GEE-Based Spatial-Temporal Dynamics in a Ramsar Wetland, Honghe National Nature Reserve, Northeast China from 1985 to 2021

Wetlands are vital to the human living environment, and with the degradation of wetland ecosystems, it is crucial to protect and restore them. Therefore, based on the long time-series Landsat images provided by Google Earth Engine (GEE), this study obtained the landscape spatial distribution maps of the Honghe National Nature Reserve (HNNR) from 1985 to 2021, analysed the spatial and temporal dynamics of the landscape patterns of the HNNR in the past 40 years, and explored the driving factors of the evolution of the HNNR wetland. The results show that from 1985 to 2008, the HNNR wetlands continued to degrade. The area of the wetland landscape declines and converts mainly into the meadow landscape, and the meadow landscape trends upwards and then downwards and converts mainly into woodland and arable land, with increased fragmentation of wetland and meadow. From 2008 to 2021, with the recovery in hydrological conditions, the area of the wetland landscape increased and fragmentation decreased. However, the meadow landscape continued to decline and fragmentation increased, with meadow converting mainly into wetland; changes in hydrological conditions were the main drivers of the evolution of the HNNR wetlands. The results of this study enable us to better understand the dynamics of the HNNR wetland landscape over the last 40 years and provide assistance for the management of the HNNR wetland ecosystems and the ecological restoration of degraded wetlands.