Analysis Of Spatiotemporal Pattern Of Eco-environmental Quality In Gansu Province

Ecological environment is the essential basic condition for human survival and development,which is urgent to recognize the quality of regional ecological environment and the importance of protecting ecological environment.This paper takes Gansu province as the research object,selects 2000-2018 as the research period,and constructs the evaluation index system from nine aspects: climate,terrain,hydrology,soil,vegetation,land,population and economy.With the help of GIS and RS technology,taking 1km × 1km as the basic evaluation unit and using the spatial principal component analysis(SPCA)method,the eco-environmental quality of Gansu province is evaluated,and the spatiotemporal change regularly of eco-environmental quality and its main influencing factors are analyzed.The main conclusions are as follows:(1)From the perspective of the spatial distribution characteristics of ecoenvironmental quality,the eco-environmental quality of Gansu province shows obvious polarization distribution characteristics.Under the influence of climate,precipitation,vegetation and other natural factors,the eco-environmental quality gradually deteriorates from southeast to northwest.The eco-environmental quality in Hedong region bounded by the Yellow River is relatively good,while that in Hexi corridor and the western region is relatively poor;From the provincial perspective,the eco-environmental quality of Gansu province as a whole is at a medium level.At municipal and county scales,there is little difference in the eco-environmental quality among the municipal and county regions in Hedong region.However,the eco-environmental quality is uneven among the cities and counties in the Hexi corridor and the western region,especially Zhangye city and Wuwei city and the counties under their jurisdiction.(2)From the perspective of spatial autocorrelation characteristics of ecoenvironmental quality,the Global Moran's I of each year reaches more than 0.93,indicating that the eco-environmental quality of Gansu province shows significant positive spatial correlation and high spatial clustering.Locally,the eco-environmental quality of Gansu province shows the distribution characteristics of high-high clustering and low-low clustering.The regions of hot spot are concentrated in the southeastern of Gansu province,and the regions of cold spot are concentrated in the Hexi corridor and the western region.(3)From the perspective of zonal distribution characteristics of eco-environmental quality,the eco-environmental quality of Gansu province shows obvious zonal change regularity.With the change of natural conditions from southeastern to northwestern,the eco-environmental quality presents a trend of gradual deterioration.In the southeastern of Gansu province,the change magnitude of eco-environmental quality index(EQI)is small,indicating that the stability of ecological environment is high;In the northwestern of Gansu province,the change magnitude of EQI is large,indicating that the stability of ecological environment is low.(4)From the perspective of time change characteristics of eco-environmental quality,the eco-environmental quality of Gansu province on the whole develops in a better direction in 2000-2018.Among them,in 2010-2018,the interconversion between different eco-environmental quality types is more drastic than that in 2000-2010.(5)From the perspective of the main factors affecting of eco-environmental quality,the eco-environmental quality of Gansu province is mainly affected by factors such as land use degree,drought resistance of vegetation,normalized differential vegetation index(NDVI),dryness index,soil erosion intensity and soil sediment content.Among them,the land use degree determines the distribution of eco-environmental quality in Gansu province;The influence of NDVI increases the most in 2000-2018,and gradually became the leading factor affecting the eco-environmental quality of Gansu province.Different influencing factors interact and influence each other to promote the development of eco-environmental quality in Gansu province.Through the evaluation and analysis of the eco-environmental quality in Gansu province,it can provide a certain theoretical basis,corresponding measures and Suggestions for the discovery and management of eco-environmental problems in Gansu province.