Water and soil environmental vulnerability of artificial oases in arid areas and its temporal and spatial differentiation and evolution

The water and soil environmental vulnerability in arid areas is mainly affected by vegetation, hydrology, terrain, and climate. To accurately evaluate the water and soil environmental vulnerability and its evolution in the Jingtaichuan Pumping Irrigation District in China, this paper, taking 1994, 2006, and 2018 as typical years, selects 13 index factors that directly or indirectly drive the water and soil environmental evolution in this area, and adopts the cloud theory and analytic hierarchy process to determine the weight of each index factor. Spatial analysis technique and supervised classification were used to obtain and standardize the spatial distribution raster maps of each index factor. The multi-source data fusion was performed according to the index weight to analyze the evolution characteristics of soil and water environmental vulnerability. The results showed that soil salinity, vegetation coverage, and land use type have a significant impact on the water and soil environmental vulnerability in this irrigation area, and most of the area is at mild risk. High risk mainly occurs in closed hydrological units in the eastern part of the irrigation area. From 1994 to 2018, the evolution process can be divided into two stages, namely the ‘environmental deterioration stage’ and the ‘environmental restoration stage’. The results showed that the water and soil environment of the irrigation area is developing in a healthy way.