[Disturbance assessment of urban wetland ecosystem services: a case study in Pingshan watershed of Shenzhen City].

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.