东北黑土水土流失区生态环境遥感动态监测

Dynamic Monitoring of Ecological Environment in Black Soil Erosion Area of Northeast China based on Remote Sensing

为及时快速地监测水土流失地区的生态环境变化状况,以拜泉县为例,选取1985年、1996年、2006年和2015年Landsat影像,反演得到能反映生态环境的绿度、湿度、热度和干度指标,利用主成分分析方法,依据RSEI(遥感生态指数)对拜泉县1985—2015年的生态环境进行评价.结果表明:1985—2015年拜泉县RSEI从0.645增至0.851,增幅为31.94%,生态环境质量改善地区面积高于退化区域面积,总体上生态质量向好的方向发展;拜泉县整体生态环境质量综合指数由3.78升至4.87,各乡镇的生态环境质量综合指数均呈现不同程度的增加,从空间分布来看,西南部和南部乡镇的变幅大于北部,中部基本保持不变,水土流失重点区域生态环境质量显著提高;逐步回归分析结果表明,所选的指标均为生态环境质量的关键指标;绿度逐渐成为研究区生态环境质量正向作用的重要指标,说明植树造林等生态治理措施对环境质量的改善起到主导作用.研究显示,RSEI能够综合刻画水土流失区生态环境质量,同时拜泉县生态环境质量整体不断改善,水土流失治理成效明显.

Baiquan County in Heilongjiang Province is a typical black soil erosion area of northeast China.After years of ecological restoration,the local ecosystem has been improved remarkably.Remote sensing ecological indices(RSEI),composed of four indicators including the green,humidity,heat and dryness indices retrieved from remote sensing images,can reveal the ecological environment status.For timely and quick monitoring of the eco-environment in soil and water loss areas,Landsat images from 1985,1996 and 2006 Landsat TM and 2015 Landsat OLI were used as a data source to retrieve values of these four indicators to form the RSEI by the principal component analysis method,and then RSEI was used to assess and analyse the ecological environment quality of Baiquan County from 1985 to 2015 based on RSEI.The study shows that in the past 3 decades,Baiquan′s RSEI value went up 31.94%from 0.645 to 0.851.The area of improved eco-environmental quality is larger than the part that remains degraded,which indicated that the eco-environmental quality has been improved on balance.The overall eco-environmental quality index of Baiquan County rose to 4.87 from 3.78,while the composite index of each county increased to different degrees.In terms of the spatial distribution,the amplitude of the indices of southwestern and southern towns were greater than those of northern towns,and indices of the central area remained steady.The quality of the ecological environment was improved significantly in the key areas of soil and water loss.Stepwise regression analysis showed that the chosen indices are key ones for eco-environmental quality.The green degree has become an important indicator of the positive effects of ecological environment quality in the study area,which suggested that ecological management measures such as the project of Afforestation and Convert Cultivated Land into Forest playing an important role in improving environmental quality.The research showed that RSEI can comprehensively characterize the eco-environmental quality of soil erosion areas,illustrating the fact that the overall quality of the eco-environment improved continuously in Baiquan County,and that remarkable results have been achieved from water and soil erosion control.