The Hexi Corridor plays a pivotal role in safeguarding China’s ecological security, functioning as a crucial conduit between economic and ecological systems. This study employs a multidisciplinary approach, integrating climate, evapotranspiration, and other variables, to analyze the trend in factors influencing ecological function and to evaluate the import of ecological service functions in the Hexi Corridor from 2000 to 2020. The findings reveal a distinctive spatial distribution pattern for regulating functions, with higher concentrations observed in the southern regions and lower concentrations in the northern regions. These functions include the storage of carbon, quality of habitat, the conservation of water, and soil and water conservation. It can be observed that the areas of general importance for ecosystem services are predominantly distributed across the northern and western sections of the Hexi Corridor, collectively representing 76.96% of the total area. Conversely, areas of general importance for ecosystem services are situated in regions characterized by a high altitude, intricate topography, and extensive glaciers as well as permafrost.

The evolution of a terminal lake at the end of a river not only reflects the climate change characteristics within the basin but also the impact of regional human activities, especially in arid areas. In the Hexi Interior of China, three terminal lakes (e.g., Halaqi Lake, East Juyanhai Lake, and Qingtu Lake) situated in the Shule River, Heihe River and Shiyang River, respectively, have been increasingly studied to support regional ecological protection and sustainable oasis development. In this study, Landsat TM/ETM+/OLI and Sentinel-2 MSI imagery were used to examine Halaqi Lake spanning from 2017 to 2022, East Juyanhai Lake from 1990 to 2022, and Qingtu Lake from 2009 to 2022. The focus of this investigation was to characterize changes in lake area and the impact of climate change and human activities. The results revealed a dramatic change in Halaqi Lake, which suddenly emerged in 2017, initially covering an area of 13.49 km², gradually vanishing nearly in 2021, and reappearing in 2022 with a reduced area of 9.53 km². The area of East Juyanhai Lake was 54.39 km² in 1990 but reduced to 40.84 km² by 2022. Throughout this period, it encountered episodes of drying up in 1992, 1995, 2001, and 2002. Qingtu Lake emerged in 2009, with an area of 0.09 km², and subsequently expanded to 2.60 km² by 2022. Climate change and human activities collectively influence the area fluctuations of these three terminal lakes. Among these factors, temperature changes have a greater impact on the lake area in East Juyanhai. Global warming has worsened glacier melting in the Qilian Mountains, resulting in increased inflow in certain years and substantial lake area expansion. Human activities are the primary drivers of changes in Halaqi Lake and Qingtu Lake. Industrial water consumption is the key factor influencing area changes in Halaqi Lake, whereas water usage in forestry, animal husbandry, and fisheries plays a dominant role in the area changes of Qingtu Lake. Furthermore, the introduction of ecological water conveyance projects has had an indispensable effect on rejuvenating and preserving the watershed areas of these three terminal lakes. It is important to emphasize that human-driven water resource management is the primary cause of sudden changes in the lake areas.