基于PSFR评估框架的太子河流域水生态安全评估

Assessment of Riverine Ecological Security for Taizi River Basin based on PSFR Evaluation Framework

以减少人类压力、保持生态健康、维持服务功能和规避潜在生态风险为出发点,建立了基于PSFR(压力、状态、功能、风险)的太子河流域水生态安全评估指标体系.通过遥感影像解译、年鉴资料查询收集和实地调查数据相结合的数据整合方式,利用综合指数法计算了太子河流域生态安全指数,并分析了造成流域生态安全退化的原因.结果表明,太子河流域划分的105个小流域中不存在"极不安全"等级,仅有下游5个小流域处于"不安全"等级,占总数的4.8%;多数小流域均处于"较安全"和"一般"等级,呈集中分布的特点,其中处于"较安全"等级的小流域有59个,占56.2%;处于"一般"等级的小流域有38个,占36.2%;处于"安全"等级的小流域只有3个,占2.8%,说明整个太子河流域的水生态安全状况整体处于"较安全"等级.研究显示,流域内农业和城镇用地的扩张是显著影响生态安全状态及生态服务功能的主要因素.

In order to reducehuman stresses,keep ecological health,maintain service functions and avoid potential ecological risks,an evaluation index system for ecological security in Taizi River Basin was established. The index system consisted of four aspects,including pressure,state,function and risk（ PSFR）. A data integration method was proposed combining interpreted data of remotesensing imaging,almanac data and survey data from field studies. The ecological security status was calculated by the multiple indices,and the reasons for Taizi River Basin degradation were analyzed. For the whole basin,the ecological security showed a centralized distribution pattern,where the proportions of the sub-basin at Grade-Ⅰ（ safe state）,Grade-Ⅱ（ relative safe state）,Grade-Ⅲ（ normal state） and Grade-Ⅳ（ unsafe state） were 2. 8%, 56. 2%,36. 2% and 4. 8%,respectively. The evaluation results showed that the whole ecological security status was in the Grade-Ⅱ.The correlation analysis indicated that the expansion of both agriculture and urban land significantly affected the ecological security status in the basin,which restricted the performance of the ecological service functions.