Land-use change in relation to climate change in East Africa

This week I will be reviewing a more technical article compared to that of the past two weeks. Thus far, all my blog posts have been on climate change and I have not explicitly touched on the issues of land-use change and its attendant effects on the environment. As such, I decided to look for an article that would touch on both climate and land-use change, which I believe to be interrelated and influence each other through feedback mechanisms.

Titled ‘Projected land-cover change effects on East Africanrainfall under climate change’ (Moore et al. 2015), the study assesses the impacts of land-cover change and climate change separately, and together on rainfall in parts of East Africa, to access the relative magnitude of each, using four different scenarios:

•           Current land-cover and current climate
•           Current land-cover and future climate
•           Future land-cover and current climate
•           Future land-cover and future climate 

The results of the study found that greenhouse gases (GHG) in general, lead to wide-scale, and usually more severe impacts compared to the effects of land cover/land-use change (LCLUC) which are more regional or local. LCLUC can affect precipitation in a variety of ways. The change from forest to cropland for instance, can result in an increase in albedo and in turn surface cooling, which reduces convective rainfall. Overgrazing removes large stretches of vegetation which increases the amount of suspended dust, resulting in radiative cooling and therefore a decline in (convective) precipitation. Under LCLUC, short heat-flux and long heat-flux may also be intensified, resulting in strengthened sea breeze and land breeze effect (due to greater heat differential between land and sea), which intensifies precipitation over and around the lakes. This is because heat differential between the large lakes of East Africa and the surrounding land result in diurnal variations in precipitation—rainfall occurs over the shore during the day and evening (when the land is warm than the lake) and over the lakes in the night and early morning (when the land is cooler than the lake) (Ba and Nicholson 1998). The intensification of rainfall along coastal areas where forests have been replaced with agriculture can potentially exacerbate the risk of floods caused by GHG, resulting in agricultural damage.

In terms of the relative impacts of LCLUC and GHG, the influence of LCLUC was as large or larger than that of GHG—approximately 25% of the domain. The precipitation in areas which had higher population density were naturally more influenced by LCLUC as there were more human and agricultural systems. Evidently, LCLUC in developing countries have a first-order impact on local rainfall.

My thoughts after reading the paper:

This paper has demonstrated, in the context of East Africa that climate change and land-use change are related processes. Both have effects on precipitation, though at different scales—the effects of land-use change are more pronounced at a local level, while the effects of climate change are usually broader. That said, the effects differ across the region due to other physical factors, such as topography and population density.

In my previous posts, I have focused mainly on the effects of climate change on water in Africa, and in turn the production of food, since water is needed for irrigation. The article, however, presents the other side of the coin—how the conversion of forest to farmland for irrigation may result in the development of a positive feedback mechanism that prevents precipitation and reinforces drought conditions (due to higher albedo, radiative cooling and high pressure conditions at the surface).

Therefore, in addition to implementing strategies that focus on the provision of safe water e.g. the building of covered wells and handpumps, I believe it is worth considering how land-use can be managed  sustainably to meet the population’s needs while minimising the overall impact on precipitation and hydrological conditions. I hope to be able to find case studies where the effects of land-use change on climate have been taken into account in land-use management, which I may reflect on my next post.

Thanks for reading and till next time~

Adapting to climate change: the Batwa Pygmie indigenous people in Uganda

Building on last week’s post on the impact of climate change on the quality of water, this week’s post is based on a paper, 'Vulnerability of indigenous health to climate change: A case study of Uganda’s Batwa Pygmies' (Berrang-Ford et al. 2012) on the vulnerabilities to climate change of an indigenous group of people in southwest Uganda called the Batwa Pygmies. Due to the low economic status and dislocation of the Batwa from the forests, the Batwa health has declined dramatically. In 2003, child mortality rates in Batwa were close to 40%, more than double the regional and Ugandan averages, with most of the diseases identified being climate-sensitive, such as malaria, malnutrition and stomach disorders. With increasing temperatures and extreme rainfall events for instance, malaria is becoming a leading health concern as the vector mosquitoes thrive in warm temperatures and stagnant pools of water. The insufficiency of available and accessible clean water is also a major contributing factor to general weakness and stomach disorders. Moreover, poor water quality is responsible for the high degree of morbidity caused by stomach disorders and waterborne diseases. Though most households have relatively easy access to water—within 15min walking distance, the water, often referred to as ‘dirty’ and ‘infected’, is often consumed untreated due to the lack of equipment like saucepans for boiling.

However, the authors also saliently pointed out the socio-political determinants of high sensitivity and limited adaptive capacity of the Batwa to climate change, including poverty, and the Batwa’s lack of political representation as they were often looked upon as lazy and backward due to their hunter-gatherer lifestyle.

Batwa People in Uganda
Source: http://www.gorillatracking-uganda.com/wp-content/uploads/2015/04/BatwapeopleUganda.jpg

My thoughts on the paper:

In a more specific context, this paper echoes the learning points as written in last week’s post. On adapting successfully to climate change, the author writes ‘climate change has little resonance on the ground, where it is over-shadowed by social and economic determinants of health’ (Berrang-Ford 2012: 1075). Given the importance of the role of accessible, clean water in improving the resilience and adaptive capacity of the Batwa to climate change, this is an important consideration to bear in mind. Policy makers ought not to direct measures and strategies at the direct impacts of climate change—higher temperatures and extreme weather events, but seek to understand the contextually-unique reasons why households are unable to access sufficient clean water or even treat unclean water and design their measures and strategies accordingly. Providing households with the means for sustainable livelihoods where basic health needs are met is therefore the best way to cope with climate change. 

Climate change and water quality: issues and adaptations

In this post, I will take a closer look at the relationship between climate change and water quality by reflecting on a paper by Heath et al. (2012): 'Testing a rapid climate change adaptation assessment for water and sanitation providers in informal settlements in three cities in sub-Saharan Africa'. Since 1990, the urban population in SSA has more than doubled, yet the proportion of people without access to improved drinking water sources (17%) and sanitation facilities (57%) has remained constant. One of  aims of the research, which looked at three case studies—Lusaka, Zambia, Naishaka, Kenya, and Antananarivo, Madagascar—was to understand the impacts of changes in temperature, mean hydrological parameters (e.g. amount or intensity of rainfall) and extreme hydrological events (e.g. flood, droughts) on the water and the sanitation technologies and services for these communities.

All three case study cities face the risk of face worse threats from floods than droughts. An increased frequency and intensity of flash floods can lead to the contamination of water supply as sewage are washed into shallow wells and exposed pipes. Flooded latrines and contaminated water increases the risk of cholera and diarrhoea. In Naivasha, Kenya, a decrease in rainfall can also cause a deterioration in water quality. Market gardening becomes impossible with less water, such that flower farms have to reduce their workforce which leads to reduced income. In turn, households are less able to pay for water and food, and water use decreases, causing hygiene levels to fall and the prevalence of diseases to increase. A decrease in the volume of Lake Naivasha can also cause water quality to deteriorate.

With regards to adapting the climate change in terms of safeguarding water quality, a mixture of infrastructural improvements, such as sealing wells and raising latrines to prevent contamination during floods, monitoring programmes and education were recommended. These need to be adequately supported by the local water utility or relevant authorities to ensure that even the poorest, who own the worst latrines, can afford the necessary upgrades.

My thoughts on the paper:

Undoubtedly, the increase in frequency of extreme rainfall events or droughts will have a negative impact on the water system. This is especially so because of the existing inadequacies in water infrastructure. The network of water kiosks, for instance, may not be extensive enough to reach every household, though concurrent improvements need to be made to the latrines if the network of kiosks were to be expanded.

Hence, I agreed with the author’s point that adapting to climate change does not need many new processes, as most of the measures can be described as good practice in flood or drought-prone areas. Moreover, the built-in resilience of the poor (impact-minimising economic strategies, social support networks) should be recognised and better harnessed with greater support, especially in terms of providing assets and resources.

Thanks for reading and till next time ~~:D 

Climate change effects on irrigation and rain-fed production

As mentioned at the end of the previous post, this entry will seek to explore how climate change might have an effect on human behaviour and choices in relation to water in Africa.

I managed to find a paper on the use of a modelling framework to explore the effect of irrigation on farm performance: ‘Endogenous irrigation: the impact of climate change on farmers in Africa’ (Kurukulasuriya and Mendelsohn 2007). The authors argue that when considering the impact of climate change, irrigation should be treated as endogenous, as opposed to exogenous, as the decision to irrigate is a choice and this is influenced by climate (Mendelsohn and Dinar 2003). Factors which influence the choice to irrigate include surface flows, soil types, and subsidies.

The Ricardian analysis, taking into account irrigation as an endogenous factor showed that warming would lead many farmers in Africa will experience net revenue losses from warming. It also showed that irrigation increases resilience to temperature change and may even realise slight gains in productivity. Therefore, by extension, climate change conditions that encourage the choice to irrigate could in fact bring about improvements in agricultural yield

In another paper by Cooper et al. (2008): ‘Coping better with current climatic variability in the rain-fed farming systems of SSA: An essential first step in adapting to future climate change?’, the effect of climate change on rain-fed farming performance (as opposed to agricultural reliance on irrigation) is explored. Rain-fed food production is the dominant source of food production and the means of livelihood for the majority of the rural poor in sub-Saharan Africa (SSA). Yet, it is vulnerable to between and within season rainfall variability, which is likely to worsen with climate change. In particular, the semi-arid tropics of Africa, where 80mil of the continent’s poorest communities live and under increasing population and livestock numbers, is also where climate variability has the most profound impacts on production. As seen below, the inherent variability increases disproportionately as one moves from the wetter to the semi-arid locations that receive between 250 and 600mm of seasonal rainfall.

Figure: Seasonal rainfall means and their coefficient of variation in Eastern

and Southern Africa.

Source: Cooper et al. (2008)

The authors suggested ways in which climate change can be coped with, in the area of agriculture, from which I have gleaned the following two learning points that I feel are rather insightful:

•  Farmers have traditionally coped with climate variability by seeking to mitigate the negative impacts of poor seasons and then fail to exploit the positive opportunities of average and better-than-average season. It is therefore important to consider climate variations holistically, and implement strategies from a long-term perspective. As said in one of my previous posts, seasons with exceptionally high rainfall may lead to groundwater recharge which may be harnessed for irrigation during dry periods.
• Coping strategies must be tailored to specific contextual factors, including physical, economic, and socio-cultural factors. For instance, some communities may be able to diversify into off-farm activities to cope with water shortage but this may be less feasible for small-holder farms in isolated and less-favoured areas if rain-fed systems in Africa. Instead, resilience in water provision to maintain agricultural productivity can be achieved by working with the available resources and present circumstances. Examples of strategies include improving water productivity and integrated management of land and water resources though more investments in farming practice would be necessary.

In the next post, I will be looking at another aspect of the relationship between climate change-water-human welfare by writing about the impact of climate change on the quality of water, till next time! :D 

Groundwater-a plausible solution? (Part 2)

Expanding on last week’s topic of the potential of groundwater as a reliable water source in Africa with population growth and an increased demand for irrigation water for agriculture. The first part of today’s post is based on an article ‘Groundwater in hard rocks of Benin:Regional Storage and Buffer Capacity in the face of change’ (Vouillamoz et al. 2015).

Like the article by Taylor et al. (2009), groundwater is said to play a major role in supplying domestic water to millions of people in Africa, and is likely to be increasingly dependent on to increase reliable water sources for domestic and irrigation purposes. The paper was based on research that sought to estimate the capacity of hard rock aquifers to buffer changes in climate and anthropogenic conditions in Benin, by comparing groundwater storage to the total discharge of the reservoirs. The research found that current groundwater storage represents about six years of total groundwater discharge—the first time the buffering capacity of groundwater storage against changes in water balance was quantified at the regional level. Climate and land use changes will most likely impact evapotranspiration and in turn groundwater storage, perhaps more than population growth will.

Some thoughts and reflections:

• The availability(?) of groundwater resources is heavily dependent on the geology, as well as the climate of the area
• Though such hard rocks is said to cover 40% of the surface area in Africa, which means substantial potential for groundwater storage
• Access needs to be considered in harnessing the groundwater for use, as well as maintaining the quality of the groundwater, and distributing it equitably

Another article: ‘What impact will climate change have on ruralgroundwater supplies in Africa?’ (MacDonald et al. 2009) supplements that last reflection point. 

The article explains that the preparing and coping with climate change will generally call for actions already identified for improving water security for communities—of which understanding the balance between water availability, access and use/demand is key. For example, there would be a need for research to match the availability of the water in groundwater storage with local demand and needs by siting sources in the most productive parts of the aquifer. 

One other way in which groundwater can be relied upon with climate change and the related changes to the hydrological system is the development of water further for small-scale irrigation. It is imperative however, for development to be done in a sustainable manner to avoid groundwater depletion caused by abstraction beyond domestic use.

Some thoughts and reflections: 

Whether or not groundwater can serve as a sustainable, viable source with climate change and population growth is dependent on many factors other than the availability of groundwater supplies:

• Enabling ease of access to groundwater supplies in a way that is productive and efficient
• Regulating abstraction for domestic use and possibly irrigation to prevent depletion of supplies
• Maintaining the quality of groundwater, by sealing the wells or constructing cement barriers around them to prevent the washing of pathogens into them
• Greater availability of data on groundwater storage and the links between climate change and groundwater to guide policy decisions and water infrastructural development

One area that may be explored in the coming weeks is the effect of climate change on human behaviour and how this may affect the use of water and the hydrogeological system in Africa. 

Benin Groundwater Resources Program
Source: https://ndigd.nd.edu/notre-dame-projects/topics/infrastructure/#benin-groundwater-resources-program

Climate change and groundwater-a plausible solution?

Following from last week’s post on the projected effects of climate and demographic changes on water resources in Africa, my post this week dwells a little deeper into the effects of climate change on groundwater in Sub-Saharan Africa (SSA), based on an article by Taylor et al. (2009): ‘Groundwaterand climate in Africa-a review’.

The paper provides a broad overview of the predicted relationships between climate change and groundwater resources, based on whatever limited data that is available on this area. For example, due to the lack of long-term studies of recharge in Africa, it is difficult to balance a highly variable episodic recharge with groundwater withdrawals over decadal, rather than annual time scales.

The potential of groundwater as a viable source of water, in the absence of surface water was nonetheless argued for in the paper:

• Groundwater may be the only source of freshwater present if surface waters are not available. 
• Groundwater is often of potable quality and does not need expensive treatment.
• Due to the slow rate of groundwater movement, and the storage of aquifers, groundwater resources may be more resilient to climate variations than surface water resources

Furthermore, empirical evidence from studies including that by Taylor and Howard (2006) showed a strong correlation between the sum of heavy rainfall events exceeding a threshold of 10mm/d and recharge flux, which is in line with the prediction that as warming continues, and the moisture-holding capacity of the atmosphere increases (defined by the Clausius-Claperyon relationship), so will the frequency of heavy rainfall events, especially in the tropics, where air temperatures are higher, contributing to groundwater recharge.

Given that small-scale farming accounts for 70% of agricultural production in SSA, the benefits of increased groundwater recharge with climate change could manifest in groundwater abstraction from discrete low-yielding aquifers in weathered crystalline rock and mudstones that underlie more than 50% of SSA may be suitable as they are self-regulating, which prevents impacts of local overdevelopment and solving the age-old problem of allocation. Low-intensity groundwater abstraction in parts of SSA has been featured as an example of the utilisation of groundwater in small-scale farming, and possibly for domestic uses.

But the sustainability of adaptation strategies employing groundwater to alleviate water scarcity brought about by increased demand or climate change is unclear. Contamination of shallow groundwater supplies, due to inadequate community hygiene in many rapidly-urbanising centres, is also of great concern.

My thoughts and reflections on the paper:

While groundwater does hold promise as a viable alternative to surface water as rainfall patterns become increasingly erratic with climate change, harnessing it effectively, in suitable and needy parts of SSA remains a long shot. As mentioned in the paper and the summary, the non-renewability of groundwater may mean that supplies could be depleted if the scale and intensity of abstraction is increased.

Moreover, the uncertainty of predictions of the effects of climate change on recharge, propagated through the use of projected parameters like rainfall and evapotranspiration and then the conversion of monthly to daily rainfall, means that the cause-effect relationship between intensification of rainfall patterns and groundwater recharge is still rather tenuous and awaits further investigation through applied, interdisciplinary research in this area.

It was also clear that active harnessing of groundwater, possibly for agriculture on larger farms, beyond that for subsistence has to be accompanied with improvements in other areas, such as the provision of sanitation to prevent contamination of shallow groundwater with faecal matter and transboundary agreements for the equitable use of groundwater, given that at least 40 transboundary aquifer systems have been identified thus far.

The paper refers to the use of ‘plausible projections of possible future’ rather than climate projections which I will read up on and seek to find out why the former might be preferred over the latter.

More to come in the coming weeks...

References: 

Taylor, R. G. and K. W. F. Howard (1996) 'Groundwater recharge in the Victoria Nile basin of East Africa: support for the soil-moisture balance method using stable isotope and flow modelling studies, Hydrological Journal, 180, 31–53.

Taylor. R.G., A.D. Koussis and C. Tindimugaya (2009) 'Groundwater and climate in Africa—a review', Hydrological Sciences–Journal–des Sciences Hydrologiques, 5,4, 655-664.

Water in Africa: Climate Change vs Demographic Change

In this blog post, I will be looking two articles—one by Carter and Parker (2009) and the other by de Wit and Stankiewicz (2006)—on the effects of climate change on groundwater and surface water in Africa respectively. Carter and Parker (2009) describes the estimated population growth in Africa, along with increased urbanisation and growing per capita consumption. By 2050, urban water demands are projected to increase by a factor of four, which Carter and Parker (2009) argue is likely to outstrip any problems caused by climate change. Population growth also puts pressure on rural land, and forces the acceleration of the development of irrigated production, further placing stress on the available water resources. On the other hand, de Wit and Stankieicz (2006) warn against the highly detrimental effects of a possible drop in rainfall caused by climate change—in regions receiving 500-600mm/year of rainfall, a 10% drop in precipitation could reduce surface drainage by 30-50%. 

Some thoughts that I had after reading the articles: 

The rather divergent views of the two studies are reflective of the high levels of variation and uncertainty involved in the climate change predictions and the estimations of its effects. Depending on which of the multitude of factors are taken into consideration, climate change predictions can vary drastically.

Moreover, both studies focus on the effects of climate change on the amounts and availability of ground and surface water, when in many circumstances, the key determinant of per capita water use is the ability of individuals and households to access safe water easily.

Questions that I hope to explore through further reading: 

Aside from the volume of water, how might climate change influence these socio-economic and socio-cultural factors that shape access to sufficient quantities of safe water? 

How might climate change affect the quality of water and possible the provision of sanitation in Africa?

Which parts of Africa might be most affected by climate change and how?

The effects of land-use change, and their drivers, on water in Africa...

References: 

Carter, R.C. and A. Parker (2009) 'Climate change, population trends and groundwater in Africa', Hydrological Sciences, 54, 4, 676-689. 

de Wit, M. and J. Stankiewicz (2006) 'Changes in Surface Water Supply Across Africa with Predicted Climate Change', Science, 311, 1917-1921. 

WELCOME :D

Hi there and welcome to my blog created as part of a third-year module I’m undertaking-‘Water and development in Africa’. Issues related to water such as water scarcity in Africa are perhaps not unheard of to the layman. With climate change at the forefront of a host of global issues we face today, and demographic change-specifically population growth-placing increasing pressures on the world’s finite resources, the chronic issue of providing safe water to the people in Africa is becoming increasingly complex, with no straightforward solution in sight.

Therefore, in this blog, I seek to explore in depth the links between environmental change (focusing on climate and land use change) and water-related issues in Africa, through reflecting on relevant articles on the issue. I will also be updating my blog regularly with current news reports and interesting facts and statistics relevant to this area of study!

Feel free to comment on my posts and I look forward to learning about this issue in depth and breadth through the course of taking this module, and hopefully beyond that! (: