Study Of Eco-Environment Water Demand And Assessment Of Ecosystem Health In River

China is one of the countries facing water crisis. With the development of economy, over-exploitation of water has become more and more widespread. And then the ecological and environmental issues are getting worse. Under the background, the theoretical concepts and the calculation methods of the river eco-environmental water demand are discussed. And then the concept and the assessment methods of river ecosystem health are analyzed. At last the Haihe River Basin is applied.The following outcomes and conclusions are obtained in the paper:1) Based on the detailed analysis of the concept, classification and researching advances of eco-environmental water demand, the correlative concepts and theories of eco-environmental water demand are introduced.2) The calculating method of river eco-environmental water demand is analyzed. River eco-environmental water demand is divided into five parts: basal eco-environmental water demand of channel, channel water demand of water quality request, water demand of evaporation and leakage, estuary eco-environmental water demand and marsh eco-environmental water demand. The calculating methods of each part are proposed. When calculating the total eco-environmental water demand of river, each water demand has crossover and superposition and it is necessary that each water demand be combined availably according to especial region status.3) The differences of eco-environmental water demand and eco-environmental water use are analyzed. Eco-environmental water demand is the intrinsic character of ecosystem, and eco-environmental water use is raised from the point of view of water resources allocation. The proportion of eco-environmental water use is applied to evaluate the continuable status of water resources.4) The study's status about the concept and assessment methods of river ecosystem health is summarized. In the paper, the river's health status is determined through an index system and the AHP method. Five components are included in the index system: hydrology, water quality, aquatic life, physical form and riverside zone.5) According to the physical geography status and hydrology character of the Haihe River Basin, the eco-environmental water demand quantity is calculated and the continuance of water resource allocation is evaluated using the proportion of eco-environmental water use. Also the assessment model established in the paper is...