Objective As the mother river of Beijing, Yongding River is an important river ecological corridor in Beijing. In the past 20 years, the rapid development of the city and the shortage of water resources have seriously affected the sustainable development of Yongding River, it is of great significance for the optimization of Yongding River landscape pattern to sort out the evolution trend and structural characteristics of scenic landscape pattern in Yongding River.
Method Taking the riparian zone of the 2000 meters buffer zone between the Luopoling Reservoir and the Daning Reservoir in Yongding River as the research object, the land use remote sensing images of 1999, 2004, 2009, 2014 and 2019 were interpreted by ENVI. The dynamic change characteristics of landscape pattern and the degree of landscape fragmentation were evaluated by the transfer matrix and the related landscape pattern indices in Fragstats4.2.
Result (1) The land use type in the study area is mainly woodland. From 1999 to 2004, due to the expansion of Beijing, the area of construction land along the river increased rapidly; from 2004 to 2014, it entered the period of rapid urban restoration. Industrial land was vacated and coastal grassland was transformed into woodland, resulting in rapid growth of woodland, at the same time the South-to-North water Diversion and continuous riverside park system promoted obvious growth of water area and obvious improvement of ecological environment of Yongding River. The period from 2014 to 2019 is in the slow restoration period. Regional waters supply had been realized for the first time in Yongding River, the area of artificial woodland had increased, and the governance effect had changed from “quantitative change” to “qualitative change”. (2) In terms of landscape pattern index, the level of woodland and waters patch fragmentation was low. The ecological management of the Yongding River had significantly restored waters connectivity and the degree of fragmentation had decreased. Ecological governance had a positive impact on the connection of forest and water green spaces, but the overall landscape level Fragmentation was increasing.
Conclusion The changing trend of landscape pattern in the study area is that the spatial form and quantity characteristics tend to be stable, but the lower reaches of Sanjiadian are in a highly dynamic area due to urban expansion. In the context of green space inventory planning, the moving window method is used to find potential high-fragment patches, combined with relevant planning to guide urban green space supplementation, to obtain an optimized green pattern, and to propose the ecological core area, buffer zone, and purification area; classification, overall planning of regional waters, woodland and other resources.