Abstract:

The contradiction between supply and demand of water resources is prominent in the Yellow River Basin of Gansu Province， which in turn exerts considerable pressure on the groundwater environment. Assessing groundwater sustainability for this area provides an important guidance for the high-quality development of the local and even the whole basin. Based on GRACE， GLDAS and groundwater monitoring well data， the variation of groundwater reserves and groundwater sustainability during 2002-2022 were analyzed for this region. The findings indicate significant seasonal fluctuations， substantial year-to-year variances， and a declining trend in the regional groundwater supplies during this period. Groundwater sustainability is generally low， with a tendency to be higher in the north and south and lower in the east and west of this region （SI=0~0.5）. The groundwater sustainability index （SI） for 2002-2022 exhibits a lowering tendency throughout that period of time， with overall high reliability， poor resilience， and high vulnerability. The intensive and extensive exploitation of groundwater for human activities （such as agricultural irrigation and industrial water use） are the key factors contributing to the loss of groundwater sustainability. The rate of groundwater decline and ongoing deterioration has been alleviated by policy initiatives， such as water restrictions and ecological restoration. In the future， the strategies of "saving water rather than withdrawing more for ecological conservation" should be considered to promote the sustainable improvement of groundwater resources in the Gansu section of the Yellow River Basin.

Key words: Yellow River Basin, Gansu Province, groundwater, sustainability, GRACE, GLDAS