Analysis On Ecologic Influence And Economic Value Of Increasing Water In The Estuary Of Nandu River

With the larger district of Haikou City, and the object of"Ecological Porch City"has been braught forward, the requirement of water is larger and larger, which enhance the contradiction of water supply and demand. The estuary of Nandu River has plentiful water, but can't be drinked and irrigated because of influenced by seawater intrusion, river ecosystem is facing the danger of destroyed, which would restrict the development speed of Haikou Ctiy to some extent.In this paper, taking the rubber dams programmed at the estuary of Nandu River as an example, the researches and estimate calculation on its ecological influence and economic value. The main studies are as follows:(1) The main problems and their harms of ecological environment at the lower of Nandu River currently was analyzed. Introducing the programming of building rubber dams.(2) River channel ecological water requirement at the estuary of Nandu River were researched by using the methods of historical flow. And evaluating the health of the ecological water by taking the flow characteristics of the practical hydrology series of Longtang station from 1956 to 2000.(3) The increased water was researched by using the soft of calculating the water level.The projects of ecologic operation was introduced, and its feasibility was analyzed. It will come ture that operating the increased water in reason in a small area, and filling up or meeting the need of social development water requirement on the basis of meeting the need of river channel ecological water requirement.(4) The service function of river ecosystem was researched, and which service value was classified. A system of evaluate index for evaluating the service function of river ecosystem was established, the economic value of increased water at the estuary of Nandu River was calculated by using the methods of market value,chance cost,shadow cost and travel expense etc.(5) A system of evaluate index was established with river service function, en- vironment function, using function and ecological function base on river function. And making out of the influence exponent of each evaluate index to the river ecological health by using the AHP. The outcomes indicate that the ecosystem of the river is healthy.