Spatial-temporal variation and driving force analysis of water production service function in Yuanjiang River Basin

The Yuanjiang River Basin is an important carrier of water ecological and environmental services.It is of great significance to study the spatial and temporal distribution characteristics and related driving factors of the ecosystem water service function in Yuanjiang River Basin for the protection and management of water resources, the realization of high quality development and the protection of ecological environment in this basin.Water production module based on InVEST model was used to simulate the water production of Yuanjiang River Basin from 2000 to 2020.Normalized Difference Vegetation Index(NDVI) was selected from two aspects of natural and human activities.NDVI,population density and Gross Domestic Product(GDP) were used to identify the important driving factors of spatio-temporal evolution of water production service function in Yuanjiang River Basin.The results showed that:(1) Urbanization intensified in Yuanjiang River Basin from 2000 to 2020,the built-up land area increased significantly, and the increased built-up land area mainly came from the transformation of forest land and cultivated land area.(2) The water yield in the Yuanjiang River Basin increased from 2000 to 2020,but the water yield depth did not show a consistent spatial distribution pattern.(3) Based on the driving analysis of 2015 annual water output, precipitation and NDVI were the dominant factors causing the spatial differences of water production service functions.The five driving factors, such as precipitation and temperature, were nonlinearly enhanced, indicating that the interaction between them enhanced the degree of explanation for the spatial differences in ecological service functions of water production.Natural and human factors jointly influenced the spatial-temporal variation of water production service function in Yuanjiang River Basin.Precipitation and NDVI were the main driving forces for the spatial variation of water yield in the Yuanjiang River Basin.The change of land use also had a certain influence on the increase of water yield in the time scale.The results can provide scientific basis for the scientific and reasonable management and sustainable development of the ecological environment in the Yuanjiang River basin.