Assessing the Habitat Quality of Aquatic Environments in Urban Beijing

Aquatic environments are important habitats for plant and animal species. In this case study we assessed the impact of rapid urbanization on the habitat quality of urban water bodies in Beijing in the past decade. The changes of surface areas, locations, and types of water bodies were estimated through interpreting QuickBird and WorldView-2 images acquired in 2002 and 2012, respectively. The land use change in areas surrounding 30 selected urban water bodies were interpreted using Landsat images. The impact of land use change on the habitat quality of those 30 water bodies was evaluated using the habitat threat index (HTI). The result showed that the total area of urban water bodies has expanded from 15.54 km2 to 16.02 km2 in Beijing in the past decade. However, the increase was mainly due to the construction of golf courses, water pools, new parks, and new drainage ditches. Most water bodies with high habitat quality such as fishponds and semi-natural ponds have been converted to other types of land cover. The mean value of HTI decreased by 8.96% between 2002 and 2015. The improvement was largely due to the large-scale urban greening projects implemented in Beijing during this period. We concluded that there is an urgent need to preserve water bodies with high habitat quality so they can play a more important role in preserving urban biodiversity in Beijing.