城市化地区湿地生态系统服务干扰评价——以深圳坪山河流域为例

Disturbance assessment of urban wetland ecosystem services:A case study in Pingshan watershed of Shenzhen City

城市化地区的湿地生态系统服务研究在湿地评价领域相对薄弱,现有的基于环境经济分析的评价模式也难以反映人为活动的干扰影响.本文从城市湿地生态系统服务的内涵确定和人为干扰方式辨识入手,建立表征干扰影响的评价因子体系,并运用层次决策分析法确定指标权重,采用两级式模糊综合评价模型考察人为活动干扰强度和干扰方式的空间分布异质性.以深圳市坪山河流域这一快速城市化典型地区为例进行试验性研究.结果显示:1)自然地理条件是影响坪山河流域湿地生态系统服务干扰的基础要素;2)南部丘陵山区以单一的植被覆被退化为主要干扰方式,干扰强度较低,但保护和管理不容忽视;3)北部平原宽谷地区的干扰强度普遍高于南部丘陵山区,且干扰方式多样化,干扰影响在空间上呈从干流上游至下游先增强、再减弱的趋势,与土地利用格局特征一致,但干扰方式的分布并不连续;4)模糊综合评价模型在湿地生态系统服务干扰评价中具有较好的实用性.

To understand the wetland ecosystem services in urbanizing area is much needed in wetland assessment. Currently,the dominant approach in assessing wetland value is the assessment model using environmental economic analysis. However,this approach can not reflect the impact of human disturbance. This paper introduced the connotation of wetland ecosystem services and the patterns of human disturbance,established an evaluation index system which could characterize the disturbance impact,and determined the weight of each index by using analytic hierarchy process. Moreover,a dual-grade fuzzy comprehensive evaluation model was applied to analyze the spatial heterogeneity of human disturbance. Our case study in Pingshan River Basin,a typical urbanizing area of Shenzhen,showed that geographic condition was the primary factor in determining the intensity of human disturbance on wetland ecosystem services. The main disturbance pattern in the south hilly area was vegetation degeneration,but the disturbance intensity was low. Even so,the vegetation protection and management in this area shouldn＇t be ignored though. The disturbance pattern in north valley area was diverse,and the disturbance intensity was much higher than that south hilly area. From the upper reach to the lower reach of the main stream,the impact of human disturbance increased first and decreased then,being accorded with the characteristics of land use pattern,but the disturbance pattern didn＇t have a continuous distribution. Our study showed that fuzzy comprehensive evaluation model had good performance in the disturbance assessment of wetland ecosystem services.