TINA SCHIEDER1, P. WEHRHEIM2
1University of Bonn, Center for Development Research (ZEF), Germany
2University of Bonn, Institute for Agricultural Policy, Germany
Water availability and an effective and sustainable management of water resources is an important factor in social and economic development. This applies notably for the case study area. The highly arid area Khorezm is situated in the Central Asian Republic of Uzbekistan and the Amu Darya delta region. The Amu Darya is directly flowing into the Aral Sea, but due to historical and recent expansion of irrigation projects and climatic fluctuations the water is often not feeding the Areal Sea any more. The region is highly dependant on water for irrigation purposes. But inefficient water consumption and management result in drastic ecological, social, and economical problems like rise of soil and water salinity, water scarcity and competition, declining yields, health problems or rising groundwater levels. This development and an increasing competition among water users within the region and between up- and downstream areas along the river calls for a more efficient water allocation and management approach for the region. In this study an integrated economic-hydrologic water management and planning model for Khorezm region is developed with the main objective to determine different water users and water using patterns and to find out strategies for a more efficient allocation and management of water resources that also allows the analysis of alternative water policy scenarios. The described research is part of the Uzbekistan project ``Economic and Ecological Restructuring of Water and Land Use in the Region Khorezm (Uzbekistan)'' of the Center for Development Research in Bonn. The modelling system is developed as a node-link network where nodes represent physical entities like water sources and demand nodes (river nodes, reservoir, groundwater, drainage, evaporation ponds, agricultural demand sites) and links represent the linkage between these entities. The water allocation model is programmed in Gams (General Algebraic Modelling System) and is made of a system of non-linear differential equations. The development of such a framework of analysis can be a step to integrate different disciplines (natural sciences, economics, social sciences) to find out a better water management including efficient, equitable, and environmentally sustainable water allocation mechanisms.
Keywords: Integrated hydrologic-economic model, irrigation, node-link network, river basin model, Uzbekistan