关中平原城市群生态环境质量时空变化特征及其驱动力

Spatial-temporal Variation Characteristics of Ecological Environment Quality and Their Driving Forces in Guanzhong Plain Urban Agglomeration,China

为探究关中平原城市群2000~2020年生态环境质量时空变化及发展趋势,基于Google Earth Engine(GEE)平台对2000~2020年6月至9月关中平原MODIS遥感影像进行优化重构,并利用绿度、湿度、干度、热度4个指标构建遥感生态指数(RSEI),分析该地区生态环境质量时空变化格局,利用地理探测器模型探究了自然环境和人类活动等10个驱动因子对遥感生态指数时空分布的影响,采用地理加权回归(GWR)构建回归模型,分析驱动因子的空间差异性。结果表明:①2000~2020年关中平原城市群生态环境质量逐年改善,遥感生态指数均值由0.448增至0.565,空间上呈南高北低的分布特征。②关中平原城市群生态环境质量改善区域占70.8%,退化区域占22.9%,改善尤为明显的区域主要分布在庆阳市、平凉市和天水市,退化区域主要分布在城市群中部西安市及其附近区域。③植被类型对关中平原生态环境质量的影响最大,影响力高达0.46。研究期间关中平原城市群生态环境质量整体趋于改善,局部恶化,尤其是人类活动密集的城市及其附近区域。

In order to find the spatial-temporal variation and development trends of ecological environment quality in Guanzhong Plain urban agglomeration from 2000 to 2020,the Google Earth Engine(GEE)platform was used to optimize the reconstruction of MODIS images of Guanzhong Plain from June to September during 2000-2020,and remote sensing ecological index(RSEI)was constructed with greenness,humidity,temperature and dryness;the spatial-temporal variation of ecological environmental quality in the region were analyzed;a geodetector model was used to quantify the effects of ten environmental and human factors on the changes of RSEI,and a regression model was constructed by geographic weighted regression(GWR)to analyze the spatial differences of driving factors.The results show that①from 2000 to 2020,the ecological environmental quality in Guanzhong Plain urban agglomeration improves year by year;the average RSEI increases from 0.448 to 0.565,with a high distribution in the south and a low distribution in the north.②The improved area of ecological environmental quality in Guanzhong Plain urban agglomeration accounts for 70.8%,and the degraded area accounts for 22.9%;the improved area remarkably distributes in Qingyang city,Pingliang city and Tianshui city,and the degraded area mainly distributs in Xi an city and its surrounding areas.③The vegetation type has the greatest impact on the ecological and environmental quality of Guanzhong Plain,with an impact power of up to 0.46.During the study period,the overall ecological environmental quality in Guanzhong Plain urban agglomeration improves with local deterioration in cities with intensive human activities and their surrounding areas.