基于GIS的怒江流域中段生态保护重要性评价

Evaluation of ecological conservation importance via GIS approach in the middle reaches of Nujiang watershed

生态保护重要性标志着某个地区对维持区域生态安全的重要程度,反映了某个地区在土壤侵蚀、生境、石漠化、地质灾害和水环境等多因子综合影响下对维持和保护区域生态环境的重要程度。本文基于地理信息系统技术,提出多因子逻辑规则组合法,即采用单因素叠置法与逻辑规则组合法相结合的方法,并将生态敏感性概念延伸为生态保护重要性概念,对怒江流域中段进行了生态保护重要性概念及其评价方法的探讨。本研究中生态保护重要性评价主要包括土壤侵蚀敏感性和生物多样性。评价结果表明:研究区生态极度重要地区主要分布在海拔1 300 m以上的河谷地区,占研究区总面积的11.43%;生态高度重要地区占研究区的比例最大,达48.02%,主要分布在海拔1 800～3 100 m的地区;生态保护中度重要地区面积占研究区总面积的35.22%,主要分布在海拔3 100 m的地区;生态轻度重要地区呈斑块状散布在整个研究区内,占研究区总面积的5.29%;生态不重要地区的面积最小,占研究区总面积的0.04%,主要分布在人类聚居区。生态保护重要性高的地区是整个区域生态系统保护的关键地区,应该重点关注其生态保护、恢复和建设。

The importance of ecological conservation at regional level is reflected in the sustainability and protection of valu-able/fragile ecosystems.Several factors（e.g.,soil erosion,eco-hydrological environment,stone desertification and geological disaster） influence ecological conservation.This paper used Geographic Information System（GIS） technology to build a combined mul-ti-factor approach to evaluate ecological conservation.The approach combined one fold factor overlay method with logical reasoning method to formulate a comprehensive systems approach.The concept of ecological sensitivity was extended to ecological conserva-tion importance,which is a critical factor of ecological conservation.The paper discussed the concept of importance of ecological conservation and evaluated the ecological conservation importance of the middle reaches of Nujiang watershed from soil erosion sensitivity and biodiversity.The results showed that the ecological conservation extremely important zone lied in the river valley region.This region was situated at an altitude over 1 300 m and covered 11.43% of the total studied area.The ecological conserva-tion highly important zone covered about 48.02% of the studied area,and was at an altitude of 1 800～3 100 m.The ecological con-servation moderately important zone was 35.22% of the studied area,located at an altitude of 3 100 m.The ecological conservation slightly important zone was small,accounting for 5.29% of the studied area,and with patched distribution.The ecological conserva-tion unimportant zone was the smallest zone,covering only 0.04% of the total area and mainly distributed in residential areas.This evaluation work provided the basis for prioritizing ecological conservation efforts,with the main focus on ecological protection,re-covery and construction.