An alternative solution?

In this blog, there have been a variety of discussions on how to increase food production and make water use more efficient in order to meet food demands in Africa. This has been interlinked with the effect climate change has on food insecurity. These are all important but they only focus on improving food production. The concept of ‘virtual water’ is an alternative to these ideas. Virtual water is a term used to explain ‘how physical water scarcity in countries in arid regions is relaxed by importing water-intensive commodities.’ The concept is simple as it suggests that countries that have insufficient water resources should import high water demand crops to avoid this drain on their domestic water. As with all concepts, there are benefits and drawbacks.

Figure 1 below shows the virtual water balance by country and the major flows of virtual water. Focusing specifically on Africa, the northern and southern areas tend to import more virtual water than the lower latitude African nations. Much of northern and southern Africa is desert and this highlights their need to import water intensive crops. Importantly from this map, all the major flows of virtual water between countries avoid Africa entirely.

Figure 1: Virtual water balance by country and direction of major flows (1996-2005)

Virtual water in Africa

Virtual water is a key component of addressing food insecurity across Africa. African countries predominantly trade in virtual water with other African countries rather than the rest of the world. The biggest connection is between two southern African countries, Zimbabwe and South Africa. It is important to note that countries in Africa frequently trade with their neighbours. The connectedness between African countries is important because virtual water trades can be mutually beneficial and meet different needs in different countries. For example, countries can specialise in certain crops that grow well in their climate without having to worry about providing a variety of crops.

There is a tentative link between increasing openness to virtual water trade and decreasing undernourishment (which is a proxy for food security). This would suggest that virtual water security is an effective method for reducing food insecurity. Globally there is a trend that, as crop exports increase, water efficiency also increases but Africa is an anomaly to this trend. Because of this, the importance of virtual water is raised in Africa due to the shortcomings of other methods to reduce food insecurity. It is likely to be the case that funding is the key reason why water efficiency has not increased as much of the technology is too expensive for small-scale farmers.

A 2013 paper, suggested that virtual water imports may lead to overpopulation in some areas which may make these areas unsustainable. Increasing populations of areas with insufficient resources puts further strain on virtual water trade and leaves the population vulnerable to agricultural changes worldwide as they are reliant on crops produced in a variety of countries around the world. The MENA region (Middle East and North Africa) has been identified as a region where overpopulation is driving an increase in food demands and thus increased food insecurity. Population has quadrupled between 1950 and 2000. In addition, there has been poor water management and declining water quality. This illustrates that countries should not be over-reliant on virtual water trade.

Overall, it is clear that virtual water has a key role to play in meeting water and food demands in Africa. It is vital to remember that it is not a complete solution and over-dependence of virtual water trade can bring about other problems such as over-population. Africa as a continent does not have to be entirely reliant on increasing food production and raising efficiency levels to meet food and water demands, virtual water trade can help too.

Food insecurity in South Africa

Early on in this blog I discussed some of the issues surrounding the current drought in South Africa. Since then, the drought has worsened and food supplies are critically low. There has also been a shortage of donor funds to support people, partly as a result of droughts having very slow impacts that can often pass donors by. The drought has led to extreme food shortages leaving many families suffering.

A paper by Kamara and Sally (2004) in Development Southern Africa investigates some of the potential water management options with regard to food security in South Africa. Although it was written in 2004, it still has relevance to the present day. The paper highlights the link between water security and food security in poor households, emphasising the need to ensure good water supply. One of the biggest problems for South Africa in this regard is the low physical productivity in agriculture and low irrigated crop yields. The low productivity of crop growth points to one key problem, the fact that South Africa is simply unable to produce enough food especially when droughts occur.

The majority of South Africa’s water use is for the agricultural sector, much like other countries around the world. In order to manage water better, this is the sector that therefore needs to be targeted with more sustainable and equitable water use. A number of different techniques to achieve this, such as drip fed irrigation, have been mentioned in previous posts.

Figure 1: Dry crops in South Africa

The paper discusses a model called Podium which is a ‘decision support tool for testing policy options that aim at striking a balance between water allocations for food production on the one hand, and for satisfying domestic, industrial and environmental needs on the other hand.’ This model is intriguing as it attempts to balance the importance of different demands within a country. The model incorporates many different aspects of water usage and water availability. This form of water management may be particularly useful in a country such as South Africa which struggles with water availability due to climate and few large river catchments in their territory.

One alternative to improving water usage is to address food insecurity through food aid. However, a paper by del Ninno et al. (2008) suggests that food aid is not very effective at reducing food insecurity in Africa and instead private markets can often been more efficient at providing food for those that need it the most. Importantly, it is the fact that food aid is poorly targeted and often has other costs associated (such as administration costs). If these could be addressed then food aid would be far more successful but only as a short term solution during periods of severe shortage as consistent food aid could reduce the desire of a country like South Africa to grow its own food.  

Between water management, the Podium model, food aid and markets, there are many solutions to deal with problems of food insecurity in South Africa and other African countries. The success of these is however dependent on how effectively they are implemented and who they benefit.

Food security and climate change

I recently watched this video highlighting the link between climate change and food insecurity in West Africa. The news clip explores a number of different aspects of this link, talking about drought and flood resistant crops, whether climate change is seen as a big issue and the effect of climate change on Africa relative to the rest of the world. A key point raised was that incidents of climate related issues in sub-Saharan Africa have gone up tenfold over the last 30 years. The impacts of climate change are going to have the greatest impacts on Africa and this means food security is going to be severely affected.

Physiology of plants and climate change

I thought it would be interesting to look at plants at a physiological level to see what impact climate change is having on them. This is of great importance for farmers and scientists to assess how crops may adapt to climate change and this is likely to have implications for crop yields and the management of farms into the future. Climate change brings about changes in temperature, atmospheric carbon dioxide levels and rainfall levels and frequency. These have impacts on the physiology of plants in a variety of different ways.

C₃ and C₄ crops

Below shows the two different forms of uptake of carbon dioxide by plants. The majority of plants fix the atmospheric carbon dioxide with the C₃ pathway such as wheat, rice and soybean. The C₄ pathway is where carbon dioxide is concentrated internally. There are fewer plants that use the C₄ pathway, these include maize, sorghum and sugarcane. The process of photorespiration, which occurs alongside photosynthesis, is where plants take up some oxygen and release some CO₂ back to the atmosphere. Photorespiration occurs more in C₃ plants as the rate of photorespiration in C₄ plants is almost zero. The impact of climate change is therefore more likely to be on C₃ crops with increased photosynthesis due to higher CO₂ levels as well as a suppressed oxygenation process. The C₄ crops are less likely to respond to changes in CO₂ because ‘these plants have an internal mechanism that concentrates CO₂ internally.'

Figure 1: C₃ and C₄ plants

Energy balance

Under the influence of climate change, the net energy balance of plant leaves will change. Increases in temperature will lead to a greater loss of water because of a vapour pressure deficit. This will increase the amount of water lost by plants and the amount of water the plant consumes to meet these losses. Despite this, rises in atmospheric carbon dioxide would actually decrease the amount of water lost by leaves because stomatal conductance would decrease as a result of these stomata remaining openfor a shorter period of time. The actual amount of water used by the plant will still be reliant on the amount of water supplied to the leaf through precipitation and irrigation. This means that the frequency of rainfalls and the availability of irrigation are still very important to crop growth.

Soil surface wetness

In areas where there is low canopy cover, such as large crop fields, soil surface wetness determines the amount of water used. If the surface of the soil is dry, this increases water consumption as there is a higher vapour pressure deficit. This subjects crops to harsher conditions which negatively impacts growth. In hot African regions such as the Sahel, this is likely to be a key issue and with the impacts of climate change into the future, the demand for water for crops is expected to increase. With rainfall also becoming more sporadic and intense, the need for irrigation techniques is greater than ever.

Impacts for farmers and the provision of food in Africa

A study in southern Africa investigated the response of crops to climate change. The paper suggested that the positive effects of carbon dioxide may be able to offset the potential negative impacts on crops of climate change. These feedbacks are important to consider and because they are highly spatial variable, it is very difficult to predict the impacts. This study also suggested that by the time we reach the latter half of the 21^st century, the fertilising effects of carbon dioxide may not be able to make up for the other negative effects. Therefore climate change may have a more long term impact on crop yields and the system may actually be able to adapt in the short term.

I believe this post has emphasised the importance of effective irrigation in Africa. There are a variety of physiological changes to plants caused by climate change and these are more likely to affect future food scarcity than existing scarcity. To adapt to increasing water loss, crops will need to be irrigated more intensively but this requires access to sufficient water resources and the technology to extract it. 

Water, Climate Change and Africa

I was drawn to writing a post on the link between water, climate change and Africa by an article discussing international agreements regarding climate change such as this year’s COP (Conference of the Parties) climate summit. African countries will see some of the most severe climate changes in the future with six of the ten countries most affected by greenhouse gases being located in Africa. This is all despite the fact that the continent receives just 5% of global climate funding. On a more positive note, ‘every single African country has included adapting agriculture as part of their climate change strategies submitted to the United Nations Framework Convention on Climate Change (UNFCCC).’ Therefore this is not a question of willingness but rather one of finance. To investigate this further I wish to look into the funding behind agriculture in Africa to understand how it here can adapted to changes in rainfall patterns, droughts, etc.

The news article highlights three main areas to target investment to ensure the future of African agriculture. These are: better soil management, water control and climate-risk management. The first of these is very important for maintaining high crop yields. Research has found that soil nutrient levels decrease with distance from water points. The areas close to water points also had a lower soil salinity level. Salinity is a key cause of land degradation; overly saline soil is unsuitable for growing the majority of crops. This is another reason why droughts are especially damaging for agricultural business as in addition to killing off crops, it can also leave land unsuitable in the long term. A concerning statistic is that 65% of soils in Africa are likely to be degraded. This statistic combined with the fact that climate change will likely cause further degradation suggests a concerning future for all of Africa, especially those involved in the agriculture sector. One idea is to plant crops that are natural fertilisers of the soil such as chickpeas and lentils that add nitrogen. This simultaneously combats the issue of degraded soils and sustains an income for farmers in the short term. It is therefore an alternative to growing existing crops.

The second of these target areas for investment is water management. Currently there is a lack of knowledge on irrigation water values in small-scale farming schemes. In the future, farmers will have to pay for the water they use and therefore the issue of water management is of economic and environmental importance. It is extremely complicated to assess the consumption of water for irrigation because there is a great variability between irrigation schemes and the type of crop grown. This makes it difficult to estimate the overall dependence on water systems and therefore how to control water resources. As well as improving the knowledge of irrigation water demand, there are a number of techniques, such as drip fed irrigation, which can be applied to reduce water consumption universally. Drip fed irrigation reduces water usage as the water is applied directly to the root of the crop through a distribution system of pipes, meaning less water is lost through evaporation and the minimum amount of water required can be added as water flow can be controlled. This research and equipment however requires funding and it reflects back on the key issue for African countries – funding.

Figure 1: Drip fed irrigation in Kenya

Climate-risk management is the final area that requires investment. This can involve the development of new crops such as climate-tolerant and disease-resilient varieties. In sub-Saharan Africa, there will be a shortage of cereals in the near future if the status quo is maintained. Insect resistant varieties of maize and cotton suitable for this area of Africa have increased crop yields. The use of genetically-modified crops, especially drought-resistant varieties, could reduce water consumption for irrigation as well as increasing the chance of survival during periods of very low rainfall. Climate-risk management is the least suitable of the three methods to implement across Africa because it would take longer to implement than the other two methods mentioned earlier.

Overall, as a continent, Africa is fully committed to mitigating the effects of climate change on the agriculture sector and have the techniques available to achieve this that are suitable for this part of the world. What they do lack however is the financial backing to implement such projects and this is where the international community should be open to helping African countries. Without financial support the future of agricultural sectors across Africa is concerning, risking crop deaths and heavily degraded land that is unusable for crops. It would leave people across Africa in an extremely difficult situation.

North Africa's problem with water

Northern Africa is one of the hottest and driest places on the planet with very low rainfall levels. The Middle East and North Africa Region (MENA) is the most water scarce area worldwide. This brings great problems in terms of water shortages for both domestic use and farming uses. In West Africa and North Africa (WANA), 75% of water consumption is for agricultural uses. This means that the agricultural sector is more greatly affected with fluctuations in water resources and therefore requires better water management than other regions of Africa. By looking into the different factors affecting North Africa, it will be possible to better understand the water difficulties facing this region and see what farmers are doing to combat these effects. This may be particularly important for other areas that are not currently water scarce but will become so in the future due to climate change.

First, we begin with one of the key issues surrounding water facing North Africa – climate. North Africa is a naturally hot and dry region that is prone to droughts. Around 85% of MENA is desert and climate change is having a profound effect on this region. Much of the rainfall in North Africa therefore occurs in the winter season and it is dry during the summer season. As can be seen by the map below (Figure 1), the dry season is very long lasting in Northern Africa, lasting at least 7 months in most areas and in some places the full year. This means that the growing season in these areas is very short without irrigation techniques. Water resources are extremely scarce in this region presently and climate change is only going to exacerbate this. A paper by Droogers et al. (2012) on how water resources in North Africa will change towards 2050 found that demand for water will increase in the MENA area under all climate scenarios as a result of population growth. This, combined with the fact that climate change will lead to more sporadic and intense rainfall, suggests that the future for North Africa and water resources is extremely problematic.

Figure 1: Months with less than 25mm rainfall in Africa

One of the fall back options for areas under drought conditions is the availability of groundwater which has built up over centuries and recharges gradually. Under North Africa there are large stores of groundwater but there is a complication with these reserves. Figure 2 shows the depth to the groundwater stores across Africa. As can be seen, much of the groundwater stored under North Africa is located deep underground with much being more than 100 metres below ground level (mbgl). This is significant because water stored deep underground is more difficult and more costly to extract and many poor farmers would not have access to the more sophisticated technology required to extract this deep groundwater. This exacerbates the problems cause by droughts as farmers cannot access the stores of water under their feet that could allow them to sustain crops longer into the dry season. As it is clear to see, North Africa has a much more severe problem with water shortages than any other area in Africa because of the climatic conditions and the unavailable groundwater resources.

Figure 2: Depth to groundwater (metres below ground level)

So what do farmers in North Africa do to counteract these problems? Two methods of improving productivity are supplement irrigation and water harvesting. Supplemental irrigation involves the adding of small amounts of water to crops during critical growth phases in order to boost the overall yield. This can substantially increase the crop growth and only requires water collection and storage during peak rainfall periods. However, farmers need the knowledge of these critical growth phases to know when irrigate their crops. The other method mentioned, water harvesting, is defined as “the process of concentrating precipitation through runoff and storing it for beneficial use”. This can be crucial for generating enough water to irrigate crops to the required level. In addition, farmers in Morocco are involved in projects that introduce drought resistant crops. These crops require less water but produce the same grain yield meaning that farmers are less vulnerable to long droughts and serious water shortages.

North Africa suffers greatly from water shortages in a variety of ways but have developed techniques to adapt. North Africa is an excellent example for areas that will experience longer droughts and less rainfall in the future as a result of climate change. The approaches to water scarcity in North Africa are relatively easy to apply to other areas of Africa and the world and emphasise people’s ability to adapt to adversity. These systems suggest a hopeful future for areas at risk of water scarcity in the future.

Solar powered irrigation

Figure 1: SunCulture solar irrigation

Today I read a thought-provoking article on the development of new technology for use in East Africa that combines the use of solar energy with the application of irrigation to cropland. This is quite different to some of the irrigation techniques I have mentioned before such as motorised pumps which do not have this eco-friendly focus. The concept of solar power irrigation is interesting as, for it to be considered useful, it needs to be both technically and economically feasible and this is much harder to achieve in certain areas of Africa due to lack of finance. One of the key ways, solar energy generated from cells would be used to provide irrigation is through the pumping of water from underground stores and then pumping the water onto the crop land.

The American company mentioned in the article – SunCulture – is a company already selling this technology in Kenya for up to $2,400 and they have plans to expand into other countries in Eastern Africa. Importantly, just 4% of Kenya’s arable land is currently irrigated meaning that food production is far below maximum capacity. In previous posts, I have mentioned the costs of irrigation methods such as treadle pumps ($20 - $100) and many of these methods are unaffordable for small scale farmers so $2,400 solar power irrigation is a far out of reach for the majority of farmers across Africa. SunCulture have worked around this through a gradual repayment scheme where farmers pay in installments throughout the year and more is paid when they have the money to pay around harvest time. In addition to the solar irrigation technology, farmers are also given access to expertise from different suppliers which can help to boost yields up to four times.

This all sounds very promising but are solar energy irrigation techniques feasible on a larger scale for most farmers? With farmers in sub-Saharan Africa being located at low latitudes, the output from solar cells is likely to be much higher than other areas as solar radiation is more concentrated around the equator. Further to this, crops are typically planted in the spring and summer and this period coincides with increases in solar radiation. The depth of the well that water needs to be drawn from is important. A greater solar panel area is required to pump water from greater depths and the area also depends on the amount of water the crop being irrigated requires.

In my opinion, this method is very feasible both technically and economically. In Africa, there is sufficient solar radiation at the correct times of the year to provide enough solar power to pump water, much of the underground water stores are at relatively shallow depth and the financial barriers are overcome by companies willing to extend time to farmers to pay them back. This is all important as well as the fact that fuel to power motorised pumps is likely to increase in price in the future. Personally, I feel that this method of irrigation has a very important role to play in the future of farming in Africa.

Paper Review: Rainfall and Water Resources Variability in Sub-Saharan Africa during the Twentieth Century

As I have pointed out in previous posts, rainfall and water resources have a key impact on the ability of farmers in Africa to irrigate their crops. This is where I felt it would be interesting to review a paper focusing on this issue and how the access to water has high variability. The paper, written by D. Conway, A. Persechino, S. Ardoin-Bardin, H. Hamandawana, C. Dieulin and G. Mahé, is titled ‘Rainfall and Water Resources Variability in Sub-Saharan Africa during the Twentieth Century'. It will be interesting to look into one area where there is much variability, sub-Saharan Africa that has a serious problem with water shortages. In this post I will study this paper in detail, attempt to draw some conclusions from it and find places where the research may be lacking or need extending.

The aim of this paper from the Journal of Hydrometeorology is to study the spatial and temporal covariability of rainfall and river flows in the sub-Saharan region of Africa. The research is categorised into four key regions, central, south, east and west. The data used in this research come from a variety of sources, mainly the Institute de Recherche pour le Développement (IRD) and other national and international sources. The focus of the paper is on the changing rainfall and river flow levels on a temporal scale from 1901 – 2002, the entire 20^th century, to see if the levels were variable throughout this century. The research studies these trends at a basin scale rather than a nation state level as this highlights that the focus is on the hydrological issues as hand rather than the political issues. Data on rainfall and river flows in sub-Saharan Africa is not perfect, there is often a lack of data for certain regions and the chronology may be incomplete or lack temporal resolution (not be recorded frequently enough). In my opinion, this paper is attempting to come to some more general conclusions at a regional level for rainfall and river flow rather than focusing on a single river basin to carry out this research. Although this provides more conclusions, it can lack detail and miss certain local differences that may also have an influence in rainfall and river variability such as water that is diverted for irrigation at a smaller-scale. There is also a concern with some of the records dating back to the early 20^th century. The data collection techniques from this time are likely to be far less sophisticated and this means that some of the conclusions may be lacking in certainty.

So what did this research actually find? One of the most interesting points that I picked up from reading this paper was that through time there has actually been a shift rather than a trend in the West African rivers. This shift occurs between the two time periods mentioned, 1931-1960 and 1961-1990. The authors go on to state that, ‘Proportionally, the shift is much greater in river flows (from -13% to -51%) than rainfall (from -7% to -14%).’ This means that river flows during the second period are a step below those in the early 20^th century. This is even more interesting when we know that the three other regions in this research do not show much variation between these two time periods, therefore West Africa is far more hydrologically unstable (see graphs in Figure 1). Something occurred during the 20^th century in West Africa that has not in the other regions. The big shift in river flows but not rainfall suggests that something or someone is altering the basin environment and changing how the river flows. Although nothing is mentioned in the article as to what has caused this, I personally feel this may have something to do with large scale dam and irrigation projects that are used in West Africa in many basins to boost food production through irrigation. This would account for the large variation in river flows but less variation in rainfall. 

Figure 1: Annual rainfall (black line) and river flow (gray line) for rivers in West Africa

Another of the figures in the paper (Figure 2) shows the strength of the relation between rainfall and runoff for different rivers studied. Many of the rivers show very strong relationships between rainfall and runoff over the thirty year periods. It is then intriguing to look at which regions have strong and weak relationships and question why this is the case. The overall relationships suggest that variations in rainfall account for the majority of runoff variation. In the instance of East Africa, the geology and unique Rift Valley system accounts for the unusual patterns observed there. Lake Victoria outflows show a very weak relationship to basin rainfall.

Figure 2: Strength of regression between rainfall and runoff for the 30 year periods

To conclude, this paper gives a very clear overview of rainfall and runoff trends through the 20^th century. It is important to remain critical of data in all instances. Data in this research is from a variety of sources that may be inaccurate or incomplete which can leave us drawing conclusions where there are none. I feel that this paper has achieved the aim of looking at these two hydrological characteristics both spatially and temporally and put forward some interesting data and conclusions to better understand the background to water resources in the sub-Saharan Africa region. Personally, I find it very interesting to look at some of the reasons behind the results that this piece of research has put forward despite the possible uncertainty with the results.

Small-scale irrigation in Africa

This post is going to focus on the activities of small scale farmers with regard to their use of irrigation. There are many problems facing small-scale farmers in Africa (especially sub-Saharan Africa) and it is worthwhile taking a look into these in some depth. This isn’t to say it is all doom and gloom as there are a number of opportunities for people to improve their irrigation techniques and earn more money from their crops. Small-scale farmers often lack access to finance for irrigation, have a lack of support from governments and international organisations, are lacking in local water resource knowledge and efficient usage and are often in competition with large scale farms. These will be looked at to investigate the issues at play for small-scale farmers in Africa.

Aid and Finance for irrigation

An article from 2013 highlighted the key problems for farmers is access to irrigation - the fact that being small-scale farmers does not provide them with the finance to develop their irrigation methods and that the government and international aid is lacking in its support of these farmers. In sub-Saharan Africa, this problem is particularly significant as many countries are reliant on aid for a large proportion of their national expenditure. The Official Development Assistance (ODA) to agriculture has been on the decline. Support for the agriculture sector has dropped from 17% in 1980 to just 6% in 2008. This shows that funding has halved in the last three decades. This is especially disappointing as the majority of this funding is likely to be spent on irrigation projects and the development of irrigation for small-scale farmers is known as a method to escape poverty. It is however still possible for many small-scale farmers to fund their own irrigation systems. One of these is known as treadle pump which is a human powered pump that draws groundwater to the surface (Figure 1). These pumps can cost in the region of $20 -$100 and despite being expensive for poor farmers in Africa, it is not impossible to gain the funds. The next stage up from this are motor pumps which are more expensive but more effective at extracting groundwater.

Elsewhere in Africa, there has been a decrease in state funded irrigation schemes such as those in Northern Province, South Africa. This included the decline in funding for central pivot irrigation and has all occurred because the state engaged in the privatisation of many services to encourage local farmers to take responsibility for their own local resources. This leads on to the next section on water resource knowledge and management.

Figure 1: A treadle pump in operation.

Local water resource knowledge, usage and management

Another major problem for small-scale irrigators is that they lack the local knowledge of resources that are available to them and how to effectively manage them. In South Africa, there is growing water scarcity and this means that water management for irrigation is becoming even more important and will continue to do so into the future. This is a major problem compounded by the fact that the new water policy will hurt small-scale farmers even more as in the near future, subsidies will progressively decline and eventually they will need to pay for the water they use. The effective management of water for irrigation will be vital because of this. Unfortunately, there is a lack of mapping of the available groundwater across Africa, which leads to great uncertainty of the accessibility to water resources. It is not known how far down the water is, the volume of water stored in underground aquifers and the rate of groundwater recharge. These are all important aspects of the groundwater resource that need to be known and understood so that water is not used too quickly and is easily accessed. Adding this knowledge would clearly benefit efficient water use for irrigation. As I have mentioned before, I feel groundwater irrigation should be used as a coping mechanism (a way of adapting) for droughts and changes in rainfall as a result of climate change both on a seasonal and inter-annual time scales. This type of research is unachievable by small-scale farmers themselves and requires the support of much larger organisations who have the expertise and finance to carry this out.

Small-scale vs large-scale

Small-scale irrigators often have to compete with larger-scale farmers in a wide variety of ways. Financial donors face the tough decision over whether to finance large-scale irrigation projects that involve dams and reservoirs or small-scale irrigation systems. A paper from 2014 investigated the advantages of investing in small-scale irrigation projects over larger projects. The research found that there was a big opportunity for the expansion of small-holder irrigation in sub-Saharan Africa that would benefit farmers with improved incomes and reduced food insecurity. There are still concerns about the effectiveness of funding these projects as individuals often lack the knowledge to utilise the irrigation techniques and land tenure insecurity reduces funding for long-term projects. This is likely to be one of the main reasons behind the continued funding of larger projects at the expense of small-holder irrigation schemes.

To conclude, it is evident that there are many factors working against small-holder irrigation in Africa but there is still hope for farmers. This area provides great potential for expansion but only if resources (time, money, expertise) are invested in it. Small-scale farming is especially important for African economies and the livelihoods of families and this is why I believe that there should be an increased focus on promoting this area of irrigated farming for growth.

The Food Energy Water Nexus

Today I watched this interesting video by WWF South Africa on Youtube which highlights the key links between water, food and energy. It neatly summarises the issues that South Africa are undergoing (nicely linking to my previous blog post on South Africa). The video made me think about the role energy plays in the relationship between food and water. This is because the role of energy is often neglected. In other words, the focus with regards to water and food is on how to find and obtain more water, not how are we going to find the energy to obtain that water. The clip states that South Africa is currently in an energy crisis and therefore this is a key issue in the country.

The video also raised a point that struck me as unusual. The statement was ‘We need to produce more food with less water.’ To me this is very strange as the obvious ways to increase food production is through increased irrigation and therefore more water consumption. Researching this further, an article titled 'How to grow more food with less water' emphasises the importance of technology to achieve this. Sensors, satellites and software can be used to assess water demand for crops on a farm. New technology is even being developed right now:

“Susan O’Shaughnessy, a research agricultural engineer at the U.S. Department of Agriculture in Bushland, Texas, is developing new sensors for center-pivot irrigation devices to help farmers ensure that precious groundwater isn’t wasted. The sensors measure leaf-canopy temperature to gauge water demand, which helps avoid over-irrigating.” 

This advancement of irrigation by the use of technology is particularly important as around 40% of the world’s food grows on irrigated land. Improved use of water for irrigation through the implementation of technologies could reduce water demands of farms by up to 50%. This includes the use of drip systems that supply water slowly onto the crops, directly at the surface so that almost no water is lost through evaporation. It is clear that there are huge possibilities to make improvements to the irrigation of croplands.

Short videos like this one can help you to view an issue from a different angle and that is always important when studying a complex problem that requires new and innovative solutions.

No mention of groundwater?

A recent article published in Bloomberg titled ‘ “Catastrophe” Seen by S. Africa Agriculture Due to Drought’ caught my eye. South Africa, one of the most developed countries in Africa, is experiencing its worst drought in more than a century. As to be expected, agriculture is being hit hardest. This is exacerbated by the fact that rivers and dams are also running dry and that the drought may well continue into 2017.

The article highlights how the drought is incurring huge financial costs for individuals and businesses in South Africa with the government spending 268 million rand on drought relief. The recent El Niño event caused the drought here and a lack of rainfall since then has halted the recovery from this. This entire article, however, does not mention groundwater what-so-ever despite groundwater being useful during droughts. This encouraged me to look into South Africa’s access to groundwater and the use of groundwater to adapt to climate change.

Figure 1: (a) Groundwater storage measure in water depth (mm) and (b) total groundwater storage by country in Africa

As can be seen from Figure 1, South Africa is not particularly lacking in groundwater storage with eastern areas having around 10,000 – 25,000 mm water depth of groundwater and a reasonable recharge rate of 25-100 mm per year. It is also worth noting that South Africa has more groundwater than around two-thirds of countries in Africa. So now we know that South Africa isn’t lacking in groundwater, why wasn’t it mentioned as an irrigation technique in the Bloomberg article?

The groundwater in South Africa is located relatively shallowly compared to other areas of Africa as shown in Figure 2. This means that it is easier to extract the available groundwater and much greater amounts can be extracted using motorised pumps – as is necessary for irrigation. This gives extra weight to the argument for using groundwater in South Africa and questions why it isn’t being used more.

Figure 2: Estimated depth to groundwater (mbgl)

South Africa’s relationship with groundwater fed irrigation is interesting. As a result of the country’s apartheid history, much of the development and financing for irrigation was focused on White Farmers. This is particularly important as 80.2% of the population in South Africa is Black African. Further to this, irrigated land of White farmers was on average 10 times larger than those of Black farmers. The majority of Black farms are therefore small scale and the irrigation technology was directed to larger scale farms. These statistics help to show that the issues surround irrigation in South Africa are in fact related to the country’s apartheid history and the lack of access to irrigation technology and finances for many Black farmers. To me, this illustrates why South Africa is having such a ‘catastrophe’ with the droughts. The majority of small scale farmers lack groundwater access to keep their crops irrigated during this prolonged dry spell despite the water resources existing in (or under) their country.

Specifically regarding smallholder irrigation schemes in South Africa, just 3.0% of land that required irrigation used groundwater sources. This is incredibly low considering the large groundwater resources that are relatively easily available in South Africa as mentioned earlier. With reduced rainfall and rivers running dry, it is easy to see why crops are dying and small scale farmers are struggling. They simply are unable to access the groundwater beneath their feet that could help them during dry periods like the one they are currently in.

So what does the next year and the future hold for South Africa? Agriculture currently accounts for 85% of freshwater usage and total consumption for agriculture is expected to double by 2050. This increased demand for water alongside climate change is going to have significant impacts on irrigation in South Africa. Figure 3 below highlights that the relative increase in water demand for crops is going to increase more significantly in South Africa than many other areas. With South Africa dominated by a few large commercial farms and numerous small scale subsistence farms, the people of South Africa will be dearly affected by climate change. It is unknown how climate change will impact food production exactly in South Africa but some models predict that under wetter and warmer conditions, welfare in South Africa will increase due to an improved competitiveness in the food market globally. Whether South Africa will get wetter and warmer is again debatable and other future situations see the country far more negatively affected. 

Figure 3: Relative increase in crop water consumption

It is understandable that the Bloomberg article neglected groundwater in the piece on the South African drought due to its relative insignificance as an irrigation technique in the country. It is worth saying however that if the country could provide good access to the groundwater as a source of irrigation, it would improve their resilience to droughts and other impacts of climate change in the future. Personally, I believe that in South Africa’s case, groundwater usage should be limited to instances of extreme drought, and therefore only used sparingly in times of greatest need as the rate of groundwater recharge is low and sustained use could leave the nation short of water.

Welcome!

Hello and welcome to my blog looking into the relationship between water and food in Africa. I thought to begin with it would be useful to introduce this topic and why I have chosen to blog about it. One particular statistic peaked my interest in the relationship water and food, the statistic being that in 2000, around 70% of freshwater extracted was used for agriculture. To me this seemed high considering most of the water use that an individual can observe is used domestically in the form of showers, washing machines and water used in cooking. It isn’t obvious in day to day life how important water is to the food we eat.

As the majority of the water use is for agriculture, I thought it beneficial to investigate further the link between the two. The focus of this blog is Africa, an area of the world that has the biggest issues with water, food production and the effects of climate change.

Introducing this topic a little more, it is necessary to look at some key background data that show some interesting trends. The graph below (Figure 1) shows global blue water withdrawal up to the present and predicted into the future. Blue water just refers to surface water (e.g. rivers and lakes) and groundwater (water stored underground, I will look into this in more detail in future blog posts). This graph illustrates the significant proportion of water consumption taken up by irrigation which is predicted to increase into the future. Interestingly, household consumption is of relatively small importance but this is projected to increase into the future, likely as a result of global population increase.

Figure 1: Estimated and predicted water consumption, abstraction and withdrawal.

This is all very interesting but tells us little about the specific area this blog is looking at, Africa. So why is water for food so important in Africa? Firstly, the very warm climate means that a large proportion of rainfall is lost as evapotranspiration (evaporation and transpiration). This is problematic as it means much larger quantities of water are required to irrigate cropland. In addition to this, Africa contains many of the poorest countries in the world. The map below, produced by the World Bank, makes it obvious to see that the greatest proportions of people living in poverty are found in many sub-Saharan African countries. In some countries in Africa, more than half of people are living on less than $1.90 a day. This illustrates the struggle in Africa, both environmentally and economically and this has an influence on water usage and food production across the continent.

Figure 2: Map of share of the population living on less than $1.90 a day.

I hope this blog will be interesting and informative. I feel this first blog post has highlighted what I aim to achieve and has given a clear introduction to the importance of water to food production and the possible problems faced by people living in Africa. I plan to look into a number of different aspects of water and food, most importantly, the effect of climate change, the idea of water scarcity, groundwater extraction, virtual water and much more…