Landscape Ecological Risk Assessment And Prediction In The Dongjiang River Basin

Landscape as a natural complex of the surface.it is an important guarantee for the survival and development of human society.Changes in landscape patterns are closely linked to ecological processes.Landscape ecological risk assessment is one of the important research contents of ecological risk assessment.It uses landscape as a risk assessment complex.By analyzing the evolution characteristics of landscape pattern,it constructs a landscape ecological risk index and evaluates the regional landscape ecological risk,thus reflecting the impact of human activities on the landscape.As an important place for human activities,the basin is an important integrated eco-geographic region connecting surface water and groundwater,land cover and ecosystem.The ecological risk assessment of river basin landscape plays an important role in the improvement and sustainable development of the river basin ecological environment.Dongjiang is one of the three major water systems in the Pearl River.It is located at the junction of Guangdong,Hong Kong and Macao.It is the main source of water for about 50million residents.The basin is rich in natural and human resources and diverse in landscape types.In recent years,with the increase of population growth,economic development,and human activities,the ecological risk problem has become increasingly prominent.This paper takes the Dongjiang River Basin as the research object,based on the land use data obtained from the remote sensing image interpretation of the basins in 1990,2000,2009 and 2016,quantitatively analyzes the characteristics of land use change in the basin over the past 26years;Traditional landscape pattern index method and moving window method are used to analyze the heterogeneity of watershed landscape;The landscape ecological risk assessment model was constructed,to analyze the landscape ecological risk in the basin from 1990 to2016 were evaluated.Finally,using the elevation data,traffic accessibility data and major socio-economic indicators,the FLUS model is used to predict the land use status of the basin in 2028 and 2042,and the landscape ecological risk in the forecast year is evaluated.The results show:(1)Forest land is the dominant landscape type in the Dongjiang River Basin.From1990 to 2016,the area of forest land,cultivated land and grassland decreased;the area of garden land,water area,unused land and urban construction increased.The transfer of forest land and the transfer of land for urban construction are the main forms of land use change in the Dongjiang River Basin.(2)From 1990 to 2016,the landscape fragmentation degree of the Dongjiang River Basin showed a trend of decreasing to the east and west sides with the river channel from the center.The landscape ecological risk is generally on the rise,and the sum of the high,high and medium landscape ecological risk areas increases from 8784 km~2 in 1990 to 11682 km~2 in2016.The Moran's I index of landscape ecological risk is on the rise.(3)From 2028 to 2042,the change of land use types in the Dongjiang River Basin is small;the landscape ecological risk is reduced,the area of high,high and medium ecological risk areas is reduced;the autocorrelation of landscape ecological risk is reduced.