Analysis of river network characteristics evolution in Chaohu Lake Basin

This study focuses on the Chaohu Lake Basin to analyze the evolution characteristics of its river network and water system from 2014 to 2024, revealing the impact of human activities on the structure of the plain river network and providing a basis for regional water system protection and management. Based on remote sensing images and ArcGIS technology, two-phase water system data were extracted, and a five-indicator system—including river network density, water surface ratio, fractal dimension, river network development coefficient, and main stream area-length ratio—was constructed for quantitative analysis from both quantitative and spatial structural perspectives. The results show that over the past decade, the river network density in the Chaohu Lake Basin decreased by 3.44%, while the water surface ratio increased by 2.83%, reflecting a reduction in total river length but an expansion of water surface area. In terms of spatial structure, the river network development coefficient increased by 3.54%, the main stream area-length ratio significantly improved by 18.30%, and the fractal dimension decreased by 1.60%, indicating a widening of main channels and a trend toward simplification of the water system structure. Regionally, the most significant changes were concentrated in the central-western areas, such as Feixi County, Shucheng County, and Baohe District. Overall, the Chaohu Lake river network exhibits an evolutionary trend of main channel widening and water system simplification, with human activities—particularly water conservancy projects and urbanization—significantly altering the river network morphology. This study can provide references for watershed water network planning, ecological restoration, and flood control management.