Scenario Modeling of Urbanization Development and Water Scarcity Based on System Dynamics: A Case Study of Beijing-Tianjin-Hebei Urban Agglomeration, China

Due to the accelerated process of urbanization in China, urban agglomerations have become the core areas for human settlement and economic development. High population and economic density has brought great pressure on water supply. Water scarcity is increasingly becoming one of the most important issues for the sustainable and healthy development of China's urban agglomerations. In this paper, a system dynamics model was constructed to simulate the current conditions and future scenarios of urbanization development and water scarcity in the Beijing-Tianjin-Hebei (BTH) urban agglomeration in 2000-2030, by examining the interaction and feedback between the six major subsystems: water supply, water demand, water pollution, population urbanization, economic urbanization, and land urbanization. It is found that the South-to-North Water Diversion Project and the improved Reclaimed Water Reuse System may greatly increase the water supply. However, the speed of population urbanization and economic growth, the spatial structure of urban agglomeration and the water consumption pattern may determine the water demand. Although all scenarios may risk water scarcity in the future at some point, we could detect a comprehensive and relatively rational scenario to balance water scarcity, regional equity, and efficiency. It might help to synthetically understand the coordinated development mode between urbanization and water resources in Beijing-Tianjin-Hebei (BTH) urban agglomeration, and provide a useful analytical and decision support tool for scientists and policy-makers to achieve the sustainable urbanization development and water resource management.