Research On The Change Of Ecological Environment In Liuyang City Based On RSEI Model And Analysis Of Its Influencing Factors

The ecological environment is the foundation of human activities and social development.Scientifically and accurately monitoring changes in the ecological environment,evaluating the impact of the urbanization process on the urban ecological environment,and analyzing its influencing factors can provide a certain basis for regional ecological environment governance.In this paper,ENVI5.1 and Arc GIS10.2 are used as data processing software,and Landsat TM images and Landsat OLI images are used to calculate the greenness,humidity,dryness and heat indicators of the stratum surface in Liuyang City,and a remote sensing ecological index(RSEI)model is constructed.The ecological environment quality of Liuyang city center and surrounding towns in 1994,2003,2009,2015 and 2020 was evaluated.According to the temporal and spatial changes of the RSEI mean value,combined with the center of gravity transfer model and the geographic detector model,the dynamic changes of the ecological environment quality and its impact shadows in the economic development process of the urban area of Liuyang and its surrounding 28 towns and towns in the past 26 years were analyzed,and the main results are as follows:(1)The mean values of the RSEI in Liuyang in 1994,2003,2009,2015 and 2020 were0.645,0.678,0.649,0.685 and 0.691,respectively.It shows that from 1994 to 2020,the RSEI index value showed a trend of rising-falling-rising,indicating that the ecological environment quality of Liuyang City has generally improved.According to the RSEI model index classification table,the ecological environment quality in most areas of Liuyang is in the "good" level,the proportion of "poor" and "poor" levels is on a downward trend,and the average RSEI index increases.(2)From the analysis of the temporal and spatial change trend of the remote sensing ecological index RSEI,the overall performance of the ecological environment quality in Liuyang City has been improved and basically unchanged in the past 26 years,both accounting for 93.69% of the city’s total area;the worsening area only accounts for 6.31%of the city’s total area..The areas with improved ecological environment in the city are mainly distributed in Guanqiao Town,Puji Town,Puchong Town and other towns;the worsened areas are more concentrated in Huaichuan Sub-district,Economic Development Zone and the southeast of Daweishan Town,indicating that population concentration and industrial Human activities such as regional and scenic development,construction of buildings and roads,and excessive felling of trees have a significant impact on the quality of the ecological environment in Liuyang City.(3)In the results of the shift of the center of gravity of each ecological index,from 1994 to 2020,the center of gravity of the four ecological component indexes and the RSEI index shifted in different directions,and the shift range was generally not large.Distributed in Guankou Street,Gaoping Town and Yonghe Town and other towns,the distribution is relatively scattered.(4)From the analysis of the calculation results of the geographic detection model,the contribution of vegetation coverage is 53.2%,which is the dominant factor affecting the temporal and spatial differentiation of the ecological environment in Liuyang City,reflecting that the vegetation coverage in the study area has a great impact on the RSEI index of Liuyang City;Precipitation,river network density,gross industrial output value and slope aspect contribution were all below 10%,which had little effect on the spatial differentiation of RSEI in the study area.