Spatiotemporal Assessment of Water Conservation Function for Ecosystem Service Management Using a GIS-Based Data-Fusion Analysis Framework

In order to improve water ecological service and ensure water resource protection, it is imperative to develop an effective evaluation method to identify the water-holding capacity of eco-environmental system. In this study, a comprehensive GIS-based data-fusion analysis framework is developed to evaluate the significance of water conservation/retention function (WCF), identify the potential effects of eco-environmental system on water-holding capability, and analyze the dynamic change of Songhua River basin for years 2000, 2005, 2010 and 2015. A general water conservation/retention function evaluation index is constructed associated with climate, geography and human factors to describe water conservation/retention function. Then, an exponential calculation method and regional integrated significance degree coefficient are used to calculate the WCF significance degrees and identify the distribution and change of WCF significance. The developed assessment framework is then applied in Songhua River basin for water ecological protection and environmental management. The results of WCF significance assessment indicate that only 0.56–2.97% of Songhua River basin is very important level of WCF ecological region with high water-holding capacity. The results of WCF significance assessment can help decision makers understand the temporal and spatial changes, identify priority areas for water resource protection, and provide a reasonable policy-guidance for mid- or long-term eco-environmental planning.