Research On Land Use Change And Evaluation Of Ecological Environment Quality

Since the implementation of the western development drive,the population of the western region of China has grown substantially,and the city has developed rapidly with the accelerating industrialization process and the improvement of infrastructure construction.At the same time,the unreasonable drive of urban land use has also caused many ecological and environmental problems,resulting in the continuous decline of the quality of the ecological environment.Especially in recent years,the contradiction between ecological environment sensitivity and vulnerability,resource development and environmental protection in the northwest region has become increasingly prominent.Therefore,this study selects the Otog Front Banner in the southern part of the Ordos Plateau in the Mongolian Autonomous Region in the Northern Agro-pastoral Eco-fragile Zone as the research area,collecting TM/OLI images,annual precipitation and temperature data of the year of 1987,1997,2007 and 2017,using remote sensing image processing system ENVI and geographic information system ArcGIS software to interpret and interpolate the data,and analyzing the land use quantity and spatial distribution trend of the Otog Front Banner.The new remote sensing based ecological index(RSEI)was used to comprehensively evaluate the ecological environment quality of the Otog Front Banner.from 1987 to 2017,and quantitatively analyze the impact of land use type change on eco-environmental quality.The research results are as follows:(1)The characteristics of the land use change of the Otog Front Banner from 1987 to 2017.(1)From 1987 to 2017,the land use type of the study area showed a trend of“five increases and three decreases”.The area of cultivated land,grassland,urban villages and industrial mining land,transportation land and garden land increased by 128.78 km~2,418.62 km~2,30.91 km~2,58.23 km~2and 0.59 km~2 respectively.The area of forest land,other land and water project facilities decreased by 204.97 km~2,431.36 km~2 and 1.8 km~2,respectively.(2)Land use types are mainly grassland and woodland,accounting for more than 80%of the area.(3)The results of the transfer matrix show that the types of land use are frequently transferred and the forms are diverse.Urban villages,industrial mining land,cultivated land,grassland,transportation land and gardens are mainly transferred positively,while water project facilities,forest land and other land are mainly transferred negatively,which indicated that the land use structure of the Otog Front Banner has undergone significant changes due to human activities.(2)The ecological environment quality of the Otog Front Banner showed a better trend from 1987 to 2017.The overall eco-environment quality was“good”and“excellent”.The average RSEI values in 1987,1997,2007 and2017 were 0.642,0.813,0.824 and 0.865,respectively.Due to human reclamation activities,the eco-environmental quality improvement areas are mainly concentrated in the cultivated land areas around urban villages,and the ecological environment in the area has been improved.The eco-environmental quality degraded areas are mainly concentrated in the northwestern forest and grassland areas,indicating the unreasonable development significantly affect the ecological environment of the region.(3)The impact of changes in land use types and areas on the quality of the ecological environment.(1)As for the land use type,the cultivated land,garden land,forest land,grassland,water project facilities land were considered as ecological land,which plays a positive role in the quality of regional ecological environment,in contrast,urban villages and industrial mining land,transportation land and other land plays a negative role to regional ecological environment quality.The greater the proportion of ecological land in the total area of the region,the better the local ecological environment,and vice versa.(2)The area of ecological land increased from9959.79 km~2 in 1987 to 10301.01 km~2 in 2017.The difference between of the proportion of ecological land change from 1987 to 2017 and the RSEI index change of the ecological environment quality from 1987 to 2017 is very small.