Water and Food in Africa

Throughout this blog, I have explored many different topics surrounding the idea of water and food in Africa. This blog has looked into different water resources, irrigation, climate change, rainfall variation, food insecurity and virtual water. By exploring these topics in different posts, it has been possible to develop a better understanding of Africa’s problems surrounding water scarcity and food insecurity. 

It is clear that Africa as a continent is in need of support in order to adapt to future food security problems as a result of climate change. This could be in the form of funding, technology or education. These can all help benefit individuals and larger farms to meet the needs of populations across Africa. By investigating this topic, I have discovered that Africa’s water and food problems are not unsolvable. There are many different options to address these problems for African countries that could have widespread benefits.

I hope you have found this blog interesting and informative. I aimed to put across some of the key ideas and my own views in an easy and reader friendly way. In my own personal opinion, the greatest barrier for Africa’s improvement in this field is the funding for new technologies, information and practices that could reduce the threat of water scarcity and subsequently food insecurity.

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.