ESTIMATION OF GROUNDWATER LEVEL IN THE HUNSHANDAKE SANDY LAND, CHINA BASED ON KBDI AND IN SITU MEASUREMENTS

摘要

Groundwater is a vital resource for agriculture, industry and domestic water use, especially in arid and semi-arid regions. Hunshandake Sandy Land in Inner Mongolia Autonomous Region, China, is abundant in groundwater resource. Whereas, this region belongs to the area where availability of water resource is declining, mainly caused by increasing water exploitation by agriculture and industry. Demonstrated by groundwater depletion and deterioration of lakes, the shortage of water resource is expected to continue not only because of increasing exploitation of groundwater resource but also changing climate. To protect this fragile ecosystem and the livelihood of local people, it is crucial to evaluate the state of groundwater resource in this region. Keetch-Byram Drought Index (KBDI). which is calculated using rainfall and temperature, is a value reflecting the dryness of the upper soil layers. KBDI is balanced with rainfall and evapotranspiration. As groundwater recharge is dominated by infiltration of rainfall, and groundwater discharge is dominated by evaporation from aquifers, in this study, we estimated the groundwater level by using satellite-based KBDI and in situ well measurements in the Hunshandake Sandy Land. Our study shows the decrease in groundwater level had a significant negative correlation with increasing KBDI. demonstrating the significance of integrating satellite observations and in situ measurements for interpreting regional groundwater changes.