基于SRP概念模型的祁连山地区生态脆弱性评价

Ecological vulnerability assessment of Qilian Mountains region based on SRP conceptual model

基于生态敏感性-生态恢复力-生态压力度(SRP)概念模型,从地形、气候、植被和社会经济因子选取8个评价指标,利用遥感和GIS技术,采用主成分分析方法求取权重,对祁连山地区启动水源涵养区生态环境保护和综合治理规划研究前后近10 a的生态脆弱性程度进行系统、定量地评估,旨在揭示生态脆弱性的分布特征、时空演变及动因,为区域生态保护、资源利用和可持续发展提供参考。结果表明:(1)从研究区生态脆弱性分布来看,祁连山地区主要以轻度和重度脆弱为主,脆弱性程度从西北向东南地区逐渐减弱,西北地区植被覆盖度小,海拔高,生态环境较为恶劣是导致脆弱性程度较高的原因;(2)祁连山地区3期生态脆弱程度呈逐渐下降趋势,综合指数分别为3.307、3.118和3.103;2005年生态脆弱性较高,极度脆弱面积为28610 km^2,2010年下降为11723 km^2,2015年降低为6174 km^2,极度脆弱面积逐渐减少;(3)从祁连山地区生态脆弱性演变动因来看,8个指标对生态脆弱性影响均较为显著,但在不同的时间影响程度各不相同,2005—2015年3期数据中对生态脆弱性影响最大的均为植被指数,降水次之,地形因子影响最小。总体来看,近年来祁连山地区生态脆弱性程度有所降低,但仍然需要加强保护力度,促进生态环境可持续发展。

Global natural environment changes and increasing human activities have greatly affected the ecological environment,leading to the emergence of many ecological problems and the high attention of the ecological vulnerability.The Qilian Mountains region is an important part of the plateau ecological security barrier in China,which guarantees the ecological security in the northwestern region of China.This region is characterized by the typical continental climate with low rainfall and dry climate,where the ecological environment has been seriously influenced with social and economic development and frequent human activities.In 2008,the government issued relevant plans for the ecological management and restoration of the Qilian Mountains region.Therefore,it is of great significance to evaluate and analyze the ecological vulnerability of the Qilian Mountains region in the three phases of 2005,2010,and 2015.In this paper,according to the ecological environment characteristics of the Qilian Mountains,the operability and relevance of the evaluation indexes and the“sensitivity-resilience-stress”conceptual model of eight indicators of NDVI,topographic fluctuations,ground fragmentation,surface roughness,and topographic factors,as well as precipitation,temperature,meteorological factors,population density,and per capita GDP selected from natural and human aspects,using remote sensing and GIS technology,the principal component analysis method is used to obtain weights and ecological vulnerability Based on the ecological index and the ecological characteristics of the study area,and based on the existing ecological vulnerability assessment standards at home and abroad,the degree of ecological fragility in the Qilian Mountains during the past 10 a is systematically and quantitatively analyzed.The study's aim is to provide references for regional ecological protection,resource utilization,and sustainable development.Results showed that:(1)From the perspective of ecological vulnerability distribution in the study area,the degree of vulnerability is gradually weakened from northwest to southeast.The vegetation coverage in southwest is small and the high altitude and the poor ecological environment is the reason for the high degree of vulnerability.(2)For the ecological vulnerability of the whole region,the Qilian Mountains is mainly characterized by mild and severe vulnerability,and the degree of ecological vulnerability has gradually decreased in the past decade.(3)The ecological vulnerability of Qilian Mountains in 2005 is relatively high with the extremely fragile area of 28610 km2,which dropped to 11723 km2 in 2010 and 6174 km2 in 2015.(4)The ecological vulnerability index of the study area was 3.307 in 2005,3.118 in 2010 and 3.103 in 2015,showing a gradual decline trend.(5)The impacts of eight indicators on ecological vulnerability are all significant,and the difference is reflected in different periods.The vegetation index has the greatest impact on ecological vulnerability in 2005—2015,followed by precipitation,and the topographic factor has the least impact.In general,the ecological vulnerability of the Qilian Mountains has been reduced in recent years due to the introduction of relevant national plans.There has been some progress in the protection and comprehensive management of ecological environments.However,it is still necessary to strengthen the environmental protection,build the ecological security barrier,maintain the ecological security,and achieve a virtuous cycle of the ecosystem in the Qilian Mountains to promote the harmonious development of human and nature.