Julie Wilk

Simulating the impacts of land-use and climate change on water resource availability for a large south Indian catchment

Abstract A monthly rainfall-runoff model was calibrated for a large tropical catchment in southern India. Various land-use and climatic change scenarios were tested to assess their effects on mean annual runoff and assured water yield at the Bhavanisagar Reservoir in Tamil Nadu, India. The largest increase in runoff (19%) came from converting forest and savanna (the indigenous control scenario) to agriculture. Mean annual runoff decreased by 35% after conversion to commercial forest and 6% after partial conversion to tea plantations. The predicted climate scenarios of reduced dry season rainfall decreased the annual runoff by 5% while enhanced annual rainfall caused a 17% increase in runoff. Even if land-use and climate changes had relatively large effects on runoff, the changes in reservoir yield which can be assured every year, were often less severe. This was probably due to the buffering effect of the reservoir and variation in the mean annual runoff.

Shocks and rural livelihoods in the Okavango Delta, Botswana

This paper describes the impacts that three shocks in the Okavango Delta, Botswana, have had on rural livelihoods: the desiccation of river channels, animal diseases, and HIV/AIDS. Primary data was collected from five study areas, using formal questionnaire interviews and focus group discussions. The paper reveals the adverse effects on rural livelihoods. It describes the way households have been exposed to poverty and vulnerability and the various ways they have coped or adapted, such as by re-allocating their labour, liquidating their assets to cover medical expenses and funeral costs, reducing the area ploughed for crops, hiring labour, digging wells and switching from flood recession agriculture to dryland farming. The Botswana government has provided safety nets to help households cope, but this paper recommends that peoples responses to these shocks should be taken into account in future policy and programme formulation.

From Water Poverty to Water Prosperity—A More Participatory Approach to Studying Local Water Resources Management

The Water Poverty Index (WPI), a tool designed for integrated analysis of water issues, was set-up in a community in Madhya Pradesh, India through a transparent and participatory process. Though the aim of the WPI is to primarily use existing statistical data, quantitative information from census and local records was combined with qualitative data from community interviews and participatory exercises. The inclusion of community chosen indicators and the adjustment of values so that higher numbers represent water prosperity rather than water poverty, led to the Water Prosperity Index (WPI+). The WPI + score was contrasted with the WPI at community level. It was also calculated for two community areas with different caste and socio-economic characteristics and weighted separately according to water issues prioritized by men and women. The WPI + revealed a great difference in water access between the two areas and in prioritized issues between men and women illustrating the importance of appropriate spatial representation and gender sensitive assessments for revealing important disparities. Results also showed that highly aggregated data hide these differences making it more difficult to target the most vulnerable groups when planning measures to increase equitable water allocation. While quantitative data reveal an important perspective of the water situation, qualitative data about adequacy of resources, services or institutions, improve understanding of which issues to prioritize. A valid and useful community water index must be based on representative participation, transparency and local influence on the methodology and subsequent results.

Adaptation to climate change and other stressors among commercial and small-scale South African farmers

Commercial and small-scale farmers in South Africa are exposed to many challenges. Interviews with 44 farmers in the upper Thukela basin, KwaZulu-Natal, were conducted to identify common and specific challenges for the two groups and adaptive strategies for dealing with the effects of climate and other stressors. This work was conducted as part of a larger participatory project with local stakeholders to develop a local adaptation plan for coping with climate variability and change. Although many challenges related to exposure to climate variability and change, weak agricultural policies, limited governmental support, and theft were common to both farming communities, their adaptive capacities were vastly different. Small-scale farmers were more vulnerable due to difficulties to finance the high input costs of improved seed varieties and implements, limited access to knowledge and agricultural techniques for water and soil conservation and limited customs of long-term planning. In addition to temperature and drought-related challenges, small-scale farmers were concerned about soil erosion, water logging and livestock diseases, challenges for which the commercial farmers already had efficient adaptation strategies in place. The major obstacle hindering commercial farmers with future planning was the lack of clear directives from the government, for example, with regard to issuing of water licences and land reform. Enabling agricultural communities to procure sustainable livelihoods requires implementation of strategies that address the common and specific challenges and strengthen the adaptive capacity of both commercial and small-scale farmers. Identified ways forward include knowledge transfer within and across farming communities, clear governmental directives and targeted locally adapted finance programmes.

Calibrating a rainfall-runoff model for a catchment with limited data

Abstract A rainfall-runoff model has been established to simulate streamflow in a regulated catchment in southern India, where data were limited in relation to the basins complexity. Within the basin is a network of hydropower reservoirs and tunnels that complicate the relationships between observed and natural flows. The basin is affected by two monsoons that dominate in different areas and can only be quantified through a relatively sparse raingauge network. These characteristics combine to make it difficult to satisfactorily define the spatial distribution of rainfall inputs to the basin. After critically assessing the data that were found to be inconsistent and unrepresentative, various assumptions about the operation of the system were tested. Despite incomplete streamflow data and the complex hydropower system, the limiting factor affecting successful simulations of streamflow at the basin outlet was the uncertain representativeness of the calculated areal rainfall. The final outcome is a model, which despite shortcomings, is considered to be a useful water resources management tool that provides a sound basis for further studies.

GIS-supported modelling of areal rainfall in a mountainous river basin with monsoon climate in southern India

Abstract Spatial rainfall patterns and seasonal variability were assessed for a mountainous river basin with monsoon climate. Factors were identified that could explain this variability, and a GIS-supported method to determine the areal distribution of precipitation was developed. To find acceptable regression equations, a division had to be made between rainfall stations dominated by the southwest-monsoons and the northeast-monsoons, respectively. Distance to the southwestern border was the main explaining factor for precipitation at southwest-monsoon dominated stations. For northeast-monsoon dominated stations, altitude and slope were the most important factors. The basin was divided into pixels with characteristics typical for northeast- or southwest-monsoon dominated rainfall stations to allow calculation of spatial rainfall. The difference when comparing regression-based estimates with Thiessen-based estimates was small when considering the annual estimates for the whole basin. However, when analysing seasonal rainfall or sub-catchments, the differences between Thiessen-based and regression-based estimates were significant.

Opening Up the Water Poverty Index—Co-Producing Knowledge on the Capacity for Community Water Management Using the Water Prosperity Index

The Water Poverty Index is a tool enabling a multisectoral description of the water situation in an area or region. Many aspects of a societys capacity to manage water, however, require qualitative and explorative approaches. Additionally, the perceptions of “the water poor” themselves may differ substantially from expert valuations built into the Water Poverty Index. The aim of this article is to open up the Water Poverty Index with a special focus on the capacity to manage water in a robust way. This is done through a process of participatory research and by transforming the Water Poverty Index into a Water Prosperity Index using a local community in central India as example. By opening up the assessment process, issues empirically identified by community members, researchers, and local nongovernmental organization (NGO) staff can be discussed and qualitatively assessed, resulting in an improved knowledge of the water situation and an approach for participatory planning.

Design and test of a model-assisted participatory process for the formulation of a local climate adaptation plan

This article presents the design and testing of a model-assisted participatory process for the formulation of a local adaptation plan to climate change. The pilot study focused on small-scale and commercial agriculture, water supply, housing, wildlife, livestock and biodiversity in the Thukela River basin, KwaZulu-Natal, South Africa. The methodology was based on stakeholders identifying and ranking the severity of climate-related challenges, and downscaled stakeholder-identified information provided by modellers, with the aim of addressing possible changes of exposure in the future. The methodology enables the integration of model-based information with experience and visions based on local realities. It includes stakeholders’ own assessments of their vulnerability to prevailing climate variability and the severity, if specified, of climate-related problems that may occur more often in the future. The methodology made it possible to identify the main issues to focus on in the adaptation plan, including barriers to adaptation. We make recommendations for how to design a model-assisted participatory process, emphasizing the need for transparency, to recognize the interests of the stakeholders, good advance planning, local relevance, involvement of local champions, and adaptation of Information material to each groups previous experience and understanding.

Simulating Climate Impacts on Water Resources: Experience from the Okavango River, Southern Africa

The Okavango River is one of the largest and most important rivers in Southern Africa. The river rises in Angola, a country that has just emerged from a civil war of three decades. The annual flood pulse of the river feeds the Okavango Delta: one of the most valuable environmental resources of the African continent. The Okavango River water and its ecosystem resources are critically important sources of livelihoods in the basin. Pressures from livelihoods and development are already impacting on the environment and are likely to increase. Moreover, future development will occur against the background of climate variability and change. This chapter describes research conducted under the EU-funded project‘Water and Ecosystem Resources in Regional Development’ (WERRD), whose aims included development of scenario modelling as a tool for integrated water resource management in the Okavango River basin. The impact of climate change scenarios on downstream river flow and flooding in the Okavango Delta are simulated using a suite of hydrological models. The simulated impacts of climate change are sensitive to the choice of GCM and the IPCC SRES greenhouse gas (GHG) emission scenarios. The simulated impacts are considerable larger that those of the selected development scenarios although the uncertainty in the magnitude of future changes remains high.

Changing Flow in the Okavango Basin: Upstream Developments and Downstream Effects

The Okavango basin is shared between the countries of Angola, Namibia and Botswana and terminates in the Kalahari MOZ (Makgadigadi-Okavango-Zambezi) depression as an extensive alluvial fan often referred to as a “Delta” (Ringrose et al., 2005a). The upper catchment area receives 1200 mm/year rainfall and flows to the semi-arid Kalahari where the nominal average 460 mm/yr is considered a good rainfall year. Most of the streamflow in the basin is generated within the Angolan upper catchment. After 27 years of civil war, the cease-fire in 2002 may ultimately result in large number of refugees returning to the Angolan headstreams area with anticipated increased demands both for irrigation water and sites for dam construction for electricity generation. As the level of development is not high most of the returning people will be dependent on natural resources. Though the provision of needs to basin inhabitants is undisputed, there are concerns that the resettlement of displaced communities might have downstream environmental impacts (Green Cross International, 2000). Development will however be slow because of the large number of remaining landmines (Mendelsohn and El Obeid, 2004).