Ecological Monitoring and Service Value Assessment of River–Lake Shores: A Case Study of the Huanggang and Taihu Segments of the Yangtze River

Riverine and lacustrine shorelines are crucial for human survival and development, but their natural and ecological environments are highly fragile and sensitive. Intensified human activities have placed unprecedented pressure on the shoreline ecosystem of the Yangtze River Basin. This study investigates the degradation of river and lake shorelines and its cascading effects on ecological service functions. Using Sentinel-2 as the primary data source, we analyzed land use/cover changes and ecosystem service values (ESV) in the Huanggang and Taihu sections of the Yangtze River from 2018 to 2022. The supervised classification results using the support vector machine (SVM) algorithm exceeded 95% accuracy. In the Huanggang section, vegetation was significantly converted into cultivated land and built-up areas (−6.17 km2), while in the Taihu section, water bodies were largely transformed into agricultural land (−3.77 km2). In this study, we quantified changes in ESV using the unit area equivalent factor method, adjusted based on net primary productivity, precipitation, and the soil conservation coefficient. The results indicate that the ESV ranking in both sections follows the order: water conservation > environmental purification > biodiversity > soil conservation. From 2018 to 2022, the ESV in the Huanggang section declined due to forest and grassland loss and an increase in bare land. In contrast, ecological restoration and habitat protection policies contributed to an improvement in ecosystem service functions in the Taihu section, with various ESV components increasing as follows: soil conservation (8.79%) > biodiversity (6.67%) > environmental purification (5.98%) > water conservation (5.52%). These findings provide valuable insights for decision-making in the protection and management of the Yangtze River Basin ecosystem.