Thank you

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Unfortunately, my blog is now coming to a close. Anyone who's followed it I hope you've learnt something about the challenges climate change will present to Sub-Saharan African water supply and development, I certainly have.

The main conclusions I have taken from my research are:

Climate change is going to impact SSA hugely through rising temperatures, changing rainfall patterns and a lack of adaptive capacity. All the while, SSA has played next to no part in inducing such climate change. 

Groundwater does offer a potential solution where it is viable and sustainable over a number of decades. Each groundwater scenario must be judged independently and a one-size-fits-all technique will not be successful in the long term, the diversity and variety of water supply within SSA is just too large. With this mapping and measurement of groundwater (and all water) resources is paramount to successful, sustainable management. 

It will require a global effort to help SSA deal with climate change, and it is likely that mass migration will occur at some point. This could be an areas carrying capacity decreases, and therefore a proportion of a population has to move, or an area becoming completely inhospitable. 

The challenges climate change will bring for SSA are very much real, but with global cooperation and a willingness to solve problems internationally a lack of clean water in SSA can be a thing of the past. 

Relationship with Population Density

So far in my blog I haven't touched upon rainfall and it's relationship with population density. For populations to increase, water is necessary. In poorer regions, such as most of SSA, this water needs to be local. Le Blanc and Perez studied the relationship between rainfall and human density in conjunction 

Le Blanc and Perez found that a threshold of 900mm/year of rainfall existed when considered a relationship with population density. When rainfall is below 900mm/year, rainfall becomes a limiting factor on population densities. If above, then density and rainfall do not have any spatial correlation.

Then they apply future population change scenarios and climate change scenarios on rainfall. With projected population growth the areas limited by rainfall, and experiencing increasing water stress, are set to increase. Le Blanc and Perez concede that the impacts of rainfall are harder to predict as different climate models differ locally, especially intermediary areas fed by the ITCZ such as the Sahel and East Africa. Predictions expect Sahelian rainfall to increase, offsetting some demographic pressures but not all. Contrastingly, East African precipitation is projected to fall. Will population increase, this will increase water stress in the region. Regarding Southern Africa, le Blanc and Perez note that population stagnation will clearly help any water stress situations.

Changing rainfall and demographic concentration and spatial distribution will play a major role in dictating which areas experience relative water stress, and which relative water security.  

Alongside Climate Change: Other Human-Induced Risks to African Water Supply

Although my blog has focused on anthropogenic climate change so far, there are other risks that have to be considered to give a full picture of future SSA water supply. One of these risks is soil degradation resulting from desertification.

As discussed by Warren et al. in 'The future of deserts', a number of factors will contribute to desertification in the future: population increase, demand per/capita for water increasing (from rising living standards), continuing oil development and ambitious water management schemes changes. All of the above apply directly, and potentially most significantly worldwide, to Sub-Saharan Africa.

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Feddema studied the impacts of soil degradation alongside climate change. Feddema used 'a GCM global warming scenario, a newly derived soil water-holding capacity data set, and a worldwide survey of soil degradation between 1950 and 1980' to simulate the future effects of climate change and soil degradation on African water resources between 2010 and 2040. 

On a continental scale, climate change had a much large impact on water resources. This is perhaps unsurprising, as all of Africa is susceptible to increasing temperatures and changing rainfall patterns, whereas only specific areas are susceptible to desertification and soil degradation. To consider this, Feddema then focused on areas where decertification could potentially be present (climates alternating between wet and dry). Here, the impacts of anthropogenic changes to water resources through desertification and climate change 'can be expected to be on the same order of magnitude'. Across the whole continent, Feddema's research suggests there will be a small increase in rainfall (this will have huge spatial variation within Africa) but a large increase in evapotranspiration resulting in drying. Furthermore to having a wet and dry climate, soil degradation will be most intense in areas with a high population density resulting in lowered water storage capacity. As such, there will be a higher water surplus in the wet season when the soil can hold less water, and water deficits in dry seasons will increase because of reduced soil water availability (as less was absorbed in the wet season). 

The overall result of these scenarios is 'an intensification and extension of drought conditions during dry seasons'.

This is an example of how climate change (increasing temperatures and changing rainfall patterns) is not the sole cause of increased water stress in Africa. Desertification is exacerbated by climate change, and many other factors, to provide specific areas of Africa, such as the Sahel region, multiple water problems. 

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Do They Know It's Christmas?

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With Christmas Eve upon us we have all undoubtedly heard the 1984 Classic numerous times. Bob Geldof, Midge Ure and Bono among others have raised millions for impoverished African countries through Band Aid. Raising money and awareness of the issues Africa faces is a worthy challenge and an area in which they have made huge progress. After Michael Buerk's infamous reporting that struck a chord with the nation, Band Aid recorded and produced the song in under 24hrs to help immediately.

The original Band Aid focused particularly on Ethiopia and Eritrea, where in 1984 was one of the worst famines in human history. Food shortages had been ongoing since before 1983 though due to insurgency and poor government policy, as explained by de Waal. The drought hitting in 1983 is the official reasoning for the famine, however de Waal's analysis shows that famine actually started to occur months before the drought; the problem was just exacerbated by the drought. This is a prime example of a combination of human and physical factors resulting in a large scale problem. The result was 400,000 deaths. Young goes on to examine how over half of these deaths weren't from famine, they were human rights abuses from counter-insurgency strategies to combat peasant revolutions due to the famine and 'social transformation' in non-insurgency areas.

Recently, the focus has shifted slightly away from East Africa, with Band Aid 30 also focusing on Ebola, a West African crisis.

As someone who has studied African water intensively over the past few months I was shocked by many of the lyrics in the original Band Aid. Some of these lyrics, although aimed at raising money, I believe have severely distorted the average person's view of Africa. Many of the lyrics from Band Aid label Africa as a dark place with no hope, giving the view that everyone is poor and starving. Obviously, this is not the case.

The negative description of Africa begins with:

"There's a world outside your window, And it's a world of dread and fear"

Which is followed by potentially the most damaging line in the song,

"Where the only water flowing is the bitter sting of tears".

From my research throughout this blog, this is clearly not true. Although originally aimed at Ethiopia, this song is now seen as a symbol for helping all of Africa. Ethiopian rainfall varies significantly throughout the year:

World Bank

The above graph is approximately 700mm/year. This does vary throughout Ethiopia, with the South generally receiving more than the North. As the North only gets rainfall once a year (due to the Northernmost limit of the ITCZ), it does make it prone to drought if the rains fail. But to have a line in such a popular song hinting there is no water flowing is a generalisation that can morph views.

Having said that, Band Aid 30 has actually cottoned onto this! This lyric has been removed from the most recent version of the song, replaced with "Where a kiss of love can kill you and there's death in every tear", which I interpreted as an Ebola reference. Although they have removed the original lyric, the replacement is equally depressing. There is one other lyric change from the original: "Well tonight thank God it's them instead of you", is replaced by "Well tonight we're reaching out and touching you". Again, a more PC lyric.

A line not removed, but equally damaging is:

"Oh, where nothing ever grows, no rain or rivers flow"

which is preceded by,

"And there won't be snow in Africa this Christmas time, The greatest gift they'll get this year is life".

Hence, this lyric is clearly aimed at the whole of Africa, not just Ethiopia. To suggest nothing ever grows, there is no rain and no rivers flowing in Africa is absurd.

One of the most famous lines,

"Here's to them, underneath that burning sun"

is another stab at the African climate, suggesting it is the cause of all the problems and the continent is a desert.

What all of Africa looks like (Source)

Band Aid labels Africa's problems as climate related, but as with the Ethiopian and Eritrean crisis in the 80s, Africa's problems are very much human induced as well. The negative legacy left post-colonially in Africa is extremely well documented in academia and is viewed as often the cause for many disputes which frequently lead to war and disruption/destruction of progress.

Another prominent example, the ever-increasing tensions over the use of the Nile are fuelled by agreements the British Empire made with Egypt (which was a British puppet government at the time, for in depth case study see here). Egypt still uses such agreements to justify its domination over the other ten countries in the Nile Basin, as Britain granted them permission in 1929 and 1959. The current Nile situation, exacerbated by rising populations and climate change is a tinder-box and a conflict waiting to happen unless action is taken.

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As with Ethiopia, these examples are present all over Africa as water shortages, drought and famine occur from human causes just as much as physical. This however, is not represented whatsoever in Band Aid's song. The cause of Africa's problems are climate, and these problems represent the whole of Africa, unfortunately both are so far from the truth.

Many of the water issues in Africa are caused by anthropogenic climate change (changing rainfall patterns and increased temperature) and poor governance. Anthropogenic climate change is clearly not caused by Africa, as discussed earlier in the blog. Poor governance and the role of the West is a huge debate regarding colonial legacies, oil and continued involvement and exploitation.

"Do They Know It's Christmas?" will have had a huge impact on how millions of people view Africa. Some of the stereotypes produced from the lyrics will have influenced in some way any who haven't explicitly studied Africa, which is the vast, vast majority. Given that, the lyrics hit home hard and are exactly what was needed in the Short Term to raise significant amounts of money, as I found out on Channel Five this Christmas Band Aid is the highest selling UK Christmas Number One (selling almost double 2nd place). On the same show Michael Buerk said that although 400,000 had died, without Band Aid that number would be in the millions.

The song has done a lot of good through raising money and awareness, but I feel it has also produced and augmented stereotypes of Africa that have lead to its negative image today.

It's not all bad...

Throughout this blog I've tried to stress the huge diversity there is within SSA, and whilst trying to make statements note that over-simplification can be misleading. One of my colleagues also writing a blog, Lulu (see here for her blog: Africa H2O under environmental impacts), commented on an earlier post that actually some areas of Africa, particularly in East Africa groundwater recharge may actually increase under climate change rainfall impacts. 

As discussed by Allan and Soden, one of the largest predicted changes in rainfall patterns is that rainfall events will become less frequent but more intense, an 'Amplification of Precipitation Extremes'. This is because when air is warmed it can hold more water. For example, a given volume of air 'at 20°C can hold twice the amount of water vapour than at 10°C' (NASA). The correlation between how much water air can hold at given temperatures is relative humidity, when it is 100% the air is saturated. When you heat up air, the relative humidity drops. So when the whole Earth gets warmed (given a few relatively localised exceptions) the air holds more water before it reaches a given relative humidity where it would start to rain. This is why rainfall events will become less frequent, but heavier (see Trenberth et al. for a more detailed explanation). Trenberth et al. go on to discuss how too rarely the frequency, intensity and duration of rainfall events is studied, instead just the quantity of rain is often modelled. As temporal variability in rainfall is key to analysing impacts, such climate change modelling can miss key aspects.

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As explained by Taylor et al., groundwater recharge in East Africa is largely dependant on extreme rainfall. Therefore, these changes in rainfall pattern could potentially increase the quantity of groundwater that is available for use in East Africa.

Climate Change in Ghana: Groundwater

Having visited Ghana, I wanted to assess its groundwater situation to analyse how it could be used it in the future.

Water is obviously vital to humans, with a very strong relationship between access to freshwater and social development/economic growth. As explained by Odada, this relationship is particularly strong in developing regions like Africa. Given this, in Western Africa climate change is expected to result in increased evapotranspiration (increased desertification in Sahel region) and a reduction in rainfall. Therefore, analysing how groundwater can potentially help Ghana in light of these changes is important.

Before I start a brief outline of Ghana. It has a population of 27million, and a Human Development Index (for explanation see here, I think this is a better measure of quality of life than GDP) of 0.573 which ranks 138th in the World. Wikipedia claims that 67% of Ghana speaks English. From my experience this is not even in the right ballpark and has been greatly exaggerated, I'd guess the real percentage was between 10-25%. Ghana is divided into ten administrative regions, which are further divided into 170 districts. Within these districts are significant differences, the largest of which is language. There are eighty different languages spoken within Ghana, of which nine are actually state sponsored. When planning and implementing changes in Ghana, from my own experience, this is a huge hurdle as none of the nine major languages understand each other. I think this lends itself to smaller schemes rather than national ones, which this obviously limits.

Ghana does have a lot of fresh water. The Volta, South Western and Coastal river systems contribute 64.7%, 29% and 6% respectively. As highlighted by Obuobie and Barry, the issue is the spatial and temporal distribution of this water, an issue that I hope resonates throughout my blog as a major challenge for Africa.

In Northern Ghana it doesn't rain for 9months straight. Also, there are issues with health such as polluted surface water sources and disease such as guinea worm. In rural areas and small towns, groundwater sources are increasingly being preferred to surface water. For reasons why, see my post 'Groundwater as a solution?'.

Gyau-Boakye et al. estimate that over 95% of groundwater abstracted in Ghana is used for domestic purposes. This clearly indicates that groundwater is providing vital functions for inhabitants including but not limited to drinking water, cooking and washing. Such groundwater contributes 33% of the total drinking water consumed. As mentioned earlier, there is a spatial unevenness in the distribution of this 33%, as depicted by Obuobie and Barry in the below table:

Population dependent on groundwater for domestic water use.

Accra, the capital, clearly does not make much use of groundwater as it uses the Volta and can control flow using the Akosombo Damn (for more information on the Dam see here). On the other hand, The Upper West and Upper East populations are clearly reliant on the supply of groundwater.

Water is currently abstracted from all geological formations in Ghana, which are depicted below and are all covered by regolith:

Across the country, there are 75000 abstraction systems, 60000 of which are hand-dug wells and 15000 boreholes, with the vast majority of these being safe for multi-purpose use (see p52 for table of issues by area). So far, groundwater appears an excellent option for Ghana with increasingly climate and water variability. But what about the sustainability of the resource?

Groundwater recharge varies across throughout Ghana. Recharge is mainly due to precipitation, with % for each region shown below:

Managing groundwater abstraction sustainably is dependent on understanding the recharge rates and longevity of groundwater resources. Unlike many African countries, such as Nigeria, Ghana actually has a national water policy. As explained by Obuobie and Barry this policy is founded on the principles of the 'Ghana Poverty Reduction Strategy, the Millennium Development Goals and
the “Africa Water Vision” of the New Partnership for Africa’s Development (NEPAD)' (p.60). Furthermore, it dedicates itself to sustainable supply and production of groundwater in Ghana.

The effectiveness of such a policy rides on the quality of policing, regulation and data collection regarding groundwater abstraction. Without such measures, creating a sustainable Ghanaian water supply system using groundwater in light of climate change is unlikely to become reality.

In Ghana groundwater has the potential to help the country grow and give a consistent water supply to its residents, especially those in the Sahelian region. Across West Africa the pressure on current water systems is going to increase through three mechanisms: population increase, wealth increase, and climate change rising evapotranspiration and reducing rainfall. With correct management, Ghana can offset some of these risks by using groundwater.

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West, East and Southern African Groundwater

I discussed fifteen countries in Sub-Saharan Africa and showed the results of Pavelic et al's book on groundwater. Grouping the region into West, East and South can provide useful insight as they are often either geographically or socially similar.

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Burkina Faso, Ghana, Mali, Niger and Nigeria are all West African countries largely dominated by Precambrian basement. In such a formation, groundwater tends to collect due to secondary porosity (as opposed to the porosity of the rock itself) due to chemical weathering, fracturing or jointing. Within these spaces is groundwater suitable for use. Aquifers in the crystalline basement rocks generally have the lowest yields ( > 1L/s). Higher yields from boreholes tend to be from sedimentary aquifers (> 20L/s). 

In this region, most groundwater is used for drinking water. Regarding how the water is used, 'Drinking water supplies sourced from groundwater for rural/small towns serve 33 percent of Ghana, 92 percent of Niger, 70 percent of Nigeria and 55 percent of Mali. Burkina Faso uses groundwater as the principal source of supply in small towns and rural areas.' This is especially important for populations living in the Sahelian zone who experience infrequent and variable rains.

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Contrastingly, the basement of Malawi, Mozambique, South Africa, Zambia and Zimbabwe in Southern Africa is predominantly crystalline. Groundwater tends to collect in fractured bedrock and weathered regolith. The groundwater aquifers in Southern Africa tend to be relatively poor due to low capacity and water quality. There are some boreholes with higher yields (>80L/s), such as the Limpopo basin and Zambian/Zimbabwean limestone aquifers, but the majority is poor.

Again, most groundwater is used for drinking, although some is used for remote mining activities. Drinking water supplies sourced from groundwater for rural/small towns serve 51 percent of Zambia, 70 percent of Zimbabwe, 65 percent of Malawi, 60 percent of Mozambique and 60 percent of South Africa'. Groundwater irrigation demand has been increasing, such as in the area around Lusaka, Zambia. The negative impacts around Lusaka have been well documented, and I might look into it in a later post.

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Similar to South Africa, the countries studied in East Africa have low groundwater reserves. Kenya, Somalia, Tanzania, Uganda and Ethiopia sit atop a Precambrian basement complex. On top of this are new, younger formations than hold groundwater reserves. The rifts and fractures in volcanic highlands and alluvial valleys have very productive aquifers, although shallow. The highest yields in East Africa are about 6L/s, relatively low compared to the other two regions.

Of the regions, groundwater irrigation use in East Africa is the lowest. Groundwater irrigation is a key source of water, especially in some arid areas where it is the only source. 'Drinking water supplies sourced from groundwater for rural/small towns serve 85 percent of Ethiopia, 50 percent of Kenya, 70 percent of Somalia, 56 percent of Tanzania and 70 percent of Uganda.' Large swathes of East Africa are in the Sahel region that only receive rainfall once a year due to the ITCZ circulation (see here for explanation). As such, during the dry season, and especially if the rains fail, groundwater is of utmost importance.

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All three regions discussed use groundwater significantly and without it the land probably could not sustain the populations it does. As promised, next I'm going to look at Ghana.