Study And Application Of Water Resources Carrying Capacity Based On Ecological Environmental Water Requirements

In recent years, There have been lots of problems in the rivers'process of development, for example, the disaster of flood, the atrophy of lake, the deterioration of grass field in area of the rivers'source, the watercourse filled up with the sediment, no flow in rivers, the rivers and the lakes polluted. These problems confine the development of national economy and affect people's production labor and healthy bodies. These problems mainly result from the unsuited scales of development. Therefore, as planners of the river valley development, during the process of it, we should draw up the reasonable development scales to assure that the development scales be not out of the limits, to reduce, even to eradicate completely the serious environment problems, to guarantee the social economy to develop continuously. This paper is just based on above purposes to study water resources carrying capacity and ecological environmental water requirements of Yangtze River basin. Through the researches of the recent years, maturer theory systems and calculation methods of ecological environmental water requirements have been formed, but its applications are few in our country, used to evaluate qualitatively the scales of river basins'development. The researches of water resources carrying capacity have been also carried on widely, the most of them establish models which make use of the amount of useable water resources as main controlled conditions to calculate quantitatively water resources carrying capacity, but the researches of water resources carrying capacity based on ecological environmental water requirements of river basins are few in our country. This paper sets out from the historical and present researches of ecological environmental water requirements and water resources carrying capacity of river basins, analyze the mechanism of ecological environmental water requirements ,its components and the calculation methods of all components, and combine with the actual circumstances of the river valley of Yangtze River to calculate approximately ecological environmental water requirements of the river basin, calculate t water resources carrying capacity of the river basin with the model whose only object is to support the most people to live. The results demonstrate: ecological environmental water requirements of Yangtze River basin is 6250.8454×108m3, the most population of Yangtze River basin whose water can support is 13.568×108～14.103×108, more than the estimated population of the river valley of Yangtze River in 2050——12×108, so Yangtze River basin is abundant in water resources.