中国生态环境敏感区评价

采用遥感和GIS技术,针对区域自然环境演变过程中出现的土地沙化、土壤侵蚀和石漠化等典型生态环境问题,建立敏感性评价指标体系及评价模型,开展生态环境敏感性综合评价,定量揭示中国生态环境敏感性程度及地域空间差异,划定生态环境敏感区的红线控制区域。研究结果表明：① 土地沙化以轻度敏感为主,敏感性程度高的区域主要位于西北和北方地区的主要沙漠边缘和沙地;土壤基质多为沙粒、冬春季节多大风且植被覆盖率较低是土地容易发生沙化的主要原因。② 土壤侵蚀以轻度敏感和不敏感为主,受降雨强度和地质条件空间差异影响,敏感性等级高的区域集中分布在西南、东南湿润地区和黄土高原丘陵沟壑区。③ 石漠化以不敏感为主,受岩溶地质条件影响,石漠化易发生区域集中分布在西南喀斯特地区。④ 综合生态环境敏感性以轻度敏感、不敏感和中度敏感为主,综合敏感性程度高的区域主要分布在北方干旱半干旱地区、西南湿润地区、东南湿润地区以及黄土高原丘陵沟壑区。⑤ 基于生态环境敏感性综合评价结果,将极敏感区划为生态红线区,在全国尺度上初步划定3大类和23个重点生态红线区域,约占国土面积的12.86%。

Evaluation of Ecological Sensitivity in China

Three typical factors including land desertification, soil erosion and rocky desertification are selected to establish the evaluation model of eco-environmental sensitivity by integrating the technologies of RS and GIS in the present study. This paper conducts comprehensive research on eco-environmental sensitivity, reveals its spatial features in quantitative way and defines the redline of ecological sensitivity in China. The results are as follows: 1) the moderate sensitivity is the main type of land desertification. The surrounding areas of deserts in semiarid areas of northern China are the most sensitive areas. This is due to the strong wind in winter and spring in these areas, and the soil that mainly consists of sand and is seldom covered by vegetation is also the reason. 2) The slight sensitivity and insensitive areas take great proportion in soil erosion. The southwestern and southeastern parts of China and loess hilly regions are the most environmental sensitive areas, which is mainly the result of the abrupt slopes and spatial variation of precipitation. 3) The insensitive area is the main type of rocky desertification. The karst areas of southwest China are the most sensitive areas. 4) The main types of comprehensive eco-environment sensitivity in the study area are slight, insensitive and moderate. The comprehensive eco-environment sensitivity in northwestern, southwestern, southeastern parts of China and loess hilly region is higher than other areas in China. 5) Based on the evaluation results of comprehensive eco-environment sensitivity, taking the extreme sensitive areas as the ecological redline areas, this paper uses top-down method to define the redline of eco-fragile areas in China. Three types and 23 important ecological redline areas are delimited across the country, and the ecological redline areas make up about 12.86% of the study area.