关键词: 遥感, 地理信息系统, 评价模型, 生态环境, 栅格数据, 湖南西部地区

Abstract: The west of Hunan Province, including Huaihua Municipality, Zhangjiajie Municipality and Xiangxi Autonomous Prefecture in the upper reaches of the Lishui and Yuanshui Rivers, has much impact on the downstream valleys of the two rivers and the Dongting Lake area. Ecological environment is vulnerable in this area. Taking remote sensing image as the major data sources, a synthetic assessment of ecological environment in the west of Hunan Province is carried out by the use of geographical information system technology. Aimed at the main ecological environment problems, form different types of factors, i.e., water and heat factors, topography and geomorphology factors, land use/ land coverage and soil erosion factor are chosen to study. Seven sub-factors, i.e., cumulative temperature above 10℃, annual precipitation, altitude, slope, soil erosion intensity, land use type and vegetation coverage are selected to transform quantitative and standardized series, thus, a complex assessment model of eco-environment quality can be constructed with grid data, the scale of which is 100×100 m². The synthetic assessment index of ecological environment quality is computed for every basis evaluation unit by using the model. Afterward, all of the synthetic assessment indexes of ecological environmental quality are divided into 9 grades. Meanwhile, the average synthetic assessment index of ecologic environment quality is computed for every county.The assessment shows that the synthetic assessment index of ecological environment quality in the west of Hunan Province is almost symmetry, in which the second grade, third grade and fourth grade of eco-environment account for 85 percent of the whole. Generally speaking, the eco-environment quality in the southeast part is better than that in the northwest part, and in valleys is better than that in hilly areas. The average synthetic assessment index of ecological environment quality is the best in Luxi County and Huaihua Municipality, and is the worst in Sangzhi County and Longshan County.

Key words: remote sensing, geographical information system, assessment model, ecological environment, grid data, west of Hunan Province