洞庭湖区城市景观生态风险评价及驱动力分析——以常德市和益阳市为例

Ecological Risk Assessment and Driving Force Analysis of Urban Landscape in Dongting Lake Area:Take Changde City and Yiyang City as Examples

以2000、2010和2020年的遥感影像作为主要数据源,构建景观生态风险评价模型,研究常德市和益阳市两个城市土地利用、景观生态风险的时空变化及其空间模式。结果表明:两个城市的土地利用类型以林地和耕地为主,近20年来两个城市的林地和耕地面积均在减少,建设用地面积增加明显;景观指数方面,两个城市呈现出相似的变化,建设用地、草地和水域景观类型分离度指数始终保持较高状态,破碎度亦较高;耕地和林地景观类型分离度指数较低,破碎度也偏低;景观生态风险方面,两个城市的高和较高风险区均分布在临湖的平原区和城市建成区,低和较低风险区分布于林地景观,景观生态风险的空间分布存在较强的空间集聚效应。

Using remote sensing images from 2000,2010,and 2020 as the main data source,a landscape ecological risk assessment model was constructed to study the spatiotemporal changes and spatial patterns of land use and landscape ecological risks in Changde and Yiyang cities.The main findings are:The land use types of both cities are mainly forest and farmland,which have decreased in the past 20 years,while the area of built-up land has increased significantly;the landscape indices of both cities show similar changes,with the separation and fragmentation indices of built-up land,grassland and water landscape types being high,while those of farmland and forest landscape types being low;the separation index of farmland and forest landscape types is relatively low,so is the fragmentation index;the high and moderate risk areas of both cities are distributed in the plain areas near the lake and the urban built-up areas,while the low and very-low-risk areas are distributed in the forest areas under their jurisdiction;there is a significant positive spatial correlation in the spatial distribution of landscape ecological risk.