Regional projections of hydrological changes
Contributions: UiO (WP Leader: Xu), collaborating institutes in Subequatorial Africa
Main purpose: Provide model estimates of changes in hydrological parameters needed for impacts on agriculture, such as soil moisture index, run-off, and water resources.
Southern Africa’s climate is heterogeneous, dominated by two major climates: seasonally arid and semi-arid tropical (Parts of Malawi, Mozambique, Zambia and Zimbabwe) and arid (Botswana, Namibia, Parts of Angola, Zimbabwe and South Africa) with patches of sub-tropical Mediterranean types common in South Africa (Hulme et al., 2001). This means that in the water balance, the region experience high rates of evapotranspiration (ET) with potential ET exceeding the amount of rainfall received for large period of the year. ET has been identified as the key element in the long-term water balance of a catchment or a region is the value of the actual long-term evapotranspiration. However, ET is the most difficult part of the all the components of the hydrologic cycle due to complex interactions amongst the components of the land–plant–atmosphere system (Xu and Sing, 2005). Despite its crucial role on the water balance of the region, detailed studies on the quantification of ET under various climate scenarios has had minimal attention in the regional climate change studies. WP2 is aimed at modelling water resources in the Subequatorial Africa region under present and future climate scenarios, applying recent advances in detailing on the role of ET on water resources of the area under present and future climate scenarios, as estimated in WP1.The spatial resolution of the WASMOD will be varied from 1km to 25km.
Activities and milestones:
2.1 Sensitivity tests of existing methods/models (i.e. WASMOD-M and WASMOD-D) for assessing regional water resources under stationary and changing climate conditions at different spatial and temporal scales in the study region
2.2: Model estimates of changes in hydrological parameters needed for impact study on agriculture, such as soil moisture index, run-off, and water resources, based on results from WP1.