Spatio-temporal quantification of patterns, trade-offs and synergies among multiple hydrological ecosystem services in different topographic basins

A comprehensive understanding of the spatio-temporal characteristics of interactions and spatial scales of multiple hydrological ecosystem services (HESs) is important for sustainable ecosystem management, but interactions among multiple HESs and their underlying mechanisms in complex socio-ecological systems in different topographic areas remain under-researched. This study discuss the spatial and temporal variation of patterns and interactions of five HESs (biodiversity maintenance, water yield, soil conservation, aquatic purification and water production) in plain and mountain regions to determine synergies and trade-offs at the sub-catchment scale and county scale from 1980 to 2015, and this study employ a case study in the western plain and eastern mountain part of the Nansihu Lake basin in eastern China. The correlation analysis and bagplot analysis were applied to analyze the linkages between HESs, and then redundancy analysis was used to identify important drivers of spatial patterns and interactions of HESs based on socio-ecological variables (e.g., climate, topography, land use, gross domestic product and population density). The results demonstrate that the intercorrelations among HESs varied significantly between the western plain and eastern mountain in both the strength and the direction of the correlating HESs. It was found that there was a trade-off between the water yield and water production in the provisioning services in the eastern mountain basin, while there was no correlation in the western plain basin. Trade-offs and synergies in the entire basin varied greatly over time and space. Compared to the sub-catchment scale, the relationships among the different HESs were mostly weak and some were not significant at the county scale. The study also revealed that topography, land use and climate were the main driving factors affecting the distribution of HESs and their relationships. This study suggested that the sub-catchment scale was more suitable for policy analysts and policy-makers that are concerned with HESs.