中亚阿姆河跨境流域景观生态风险时空演变特征分析

Spatial-temporal evolution characteristics of landscape ecological risk in the transboundary basin of Amu Darya River,Central Asia

以中亚阿姆河流域1995—2018年6期土地利用遥感数据为基础,应用景观生态风险指数模型、半方差分析、空间自相关等方法分析该跨境流域景观生态风险时空演变规律。结果表明:(1)自1995年以来,研究区景观格局发生了显著变化,裸地面积增加最多(22704.66 km^(2)),以林地、草地、水体转入为主,水体面积减少最多,占比由6.36%下降至3.12%,主要转出为草地和裸地;(2)区域内高风险区呈现流域上游集中且向外扩展而下游缩减的两极分化特征,咸海湖盆生态风险明显升高,除低风险等级面积减少(-32.22%),其余生态风险等级面积均有不同程度增加,景观生态风险趋于恶化;(3)流域6期景观生态风险Moran’s I值均在0.77以上,表现为较强的空间聚集分布特征,高-高聚集区主要分布于研究区西南、东南部及咸海三角洲,低-低聚集区主要位于研究区北部和东部。

Based on the six periods of land use remote sensing data in the Amu Darya River basin in Central Asia from 1995 to 2018,the landscape ecological risk index model,semi-variance analysis and spatial autocorrelation methods were used to analyze the temporal and spatial evolution of landscape ecological risks in the cross-border basin.The results showed that:(1)Since 1995,the landscape pattern of the study area had undergone significant changes,the area of bare land has increased the most(22704.66 km^(2)),with woodland,grassland and water bodies transferred mainly.The area of water bodies had decreased the most,with the proportion falling from 6.36%to 3.12%,mainly transferred out to grassland and bare land.(2)The high-risk area in the region presented the polarization characteristics of the upstream of the watershed being concentrated and expanding outward,while the downstream was shrinking,and the ecological risks of Aral Sea lake was significantly increased.Except for the decrease in the area of low-risk grade(-32.22%),the areas of the other ecological risk grades had increased to varying degrees,and the landscape ecological risk tends to deteriorate.(3)The Moran’s I value of the six stages of landscape ecological risk in the basin were all above 0.77,showing strong spatial aggregation distribution characteristics.The high-high agglomeration areas were mainly distributed in the southwest,southeast of the study area and Aral Sea Delta,while the low-low agglomeration areas were mainly located in the north and east of the study area.