Analysis of the Impact of Water Conservancy Projects on Water Resource Use Efficiency and Vegetation Net Primary Productivity in an Arid Inland Basin

Vegetation Net Primary Productivity (NPP) is vital for assessing carbon cycles, particularly in arid regions where dynamics rely on water availability. This study investigates the mechanisms by which ecological water conveyance impacts NPP in the Aiding Lake Basin. Integrating Remote Sensing Hydrological Station technology with the Google Earth Engine platform and the CASA model, we analyzed the spatiotemporal feedback between water conveyance and NPP from 2016 to 2023. Results showed increasing runoff and significant variation in conveyance volumes, with the Baiyang River exhibiting the highest efficiency. Mean annual NPP displayed a significant declining trend, characterized by higher values upstream than downstream and in the west compared to the east. Ecological water conveyance positively enhanced regional vegetation productivity, demonstrating a significant positive correlation with NPP that was stronger at the annual scale. These findings provide a new framework for evaluating the benefits of ecological water conveyance, offering a theoretical basis for ecological conservation in Northwest China.