改进生态位理论用于水生态安全优先调控

引进模糊数学隶属度的概念,改进了传统的生态位理论,以漳卫南运河流域上、中、下游的3个典型城市(县)(潞城市、新乡县与德州市)为例,计算其在12个资源轴不同梯度上的隶属度、生态位宽度与生态位重叠,并基于此分析了水生态安全的优先调控区与优先调控指标. 结果表明:①潞城市、新乡县、德州市的平均生态位宽度分别为1.332、1.441、1.289,说明新乡县在12个资源轴上均具有较强的适应能力,而德州市的适应能力最弱；潞城市、新乡县、德州市的平均生态位重叠分别为2.097、2.285、2.318,说明德州市与其他2个典型城市(县)在资源利用上具有相似性,尤其是德州市与新乡县在资源利用上具有较高的相似性,可能存在潜在竞争. ②3个典型城市(县)均对森林覆盖率、万元GDP用水量、水资源开发利用率的改变具有较强的适应性；3个典型城市(县)在人均水资源量资源轴上的生态位重叠最大,并集中于一个较窄的梯度区间内,可能会引发潜在竞争. ③德州市是漳卫南运河流域未来水生态安全保障的优先区和水生态安全改善的优先调控区,而人均水资源量、人均GDP、产水模数、城市环境用水所占比例等4个指标均可作为未来水生态安全改善的调控指标,其中人均水资源量是优先调控指标. 

Study on Priority Regulation for Water Ecological Security Based on Niche Theory

It is important to study water ecological security for integrated basin management. In the present study, the niche theory was creatively adopted to assess water ecological security. Traditional niche theory was improved based on the concept of degree of membership. Dezhou, Lucheng and Xinxiang in different reaches of the Zhangweinan Canal River Basin were chosen as typical cities. The pressure-state-response concept model was used to establish an indicator system for assessment of water ecological security. Subsequently, the degree of membership, niche width and niche overlap of 12 water ecological security indicators were calculated to identify the priority regulation area. The results showed that the niche widths of Lucheng, Xinxiang and Dezhou were 1.332,1.441 and 1.289, respectively, indicating that Xinxiang is the best, while Dezhou is the worst, when evaluated by such indicators. The niche overlaps of Lucheng, Xinxiang and Dezhou were 2.097,2.285 and 2.318, respectively, indicating that Dezhou has a similar resource utilization pattern as Xinxiang, which suggests that there is potential competition between them. It was concluded that Dezhou should be regarded as the priority control region of the river basin. All three typical cities showed better adaptabilities to the change of forest coverage rate, water consumption per 10⁴ CNY GDP and water exploitation and utilization indices. All three typical cities had the largest number of niche overlap on the indicator of water resources per capita, indicating that the similar utilization of water resources may cause competition among the selected cities. In addition, water resources per capita, GDP per capita, water production modulus and environmental use of water in the city can be regarded as control indicators, among which water resources per capita should be regarded as the priority control indicator.