Monitoring And Analysis Of Land And Ecological Environment Of Ping Xiang City Based On Landsat Remote Sensing Images

Land not only provides human being with natural and material resources,but also provides human habitation,which is the material basis for human survival and development;and a good ecological environment can bring humans a comfortable space life.With the rapid development of the economy and the acceleration of urban construction,the problems of land use /cover change and ecological environment have become particularly prominent and become one of the core contents of domestic and foreign research.Pingxiang enjoys the reputation of "the coal capital of the south of the Yangtze River" and is a typical representative of the Jiangxi’s resource-exhausted cities.The city’s land use information and ecological environment have changed significantly.This article takes Pingxiang City as the research object,analyzing and monitoring the city’s land use information and ecological environment can help human comprehensively understand the city’s land use/cover information and ecological environment,and provides a reference for the city’s rational use of land and ecological civilization.The Landsat series of remote sensing data from 2002,2007,2013 and 2018 was selected.With the support of GIS and remote sensing technology,the support vector machine method in supervised classification was used to extract the land use information in the study area.Spatial-temporal change analysis of land use interest in Pingxiang City by methods such as land change amplitude,land use dynamics,and land transfer matrix;meanwhile,by extracting greenness index(NDVI),dryness index(NDSI),humidity index(WET)and thermal index(LST)and other four evaluation indicators are used to construct a remote sensing ecological index(RSEI)of the study area by using the principal component analysis method,the ecological environment of the study area from 2002 to 2018 is analyzed,and performing a regressive analysis on each evaluation indicator and RSEI,the results are as follows:(1)From 2002 to 2018,forest land has always occupied most of the area of the study area,accounting for more than 63%.From 2002 to 2018,forest land,waters,and arable land decreased first and then increased,showing an overall decreasing trend;construction land has been increasing;the grassland is increasing first and then decreasing,and it is generally increasing;the unused land is decreasing first and then increasing,and it is generally increasing.From 2002 to 2018,the largest increase in construction land,and the largest decrease in cultivated land;the utilization dynamics of cultivated land is the smallest,and the utilization dynamics of unused land is the largest.From the perspective of transformation,there is a certain degree of mutual transformation among land use types.From a spatial point of view,the topography,economic development and urban construction of different districts and counties are different,and the proportion of each land use type is also different.(2)The ecological environment conditions of the study area generally showed a trend of improvement from 2002 to 2018.The average RSEI values from 2002 to 2007 are respectively 0.614 and 0.647,and the ecological environment conditions is at a "good" level.In 2013 year,the average RSEI value is 0.587,the ecological environment is at the "average" level;the average RSEI value in 2018 is 0.621,and the ecological environment is at the "good" level.From the perspective of spatial changes,the ecological environment of Lianhua County is the best in 2002,with the average of RSEI is 0.624;the ecological environment of Anyuan District ranked last,with the average of RSEI is 0.565.In 2007,2013,and 2018 year,the ecological environment of Luxi County is the best,with the average of RSEI is respectively 0.668,0.621 and 0.660;the average RSEI of Anyuan District is respectively0.599,0.500 and 0.528,and the ecological environment status ranks last among the districts and counties.At the same time,it was found that the greenness index and humidity index were positively correlated with the ecological environment,while the dryness index and heat index were negatively correlated with the ecological environment.(3)From the perspective of the relationship between land use types and ecological environment,it is found that forest land,grassland and water ecological land play the role of protecting and stabilizing the ecosystem balance;construction land and unused land play a negative role on the ecological environment.