Effect of Land-Use Change and Artificial Recharge on the Groundwater in an Arid Inland River Basin

In arid inland river basins, groundwater in the lower reaches is more sensitive to climate change and human activities than that in the upper reaches. Groundwater in oases plays an important role in economic development and the ecological environment; therefore, it is important to investigate the dynamics of groundwater in such areas.

The impact of climate change on water resources is obvious on long temporal scales. However, human activity has a greater effect on such resources at spatial and short temporal scales. Land use, one of the main representatives of human activity and primary driving factors of hydrological changes, can affect interception, infiltration capacity and surface evaporation. The intensity of human disturbance on water resources, especially groundwater in arid inland river basin, has resulted in continual degradation of the ecological environment. Artificial recharge is an effective method to resolve the problem of depletion of groundwater resources and ecological deterioration. Identification of methods to recharge aquifers quantitatively and effectively is still an area of focus.

This study focused on groundwater changes in the Alagan area within the Tarim Basin, China, with the aim of analyzing the effects of land-use change and artificial recharge on the response characteristics of groundwater. The distributed hydrological model MIKE SHE was introduced for modeling the influence of land use and artificial recharge on groundwater. Based on the runoff variation of this area, we selected three periods to simulate and analyze the response of groundwater.

The results of land-use change indicated that there were significant changes from 1980 to 2000. The changed region accounted for 11.93% of the total area, and the low coverage grasslands showed the greatest reduction. The simulation of hydrological processes before artificial recharge showed that the groundwater depths differed greatly with land use types.

Response analysis of groundwater to artificial recharge showed that the regions in which groundwater decreased were mainly distributed in grassland and bare land. Moreover, spatial autocorrelation coefficients indicated positive spatial autocorrelation of groundwater depths, but these began to reverse in 2010. Overall, land use and artificial recharge have a great influence on the time and spatial distribution of groundwater. Artificial recharge has played a positive role in improving groundwater conditions, but did not change the decreasing trend in time and space. The adaptation of environment to the decrease of groundwater presents as degradation. Groundwater conditions could be improved to some extent by the artificial recharge, but its change seems to be an irreversible process.

This response study provides insight into estimations for exploration of water resources in arid areas. The result was published in Water Resources Management in August 2013.