Impact of Climate Change on Water Resources in Eastern Africa

Climate change is causing great impact on water resources in Eastern Africa, and there is need to establish and implement effective adaptation and mitigation measures. According to IPCC, less rainfall during the months that are already dry could increase drought as well as precipitation, and this has great impact on both permanent and seasonal water resources. Increased sea surface temperature as a result of climate change could lead to increased drought cases in Eastern African and entire equatorial region. Climate change will also result in annual flow reduction in various river resources available within the region such as the Nile River. IPCC predicts that rainfall will decrease in the already arid areas of the Horn of Africa and that drought and desertification will become more widespread, and as a result, there will be an increased scarcity of freshwater even as groundwater aquifers are being mined. Wetland areas are also being used to obtain water for humans and livestock and as additional cultivation and grazing land. This chapter reviews the climate change impacts on water resources within the Eastern Africa Region. The climate change impacts on different water resources such as Ewao Ngiro have been highlighted and projection of future climate change on water resources examined. Stream flow for Ewaso Ngiro was found to have a significant increasing trend in 2030s of RCP4.5 and non-significant decreasing trend in stream flow in 2060s for RCP4.5.

Kenya Success Story in Water Resources Management

Management of water resources is at the heart of political discourse to raise awareness among local stakeholders for support in policy formulation and implementation of water sector development plans. The concept of integrated water resources management (IWRM) has been largely disseminated by the Global Water Partnership. Though theoretically appealing and sound, the process of implementation of participatory water resources management still has potential to yield results at local level. One reason is that the top-down approach used is too broad to be implemented and neither does it facilitate better understanding of the needs of each sector involved in the inter-sectoral collaboration to foster planning and benefit sharing of water resources. It is in favor of such practical action for water sector planning and development at small-scale catchment level that the concept of “light” IWRM or integrated watershed management (IWM) was developed to reduce various threats and severe water constraints affecting local stakeholders.

Probabilistic Studies of Hydrologic Drought Events in Juba River in Somalia

Juba River runs from its headwaters in Ethiopia through Somalia and discharges into the Indian Ocean near Kismayo. Severe droughts recur in Juba River Catchment. This chapter examines the time series of hydrologic droughts and the factors influencing their occurrence in the catchment. The author further demonstrates the application of probability distributions to compute the exceedance probabilities of the hydrologic drought experienced in the catchment in the past, from 2001 to 2014. The fits of the probability distributions are compared to show the best fitting of all distributions. The probability distribution that will reasonably fit well to the data set is adapted to generate graphical plots for forecasting the return periods of drought events in the catchment. Reconstructing past drought episodes and future drought predictions is useful in drought risk management in Baardheere region of Somalia.

Effects of Irrigation Management Practices on Water Allocation Among Farmers in Kiladeda Sub-Catchment, Tanzania

Kiladeda River in Pangani Basin, Tanzania plays a vital role of providing water for agricultural activities of the sub-catchment. However, it is experiencing a problem of inequitable distribution of irrigation water among farmers. Cross-sectional data was collected from farmers both in upstream and downstream using questionnaires, while river discharge measurements were conducted in referenced spot gauging stations. WEAP model was used to analyze water demand and allocation among farmers. Furrow irrigation (94%) and plastic buckets (6%) were the main irrigation water management practices. The model results revealed a water shortage of 46.4% of the total irrigation water required. The annual irrigation water demand and unmet demand were 13.93mm3 and 7.47mm3, respectively, and are both expected to increase twice in 2020. This high water demand for irrigation could be the main cause of excessive water abstraction. A partnering approach is recommended to improve irrigation water management, reviewing of laws, regulations, and water rights.

The Effects of Streamflow Variability on Salt Flux in a Semi-Arid Tropical River Basin in Eastern Kenya

This chapter presents the results of a study on the influence of streamflow variability on salt fluxes in a semi-arid Tiva River Basin located in Eastern Kenya. Measurements of salinity, total dissolved solids (TDS), conductivity, and river discharges were undertaken in sampling stations located within the main branch of the river as well as in the tributaries, namely Kauwi, Kalundu, Nzeeu, and Mwitasyano Rivers in the Upper Region of the Tiva River Basin. The mean and maximum river discharges for the sub-basins of the river ranged from 11 to 33 m3s-1 and from 118 to 210 m3s-1, respectively. The peak river discharge at the main Tiva branch was 270 m3s-1. The study shows that there is a significant relationship between the variability of streamflow and the variability of salt fluxes in the river as exemplified by variation of salinity, conductivity, and TDS in the river.

Effects of Long-Term Variability on Water Resources Management Along the Boteti River in Botswana

This chapter examines how the availability and non-availability of river flows has affected benefits realized by communities residing along the Boteti River in Botswana. The Boteti River, which is about 350 km long, derives all its flows from outflows of the Okavango Delta and then discharges into the Makgadikgadi Pans. Peak outflows from the delta occur during the dry season, June to October, and during wet years such as from 1974 to 1982, water flows along the whole river from the delta to the Makgadikgadi Pans. Since 1991, outflows from the delta have only covered about 50 km, with the rest of the river being dry. There has been lack of flows on the downstream section in some years (e.g., 1929-39, 1941-47). Communities residing along the 50 km stretch that is annually flooded benefit from the river through livestock watering, flood recession crop cultivation, fishing, and harvesting of aquatic plants for food and construction. These benefits were not realized by those residing along the rest of the 300 km stretch that was not receiving flows from the delta during the 1991-2008 period.

Advancing New Pathways for Sustainable Deployment of Agricultural Ground Water With Gender-Sensitive Data Sharing

At the basin level, watershed resources (water, land, and ecosystem services) are often managed in “silos,” whereby gender-sensitive data and analytics are employed by different stakeholders without regard to existence of similar systems in other parts of the same sub-catchment. These cases create missed opportunities and insights for harnessing better innovative water interventions from baseline scenarios by examining the relevant frameworks, protocols, and tools for data sharing as well as the means of disaggregating water and climate change data into gender-sensitive formats transferable to similar sub-catchments. Innovative water solutions would enable optimal water services provision and financing without farmers depending wholly on external organizations to provide solutions to their financial challenges through taking part in technological development of viable water infrastructure.

A Spatial Database of Hydrological and Water Resources Information for the Nyangores Watershed of Kenya

Advances in environmental remote sensing have provided an opportunity to monitor water resource systems in vulnerable regions with data scarcity. The spatial datasets can be used to build spatial models of reality to enable derivation of catchment-based characteristics, also often required by models in hydrology. The derived estimates can then be mapped and cartographically presented to support water resources planning within the concerned developing regions. This contribution presents a database of water resources information for an upstream catchment of the Mara River Basin of Kenya developed from freely available spatial datasets. Additionally, water quality parameters (pH, electrical conductivities, and total dissolved solids) selected as essential indicators of the suitability of the water resources for domestic applications were measured and mapped. The database, packaged as spatial maps, has been presented to the local stakeholders for developing appropriate catchment management strategies within the important watershed.

Hydrology and Best Practices for Managing Water Resources in Arid and Semi-Arid Lands in Kenya

This chapter provides a critical analysis and evaluation of the water issues relevant to Kenya's ASALs. This has particularly been centered on the current resource development and management, future resource demand, as well as extent of its vulnerability to climate variability and change. The water development policy interventions have also been evaluated. The analysis has revealed that water resources are being utilized to satisfy a myriad of demands and that in fact a water shortage already exists in these ASALs. A number of factors including population pressure, poor resource use and management, and other socio-economic activities have been noted to increase the vulnerability of the available water to the impacts of climate change. Recommendations for purposes of ensuring the sustainable utilization of the vital water resource have been proposed.

Multi-Temporal Landsat Remote Sensing for Forest Landscape Fragmentation Analysis in the Yoko Forest, Kisangani, DRC

This chapter assessed the impact of human activities on deforestation and sustainability of water resources and livelihoods in the Congo Basin. It mainly aimed to assess forest degradation in the Yoko Reserve from 1976 to 2015 and investigate the compatibility of Landsat imagery for forest monitoring. Digital image processing for unsupervised classification was done using ENVI software while supervised classification was done by means of ArcGIS 10. Results show that forest landscape faced large-scale human-induced fragmentation over the last 40 years. If these trends continue, they will affect the sustainability of water resources and livelihoods in the Congo Basin of the Democratic Republic of Congo. Hence, policymakers need to look at key drivers and address impacts that may threaten the future of hydrological ecosystems services, including water and land resources in the Congo Basin. Authorities have to apply an integrated management of water, land, and ecosystems.