Water resource system risk and adaptive management of the Chinese Heihe River Basin in Asian arid areas

Water scarcity is a challenging environmental problem in global arid regions in the twenty-first century. Global climate change and urban economic development exacerbate the problem of limited water supply and water shortage. In Asian arid areas, water has been being an important economic lifeline to maintain a healthy and sustainable oasis system. This study took the Heihe River Basin (HRB) in China’s north-western arid area as a typical case region, identified an analytic framework of water resource system risk (WRSR) and analysed systematically the WRSR degree from the different perspectives. The results indicated that the runoff from mountainous watershed showed an increasing trend, but the total amount of watershed water resource showed a decreasing trend in the HRB in the past 50 years. Besides serious drought risk in recent 20 years, the WRSR is mainly from excessive water use in agriculture irrigation. Overall, the WRSR has increased from the year 2000 onward and is expected to increase and fluctuate in the future. Similarly, the potential WRSR is also huge in some arid watersheds relied heavily on glacial runoff in the world. In order to reduce water scarcity risk, it is necessary to implement and carry out effectively the watershed management policies of water resource; coordinate with the balance between the river and tributaries, surface water and groundwater and water quantity and quality to ensure the reasonable water supply in the different regions and water sectors; and promote rational industry structure adjustment and the innovations and applications of water saving and conservancy science and technology.