Research on the Influence of River Network System Evolution on the Storage Capacity under the Background of Urbanization in the Xiangjiang River Basin, China

Abstract

This project focuses on the flooding caused by river network systems decay in the rapid urbanization process and the contradiction between urbanization and river network protection in the Xiangjiang River Basin. Firstly, we use the integrated remote sensing and geographic information spatial analysis technology to analyze the land-river progress with constructing the evaluation index system of river network system. Secondly, combining the water production model with constructing a comprehensive evaluation system, we analyze the basin regulation and storage capacity change and response to urbanization. Thirdly, we use the geographically weighted regression model to analyze the driving factors and influences of the change of the basin regulation and storage capacity. The results show that: (1) river network system has declined rapidly in the past two decades under the rapid urbanization in the Xiangjiang River basin, and the trunk characteristic of river network system is prominent. There are frequent inter-class changes in different parts of the city, especially in water area and construction land. Human factors are very significant in driving water system change. (2) Due to the lag of basic water conservancy facilities and the influence of extreme climate events and other factors, the water production and storage capacity of the river system in the study area is weaker with the deeper urbanization degree. The capacity of flood drainage in Xiangjiang River basin is gradually weakened. (3) The relationship between urbanization and river network system in the study area showed from confrontation to coordinated adaptation. The intensity of the influence of the main driving factors on the regulation and storage capacity in the study area showed the spatial characteristics of strong north and weak south, with the disturbance of the underlying surface in the urban area being the most severe, and the river network system regulation and storage capacity was significantly weakened. The geographically weighted regression model describes the changes of river system regulation and storage capacity and its driving factors in the river basin, which is conducive to obtaining local information and can scientifically characterize the reasons for the evolution of river systems.