Due to climate change and increased human impact, water use and its protection have become one of the major regional issues in Central Asia. As the availability of surface water is decreasing and becoming erratic, the reliance and pressure on groundwater resources are constantly growing. That is also a case with the Pretashkent Transboundary Aquifer (PTBA), located between the Republic of Kazakhstan and Uzbekistan. Groundwater withdrawal from the aquifer is increasing, responding to the high demand for water supply and irrigation. Aquifer-sharing countries have started a dialog about water policy and management tools for the PTBA, including the development of an operational numerical model. This model is required for better understanding of the aquifer dynamics and for development of scenarios for utilization of this hardly renewable aquifer.
The aim of this research is to develop a conceptual hydrogeological and a numerical model of the PTBA in a framework of transboundary cooperation.
The model is developed using the Groundwater Modeling System software (GMS). The model input preparation, including challenging transboundary harmonization (differences in language, classification, reference system, etc.) is conducted through a process of intensive discussion and collaboration among all international stakeholders. That was the main novelty of the conducted research. The conceptual model is the first major step in the development of the PTBA model and the first visible result of joint efforts to improve management of precious groundwater resources in the region. The following modelling steps are already stipulated by geological surveys of aquifer-shared countries and will be conducted with the continuous support of UNESCO-IHP and the Swiss Development Cooperation.