Research On Dynamic Change Of Eco-environment In Three Gorges Reservoir Area In Main District Of Chongqing Based On RS And GIS

The eco-environmental problem has become an important issue faced by human-beings'daily life development recently. Knowing and realizing the reasons for eco-environmental changes, keeping the balance of developing economy and protecting environment, maintaining the manner of sustainable development, has draw attention from all over the world.Base on the development of RS and GIS technology, the observation of space and obtainment of information become more convenient than ever. It greatly promoted the quantitative research on eco-environment.This study takes main district in three gorges reservoir area of Chongqing as an example, choosing two temporal Landsat TM/ETM+ remote sensing images. Though geometric collection, inlay and cutting out, projection transformation, image enhancement, it decodes and extracts the information of multi temporal remote sensing images. Based on GIS and combining with other auxiliary data, the trend and features of dynamic changes of eco-environment have been analyzed in this paper. Analytic hierarchy process and weighted summation model have been used to quantitatively analyze and evaluate the eco-environment situation and changes. The study can be divided into several parts above.The first part is the extracting of RS information. Through analyzing RS images and extracting information that is useful to analyze the environment changes, the research uses RS images in two periods with the reference to the relative auxiliary data based on the previous study, and classifies the land in researching area to obtain informational data of land use changes and vegetation.The second part is the analysis of eco-environmental changes influencing factors. Including terrain factor analysis, water and heat regime analysis, dynamic change of vegetation coverage analysis, land-use change analysis and soil erosion situation analysis.The third part is the evaluation of eco-environment situation. According to the principle of choosing evaluation indexes, and combined with main eco-environment problems in researching area, the study chooses topography and geomorphology condition, water and heat regime, vegetation coverage situation, land-use situation and soil erosion situation as first grade indexes. The slope, altitude, accumulated temperature (≥10℃), annual precipitation, vegetation coverage rate, edge density index, Shannon diversity index. plaque aggregation rate index and soil erosion rate are chosen as the second grade indexes. Using analytic hierarchy process and weighted summation model, the research gives a comprehensively evaluative study on the situation and change of eco-environment in main district in three gorges reservoir area of Chongqing。The appraising results illustrate that the eco-environment stays in a good condition and the status quo of the eco-environment is improved slightly.