The Nile River basin (NRB) suffers from increasing water stress due to population increase and competing demands on limited resources (water, food, energy). Currently the water use management is event driven and not subject to any rational and sophisticated decision support system. For the first time this project will develop an integrated management tool (NIMA-NEX) based on the present and projected future climate of Africa, the availability of water in reservoirs, groundwater and soil moisture, to optimize the overall water use of the NRB so as to maximize its overall economic, social benefits and its political stability. NIMA-NEX is based on the following three pillars: A regional climate module (CLI-NEX), a water resources/hydrologic module (HY-NEX) and an energy and reservoir management module (MA-NEX). NIMA-NEX will nicely integrate with the DAAD-NeXus project of Prof. Rutschmann (A network which also involves two EuroTech universities, EPFL from Switzerland and DTU from Denmark, and funded at 250.000/year for four years). DAAD-NeXus not only establishes local relations but also supports the exchange of scientists involved in the Nexus research. Under CLI-NEX, the future changes of the NRB of Africa will be comprehensively assessed by simulating future climate of NRB using a stand-alone regional climate model (RCM), and also a RCM coupled with a land surface scheme (LSS). Using an ensemble, multi-climate modeling approach on the complex feedbacks between land-atmosphere, the effects of climate change based on the 4th Assessment report, SRES (Special Report on Emissions Scenarios) and the latest, Coupled Model Intercomparison Project Phase 5 (CMIP5)’s new scenarios, called RCP (Representative Concentration Pathways) climate projections of IPCC‘s (Intergovernmental Panel of Climate change) GCMs (General Circulation Models), climate anomaly (El Nińo and La Nińa) and landuse changes (LUC) will be simulated. HY-NEX applies the climate projections of CLI-NEX to assess the availability of surface and ground water under the effects of climate change, LUC, irrigation management, and societal changes such as population growth. In some sense, CLI-NEX and HY-NEX will be loosely coupled together. HY-NEX will be more strongly coupled to MAN-NEX as the demand for water among competing users will affect agricultural productivity and population growth. The optimal allocations of water between municipalities, industries, energy and food production will be simulated using global search algorithms that maximize certain objective functions subjected to sets of physical constraints. In addition to using stand-alone RCM and coupled, RCM-LSS, the climate change impact using a simpler, statistical teleconnection approach will also be developed, which will be based on WPCAs (wavelet principal component analysis) of sea surface temperature (SST) of the Indian oceans projected by IPCC‘s GCMs as predictors to a teleconnection model. An analysis based on remotely sensed vegetation indices and drought indicators will be carried out to assess the impacts of past droughts on the selected sites. Various options to investigate sustainable management of the sites will be considered, e.g., restoring land fertility, zero-tillage farming, rehabilitation, rainfall harvesting, diversify crop production, promote drought-resistant crop varieties, seeds that use water efficiently, reforestation, improvement irrigation water use, and existing regional EWS (Early Warning System) of NRB will be improved.
Polanco, E. I., Fleifle, A., Ludwig, R., and Disse, M. (2016): Improving SWAT model performance in the Upper Blue Nile River Basin using meteorological data integration and catchment scaling, Hydrol. Earth Syst. Sci. Discuss., doi: 10.5194/hess-2016-6