Climate Change

Hello all,

In the last two weeks, I have spoken about how an ecosystem services approach may aid in policy applications to inform decision-making in biodiversity conservation and land use change. In the final post of this blog, I will speak about how an ecosystem services approach may be used to understand climate change.

Water and Food

Africa is undisputedly one of the least resilient continents when it comes to climate change due to its spatial location relatively in the lower latitudes. The immediate impact would be the changes in water levels through the differing water bodies, with Africa likely experiencing more intense and less frequent precipitation events, leading to a total alteration of the present river regime (Magadza, 1994). Some presently perennial water bodies may even be lost to climate change due to a general reduction in river output, which may hit Africa as a continent most due to its reliance on direct ecosystem services for livelihoods - water consumption, collection of water from these rivers for sanitary purposes, and pollution regulation for heavily contaminated rural areas.

On top of climate change affecting water consumption, a reduction in river output is likely to directly affect food production negatively. Increases in global temperatures within Africa has also been found to cause up to a 30% decrease in crop yields (Parry et al. 2004), and a study on impact of climate change on fisheries identify coastal west and central Africa as the most vulnerable (Allison et al. 2009). Most African countries depend on direct ecosystem services provided by subsistence crops for their livelihoods and fish stocks as a source of protein and cash earnings, for example 45% of animal protein in Congo is from fish. Negative effects of climate change on crop yield and fish production may therefore severely threaten the livelihoods of people in these countries (Egoh et al. 2012), and force migration in search for food.

Although most crop modelling studies agree on overall agricultural yield declines, these predictions can be very uncertain spatially. For example, East Africa has been cited to agree on rainfall increases in most seasons through the GCMs. Increased rainfall may promote net primary productivity and carbon storage due to the shift towards a more tree-dominated ecosystem, improving ecosystem conditions for greater agricultural output (Doherty et al. 2010). A fundamental shift to a different ecosystem however, means that trade-offs are bound to occur in the lost ecosystem. At this point, by using the mapping and modelling approaches mentioned in my previous post in addition to crop modelling, it may be possible to derive whether such ecosystem service changes are for the better in this particular area - supplementing a monetary valuation to this approach may then allow us to derive whether climate change is economically beneficial to a region. Safeguarding these ecosystem services provisions is arguably in line with many governments' objectives to improve the livelihoods of their citizens, and should therefore lie at the forefront of policy-making.

In my next post, I would conclude the contents of this blog. Thank you for all the comments thus far!

Monitoring Changes in Ecosystem Services

Hello all!

In my previous post, I concluded the examples of both monetary and non-monetary valuations of ecosystem services for the environmental policy-making. Although the referred reading is filled with mathematical jargon, I hope to provide a brief and comprehensible summary on how mapping and modeling approaches can be used to quantify biophysical changes in ecosystem services, which are beneficial to management scenarios in consideration of future changes. They combine ecosystem service analyses with the emerging field on Geographic Information Systems (GIS), both of which are emerging academic fields in their own right.

Ecosystem services change in West Africa (Leh et al. 2013)

Tools such as the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) tool (Tallis et al. 2011) were used to quantify individual ecosystem services – selecting and quantifying for biodiversity, surface water yield, carbon storage, sediment retention, nitrogen retention and phosphorus retention across 40 hydrological basins in both Ghana and Cote d’Ivoire. These were run using previously published literature on the formulae deriving each ecosystem service (FAO, 2004; Tallis et al. 2011; Wischmeier and Smith, 1978; Woomer et al. 2004; Hassan et al. 2005).

These indices were standardized across all 40 basins for comparison and subsequently combined in the study to provide an overall value of the ecosystem status, and GIS analysis through remote sensing was subsequently carried out to visualize ecosystem changes at the basin and sub-basin scales from changing land use.

Figure 5. Map representation of Ecosystem Services Status Index (ESSI) for the numbered hydrological basins in Ghana and Cote d’Ivoire.

Figure 6. Basin-scale Ecosystem Services Change Index over time relative to 2000, for the 40 numbered major hydrologic basins in Ghana and Cote d’Ivoire.

The ESSI allows us to first prioritise the location of these services by identifying which basin has shown the most negative impacts, and subsequently the ESCI allows for us to identify which individual ecosystems services have been depleting to prioritise for mitigation and conservation. The ESSI values for basin 10 in both 2005 and 2009 indicate critical danger with about 38% loss in total number of ecosystem services analysed relative to 2000 as seen in Figure 5. The ESCI supplements this understanding to identify which services ought to be given extra attention, for example in basin 10 biodiversity and water yield should be targeted since there is a loss of 63% and 19% of services respectively relative to 2000 conditions seen in Figure 6. These two highlighted figures are often in synergy - biodiversity loss can often be linked to losses in water yield, or vice versa. They provide quick and essential information required for the management of ecosystem services.

The study was one of the first studies in data scarce West Africa on mapping multiple ecosystem services statuses at the basin scale. Modelling and mapping these ecosystem statuses allows for the cumulative impression of all activities on ecosystem health, especially in response to changing land use. Overall, there was a general decrease in ecosystem services from 2000 to 2009. Such findings could be simulated for areas with better geospatial information, where future scenarios of land use could be modeled to identify for the losses in ecosystem services. Nonetheless, caution is necessary in interpreting these simulations, as they are sensitive to the geographic resolution and choice of ecosystem services, as different sets of ecosystem services would see significantly different results from the trade-offs between ecosystem services.

In this post, I have mostly spoken about how geographical information systems may be paired with an ecosystem services approach to identify impacts of changing land use, with a case study focus on data scarce West Africa. In my next post, I would speak more about an ecosystem service approach in the face of future climate change, and the impending threats to livelihoods.

See you!

Biodiversity Conservation

Hello all,

In my previous posts, I have elaborated largely on the identification and measurement of ecosystem services, and an example of trade-offs that could occur using an ecosystem approach. In this post, I will subsequently speak more about the application of the ecosystem services approach to biodiversity conservation.

1. Informs Decisions on Biodiversity Conservation

The ecosystem services approach informs decision-making for biodiversity conservation, especially for uninterested communities. In the South African Municipality of uMhlathuze, there was enormous pressures to expand development projects into sub-catchment areas in response to population growth (Ingram et al. 2012). Tensions between biodiversity conservation and development arose. To the underprivileged communities, the biodiversity conservationists were indirectly expressing that protecting species diversity was more important than the developmental needs of the community.

In response, the municipality carried out the Strategic Catchment Assessment to value ecosystem services in the catchment area. The study highlighted the free ecosystem services that have always been provided to the neighbouring population: nutrient cycling, waste management, water supply, water regulation, flood regulation and drought management, all of which valued to about US$200 million a year. Subsequently, the community was more encouraging in the protection of the natural environment as they realised that the sub-catchment area and its water resources provided large economic benefit; biodiversity was not the sole reason. 

2. Increases Value of Larger Protected Areas

Large protected areas currently hold many of the world's endemic and rare species, and these areas have often been earmarked for conservation for the purposes of maintaining biodiversity. In situations of land pressure and limited biodiversity funding for protected areas however, it is increasingly difficult to maintain these huge areas of land for the sake of biodiversity alone. Biodiversity conservation may therefore be in greater support if there is recognition of the ecosystem services provided, which are especially beneficial in large protected areas.

For example, these protected areas are important to provide for direct (eg. food and timber) and indirect (eg. clean water from regulation) provisioning ecosystem services, benefits that the underprivileged may not be able to replace immediately (Turner et al. 2012). In particular, regulatory services are especially pronounced in these large protected areas - the "invisible services" that are difficult to measure and are not directly consumed by humans, such as nutrient cycling and pollution control (Ingram et al. 2012: 5). For example, large conservation areas like wetlands increase the transport distance of polluted water flowing through them, increasing their potential for landscape-scale pollutant retention (Quin et al. 2015). The increased perceived value of the protected areas may therefore ensure for the continued persistence of these huge areas of protected land, which may initially be economically unjustifiable.

Limitations (Ingram et al. 2012)

1. The approach cannot capture all critical species, especially the species that are not "useful" or "valuable" to people. For example, rare and endemic species often do not have an important functional role, and it may therefore be difficult to justify their ecological importance to the community.

2. The approach may not prioritise important ecological processes to species, unless they deliver benefits to humans. Fire regimes are often designed to reduce chances of negative impacts of humans, but they are not beneficial to the native community and can lead to major changes in community structure within the landscape.

*3. PES approaches that aim to restore completely degraded ecosystems may lead to trade-offs (recall: Carbon and Water trade-off), as PES approaches often aim to optimise a single service which may undermine other critical ecological functions. In general, it may be most ideal for PES programmes to preserve and enhance existing ecosystems instead, to have the best combined impact on biodiversity and ecological processes (eg. paying native communities to preserve grasslands and wildlife for safari tourism).

The ecosystem services approach is especially important to communities that may place their own needs over biodiversity conservation, as it explicitly highlights the benefits that may otherwise have been neglected. Linking to the water and development goals within Africa, the ecosystem services approach has illustrated how the optimal decision can be made when considering the trade-off between development and biodiversity in the above-mentioned examples. These two management approaches were only possible to carry out as the revenue stream from water-related ecosystem services far exceeded the benefits from destroying these critical conservation areas for development purposes.

These have all encouraged the local communities to engage in sustainable resource practices and decision-making in support of biodiversity conservation, and is therefore also applicable for future biodiversity conservation intentions. However, to improve further, it is important to evolve in our understanding of an ecosystem service approach to include more forms of improved well-being (eg. in consideration of endemic species) to protect the range of ecosystems and species diversity on Earth.

In my next post, I will use another case study on how an ecosystem services approach may assist in resource management and decision-making through their application to land use change.

See you next week!

Non-Monetary Valuations of Water

Hello all,

In my previous posts, I spoke mostly about monetary valuations of ecosystem services, which have been used widely in the field due to their applicability.  In this post, I will describe in further detail about the attempts to measure cultural ecosystem services.

Intangible benefits, compared to the measurable quantities of ecosystem services, are more difficult to standardize and quantify across plurality of perspectives (Ament et al. 2017). They can only be measured qualitatively, through interviews or soft knowledge from people, but even so such responses are difficult to grapple with as the perception of value of cultural ecosystem services are often influenced by one’s cultural upbringing and beliefs. Further research however, has recognized that different ecosystem services often occur together in “service bundles” (Cumming and Peterson, 2005), either because of co-provisioning when one ecosystem provides several services or co-dependence when one ecosystem service requires another service.

These bundles have been seen through synergies and trade-offs, as I have written about in a previous post using the ecosystem services approach to determine the most financially justifiable approach. Similarly, decisions made in favour of the environment should also recognise the most balanced cultural service bundles, or which particular bundle to favour that should provide the maximal benefit to human wellbeing.

Case Study: National Parks in South Africa (Ament et al. 2017)

Visitors to the park were encouraged to complete self-explanatory questionnaires rating their appreciation of different aspects of protected areas on a five-point scale. These questions underwent exploratory factor analysis and it was found that five bundles of cultural ecosystem services explained 35.3% of the variance in survey responses, which were then grouped into titles: natural history, recreation, sense of place, safari experience, and outdoor living. These five bundles saw synergies within certain parks, but large trade-offs were also evident in certain parks.

1. Trade-off/synergies between natural history and (water) recreation

Most parks showed a trade-off between the bundles of natural history and recreation, such as the Tankwa-Karoo and Namaqua Park. These two parks are situated in the Succulent Karoo biome, a fragile biodiversity hotspot that may see losses to biodiversity if thrilling adventurous activities such as mountain biking were to be permitted within the park.

However, some parks saw synergies, such as within the Richtersveld and the West Coast Park with large water bodies enabling cultural services from water. The community has always managed these parks, with varied longstanding activities such as fishing and water sports amid the high demands for natural history in the rich biodiversity of the region. These must however be delicately managed – to ensure that biodiversity is not sacrificed while pursuing for the continued provision of the communal services provided by water in the form of recreation to park visitors.

2. Synergies between natural history and safari experience

Most parks generated synergies between these two ecosystem bundles, which show evidence that promoting wildlife safari experiences were a means to promote natural history and encourage biodiversity conservation.

3. Trade-off between safari experience and recreation

All parks showed this trade-off, with the trade-offs being larger in parks that contained some or all of the big five (African lion, African leopard, African elephant, Black and White rhinoceros, and Cape buffalo). Realistic opportunities for activities are limited in the presence of large and dangerous wildlife, explaining the trade-off being cited by most people.

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These qualitative measurements have strong practical applicability to the area of environmental management especially in protected areas. Park managers ought to align with the specific requests of cultural ecosystem services demanded by park-goers. For example, nature parks with naturally rich biodiversity and high demand for services of natural history should increase investment in educational and viewing resources such as species lists, bird hides, and vegetation maps; parks with greater demand for recreational activities may look to publishing promotions on equipment hire such as horse-riding, camel riding or bike tours. In interest of economic returns from park tourism, there is also little reason to introduce recreational activities into a park if park-goers appreciate it most for their safari experiences.

Taking a macro-perspective to the management of the parks in a country may also be useful. It may be most financially feasible to spread bundles cultural ecosystem services across the 19 parks equally, such that certain parks are best known for their provision of certain bundles – with the Namaqua most known for natural history and Marakele set aside for safari experiences. These would increase visitorship across all parks, as demands for different bundles have to be met in different localities.

This post forms the conclusion to the case studies on ecosystem services valuation and their practical applications to policy-making, as I would subsequently move on to further applications of an ecosystem services approach for our future: monitoring change and incentivising change.

See you next week!

Trade-offs and Challenges (WfW Programme)

Hello all!

In this post, I will elaborate more on the problems facing the WfW Programme in South Africa that I  spoke about last week, and my personal opinions on the contesting uses.

1. Tradeoff between Ecosystem Services: Carbon vs Water

In a separate study, it was found that afforestation of Pinus radiata (one of the invasive species) and the associated benefits of carbon sequestration and timber production are more economically viable than the benefits from increased water resources from clearing out invasive species at current water tariffs (Chisholm, 2010).  However, I beg to differ as water tariffs imposed on the forestry industry are estimated based on streamflow reductions from establishing the plantations, but they have hardly considered for the actual costs of land-use change and water losses for reasons below:

a) Streamflow reduction was estimated to be 90mm for Jonkershoek, a mere third of the actual streamflow reduction. Water tariffs were therefore priced much lower ("water valued [at a] fraction of one percent of the true value of water").

b) There are sunk costs from the loss of biodiversity from invading species, due to the conversion of Fynbos spp. to Pinus spp, and the potential uncontrolled invasion of P. radiata following future fires from warmer temperatures.

c) A treeless landscape associated with the Pinus plantations may lower albedo, rendering climate change mitigation ineffective from carbon sequestration.

d) Future increases in value of water, increasing water demands from population growth and decreasing supply from decreased rainfall in the Fynbos biome will seriously challenge the viability of afforestation. Continued large-scale afforestation will deplete the scarce water resources, increase water scarcity and possibly lead to large economic losses.

The article steers clear of establishing a conclusion for the future, as the net benefits between carbon and water depend on their future estimated costs. If the sum of economic benefits from carbon sequestration within the Pinus plantations were to outweigh the value of water at an extreme scenario of $257/tCO₂ in the event of extreme increases in carbon prices, an ecosystem services approach would call for the afforestation of trees at the expense of water resources as water and its associated benefits are economically viable only for carbon pricing scenarios under $100/tCO₂.

In my personal opinion however, water scarcity is clearly a greater developmental issue than increased CO₂, as the lack of water for domestic uses and consumption will seriously threaten livelihoods directly, while an increased CO₂ from a contracted carbon sink presents its risk to human health only in indirect ways. These may materialise in the forms of increased temperatures causing climate change and extreme weather events, but are arguably not as pressing as the lack of water to get by on a daily basis. These circumstances are when an ecosystem services approach may be lacking, as they do not consider for indirect benefits from water as a service providing unit; for example, 100ml of consumed water can be quantified in cost, but it may be tricky to attribute a value to positive externalities such as good health and well-being from the consumption of water. 

2. Challenges to Poverty Alleviation (McConnachie, 2013)

a) The WfW project only provides temporary employment, therefore making a small impact on the actual percentages of unemployed people within the country. Even so, the pool of unemployed people was from selection committees, and nepotism from local community leaders had disadvantaged the neediest.

b) The low wages for the poorest meant that workers were unmotivated, likely unskilled and inexperienced, leading to many wasted resources and fewer environmental benefits arising from inefficiencies (recall: concept of economic efficiency).

c) Beyond the two-year contract, the programme worsened the long-term livelihoods of workers as it diverted them from finding more sustainable income flows, but had not value-added to their lives and skill sets due to the low quality of training.

d) Clearing alien plants may actually have led to a loss of livelihoods for the poor who depended on harvesting timber and fuelwood in domestic trade and personal use (Wilgen and Wannenburgh, 2016).

In spite of all these issues challenging the personal development of the underprivileged communities, I still think highly of the Working for Water programme due to its well-meaning ecological and developmental intentions for South Africa. The effectiveness of public works programmes for poverty alleviation may potentially be enhanced by improving work conditions, providing employment benefits and imparting transferable skills into more well-paying opportunities within the agricultural sector. Ecological restoration based on the value of water however, should require a more detailed economic valuation of the true costs/benefits of water for greater economic justification.

Thank you for following through on South Africa for two weeks. In so far, I have mostly spoken about the economic valuation of ecosystem services. In my next post, I hope to talk more about non-monetary approaches to the valuation of water as an ecosystem service, so as to expand our understanding of what an ecosystem service approach encompasses.

See you next Thursday!

Conservation and Poverty Relief (WfW Programme)

Hello all!

I will write more about ecosystem services in line with poverty relief as mentioned in my previous post, and I hope this would contextualise the current state of human development in Africa within ecological objectives. After writing about the wetlands and rivers in the wetter regions of Africa, I will briefly share my thoughts about the semi-arid South Africa's Working for Water (WfW) Programme.

Working for Water (WfW) Programme, South Africa (Turpie et al. 2008)

In South Africa, the introduction of hectares of alien trees from afforestation had led to uncontrolled populations of invasive species which out-competed the indigenous tree species. These wiped out the original heterogeneity and biodiversity of the landscape and led to a presence of single-species strands of trees. Even though this invasion had presented forestry benefits (eg. timbre and carbon sequestration), these alien tree species had demonstrated a large negative effect on stream runoff. They were studied to have extremely intensive water uses and high losses through to evapotranspiration; the current invasion saw 15 invasive species utilising as much as ~7% of the runoff of the country (Wilgen et al. 1998). Their uniform presence within the landscape had reduced the catchment runoff drastically, especially in their situation close to watercourses.

In response to the issues of invasive species and water scarcity defined as 500-1000m³/person by Turpie et al. (2008), the WfW programme was initiated as a Payment for Ecosystem Services (PES) approach. Monetary payments were made to the poorest of the poor for their contribution to ecosystem restoration through the ambitious project to restore the presence of rivers within the landscape. They were offered two-year contracts to perform restoration work by clearing alien plants through slash-and-hook and chainsaw methods, at a minimal but nevertheless living wage (Wilgen et al. 1998).  In 2005, the WfW employed 32k people through an annual budget of US$68m gathered mostly from poverty relief funding, and evidence of success has been sighted through accounts of rivers running where water had been absent for several years (Powell, 2006).

The programme has been cited as a "win-win" solution as they achieve societal and environmental goals at the same time (McConnachie et al. 2013: 544): a) promote biodiversity and ecosystem services by restoring the pre-existing water ecosystem functions of the landscape, b) increase scarce water resources to the region at a lower cost compared to developing additional water supply schemes, and c) alleviate poverty by providing paid employment to the poorest communities in South Africa. It presents, yet again, the potential of attaching a monetary value to ecosystem services for the management of ecosystems.

I will carry out more research into this area, and elaborate more on the limitations of this WfW programme next week. See you!

Floodplain Inundation vs Irrigation

Hello all!

In my previous posts, I spoke broadly about the different types of water valuation - monetary and non-monetary. In this post, I will elaborate more on the Hadejia-Nguru Wetlands example that I spoke about previously, and highlight the usefulness of water valuation for resource management.

Continuation from previous post: Case study of the Hadejia-Nguru River Basin, Nigeria (Barbier and Thompson, 1998)

The floodplain benefits outlined previously however, have increasingly been challenged by the other large-scale water resource schemes in the region, circled in red in Figure 4. The Kano River Irrigation Project (KRIP) presently irrigates an area of 22000 hectares (Tanko, 2010), while the Hadejia Valley Project irrigates an area of 12500 hectares (Kimmage and Adams, 1992). Both of these large-scale irrigation schemes have not considered the opportunity costs arising from the reduction in flood extent to the Hadejia-Nguru wetlands further downstream, and this case study quantifies the economic benefits of the floodplains by comparing the net agricultural benefits from the large-scale irrigation projects and the net values of the agricultural, fuelwood and fishing benefits of the floodplain.

A hydrological model was developed to estimate the impacts in flood extent on the Hadejia-Nguru wetlands from the employment of various irrigation scenarios - this may be familiar to colleagues who had similarly done GEOG2020 in the previous year.  To illustrate my point, I will only utilise 2 scenarios with respect to the KRIP described in Table 3. Using the estimated overall floodplain benefits (fishing, fuelwood, agriculture) of USD34-50/ha and the estimated agricultural benefits of the KRIP of US20-31/ha, the forgone floodplain benefits from the hydrological scenarios were quantified.

Table 3. Net loss from the operation of large-scale irrigation schemes.

	Description	Regulated releases (106 m3)	Differences in mean peak flood with baseline scenario (km2)	Net loss = irrigation value – floodplain loss (in US$)
Scenario 1	Tiga dam present, not in operation.	Naturalised flow from Wudil river.	0	0
Scenario 2	Tiga dam in operation. KRIP over area of 27000ha.	None	-150.62	-3362041
Scenario 3	Tiga dam in operation. KRIP over area of 14000ha.	400 in August.	-95.25	-2203912

Using these two scenarios, it is evident that a) a reduction in production by the KRIP, and b) provision of artificial water to replenish the floodplain, would reduce the economic losses by more than a million USD. The large-scale water resource schemes were disadvantageous to the Hadejia-Nguru river basin, and the way forward to minimise losses was to follow Scenario 3, where regulated releases are still supplied to inundate the floodplain to ensure the continued viability of the wetlands.

There were three main limitations to the case study:

1. The economic benefits of Tiga dam in supplying water to Kano was not quantified, but preliminary evidence argues that it is unlikely to be substantial enough to justify the substantial floodplain losses.

2. The full economic benefits from the floodplain has not considered for pastoral grazing and groundwater recharge, although this was quantified in a study few years later to be USD413/ha of irrigated agriculture extracted from the aquifer, with the potential loss in 1m of groundwater level valued at USD62249 (Acharya and Barbier, 2000).

3. There are other costs to dam construction and operation, eg. excessive flooding of schools and villages affecting households and livelihoods downstream of the Tiga, changes in fish stocks downstream, health hazards such as waterborne diseases from ponding behind the dam and waterlogging when farmlands are excessively flooded (Idris, 2008).

Summary and Thoughts

There have been other more recent studies on ecosystem benefits valuation of wetlands (McCartney et al. 2011; Turpie et al. 2008), but I felt that this case study on the Hadejia-Nguru wetlands would be relatable to most of us due to our acquired experience with hydrological modelling (and STELLA) in the previous academic year. It might therefore serve as a useful starting point to extend our knowledge on water resources and ecosystem services. Notably however, the case study dates to two decades back. The Hadejia-Nguru wetlands have been facing longer agricultural droughts in recent years, with the northern regions of Sub-Saharan Africa facing a 11% decline in rainfall, which is further threatened by the proposal of the Kafin Zaki dam construction (Shettima, 1997). Despite the delay for a few decades now, there has been no consensus on the intentions over the dam construction. It is therefore essential, and of strong economic justification, for regulated releases of water to replenish the floodplain during wet seasons, and to alleviate instances of prolonged droughts; this recommendation comes in contrast to the full implementation and further construction of the irrigation schemes as earlier proposed.

Although I find myself convinced that economic valuation of water is indeed the most practical solution moving forward for water resource management, I have also taken a strongly economic (and perhaps, rather inhumane) approach to valuing water, along with basic economic jargon such as opportunity cost. In my upcoming posts, I hope to bring a stronger human touch when writing about water and ecosystem services, in particular addressing livelihoods and poverty in Africa, and the potential for economic valuation to address these issues.

See you next week!

Types of Water Valuation

Hello all!

In my previous post, I spoke about the differing physical characteristics of countries within the African continent, taking examples from the wetter parts of Central and Western Africa. In this post, I will speak more about the different types of water valuation, in a bid to clarify further what "ecosystem valuation" means.

Monetary Approaches

Monetary approaches are directly influential on policy-making decisions, as they provide humans with accessible and comprehensible values of water through an economic unit. They are supported by the quantification service production, delivery and consumption, which necessitates the biophysical measurement of ecosystem services. These approaches have been classified as a "neoclassical paradigm" to address environmental issues due to their applicability in the modern context when development is causing the demise of many ecosystems (Pandeya et al. 2016: 254). They have been divided into use and non-use categories, and the values derived from both categories and their sub-units are subsequently summed up to form the Total Economic Value (TEV) of an ecosystem service - in this case, water. I have drawn up an example in Table 2 to hopefully explain this in better detail.

Table 2: Example of the Total Economic Value framework (by me).

	Benefit flow to humans per 1000 people	Monetary valuation per 1000 people
Tangible human benefits (provisioning and regulating)
Water for domestic consumption	100 gallons of water	Eg. $100
Water for crop plantation	3 ha of crops	Eg. $500
Water as a regulator of pollution	Reduced toxic exposure by humans and improved health.	Eg. $2000
Intangible human benefits (non-use)
Water for eco-tourism and education	People may study rare bird species in wetlands, gain cultural appreciation of species and be more aware of biodiversity.	Eg. $100
Water for increased forest coverage and greater carbon sequestration	Larger carbon store and reduction of global warming.	Eg. $5000
		= Sum of $7700

In this rough worked example, we can arguably already see some limitations immediately. How do we assign a value to all of these benefit flows for water? How do we value the education from cultural appreciation, and how do we value regulating services performed by water which may not be immediately obvious? Of course, a range of monetary valuation techniques have already been introduced and increasingly refined to estimate the value of all these ecosystem services. They can be valued in the form of market transactions - for example when drinking water is transacted between populations and water vendors, or when transactions with indirect associations are made when crops are transacted in the market. By correlating sustainable water resource management with economic well-being of people, it allows development boards to make informed decisions in the pursuit of development. They may even improve socioeconomic conditions, especially if biodiversity conservation is simultaneously pursued with ecosystem management (Adams, 2014).

Nonetheless, it continues to be challenging to assign monetary values to many uses, such as education, cultural heritage and the beauty of the landscape. As a result, non-monetary valuation approaches have also been set up in complement, to offer an alternative to the near impossibility of a wholesome monetary approach.

Non-monetary Approaches

These focus largely on stakeholder participation and group perceptions of ecosystem services. These stakeholders are tasked with assessing the cultural values of natural resources and services, their role in our improvement of social well-being, and their valuation in our lives. However, these non-monetary frameworks are often arbitrary as understanding spiritual values of ecosystem services are difficult, and the field is still relatively young at this stage when exact measurements are little found and made. nonetheless, for the valuation of ecosystems to be wholly useful in policy-making, it is integral to develop non-monetary methods for water uses that cannot be immediately quantified.

Some solutions that have been suggested include inclusive and participatory valuation of local needs, especially in data scarce environments such as remote mountainous areas. They combine citizen science with known and experienced human impacts on the water cycle in these regions where conventional data is not easily collected, with scientific processes of the hydrological cycle (Buytaert et al. 2014). These represent measures to make valuation processes more policy-oriented as they cater to local needs to increase the validity of the ecosystem services approach in a specific area.

However, as the field on ecosystem services is relatively new, most of these approaches have been suggested and acted on independently. For future improvements to the overall valuation of water and its associated benefits to human well-being, it is vital that both approaches are taken to provide an overall ecological underpinning of the decisions made on water resources. In my next few posts, I will use case studies to argue how valuation of economic services may help in water resource management, mostly through the monetary approach due to its current applicability in the field.

See you next week!

Ecosystem Services Delivery in Sub-Saharan Africa

Hello all!

In my previous post, I elaborated a bit on the physical characteristics of Sub-Saharan Africa. In this post, I will be using two case studies to illustrate the ecosystem benefits from water resources, from the previously mentioned wetter areas that span across Sub-Saharan Africa (western and central Africa).

The Hadejia-Nguru Wetlands, Western Africa (Barbier and Thompson, 1998: 435)

Figure 3. Hadejia-Nguru River Basin, comprising of the Hadeija-Nguru Wetlands (circled in blue) and the upstream irrigation projects of Hadejia Valley Project and Kano River Project (circled in red).

The Hadeija-Nguru wetlands are formed where the Hadejia and Jama'are rivers converge to form the Yobe River in Nigeria, circled in blue in Figure 3. Extensive areas up to 1000km² are inundated in August and September during the rainy seasons when the ITCZ shifts northwards as Nigeria lies at a latitude of 9°N (recall: physical characteristics of Africa); outside of these rainy months, the floodplains remain dry. Here is a brief list of the floodplain ecosystem benefits using the CICES framework:

1. Provisioning services: Earnings from sales and food consumption from agricultural products, grazing, fuelwood and fishing. Dry-season grazing for nomadic pastoral farmers. Agricultural surpluses for other cities. Migratory habitats for wildlife (eg. wader birds).

2. Regulation and maintenance services: Recharge of the aquifers within the Chad formation.

3. Cultural services: Ecotourism for educational and scientific purposes due to its rich habitat.

With increasing pressure from droughts and dam construction in the Sub-Sahara African region, it has been found that existing wetlands in Africa have increasingly fragmented into isolated pockets; natural wetland connectivity with the annual floods have therefore been lost (Stratford et al. 2011). I will expand more on the valuation of these ecosystem services for the management of wetlands later, as they are currently beyond the scope of understanding of this entry.

The Mara River Basin, Central Africa (Dessu et al. 2014)

Figure 4. The Mara River Basin, with the lakes and rivers outlined in blue (Dessu et al. 2014: 105).

The Mara River drains a combined area of 13,750 km² spanning across Kenya and Tanzania as seen in Figure 4. The Nyangores and Amala rivers are perennial due to the orographic effect from higher altitudes in the north, while the Talek and Sand rivers are ephemeral due to lower altitudes in the west. The livelihoods in the Mara River Basin rely heavily on these rivers for the provision of ecosystem services as seen below:

1. Provisioning services: Economic benefits from farming, livestock husbandry (major economic activity of Massai Tribe), and high-grade gold mining. Tea plantations, rain-fed wheat farms and commercial irrigation farms contribute to food security of Kenya. Forests contribute to economy through logging and charcoal burning.

2. Regulation and maintenance services: Recharge of sub-basins in low flow months of February and March. Carbon sequestration by the forest reserves in the north.

3. Cultural services: Tourism (accounting for 8% of all tourist bed nights, revenue of $20 million).

Similarly, loss of native forest cover, agricultural intensification, growing tourist facilities and pollution have altered the river's natural hydrological regime, resulting in lower low flows and higher peak flows. The population in the Mara River Basin however, is projected to increase through the 21st century, and the basin may therefore experience severe pressure on water resources.

In these two case studies, I have briefly covered the ecosystem benefits delivered by wetlands and rivers to the human population in two regions of Sub-Saharan Africa. In my next post, I will talk about methods of ecosystem valuation of water, and subsequently cover case studies of examples doing so.

See you next week!

Physical Characteristics of Sub-Saharan Africa

Hello all!

Previously, I spoke about Sub-Saharan Africa and how it has been met with ecosystem degradation due to an undervaluation of ecosystem services. In this post, I will touch on the general physical characteristics of Sub-Saharan Africa, which will subsequently help us to understand the distribution of water as an ecosystem function within the region.

Physical Characteristics

Sub-Saharan Africa, as a whole, encompasses a massive land area of about 24 million km² (Hammond and Antwi, 2010); the SPUs including lakes, wetlands, rivers and reservoirs span 6% of the continental area of Sub-Saharan Africa with an overall area of 1,448,771 km² (Rebelo et al. 2010). This area is marked by large spatial heterogeneity: 66% of the land area is characterised by arid and desert conditions, and only 26.9% of the total land area is viable arable land for livestock cultivation and food production (Cotula et al. 2009). The disparity in natural conditions is largely explained by the large variability in climatic conditions, which is controlled by global patterns of atmospheric circulation (Taylor, 2004).

Quintessentially, the Hadley cell controls most of Africa's atmospheric circulation. Around the world, a low pressure belt forms where insolation is concentrated at the equator, rises and flows towards the polar regions. As this air flows poleward, it cools and descends at latitudes of approximately 30°N and 30°S forming a high-pressure belt with stable air conditions and little moisture. Subsequently, the subsiding air at these latitudes either head poleward or equatorward to complete the Hadley cell. Due to the Earth's rotation, the Coriolis force comes into play and these equatorward air movements are deflected clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere to form the northeasterly and southeasterly trade winds respectively. They converge to form the Inter-tropical Convergence Zone (ITCZ), where the convective and convergent uplift bring a large amount of rainfall to the region within the ITCZ as seen in Figure 2.

Figure 2. a) January and b) August. The migration of the ITCZ (red band) over the course of the year creates great seasonality over the African continent, bringing most rainfall to Central Africa in August and most rainfall to South Africa in January. Picture from Ziegler et al. (2013)

Due to Africa spanning across equatorial and subtropical latitudes and the movement of the ITCZ, the mean annual rainfall is characterised by marked spatial variability, ranging between 100mm at the Sahel regions and 1500mm at the coast of West Africa (Eltahir and Gong, 1996). Concomitantly, such diverse climatic conditions deliver different distributions of Ecosystem Service Providing Units (SPU) throughout Sub-Saharan Africa, and within countries their dependency on types of ecosystem services varies as physical conditions change (Egoh et al. 2012). In the wetter regions of western and central Africa, agricultural produce of food and benefits from raw materials are more important ecosystem services; in the arid and semi-arid countries of southern and northern Africa, tourism, grazing and water are of greater priorities.

The important role of water resources delivering ecosystem services within Sub-Saharan Africa will be elaborated more in the next post, where I will be looking at the water bodies in greater specificity.

See you next week!

State of Sub-Saharan Africa

Hello all!

In my previous post, I have briefly talked about what ecosystem services are, and the role of water in ecosystem functions. In this post, I will talk further about the relationship between water and ecosystem services contextualised in Sub-Saharan Africa, and why we should use an ecosystem services framework for decision-making in the pursuit of development.

Sub-Saharan Africa

In the literature, Sub-Saharan Africa has been facing a high incidence of ecosystem degradation in from urbanisation, comparable to that of the 19th century industrial revolution in Europe (Wangai et al. 2016).  Demand on ecosystem functions (eg. water for consumption, wood for timber) have exceeded that of supply, and this has diminished the supplies of ecosystem services through the overexploitation and fragmentation of ecosystems (Cumming et al. 2014). Current population growth of Sub-Saharan Africa at 2.7% is likely to continue inducing pressure on water resources and initiate large-scale water resource schemes in response to human needs, which may further threaten water availability (World Bank, 2017) - within urban East Africa, the 30 years elapsed between 1967 and 1997 have already seen a dramatic decline in mean per capita water use in all urban households from 98.7L to 54.9L per day (Thompson et al. 2000). There was also a tripling of average time spent collecting water for households without piped supplies, resulting from reasons such as over-strain on municipal water supplies due to urban overpopulation.

A continued desire to exploit the scarce resources for use may result in: a) resource conflicts, such as for countries along the River Nile and Okavango Delta (Hobbs, 2004) and b) continued degradation and losses of vulnerable water bodies such as wetlands. Climate change has been predicted to cause further desertification within Sub-Saharan Africa (Wangai et al. 2013), and hence it is essential to to ensure for a continued supply of ecosystem services to sustain livelihoods and safeguard agricultural productivity in our pursuit of development.

So far, ecosystem functions have been considered a "public good" where there is no excludability or rivalry from accessing an ecosystem good (Wangai et al. 2016: 227), and the abovementioned incidences of ecosystem degradation in Sub-Saharan Africa arguably stems from this undervaluation of ecosystem services in conventional policy-making (Potschin et al. 2016). Valuation of water as an ecosystem service is therefore an appealing approach to the management of water resources and establish conservation strategies for the future. In particular, the ecosystem services approach encompasses identifying, measuring, modelling the stocks and flows of ecosystems, and the synergies or trade-offs that occur from decision-making. Although this may sound unclear at present, I will elaborate more on these ideas in the following posts through the following themes:

1. Identification of ecosystem service functions and delivery in Sub-Saharan Africa, and the differences within.

2. Application of ecosystem services approach and valuation of water in Sub-Saharan Africa through measurement of ecosystem services.
3. Modelling ecosystem services for the future (eg. threat of climate change, how to include them in conservation strategies).

4. Limitations of the ecosystem services approach in the current literature, and trade-offs that may occur in decisions.

These area of interests are likely to change as I progress in my knowledge around this topic. Having also read through the past year examples (1, 2, 3), I will try my best to minimise content overlap, and ideally further my seniors’ ideas and frameworks for a more comprehensive understanding of this topic.

See you next week!

Ecosystem Services: Why and What

Hello all!

Having enrolled in the ‘Water and Development in Africa’ module, I have chosen to examine the relationship between water resources and the provision of ecosystem services. My choice stemmed from my module preferences in the previous academic year: a) Ecological Patterns and Processes, b) Surface and Groundwater Hydrology, and c) Development Geography. The premise of water being considered an ecosystem service therefore stood out to me as an effective way to consolidate my knowledge from these three different subject areas of Geography. In this post, I will briefly talk about  the role of water within ecosystem functions, and provide a framework which may help for future posts.

Water: The Heart of Life

Figure 1. Basic ecosystem services/functions arising from water (Van Leeuwen et al. 2012).

Ecosystem services can briefly be defined as “the benefits human populations derive, directly or indirectly, from ecosystem functions" (Costanza et al. 1997). Water lies at the heart of many of these ecosystem functions, evident from Figure 1 - water is a necessity to the survival needs of human population, to the maintenance of biodiversity (eg. habitat for fish, for human consumption and livelihoods), and to the maintenance of forests for timbre and wood. Water has therefore also been cited as an "umbrella service" within the field of ecosystem functions, and that efforts to better manage and conserve water in watersheds indirectly help to preserve other ecosystem functions as explained earlier (Turpie et al. 2008: 789) .

The Common International Classification of Ecosystem Services has emerged as a framework to represent ecosystem services in the form of a hierarchy, classifying ecosystems services at the most general level in the familiar categories used in the Millenium Ecosystem Assesment (2005): provisioning, regulating, and cultural services. I have chosen the CICES as a framework in preference to the MEA due to the explicit quantification of benefits to human populations within the sub-categories; the CICES is also broader in its functions, including abiotic energy sources such as tidal energy (Turpie et al. 2017). I have extracted examples from the CICES Version 4.3 in relation to water resources in Table 1 as shown below (BISE, 2017)

Table 1. Selected sections of the Version 4.3 Common International Classification of Ecosystem Services (BISE, 2017).

Section	Division	Group	Class	Class Type
Provisioning	Nutrition	Water	Surface water for drinking	Eg. 100mm of surface water from rivers for drinking
			Groundwater for drinking	Eg. 240mm of freshwater from groundwater for drinking
	Materials	Water	Surface water for non-drinking purposes	Eg. 100mm of abstracted surface water from rivers for washing and cleaning.
			Groundwater for non-drinking purposes	Eg. 240mm of freshwater from groundwater for irrigation and livestock consumption.
Regulation and Maintenance	Mediation of waste, toxics and other nuisances	Mediation by ecosystems	Dilution by atmosphere, freshwater and marine ecosystems	Eg. Dilution of fluids and solid waste in lakes.
	Mediation of flows	Liquid flows	Hydrological cycle and water flow maintenance	Eg. Rainfall recharge into a 200m^3 river.
	Maintenance of physical, chemical and biological conditions	Water conditions	Chemical composition of freshwaters	Eg. Buffering of chemical composition of freshwater column by re-mineralisation of phosphorus.
			Chemical composition of salt waters	Eg. Buffering of chemical composition of seawater column and sediment for favourable living conditions (eg. denitrification).
Cultural	Physical and intellectual interactions with biota, ecosystems and landscapes.	Physical and experiential interactions	Experiential use of plants, animals and landscapes in different environments.	Eg. Snorkelling, diving.

In my next post, I will elaborate more on the academic motivations for studying the relationship between water and ecosystem functions, and hopefully contextualise within my regional area of interest: Sub-Saharan Africa.

See you next week!