Natural and Anthropogenic Causes of Vegetation Changes in Riparian Wetlands Along the Lower Reaches of the Yellow River, China

There are many natural and anthropogenic impacts on the vegetation in riparian wetlands. The Yellow River in the North of China is one of the biggest rivers of the world, but the riparian wetland area is very small. The monitoring of these wetlands has increased in the last years because of the high ecological importance and increasing pressure due to economic development and increasing use of water resources. We use remote sensing and hydrologic data to analyze the change of wetland vegetation in the Zhengzhou natural reserve, which is affected by a rapid population growth and change of water flow. The main findings are: (1) the vegetation cover of the study area decreased from 1984 to 2011, (2) the hydrologic boundary conditions changed dramatically after the construction of a dam upstream and floods have almost disappeared under the new water resource management, (3) there is a conflict between the protection of the wetland vegetation and its use for recreation and tourism. Actually, anthropogenic factors are the main reasons for wetland degradation, and the government and the water management department should pay more attention to the protection of the remaining wetlands and the environmental balance.