Land use changes- the Remaining Available Aquifer Storage (RAAS) response in arid-semiarid regions: the Baicheng case study

Managed Aquifer Recharge (MAR) is an important approach to the sustainable development and utilization of groundwater resources in arid-semiarid regions. However, research on MAR has not been well developed with regard to the remaining available aquifer storage (RAAS), and in particular the impact of land use changes on the RAAS has not been fully explored. This study takes the Baicheng area as an example, calculates the RAAS on the basis of determining the remaining available aquifer, extracts the precipitation- and groundwater extraction-affected RAASs through independent component analysis, establishes regression equations for the areas of land use types and the precipitation- and groundwater extraction-affected RAASs using stepwise regression and all-subsets regression. The response of the precipitation- and groundwater extraction-affected RAASs under three future land use change scenarios is explored. The results show that the RAAS responds significantly to land use changes. The land use changes were active from 2000 to 2018, and the RAAS showed a fluctuating upward trend, reaching a maximum value of 22.39×10⁸m³ in 2010. In the 2036 economic development scenario, the precipitation-affected RAAS is the largest and the groundwater extraction-affected RAAS is the smallest of the three scenarios, contrary to the results in the baseline scenario. The woodland conservation scenario shows that reasonable woodland conservation measures is conducive to groundwater development and utilization, maintaining the groundwater level at a stable level and ensuring the stability of the RAAS, which is conducive to the design and implementation of artificial recharge schemes based on this. The results quantify the relationship between the precipitation- and groundwater extraction-affected RAASs in response to land use changes, and provide a reference for groundwater development and sustainable water resource management in arid-semiarid regions.