Health Assessment of Wetland Ecosystems in the Heilongjiang River Basin, China

Data from Landsat ETM+ images, meteorological records, digital elevation mode data and other statistical data were used to extract wetland-related information for the Heilongjiang River Basin, China, an area significantly affected by global climate change. Based on a pressure-state-response conceptual model, an integrated assessment index was constructed. The health status of the wetland ecosystem was assessed and mapped by an analytical hierarchy process and spatial analysis to integrate the regional characteristics. The health status of the wetlands was described as very healthy, healthy, sub-healthy, unhealthy or sick. This status decreased from the northeast and east to the west and southwest and was affected by the pressure-state-response characteristics. Most wetlands were healthy or very healthy and were mainly in the east, accounting for 35.95 % of the total area of wetland. Sub-healthy wetlands accounted for 18.69 % of the total area. Unhealthy and sick wetlands were mainly located to the west of the Greater Khingan Mountains and the Songnen Plain and accounted for 21.14 and 13.06 % of the total area, respectively. These wetlands were affected by higher pressures from human activity, their vulnerable state and severe land degradation. The protection and scientific management of these areas should be strengthened.