基于遥感的两当河上游生态修复工程监测与分析

Remote Sensing Monitoring for Ecological Rehabilitation Project in Liangdang County

生态修复水土保持是一项旨在注重依靠大自然的自我修复能力,在加强预防保护和开展人工辅助治理的前提下,在较短的时间内实现大面积水土流失初步治理,区域生态环境逐步恢复,最终实现人与自然和谐共处的水土保持措施。两当县位于秦岭以南,属嘉陵江水系,该县为长江上游实施水土保持生态修复8个试点县之一。位于该县北部的研究区总面积327.26 km2,是水土流失的主要区域,2001至2003实施生态修复工程。为配合项目区评估利用遥感(RS)和全球定位系统(GPS)技术对试验区进行监测与分析。通过项目开始(2001)和两年后(2003)的遥感监测、对比分析和结合参考常规观测资料,对试验区生态环境类型的变化状况和退耕还林还草,坡改梯田和集水灌溉等辅助措施在生态修复中的作用进行评估。研究结果表明自生态修复工程实施后植被状况有明显变化,植被覆盖率从86.50%增加到98.04%,增长11.54%,说明研究区生态与环境向逆转方向发展。在实践应用当中,较高分辨率的卫星资料(TM,SPOT 4,SPOT 5)可以用于生态修复工程的遥感监测和工程执行的效果评价。

Water and soil conservation ecological rehabilitation is an effective measure of environmental protection, which mainly depends on self rehabilitation ability of nature and under the precondition of strengthening preventability protection and the assistant measure by manpower. The water and soil loss in large area would be controlled initially in a shorter time period and the regional environment will be restored step by step, and the harmonious coexist between human and nature will be realized finally. The Liangdang County is located in the southern Qinling Mountain and in the Jialing River water system, which belongs to one of the eight experimental counties of implementing the Water and Soil Conservation Ecological Rehabilitation Project in the upper reaches of the Yangtze River. The study area with total area of 327.26 km^2 was selected in the northern county where was the key region of water and soil loss and the ecological rehabilitation project was carried out from 2001 to 2003. In order to cooperate with the evaluating of the project, the Remote Sensing （RS） and the Geographic Information System （GIS） techniques were used to perform the monitoring and analysis in the study area. The change status of environment types in study area and the assistant measure effect of returning forest and grass from cultivated land, converting slope cultivated land into engineering terrace and catchments irrigation in the ecological rehabilitation were evaluated by remote sensing monitoring at the beginning （2001） and after 2 years （2003） of carrying out the project, contrast analysis combined with referencing conventional observation data. The research results showed that the vegetation status have changed obviously since carrying out the project, the coverage rate of vegetation raised from 86.50% to 98. 04%, increased by 11. 54%, which also showed that the environment develops toward reversion direction. The higher resolution satellite data （TM, SPOT4, and SPOT5） can be used for remote sensing monitoring in ecological rehabilitation project and effect evaluation of the project actualizing.