Asymmetric impacts of natural and anthropogenic factors on wetland landscape evolution in Fenhe River Basin, China

In recent years, Fenhe River Basin (FRB) wetlands have been facing severe challenges due to climate change and human activities. It was of great significance to understand the dynamic changes of FRB wetlands and their driving factors for ecological protection. Based on the land use data, runoff, rainfall and GDP data of FRB from 1980 to 2020, the evolution characteristics and driving factors of wetland pattern in FRB were analyzed. The results showed that the wetland types in FRB mainly included paddy, reservoir, river, beach and marsh. Among them, natural wetlands accounted for 72.46 %, and constructed wetlands accounted for 27.53 %. The main types of wetlands in FRB were river, reservoirs and beach, which account for 92.26 % of the whole wetland area. However, the dominant position of reservoir patch was more obvious than the others during 1980–2020. Landscape index showed that the shape of landscape tended to be regular and became more fragmentation. The transfer between wetlands and other land use types mainly occurred in the northern and southern parts of the FRB, and the main conversion types were occurred between dry land and wetlands, grassland and wetlands. Both natural and human factors drove the evolution pattern of wetlands, but the emphases were different. Runoff had a significant effect on wetland pattern at landscape level, while rainfall had a more significant effect on wetland evolution at class level. Urbanization rate and GDP had important effects on the evolution of wetland pattern at both class and landscape levels.