tool in the sense that it’s a target to be avoided. </p>
<p>There are encouraging signs suggesting that the city will get through this difficult period. For now, the city’s water risk model is showing how Day Zero is being managed. This is creating greater trust and confidence in the technical capacity of water managers along with the collective public and private efforts to reduce demand and avoid disaster. </p>
<p>Day Zero is not, as some have suggested, a hoax. It is a vital concept that is helping to strengthen the city’s ability in managing the water crisis.</p><img src="https://counter.theconversation.com/content/92055/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Day Zero will be the start of active water rationing when taps will be cut off and people will have to go to collection sites.Kevin Winter, Senior Lecturer in Environmental & Geographical Science, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/829482017-08-30T14:06:40Z2017-08-30T14:06:40ZDesalination? Africa should rather manage its water resources better<figure><img src="https://images.theconversation.com/files/183969/original/file-20170830-23681-rot52r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Modern desalination plant on the shores of the Arabian Gulf where the most desalinated water is produced.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Access to clean water in the future is by no means certain for many regions in Africa. These include semi-arid regions like the Western Cape of South Africa, where droughts are predicted to <a href="http://www.resilientafrica.org/Resources/Final%20Resources/ICLEI%20Africa_5%20City%20Adaptation%20Network_Cape%20Town%20Downscaled%20Climate%20Report.pdf">intensify under climate change</a>, and wetter countries like Nigeria, where many water resources are <a href="https://link.springer.com/article/10.1023/B:ENVR.0000031357.89548.fb">polluted</a>. Population growth, industrialisation and pollution will also add to the problem for <a href="http://www.wri.org/blog/2016/06/future-fresh-water">people needing clean water</a>.</p>
<p>South Africa has recently experienced one of the worst droughts <a href="http://www.bbc.com/news/world-africa-40002770">on record</a>. In particular, the levels of dams in the Western Cape have been <a href="http://www.dwa.gov.za/Hydrology/Weekly/ProvinceWeek.aspx?region=WC">dropping alarmingly</a>. The drought has had a bad effect on agriculture in the region which employs almost a quarter of the country’s <a href="http://www.farmersweekly.co.za/agri-news/south-africa/western-cape-droughts-knock-effect-sa-economy/">agricultural workforce</a>. Most of the <a href="http://www.aljazeera.com/news/2017/01/food-security-crisis-southern-africa-drought-170105094830319.html">southern African region</a> shares this water scarcity. </p>
<p>Desalination has been proposed as one of many strategies to deal with the water shortages in the <a href="https://www.timeslive.co.za/politics/2017-08-17-de-lille-unveils-r33bn-cape-town-water-plan-and-warns-of-higher-bills/">Western Cape</a>. <a href="http://www.water-technology.net/projects/region/africa/">Algeria, Ghana and Namibia</a> are also building desalination plants.</p>
<p>Desalination involves removing salt from salty water, like sea water. In the process, a highly saline brine is produced which is discharged into the sea. </p>
<p>Desalination is sometimes said to be relatively <a href="http://www.sciencedirect.com/science/article/pii/S0011916405006089">environmentally friendly</a> compared to the building of dams or transfer schemes. But it’s an expensive way of producing fresh water because it consumes a lot of <a href="http://www.sciencedirect.com/science/article/pii/S0011916410006296">energy</a>. In addition, the brine put back into the sea can <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">damage marine life</a>.</p>
<p>The world’s main producers of desalinated water are in the Arabian Gulf region. In 2008 they were collectively producing about <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">half of the global total</a>. Only about 1% of the world’s population is dependent on desalinated water for the majority of their domestic use, but this is expected to increase to <a href="https://www.globalwaterintel.com/desalination-industry-enjoys-growth-spurt-scarcity-starts-bite/">about 14% by 2025</a>.</p>
<p>Other regional centres of production have emerged, such as the Mediterranean Sea and Red Sea and the coastal waters of <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">California, China and Australia</a>. These are oil-rich or relatively wealthy countries which can afford the high energy cost of desalination. African countries are not as wealthy and have to consider the cost of desalination plants.</p>
<h2>The challenges</h2>
<p>There are two broad categories of desalination technologies. </p>
<ol>
<li><p>The first large desalination plants to be built, mostly in the <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">Middle East</a>, are based on distillation technology. Here, salty water is heated until it evaporates and then condensed to produce fresh water. This technology requires a lot of energy. </p></li>
<li><p>Plants built more recently tend to use reverse osmosis technology. Here, salty water under high pressure is forced through a semi-permeable membrane. The salt stays behind while the water goes through. This is the most energy-efficient form of desalination technology, and most new plants outside the Middle East use <a href="http://science.sciencemag.org/content/333/6043/712">variants of it</a>.</p></li>
</ol>
<p>The second process requires between 4 and 7 kilowatt hours of energy per cubic metre of water, depending on the technology used. A reverse osmosis plant with a capacity of 25,000 m3/day and energy demand of 5 kW h/m3 consumes about 125,000 kW h/day of energy. This plant could supply around 48 000 four-person homes with water. The energy used in desalination could supply about 10 300 of the same households <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">with electricity</a>. </p>
<p>The type of energy used is a problem too. Running plants on fossil fuels <a href="http://www.sciencedirect.com/science/article/pii/S0011916405006089">creates more greenhouse gas</a>, which contributes to climate change. </p>
<p>Desalination plants can be harmful to the <a href="http://www.sciencedirect.com/science/article/pii/S0011916407006005">environment</a>, particularly marine life. </p>
<p>Pipes used to suck water in to the plants can kill marine life and disturb sediments. And the saline brine released into the ocean tends to sink to the bottom layers of the ocean as this water is heavier. There, it kills species that aren’t adapted to such saline conditions. </p>
<p>The brine is also relatively hot, leading to further environmental damage, as certain fragile marine ecosystems, particularly coral reefs, are sensitive to temperature. Chemicals and toxic metals that may be produced and added to the brine before and after treatment are another threat to environments. </p>
<h2>Mitigating the risks</h2>
<p>The environmental impact of desalination plants must be assessed before they are built. Cape Town is going to speed up the environmental assessment associated with a planned <a href="https://www.desalination.biz/news/0/Western-Cape-looks-to-desal-as-Eksom-issues-RFP/8755/">mobile desalination plant</a>. </p>
<p>If possible, lightly salty groundwater should be used instead of sea water. This would use less energy and produce less brine. Where possible, desalination plants should use renewable energy. </p>
<p>Still, there’s a case to be made that desalination is energy-expensive and environmentally harmful. A better course of action would therefore be to manage water resources more efficiently. This means reducing water losses and water demand and reusing waste water. But these problems are complex and require long-term planning and large infrastructure investments. Desalination in contrast allows the immediate need for an additional source of water to be satisfied.</p><img src="https://counter.theconversation.com/content/82948/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Slaughter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Desalination has been proposed as one of many strategies to deal with the water shortages. But the process is known to be expensive and harmful to the environment.Andrew Slaughter, Researcher, Rhodes UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/818452017-08-07T16:01:27Z2017-08-07T16:01:27ZWhat’s driving Cape Town’s water insecurity, and what can be done about it<figure><img src="https://images.theconversation.com/files/181005/original/file-20170804-27491-1wb4fh6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cape Town's main storage dam, the Theewaterskloof in May 2017 with 9% of water left in storage.</span> <span class="attribution"><span class="source">Kevin Winter</span></span></figcaption></figure><p>In pre-colonial times the Khoisan called Cape Town, <em>//Hui !Gaeb</em>, the place “where clouds gather” and <em>Camissa</em> “the place of sweet waters”. The future of the city will be shaped by water as it was in the past. But far more attention will need to be paid to the drivers and early warning signs.</p>
<p>The city has been experiencing well below average rainfall over the last two-and-a-half years resulting in limited recharge of its main storage dams. The Western Cape region has been <a href="http://www.news24.com/SouthAfrica/News/western-cape-declared-disaster-zone-over-drought-20170522">declared a disaster area</a> amid a prolonged drought. </p>
<p>Rainfall over the next six weeks will be crucial. Cape Town has a Mediterranean climate with rains falling in the winter months. If there are no major thunderstorms and no significant interventions to bolster supplies from alternate sources such as local aquifers, treated effluent or desalination, then the city could run out of water by the end of year, or in early 2018.</p>
<p>Cape Town is almost entirely dependent on surface water from six main storage dams. Despite population growth and increased demand for water, it has successfully used water demand management over the past 17 years to conserve water by fixing leaks, reducing water pressures, educating users and restricting outdoor water use. But on their own these steps are unlikely to be adequate to avert “day zero”. Alternate water supplies need to be added.</p>
<p>There are two things that Cape Town needs to get right: firstly, it must improve its early warning systems. That is easier said than done. The current drought arrived at a speed and without a confident warning from the scientific community. And, secondly, it must diversify its water supply and become less reliant on surface water supplies.</p>
<h2>Early warning systems are not enough</h2>
<p>Early warning signs of a pending drought in 2017 were not clear or loud enough to <a href="https://africacheck.org/2016/02/03/frequently-asked-questions-about-south-africas-drought/">prompt timely actions</a>. As a result, the city was caught relatively unaware. Perhaps the success of the water demand programme created a false sense of security. </p>
<p>Citizens, businesses, officials and politicians responded slowly to early warnings about potential shortages. This is for a number of reasons. Water is taken for granted; there are too many confusing messages about how to manage water; and there is general apathy to adapt to water scarcity because it doesn’t seem to be a priority until it’s in short supply.</p>
<p>Lessons from the 1996 to mid-2010 <a href="http://www.bom.gov.au/climate/updates/articles/a010-southern-rainfall-decline.shtml">Australian Millennial Drought</a> show that threat of drought was clearly understood following several severe droughts. Despite the experience, central government was only able to act once the risk became extreme. But then it acted swiftly, investing heavily in <a href="https://theconversation.com/what-california-can-learn-from-australias-15-year-millennium-drought-55300">new technologies and infrastructure</a>.</p>
<p>This meant substantial increases in the unit cost of water. But Australians understood, and accepted them. </p>
<p>Australians also learnt that there are no quick fixes. They are still working on new interventions and education 10 years after the drought ended.</p>
<p>The City of Cape Town is following a similar trend by investigating new technologies. But these will take time to implement and deliver water in sufficient volume to rescue the city from disaster. In the meantime, saving water is the only game in town in the hope that it will buy the city sufficient time until the next winter rainfall in 2018. </p>
<h2>What should be done?</h2>
<p>Drivers of water resources are like the cogs in a mechanical system. They turn slowly – some more so than others. Often they fail to attract political will or financial attention because water management is competing with other priorities and demands. </p>
<p>The immediate imperative is to ensure that Cape Town has sufficient water to serve 4 million people with a collective demand of at least 500 million <a href="http://www.sapeople.com/2017/07/04/cape-town-warned-reduce-water-consumption/">litres per day</a>. It will involve significant investment in alternative water supplies like stormwater, groundwater, seawater or treated wastewater for non-potable use. </p>
<p>But investment to alleviate the crisis must be carefully managed. Emergency spending can restart further crises which in turn could lead to installing new technologies that can’t be used because they are inappropriate or not affordable.</p>
<p>The long term plans need to focus on “climate proofing” the city to ensure that it becomes a water sensitive city. These plans should include treating the city as a catchment where water is collected naturally. Water should be captured and stored in rain tanks, detention ponds, in recharged groundwater and floodplains.</p>
<p>Plans should also include bringing new life to the city’s waterways and regenerating natural systems. This is about rethinking the value of springs, rivers and streams. These blue and green corridors are water sources as well as valuable in <a href="https://link.springer.com/article/10.1007/s10584-016-1596-2">reducing urban temperatures.</a></p>
<p>The city must ensure it has proper plans in place that anticipate future events, such as prolonged changes in weather patterns, so that it can respond quickly. This must include being able to unlock investments and establishing private and government partnerships. </p>
<p>In addition, this drought is setting the conditions for the “new normal” in which citizens will need to become skilled at adapting to a sustainable threshold of water use.</p><img src="https://counter.theconversation.com/content/81845/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Early warning signs of a pending drought are difficult to recognise but cities will have to be better prepared for prolonged changes in weather patterns, so that it can respond quickly.Kevin Winter, Senior Lecturer in Environmental & Geographical Science, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/655942016-10-26T17:43:11Z2016-10-26T17:43:11ZHow a climate crisis can lead farmers to joint planning and response<figure><img src="https://images.theconversation.com/files/143046/original/image-20161025-31486-1kr9hmt.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Droughts in South Africa has led to coordinated joint planning and partnerships to combat the problem.</span> <span class="attribution"><span class="source">Stephanie Midgley</span></span></figcaption></figure><p>There is nothing like a major climate disaster to raise interest in the problem of climate change among farming communities. Farmers in many parts of the world have, in the last decade, strained under extended droughts and intense flooding. But farmers in southern Africa last experienced a major drought 30 years ago – and memories tend to fade – until the current devastating <a href="http://www.nstf.org.za/wp-content/uploads/2016/06/Agri-SA-Drought-Report_CS4.pdf">drought hit</a> the farming community. </p>
<p>Farmers are deeply optimistic people. They have to be, considering the huge numbers of risks they have to deal with. And climate change is usually not anywhere near the top of their list of priority challenges. This seems strange to climate scientists, whose work shows clearly that the agricultural sector is one of the most vulnerable sectors to <a href="http://www.sanbi.org/biodiversity-science/state-biodiversity/climate-change-and-bioadaptation-division/ltas">climate change</a>, particularly in water-scarce regions. </p>
<p>The current severe <a href="http://www.nstf.org.za/wp-content/uploads/2016/06/Agri-SA-Drought-Report_CS4.pdf">drought</a> appears to have made the penny drop and role players are scrambling to deal with the crisis while assessing what needs to be done to create greater resilience. The message that more frequent climate disasters like droughts can be expected in future is also being taken seriously.</p>
<h2>Constructive discussions</h2>
<p>A team of researchers completed an <a href="http://www.greenagri.org.za/smartagri-2/smartagri-plan/">assignment</a> from South Africa’s Western Cape Government to develop a provincial climate change response strategy and to implement a framework for the agricultural sector. The SmartAgri Plan project <a href="http://www.acdi.uct.ac.za/research/smartagri">began in August 2014</a>, many months before the first signs of the drought appeared. But at the end of the project, in March 2016, the province and country were in the grip of a two-year drought.</p>
<p>This fortuitously provided an environment ripe for engagement on the issue of climate change and how to respond to it. From the start, the project remit was to engage thoroughly across the sector – and related sectors like water and environment – and across the province. The plan was to find out what farmers, government and others are already doing to deal with climate risks. But also, to find out what approaches and measures are needed to build climate resilience.</p>
<p>During the first rounds of engagement it became clear that dialogue between government and the farming communities is sensitive to issues of mistrust and misunderstanding. This emanates from past injustices and present policy uncertainties. The team was surprised at the willingness of all participants to hear each other and try find solutions which benefit everyone, in the context of farming and non-farming problems.</p>
<p>There was real concern for the fate of the most vulnerable farmers, often smallholder communities and new farmers, who needed more support. Equally, all types of farmers generally place a high premium on good catchment management, water management and fire management. Their role in platforms like water user associations and fire protection associations was acknowledged.</p>
<h2>A coordinated response</h2>
<p>This made a valuable contribution to the development of a plan which represents a road map for an integrated and inclusive response across a number of time scales. It is supported by scientific and local knowledge and experience, linking top-down policy guidance with practical bottom-up perspectives. Critically, disaster risk reduction and management is prioritised as a discrete strategic focus area needing greater attention. If this plan is well-resourced for implementation it will strengthen the ability of the sector to plan for and manage multiple interacting climate stresses and contribute to reducing vulnerability.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143047/original/image-20161025-31462-1ymsv0v.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It is crucial for collaboration to adopt approaches and measures to build climate resilience.</span>
<span class="attribution"><span class="source">Stephanie Midgley</span></span>
</figcaption>
</figure>
<p>So far so good. Then, towards the end of 2015 and first half of 2016, the drought hit with a vengeance across the region especially the Western Cape’s west coast and central Karoo (a semi-desert in the southern interior of South Africa). Crop harvests failed with losses of 200 000 tonnes of <a href="http://www.greenagri.org.za/smartagri-2/wcdoa-drought-dialogue-2016/">wheat</a> (50-100% per farm), 230 ha of potatoes and 15% of fruit, and numerous livestock. The knock-on impact was up and down the agricultural value chain, and for farming communities struggling with unemployment, was critical. </p>
<p>Relief was provided in the form of fodder assistance to the most desperate farmers, to feed around 17 000 <a href="http://www.greenagri.org.za/smartagri-2/wcdoa-drought-dialogue-2016/">cattle</a>. The Western Cape provincial government convened a two-day provincial drought dialogue with all involved in June 2016. The aim was to discuss what else the provincial government could do to strengthen the response to the current and future droughts. </p>
<p>Agreement was reached on a set of 32 high priority interventions with further prioritisation of five actions. These focus on bridging finance for farmers to keep farmers on the land, optimising water usage, accurate drought forecasts, a social security net for vulnerable communities affected by the drought, and revisiting water management and policies currently hampering new infrastructure.</p>
<h2>Looking ahead</h2>
<p>Interestingly, the drought dialogue priorities correspond closely with the SmartAgri Plan. Rather than being confined to the strategic focus area on disaster management, they were spread widely across other focus areas as well. They intersected strongly with natural resources like, soil and water management. They focused on proactive joint planning and coordination, information and communications, regulatory and financial barriers, and social vulnerability. </p>
<p>The role of government in creating a cooperative and supportive environment emerged as the key requirement for building resilience. The provincial government has taken the recommendations forward into further planning and implementation, together with the SmartAgri Plan.</p>
<p>There is certainly value in bringing all involved to the discussions. Government officials, farmers and their leadership, and others like water and conservation managers come together around a table. They jointly built strategies around how to respond to current and future climate challenges. The drought has provided an opportunity to focus minds, acknowledge the urgency of action and identify priorities.</p>
<p>It has also reinforced the understanding that coordinated joint planning and partnerships which enable the much needed shift from typical responses to prevention are required. Everyone would prefer the building of greater resilience to climate stress and disasters compared to the current unsustainable reliance on government relief. </p>
<p>The time to make it happen is now. And hopefully the role players will keep talking and listening. This will build capital based on trust and a common vision of a shared future.</p><img src="https://counter.theconversation.com/content/65594/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephanie Midgley receives funding from the Western Cape Department of Agriculture. </span></em></p>Drought is a problem in South Africa and it affects farmers. As a result, farmers and government are working together to develop strategies.Stephanie Midgley, Researcher and Project Manager in Agriculture, Food Security and Climate Change, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/604612016-06-14T15:20:54Z2016-06-14T15:20:54ZResilience in South Africa’s urban water landscape<figure><img src="https://images.theconversation.com/files/126519/original/image-20160614-22416-1qlxgci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some informal settlements in Cape Town are located on or near wetlands.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Resilience is becoming a core concept in water governance. It refers to the ability of communities, cities or regions to withstand the challenges posed by an increased intensity and frequency of floods and droughts. </p>
<p>Resilience often involves adopting diverse, flexible, adaptive and redundant or supplemental systems. This pertains to both physical infrastructures and governance arrangements. Resilience in the urban water sector also focuses on restoring and maintaining water ecosystems, such as wetlands, rivers or streams.</p>
<p>The Stockholm-based <a href="http://www.resalliance.org/">Resilience Alliance</a> and other Euro-American institutions have largely driven the frameworks for resilience. However, they are now increasingly being applied in African cities. For example, Accra, Cape Town, Dakar, Durban, Enugu and Kigali are all participating in the Rockefeller Foundation’s <a href="http://www.100resilientcities.org/#/-_/">100 Resilient Cities</a> initiative. Each city appoints a <a href="http://www.100resilientcities.org/blog/entry/what-is-a-chief-resilience-officer1#/-_/">chief resilience officer</a> to lead action on addressing its specific resilience challenges. For <a href="http://www.theguardian.com/cities/gallery/2016/may/25/resilient-cities-addis-yiwa-manchester-washington-in-pictures">Cape Town</a> these include civil unrest, rainfall flooding, infrastructure failure and disease outbreaks.</p>
<p>Another example from southern Africa is the <a href="http://www.africancentreforcities.net/programme/future-resilience-for-african-cities-lands-fractal/">Future Resilience for African Cities and Lands</a> programme. It engages decision-makers and officials in cities like Cape Town, Windhoek, Maputo and Lusaka to develop plans for resilience to climate change.</p>
<p><a href="http://icgc.umn.edu/collaborations/international-partnerships/partnership-university-british-columbia/international">Our research</a> looks at the meaning, application and utility of resilience in urban water governance in African contexts. We focus specifically on Cape Town, in South Africa’s Western Cape province. </p>
<h2>An African focus</h2>
<p>African cities are often sites of rapid or unplanned growth, with poorly coordinated or spotty development. This has important implications for resilience planning in the face of floods and droughts. It requires addressing both formal and informal forms of urban development.</p>
<p>The Western Cape faces additional challenges. The projected impacts of <a href="https://www.capetown.gov.za/en/EnvironmentalResourceManagement/publications/Documents/Framework_for_Adaptation_to_Climate_Change_(FAC4T)_08_2006_38200713832_465.pdf">climate change</a> include increasing mean annual temperatures, changes in precipitation patterns and decreasing winter rainfall in the western parts of the region. More intense storms are also expected. This will likely lead to flooding, which already poses serious concerns in the region. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/126515/original/image-20160614-22418-12dplxc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Flooding in Cape Town’s informal settlements poses a serious risk to people living there.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Addressing urban resilience also requires meaningful engagement with historical patterns of colonial development and apartheid legacies. Cape Town is a stark example of persisting high levels of social, spatial and structural inequalities. This is despite various efforts to address these issues.</p>
<h2>Key dimensions of water resilience</h2>
<p>Our ongoing research focuses on the question: what does resilience mean – or what should it mean – in Cape Town’s urban water sector? </p>
<p>Preliminary literature and policy analyses show a few key factors of water resilience.</p>
<ul>
<li><p>Resilience in <a href="http://poliswaterproject.org/publication/854">water governance</a> comes from a mix of government structures, watershed groups and various stakeholders. Effective coordination, little conflict and working partnerships between government and stakeholders are key drivers of resilience. For Cape Town, this means increased collaboration between government, civil society and other key actors.</p></li>
<li><p>Healthy watersheds and high biodiversity contribute to resilience in the face of climate change. Natural systems like wetlands provide <a href="http://www.annualreviews.org/doi/abs/10.1146/annurev.energy.32.031306.102758">many mitigation services</a>. These include temporary floodwater storage, ground water recharge and storm water purification. This calls for deeper integration of hydrology and ecology in water management policies.</p></li>
<li><p>Resilience often means living and dealing with floods. It requires accepting certain levels of flood risk, preparing for the unexpected and adopting more innovative approaches. These include natural flood retention systems and other soft approaches to flood protection. This requires addressing informal urbanisation, which often happens in sensitive watersheds.</p></li>
<li><p>For disaster response, resilience calls for proactive approaches. This means that cities should focus on building capacity to deal with disasters as opposed to relying on relief when they happen.</p></li>
<li><p>Building community resilience to floods, droughts or other water risks is a crucial aspect. Livelihood diversification, flexible settlement options and greater reliance on community level planning are some of the proposed strategies. This requires capacity building in various areas, including in impoverished and informal settlements. </p></li>
<li><p>Flexibility in governance and infrastructure systems is also necessary to manage different conditions of water availability or water-related risks. This means learning, reflection and experimentation should be built into governance and planning processes.</p></li>
</ul>
<h2>Embracing African urbanism</h2>
<p>Some of these insights seem rather obvious but it remains unclear how effective they’ll be in the context of the high levels of informality, poverty and inequality. </p>
<p>In terms of flooding, some informal settlements in Cape Town are located on or near wetlands or flood detention ponds. These are designated areas for absorbing excess water to protect against flooding. During floods, these <a href="http://www.acdi.uct.ac.za/news/flooding-cape-town-under-climate-risk-fliccr-project-report">settlements are highly vulnerable</a>. </p>
<p>Flood detention ponds can increase overall urban resilience to floods but they may also increase the vulnerability to flooding of informal settlements located on these sites. Unfortunately impoverished urban residents do not have the capacity or resources to plan where to build their communities. Informal settlements are often built on an ad hoc basis. </p>
<p>Addressing urban inequalities is central to formulating water resilience strategies. Embracing endemic, non-Western or <a href="http://www.africancentreforcities.net/can-transcend-slum-urbanism-africa/">more organic</a> forms of urbanism is crucial. This means working with, rather than against informality. It is also important to build governance capacity to help address these issues. </p>
<p>The complexities of African urbanism and persistent social and environmental concerns should be central in defining and planning for resilience. Resilience in an African urban context should adopt a transformative character. This can be done by building on diverse governance and development processes, including informal ones.</p><img src="https://counter.theconversation.com/content/60461/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucy Rodina receives funding from the Social Sciences and Humanities Research Council and the University of British Columbia. </span></em></p><p class="fine-print"><em><span>Leila Harris receives funding from the Social Sciences and Humanities Research Council of Canada for work related to this article. </span></em></p>Many African cities are sites of rapid urbanisation. To ensure that such societies are water resilient, it is necessary to address formal and informal forms of development.Lucy Rodina, PhD Candidate, University of British ColumbiaLeila Harris, Associate Professor, IRES, Institute for Gender, Race, Sexuality and Social Justice, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/505342015-11-16T11:32:09Z2015-11-16T11:32:09ZSouth Africa is failing to rise to its water challenges<figure><img src="https://images.theconversation.com/files/101577/original/image-20151111-9388-1u3ivg9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A lone cow stands next to a dried up river in South Africa.</span> <span class="attribution"><span class="source">Siphiwe Sibeko/Reuters</span></span></figcaption></figure><p>A country like South Africa, where rainfall is variable and unpredictable, has to plan for the worst. Specifically, it has to plan to manage the impacts of drought. For cities, present practice is to store enough water to supply the needs of each region during the worst conditions likely to occur in 50 years.</p>
<p>To meet that target for the growing population of Gauteng, the country’s economic hub, a new dam must be built. The site has been chosen, the <a href="http://www.engineeringnews.co.za/topic/polihali-dam">Polihali Dam</a>, identified as Phase 2 of the <a href="http://www.lhda.org.ls/">Lesotho Highlands Water Project</a>.</p>
<p>As so often in South Africa, the problem is not the plan but the delays in its implementation. According to the original planning, the dam should be completed by 2018. Given slow progress, my understanding is that it is now not possible for it to deliver water before 2024. </p>
<p>So, for at least six years, there is a risk that the water needs of Gauteng, which contributes more than <a href="http://www.southafrica.info/about/geography/gauteng.htm#.VkNUY7crLnA">one-third</a> of the country’s GDP, will not be met reliably.</p>
<p>It only took a few days of hot weather in Johannesburg for two things to happen: suburban reservoirs ran dry, and residents panicked. City authorities introduced restrictions on watering gardens and washing cars, and residents reacted as though this had never happened before, which in fact it had.</p>
<p>The extreme weather can serve a useful purpose: it should focus the attention of people and policy makers on the deadline to build the new dam. If no action is taken, policy makers will have only themselves to blame when failure of another vital service disrupts people’s lives, and the economy.</p>
<p>To understand why the Lesotho Project is so important, it is necessary to understand how droughts affect the country and what should be done about planning for water security in the face of drought. </p>
<h2>Agricultural versus hydrological droughts</h2>
<p>There is a difference between an <a href="http://drought.unl.edu/DroughtBasics/TypesofDrought.aspx">agricultural drought</a> and a <a href="https://www.ncdc.noaa.gov/monitoring-references/dyk/drought-definition">hydrological drought</a>. </p>
<p>Agricultural drought occurs when limited rainfall reduces soil moisture and affects crop growth - which is already happening in five provinces. Hydrological drought is where a reduction in rainfall reduces the amount of water that flows into rivers and streams and into storage in dams and underground.</p>
<p>For farmers, three months of dry weather will ruin a year’s rainfed crops. While perhaps half of the country is already affected by an agricultural drought, it is not yet suffering a hydrological drought – although one may have begun.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=513&fit=crop&dpr=1 754w, https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=513&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/101578/original/image-20151111-9369-ch6ww6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=513&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Better planning could have seen South Africa’s water crisis avoided.</span>
<span class="attribution"><span class="source">Rogan Ward/Reuters</span></span>
</figcaption>
</figure>
<h2>The role of El Nino</h2>
<p>Hot dry Novembers are not unusual in South Africa, although this year has been on the extreme side. In Johannesburg, temperatures <a href="https://www.enca.com/weather/another-heatwave-drought-worsens">reached</a> 36°C, the hottest in 30 years. Similarly, the temperature at the Irene weather station in Tshwane north of Johannesburg was 36.6°C, the highest in <a href="http://www.weathersa.co.za//media/data/climate/nr_records.pdf">40 years</a>. </p>
<p>The current weather was predicted some months ago by the <a href="weathersa.co.za">South African Weather Service</a>. Its June Seasonal Climate forecast reported that an “El Nino” phenomenon was developing in the Pacific Ocean. It <a href="http://www.waterwise.co.za/export/sites/water-wise/water/weather-forecast/downloads/Seasonal_Climate_Watch_-_May_2015.pdf">warned</a> that El Nino was associated with reduced rainfall and high temperatures in southern Africa.</p>
<p>The last El Ninos of similar intensity happened in the 1981-82 and 1997-98 <a href="http://www.vox.com/2015/8/17/9164499/el-nino-2015">seasons</a>. </p>
<p>In South Africa, the first was associated with a <a href="http://www.wrc.org.za/Knowledge%20Hub%20Documents/Water%20SA%20Journals/Manuscripts/1987/01/WaterSA_1987_01_418.PDF">crippling drought</a> that saw widespread crop failures and severe water use restrictions across much of the inland areas. The second caused significant crop losses but far less impact on water supplies.</p>
<p>So the occurrence of an El Nino does not necessarily mean that there will be a major drought this time. It serves as a wake-up call to water managers and the community at large about the need to be prepared. And to speed up the construction of that damn.</p>
<h2>The other weather pattern worth mentioning</h2>
<p>South Africa potentially faces a very different set of weather challenges – massive floods – driven by a phenomenon with a much less catchy name: the <a href="http://www.bom.gov.au/climate/enso/history/ln-2010-12/IOD-what.shtml">Indian Ocean Dipole</a>. It is a measure of temperature differences in the Indian Ocean and is considered to be a good predictor of monsoon rains in India as well as of cyclones in the south west Indian Ocean.</p>
<p>Those cyclones are important because they have been responsible for some of South Africa’s most extreme rainfall. They usually take place in the first few months of the year. </p>
<p>It’s happened before. <a href="https://www.dwa.gov.za/iwqs/reports/tr/TR_122_1984_Domoina_floods.pdf">Cyclone Domoina</a> caused devastation in KwaZulu/Natal in 1984 and in 2000 when <a href="https://www.dwa.gov.za/hydrology/weather.htm">cyclone Eline</a> filled the dams of Limpopo and Mpumalanga.</p>
<p>Even if the full force of such storms doesn’t reach the coast, it often causes rainfall as far inland as Gauteng. It was Eline that saw 500mm of rain fall in Levubu, Limpopo province in just three days and caused devastating floods in <a href="http://news.bbc.co.uk/2/hi/africa/655227.stm">southern Mozambique</a>. </p>
<p>So while El Nino spells dry weather, fluctuations in the Indian Ocean Dipole may signal more tropical storms. In that case we may see floods as well as drought.</p>
<h2>Pressures at the local level</h2>
<p>Given the electricity shortages in the country and what euphemistically became known as <a href="http://www.eskom.co.za/documents/LoadSheddingFAQ.pdf">load-shedding</a>, many people have started to assume that long feared <a href="http://www.bdlive.co.za/national/2015/11/03/brace-for-water-shedding-say-experts">water-shedding</a> had begun. The commentators who sought a more strategic view talked about an intense drought and the impacts of climate change. They were wrong.</p>
<p>In fact most of the problems over the past few weeks have occurred in the domain of municipal water supply management. </p>
<p>The suburban challenge for planners has been whether to invest in larger local distribution reservoirs to allow people to water their gardens regardless of how hot the weather gets. In Johannesburg 46% of household water supply is used for swimming pools and watering <a href="http://www.joburg.org.za/index.php?option=com_content&view=article&id=10174:reduce-water-demand-minister-urges-jozi-residents&catid=88:news-update&Itemid=266">gardens</a>. </p>
<p>If they don’t want to do this, municipalities have to improve their ability to persuade their citizens to use less water during times of stress. So far, they have singularly failed to do this.</p><img src="https://counter.theconversation.com/content/50534/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Muller has received funding from the South African Water Research Commission and advises a range of private and public organisations on water and development matters at national, regional and international levels.</span></em></p>The water crisis in South Africa could have been avoided through better planning.Mike Muller, Visiting Adjunct Professor, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/504912015-11-11T18:52:32Z2015-11-11T18:52:32ZEl Niño threatens southern Africa with yet another drought<figure><img src="https://images.theconversation.com/files/101582/original/image-20151111-9381-6h6npv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A farmer sitting on a water tank he uses to supply his livestock.</span> <span class="attribution"><span class="source">Reuters/Siphiwe Sibeko</span></span></figcaption></figure><p>Southern Africa is in for a bumpy, dry ride. There is a 50% chance of a drought occurring this summer that could have an impact on the whole <a href="http://reliefweb.int/report/democratic-republic-congo/statement-nineteenth-southern-africa-regional-climate-outlook-forum">region</a> which still bears the effect of last year’s drought. Any new drought will have a compounding <a href="http://www.gfcsa.net/csir.html">effect</a>. </p>
<p>During the 2014-15 southern hemisphere summer southern Africa suffered one of the <a href="http://mg.co.za/article/2015-09-24-00-drought-predictions-for-southern-africa">worst-ever</a> droughts. This severely affected the agricultural sector as well as the economies of the countries in the region. In addition, the drought seriously depleted <a href="http://citizen.co.za/429490/kzn-water-depletion-fears-calmed/">water reserves</a>.</p>
<p>The current drought in the region is as a result of a powerful <a href="https://theconversation.com/explainer-el-nino-and-la-nina-27719">El Niño</a> event. El Niño is a natural and periodic phenomenon that comes back every three to five years and can last for <a href="http://www.elnino.noaa.gov/lanina_new_faq.html">up to two years</a>. It increases temperatures in the Pacific and Indian Ocean which in turn can cause <a href="https://theconversation.com/when-the-indian-ocean-and-el-nino-join-forces-things-can-get-hot-and-dry-48969">drought</a> conditions. </p>
<p>During 2015 the Pacific became even warmer leading to one of the strongest El Niño events ever <a href="http://www.elnino.noaa.gov/">observed</a>. <a href="https://www.researchgate.net/profile/Yves_Richard/publication/255616482_Intensity_and_spatial_extent_of_droughts_in_southern_Africa/links/00b7d53c0e25b4ad96000000.pdf">Research</a> shows that eight of the ten strongest droughts in southern Africa since 1900 occurred during the mature phase of El Niño. It has also been noted that El Niño events have led to a severe drought half of the time they occurred. </p>
<p>The effect of El Niño on droughts has been exacerbated over the past 50 years. This has been because continental and oceanic temperatures have risen globally but not uniformly during due to the increase in <a href="http://www.giss.nasa.gov/research/news/20150116/">carbon dioxide</a>. </p>
<p>El Niño events leading to droughts in the region have been particularly marked since the late 1970s. Most have occurred between December and March. Recent studies show that El Niño has affected summer rainfall with increased dry spells, reductions in the flux of moisture from the Indian Ocean to the continent, and by shifting large scale rain bearing systems to the Indian Ocean.</p>
<h2>Successive droughts over the last century</h2>
<p>Over the last century, southern Africa has suffered from dramatic year-on-year changes in climate leading to severe droughts and disturbance in the marine or terrestrial ecosystems. Such variability of climate affects the agricultural industry, water reserves, fisheries and as a result the broader economy. It also affects the flow of water in streams, vegetation and the fluxes of nutrients into the ocean.</p>
<p>It has a particularly detrimental effect on:</p>
<ul>
<li><p>rural subsistence farmers and fishermen;</p></li>
<li><p>the health of people in rural areas; and</p></li>
<li><p>the management of a sustainable natural environment. </p></li>
</ul>
<p>During the last decades research projects have shed a great deal of light on how the oceans can influence the climate of southern Africa. But more research is needed to find out the effects of El Niño. Two critical questions in particular need to be answered:</p>
<ol>
<li><p>why does El Niño sometimes not lead to drought; and </p></li>
<li><p>why a weak El Niño can trigger a severe drought while a strong El Nino can trigger a less severe drought.</p></li>
</ol>
<p>In addition, more information needs to be gathered on how natural climate events such as El Niño and climate change interact. And there is a serious need to improve our understanding of the impact these large scale variations have on smaller scales. We must also keep in mind that describing the nature of climate variability’s impact is essential to being able to anticipate future climate changes and the need to define adaptation strategies.</p>
<p>Given that El Niño does not result in a drought 100% of the time, it is important to establish what measures should be taken in the case of a risk of drought. This would enable countries to prepare for major disturbances which are increasing in frequency as a result of climate change.</p>
<p>El Niño could have dramatic consequences for southern Africa. Food shortage, famine, unrest, economic hardship and further decrease of the gross national <a href="http://www.news24.com/SouthAfrica/News/The-high-cost-of-SAs-worst-drought-in-23-years-20150708">product</a>. Hopefully the region will not be hit as hard as it was in the <a href="http://www.vox.com/2015/8/17/9164499/el-nino-2015">1997-98 El Niño</a> effect. But we shouldn’t gamble on that.</p>
<p>It is imperative for countries, and individual citizens, to take preventive measures for what is now known to be a recurring pattern in southern Africa. This includes selling cattle, restricting water, fixing leaks, planting drought resistant crops and getting ready for a drought.</p><img src="https://counter.theconversation.com/content/50491/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mathieu Rouault receives funding from ACCESS, Water Research Commission, NRF (South Africa), Nansen Tutu Center and the EU FP7/2007–2013 under Grant Agreement No. 603521. Mathieu Rouault is affiliated with SASAS, AGU, AMS, CLIVAR.</span></em></p>The current drought in southern Africa is as a result of a powerful El Niño event. Better planning and forecasting could help mitigate the effects.Mathieu Rouault, Associate Professor in Oceanography, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.