Ecological Water Demand of Taitema Lake in the Lower Reaches of the Tarim River and the Cherchen River

Taitema Lake, located in the lower reaches of the Tarim River and the Cherchen River, is one of the most important ecological barriers in Ruoqiang County. The amount of water in Taitema Lake plays an important role in maintaining a healthy cycle within the ecosystem, curbing sandstorms, and improving salinization and desertification. The aim of this study was to reasonably determine the volume of ecological water conveyance by calculating the ecological water demand. We systematically analyzed the spatial and temporal variation characteristics of Taitema Lake during 21 ecological water conveyance processes from 2000 to 2020. The results showed that the area of Taitema Lake increased at a rate of 144% per year because of the Ecological Water Conveyance Project (EWCP). The areas of water in dry, normal, and high flow years were 30.35, 57.76, and 103.5 km2, respectively. The corresponding ecological water demand was 1.58 × 108, 3.09 × 108, and 5.66 × 108 m3, respectively. We calculated that the Cherchen River and the Tarim River carried 0.87 × 108–3.11 × 108 m3 and 0.71 × 108–2.55 × 108 m3 of water, respectively, under different inflow frequencies. This study has significance as a reference for estimates of the ecological water demand of terminal lakes under the condition of artificial water transport in arid inland river basins, and provides the basis for the rational allocation of water resources in the Tarim River Basin.