城镇化视角下三峡库区重庆段水生态安全评价

AQUATIC ECOLOGICAL SAFETY EVALUATION UNDER URBANIZATION PERSPECTIVE IN THE THREE GORGES RESERVOIR IN CHONGQING

基于驱动力—压力—状态—影响—响应(DPSIR)框架选取25个能反映水生态安全状态的指标,通过指标权重确定、数据标准化处理和水生态安全评价模型的构建,以三峡库区重庆段为例,从城镇化视角分析三峡库区重庆段自2007年三峡库区水位达156m高程以来的水生态安全状态。为了使AHP所确定的指标更客观,运用熵权对AHP进行修正,得到综合权重值来表示指标的权重。分析结果表明:三峡库区重庆段水生态安全自2007年三峡库区水位达156m高程至2010年三峡水库蓄水达到175m最终水位水生态一直处于不安全状态,2011~2012年升至警戒状态,总体趋势在逐年升高。影响三峡库区重庆段水生态安全的劣势因子是资源环境压力,其次是资源环境影响;影响三峡库区重庆段生态安全程度的优势因子是经济社会驱动力和经济社会响应。由权重值判断生态安全影响程度,资源环境影响对三峡库区重庆段水生态影响最大,其次是资源环境压力,影响最小的是资源环境状态。从指标层来看,对三峡库区重庆段水生态安全影响最大的前3个因素依次是灾害损失、万元GDP用水量、万元工业增加值用水量;影响最小的是水土流失面积比例。

Based on the Driving Force-Pressure-State-Impact-Response(DPSIR)conceptual model,25 indexes which can reflect the state of aquatic ecological security were selected.The aquatic ecological security state of Three Gorges in Chong Qing section since 2007 when the water level reached 156 meters was evaluated from the perspective of urbanization via the methods of determining indexes weight,standardizing data and building aquatic ecological security evaluation model.In order to objectify the indexes determined by AHP,entropy weight was used to correct AHP,and the weights of indexes were indicated by integrated weights.The results showed that,from 2007 when water level reached 156 meters to 2010 when water level reached 175 meters,the aquatic ecological state of Chong Qing section was unsafe,which was on alert from 2011 to 2012,and the overall trend is increasingly year by year.The primary negative factors that affect the aquatic ecological security of Three Gorges in Chong Qing section was resource and environmental pressure,the secondary was resource and environmental response.The advantage factors that affect the aquatic ecological security of Three Gorges in Chong Qing section are economic and social driving force and response.When the influence of ecological safety was estimated by indexes weight,what affected the aquatic ecological security the most in Chong Qing section was resource and environmental impact,the next was resource and environmental pressure,while the least-affected factor was resource and environmental status.From the perspective of index layer,three factors which affected aquatic ecological security the most were losses from disaster,water consumption per 10 000 yuan GDP and water consumption per 10 000 yuan industrial added value,while the minimal impact factor was the proportion of soil erosion area.