西南喀斯特区域生态环境敏感性评价及其空间分布

ECO-ENVIRONMENTAL SENSITIVITY AND ITS SPATIAL DISTRIBUTION IN KARST REGIONS,SOUTHWEST CHINA

西南喀斯特区域生态环境本身的脆弱性再加上不合理的人类活动的影响,生态环境问题突出,识别易发生生态环境问题的区域,为西南喀斯特地区生态环境保护和恢复提供科学依据十分必要。在ArcGIS支持下,选取影响西南喀斯特区生态环境的4个敏感性因子(水土流失、石漠化、酸雨及生境生物多样性)作为评价因子,采用层次分析法和综合指标法,评价西南喀斯特区域生态环境敏感性程度及空间分布情况。结果表明:西南喀斯特地区水土流失、石漠化、酸雨敏感性很高,前二者的中度敏感以上区域均占西南喀斯特区域总面积的60%以上,酸雨中度敏感以上区域达50%以上;生境生物多样性敏感性相对较低,不敏感区占西南喀斯特区总面积的40%。西南喀斯特区生态环境综合敏感度极高,中度敏感以上区域占整个研究区总面积的80%以上,不敏感和轻度敏感区主要分布在湘中南、鄂东南、广西中部喀斯特峰林平原区及云南、贵州山间盆地及河谷地区。地质背景、地形及气候是西南喀斯特区域生态环境敏感性的主导因素。

Because of the fragility of ecological environment and the influences of human activities,eco-environmental problems in karst regions are serious.It＇s necessary to identify the sensitive region that is prone to be degraded for ecological restoration and rehabilitation.Based on GIS,four sensitivity factors,that is,water and soil loss,rocky desertification,acid rain,and bio-inhabitation,were selected to assess the eco-environmental sensitivity.The degree of ecological sensitivity and their spatial distribution in karst regions of southwest China were explored with analytic hierarchy process（AHP） and comprehensive index.The results showed that the sensitivity of water and soil loss,rocky desertification and acid rain was generally high.More than 60% of karst regions were moderate and even more sensitive to water and soil loss sensitivity,rocky desertification,and acid rain sensitivity;while the sensitivity of bio-inhabitation was relatively low,with the proportion of 40% of insensitivity.Our study indicates that the sensitivity of eco-environment in karst regions of southwest China was high;more than 80% of karst regions are moderate and even more sensitive regions.The insensitive regions were mainly distributed in middle and south Hunan,southeast Hubei,karst peak forest plain of middle Guangxi,intermountain basin and valley of Yunnan and Guizhou.Geological setting,topography and climatic factors were the dominant factors affected the regional eco-environment sensitivity.