The Monitoring And Evaluation Of The Ecological Environment Of Songpan County In The Upper Reaches Of Minjiang River

The Minjiang River is one of the important tributaries of the Yangtze River, andSongpan as the birthplace of the Minjiang River. The quality of its ecologicalenvironment both affects the Yangtze River Water Resources, also affects the livingwater, industrial and agricultural water of the Upper of the Minjiang River, even morerelated to the sustainable development of economic and social. More pressure ofSongpan County environment and increasingly it affects the ecological environment.Many scholars had studied on the ecology of the Songpan from the soil investigationand monitoring the quality of soil environment and evaluating the soil fertility, toprobe the role of soil erosion on land resources; Revealing the mechanisms ofecological changes through researching on the change to landscape pattern inSongpan County; Studying on ecological processes from species and communitycharacteristics in Songpan County; And monitoring ecosystems of natural grassland toexplore the mode of ecological recovery. These studies are only studies on ecologicalenvironment of Songpan from a single impact factor, has not been involved in theentire monitoring and evaluation of the ecological environment of Songpan County.Based on of the previous studies, there is a comprehensive evaluation of theecological environment in Songpan County, to analyze of spatial distribution rule inorder to explore the factors to impact on ecological environment. It is significance toprotect environment and to recovery ecological.Paper is used of GIS and RS technology, combined with multi-sources spatialinformation on the application in the evaluation of the ecological environment,monitoring the ecological environment on the upper reaches of Minjiang River,Songpan County. And basis on of the monitoring, implemented to evaluate theeco-environmental quality. The main data have Landsat TM remote sensing and DEM,in combination with other statistical information. It is built a comprehensive evaluation model to use those data and the natural human characteristics. Then, it isused AHP to access the ecological state of the environment in Songpan County, andanalyzed the relation between each other elements and environment. The mainachievements obtained by the paper and understanding the following:(1) It is used of remote sensing and geographic information systems technology,theory and methods that it established the index of image interpretation according tothe sign of the natural characteristics of the study area. And the image is extractedinformation about land use, which is used of supervised classification method forcomputer automatic classification and manual inspection amendment conjunctionwith each other. It is selected land use/land cover, topography, water resources, soilerosion and human activity as the influencing factors for the ecological environment.(2) It was selected AHP to build three-layered structure, they are the target layerwhich was the eco-environmental quality assessment, the rule layer which was landuse/land cover, topography, water resources, soil erosion and human activity, thebottom of index layer which was about specific indicators of the rule layer. Then thejudgment matrix was established by the method of1to9scale, and calculated itseigenvalue as weight for each index of participate in evaluation.(3) The unit of evaluating analysis was selected grid. It was used spatial overlayanalysis method by GIS, and according to the ecological environment evaluationindex model to calculate the characteristics data of each grid cell for the thematicindicators. It was meted the quantitative and qualitative analysis of comprehensiveevaluation of the ecological environment, got the ecological and environmentalconditions in Songpan County. The results showed that the whole eco-environmentalcondition was good in Songpan County. The percent of excellent and good was61.02%of the county’s area, they were mainly distributed on the both of the valley inMaoergai River, Baicao River, and on both sides of the Fu River. The percent ofmiddle area was25.81%, they were distributed in the grasslands of the northernSongpan County. Poor and inferior area accounted for13.07%, they were mainlydistributed in the eastern part of high altitude.