基于栅格空间信息定量化的湖南西部地区生态环境综合评价

Synthetic Assessment of Eco-environment in the West of Hunan Province Based on Quantitative Grid Data

以湖南西部地区为研究区域 ,采用遥感影像作为主要数据源 ,针对区域主要生态问题 ,利用栅格数据结构为主的数字环境模型 ,建立了生态环境质量综合评价模型 .对区域生态环境质量的空间分异格局进行了研究 ,通过将评价结果与数字高程模型迭加分析 ,研究了生态环境质量的垂直地带性分布规律 ,探索适合以山高坡陡为主要地貌特征的山区生态评价方法 ,结果显示 ,湖南西部地区生态环境综合指数呈正态分布 ,大部分地区环境质量属一般 .总体环境状况东南部好于西北部 ,河谷盆地优于山地 .研究表明 ,利用遥感和地理信息系统技术进行区域生态环境评价 ,具有数据采集快速、客观 ,评价和制图自动化 ,评价结果空间定位精度高 。

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 .