Risk control of groundwater exploitation for Zhangye basin in the middle reaches of Heihe River basin, China

Abstract. Regulation of the water table is a feasible and effective way to reduce the risk of groundwater exploitation. An index system of groundwater exploitation risk evaluation is developed. The groundwater numerical simulation model is established for Zhangye basin in the middle reaches of Heihe River basin, China. Based on the identification and validation, the model is used for numerical simulation and forecast of groundwater exploitation under the conditions of current and planned development. The results show that the increase of groundwater exploitation amount causes the falling of water table. The increase of groundwater exploitation is 7600 × 10⁴ m³, which can displace the surface water amount of 10 100 × 10⁴ m³. The annual river runoff can increase 7536 × 10⁴ m³. It is beneficial to the let-down flow from Zhengyi Gorge cross-section, and also provides the basis for decision on risk control of groundwater exploitation.