Evaluation Of Ecological Environment Quality In The Source Basin Of Dongjiang River Based On Remote Sensing Ecological Index

The ecological environment is an important foundation for human survival and development,and it is also an important guarantee for the stable development of society and economy.With the development of society,the ecological environment has been severely damaged,and the issue of ecological environment has become a hot spot of concern to all countries.How to comprehensively and objectively evaluate the quality of the ecological environment is of great significance to the sustainable development of the region.The basin has the functions of purifying the ecological environment,providing fresh water and generating electricity.The evaluation of the ecological environment quality of the basin is helpful to the ecological protection of the basin and the construction of ecological civilization.The source of the Dongjiang River is located in the hilly area of the south and is the source of drinking water in Hong Kong and parts of Guangdong Province.In the past time,due to the mining of rare earth mines,the ecological environment has been damaged to a certain extent.The development of remote sensing and geographic information technology provides important technical means for the evaluation of ecological environment quality.Grasp the temporal and spatial change law of the ecological environment of the source of the Dongjiang River,and provide a theoretical basis for the ecological environment management of the river basin.This paper takes in the source basin of Dongjiang River as the research area,selects the 7Landsat remote sensing images from 1991,2000,2004,2010,2013,2018,2019,and uses the remote sensing ecological index RSEI to evaluate the ecological environment quality changes in the source basin of Dongjiang River,and discusses Influencing factors of the ecological environment changes in the source basin of Dongjiang River,this article mainly draws the following conclusions:(1)In 1991,2000,2004,2010,2013,2018,and 2019,the average RSEI index in the source basin of Dongjiang River was 0.628,0.653,0.511,0.540,0.689,0.671,and 0.772.The ecological environment quality in the source basin of Dongjiang River increased from 1991 to2000.—The quality of the ecological environment in the source basin of Dongjiang River declined in 2004,the quality of the ecological environment in the source basin of Dongjiang River increased from 2004 to 2013,the ecological environment in the source basin of Dongjiang River declined slightly from 2013 to 2018,and the ecology in the source basin of Dongjiang River from 2018 to 2019 Environmental quality continues to improve.The quality of the ecological environment in the source basin of the Dongjiang River presents a trend of first rising,then falling and then rising.From a spatial point of view,areas with good ecological environment quality are mainly distributed in places with high vegetation coverage,and areas with relatively poor ecological environment quality are mainly distributed in places with more human activities.From the perspective of time and space,the quality of the ecological environment in the source basin of Dongjiang River is developing in a good direction.(2)Analyzing the correlation between the monthly rainfall and average temperature of the Xunwu station and the average RSEI in the source basin of Dongjiang River,the R2 between rainfall and ecological environmental quality reached 0.3297,and the R2 between average temperature and ecological environmental quality reached 0.4237,the correlation between rainfall and ecological environment quality is weak,and there is a certain correlation between average temperature and ecological environment quality.(3)In 1991,2000,2004,2010,2013,2018,and 2019,the average value of vegetation coverage in the source of the Dongjiang River was 0.745,0.817,0.711,0.776,0.831,0.847,and 0.857,respectively.From the perspective of time,the vegetation coverage first increased and then decreased The upward trend.The change trend of vegetation coverage in the study area is basically consistent with the change trend of ecological environment quality.(4)The soil erosion intensity in the source basin of the Dongjiang River is mainly non-erosion and slight erosion,and changes in soil erosion intensity will affect changes in the quality of the ecological environment.From an overall point of view: the intensity of soil erosion in the source basin of Dongjiang River has shown a decreasing trend,and the ecological environment has improved.From 1991 to 2000,the ecological environment in some areas in the source basin of Dongjiang River had a deteriorating trend,but overall,the erosion degree in the source basin of Dongjiang River weakened and the ecological environment condition improved.From 2000 to 2004,the non-eroded area of the Dongjiang River Basin dropped sharply,and the area of the remaining erosion intensity increased,and the ecological environment deteriorated.From 2004 to 2010,the intensity of soil erosion in some areas in the source basin of Dongjiang River increased,but overall,the intensity of soil erosion in the source basin of Dongjiang River declined and the ecological environment improved.From 2010 to 2018,the intensity of soil erosion in the source basin of Dongjiang River weakened and the ecological environment was developing in a good direction.(5)Land use change is an important factor affecting the change of ecological environment quality.Land use types are closely related to the quality of the ecological environment.By comparing the mean values of remote sensing ecological indices of different land types,it is found that the mean RSEI of forest land is higher than the mean RSEI of other land use types.Land use changes will affect the changes of ecological environment quality.