Limpopo River Basin
Background & Objectives
The Limpopo River Basin (LRB) is the fourth largest international basin in Southern Africa and it resides in a region that is classified as arid to semi-arid. The water resources (both surface and underground sources) are under severe pressure, due to constant increases in water demands from agriculture, domestic, mining, and the environment as well as negative impacts associated with climate change and unsustainable land utilization and conservation practices. The total catchment area of the LRB of nearly 408,000 km2 and its water resources are shared by four countries: South Africa, Botswana, Mozambique, and Zimbabwe. The LRB drains to the Indian Ocean via Mozambique. The basin experiences frequent drought and flood events which not only have negative effects on the economic, social, and environmental conditions of the population but also influence the geopolitical relationships between the four riparian countries. Efficient transboundary water resources management is required to support regional integration.
Extended periods of drought or flood severely affect food security and put in jeopardy potential investment decisions in strategic sectors (agriculture, energy, chemical, and mining industries) that contribute to promoting employment opportunities and inequality reduction. This exacerbates the already fragile economic conditions that are encountered in the region, particularly in the rural communities. Despite some progress made so far in terms of promoting appropriate governance structures, the threat associated with such environmental risks has not entirely vanished. This is mainly because the LRB is expected to experience an increase in its population, which will create more competition on water use between sectors and across riparian countries. Previous estimates show that 18 million people live in the LRB, and by 2040, 20-23 million are expected to reside in the basin. Almost all of them rely on water resources to perform some economic and social activities. Agriculture remains the main source of income and the major water user in the basin with 60% of the total water resources allocated to farming practices, followed by the residential sector (30%) and other sectors such as mining, services, and fisheries which consume the remaining 10%.
An additional feature of the basin is the spatial disparity between geographical regions across the catchment. Although the overall mean annual rainfall in the basin varies between 200 and 1500 mm, the northern and western parts remain under severe water scarcity. This has tremendous consequences when it comes to designing and building water supply infrastructures that aim at supporting long-term mitigation strategies against water scarcity. Additionally, the decrease and fluctuations in the water supply are exacerbated by climate change, which will affect irrigation water supply reliability, evapotranspiration, and annual mean precipitation. Crop production in the LRB is variable both spatially and intertemporally, and unreliable primarily due to low and erratic rainfall. This leads to seasonal variability in yields between not only the riparian countries that share the LRB but also the other neighboring nations in the SADC region since they are indirectly affected by any policy measure implemented within the basin.
Another important issue related to the problem of water security in the LRB is the deterioration of water quality. Both polluted agricultural runoffs and mining, and industrial effluents released to the river tend to increase salinity, sediment load, and metal contents. Coal mining, power generation, and chemical industries have all contributed to the deterioration of water quality in the river. This not only requires heavy investments in smart and cost-effective wastewater treatment options, but also a sophisticated water management strategy that takes a holistic approach that combines water with health and ecosystem protection. Such initiatives allow countries in the basin to reach the sustainable development goal (SDG6), but also any other SDG that relies indirectly on access to good quality water at an affordable price.
This research group is made of scientists based at the University of Cape Town (UCT), in South Africa, the University of California Riverside (UCR), and an independent expert consultant in the US. The group investigates several aspects related to water resources management in the LRB. For instance, issues such as (i) Water use in agriculture, (ii) water quality mitigation to protect human health and ecosystem services, (iii) the transaction costs and institutional impediments associated with efficient water resources management, (iv) the dynamic of hydrological variations under various climatic conditions, (v) the nexus between water-energy and food, (vi) the impacts of water reforms in driving behavioral changes in water conservation practices will be investigated. The group makes use of various methodological tools to address the thematic tools highlighted above.
Limpopo River Basin Team
Please click on the picture of each team member for their bio& contact information.
Djiby Thiam, Ph.D.
Djiby Thiam is an associate professor in Economics at the University of Cape Town, South Africa. His research focuses on resources and environmental economics, water resources economics, agricultural economics, and development economics. He has coordinated various research projects in the field of water and resources economics, development economics, and agricultural economics. He leads a research team made of postdocs, PhD-students, and Masters-students, all working on various issues related to water, development, and resources economics applied in South Africa and Africa as a continent. His work covers the Limpopo River Basin where he looks at (i) the efficiency of water use in agriculture, (ii) the factors that drive adoption of index-based drought insurances in the basin, (iii) the evolution of the hydrological cycle of the basin under various climate and socio-ecological changes, and (iv) the questions of land subsidence that affects groundwater management and water supply infrastructure planning.