Ecosystem Health Assessment For The Huangqihai Wetland

Wetland health assessment is the basis of wetland restoration, protection and management.Located in the arid and semi-arid region of China, the Huangqihai basin is experiencing serious degradation. Since the1980s, the Huangqihai Lake area has been decreaced year by year, and become completely dry by the year2008.To analyze the degradation of the Huangqihai wetland ecosystem,the ecosystem health assessment of spatial and temporal dynamic should in the first place.Due to the lack of long-term historical monitoring data,choosing a method which needs less data and simple operation for the Huangqihai wetland ecosystem health assessment is extremely important.We used landscape development intensity(LDI) method and rapid evaluation method to assess the Huangqihai wetland health. LDI method used landscape development intensity coefficient, combined with the six-stagespatially explicit land use data, to assess the Huangqihai wetland health for temporal dynamics in historical period.Rapid evaluation method assessed by the questionnaire forms.The main results are as follows:(1) The LDI coefficient in the Huangqihai lake between1976-2010showed an increasing trend. It indicated that the intensity of human interference enhanced, the health of the Huangqihai lake has a downward trend. From the spatial distribution side,the LDI of lake district minimumm, increased with the expansion to the lakeshore. It showed that the human interference gradually increased from the center to the edge of the lake.(2) The rapid evaluation method showed that,the environment of the east bank of the Huangqihai lake is better,the degradation of the south bank is most serious.The ecological health score decreased from73.6to29.9. Human disturbance and the changes of hydrological conditions are the indicators which severely affected the Huangqihai ecological health,and showed continued strengthening trend.(3) The evaluation results of LDI method and rapid assessment is consistent.They showed that from1976to2010, the ecological health of the Huangqihai lake wetland continued to get deteriorated. Among them, the study areas were in the state of "healthy" in1976-1993, followed by the period of transition from "healthy" to "unhealthy" during1993-1999, and completely transformed into "unhealthy" in1999-2010.The results indicated that the illegal farming and grazing, as well as the agricultural non-point source pollution were the main reasons for the increasing deteriorate. At the same time, nature reserve plays an important role to curb the deterioration of the environment. We therefore suggest improving the enforcement of regulation in the protected area, banning grazing and farming in the lake, and setting up the lakeshore buffer to reduce the non-point source pollution.