Eco-environmental Water Requirement Problem Of Zhalong Wetland Ecosystem

On the basis of comments on the status of the study on the eco-environmental water requirement, the problems of the ecological security in Zhalong Wetland, the concepts and calculating methods about the quantity of the eco-environmental water requirement, the land use parameters for calculating the quantity of the eco-environmental water requirement, the suitable quantity of the eco-environmental water requirement, the minimum quantity of the eco-environmental water requirement and the process of the supplying of the eco-environmental water requirement for Zhalong Wetland are researched.The quantity of the eco-environmental water requirement is the needed dissipative total quantity of water resources that keep the environment in the location and no longer deteriorate, then improve it. The quantity of the water requirement of the ecosystem is the needed quantity that keeping the special eco-value of the ecosystem in lower risk, the water requirement of the ecosystem more pay attention to and stress the ecological water requirement, but at the same time also included the environmental water requirement, in a general way, the quantity of the water requirement of the ecosystem is equal to the quantity of the eco-environmental water requirement. A catchment is a complete eco-environmental unite, it is suitable to study the quantity of the eco-environmental water requirement systematically and easy to development a unitary analysis method, with it the time-space variety regulation of the eco-environmental water requirement can be researched, the calculating methods about the quantity of the eco-environmental water requirement in Zhalong Wetland should include the lake, the Wetland plant, the Wetland soil, the habitat of wild-animal and so on.For checking the land use variety circumstance of different years in Zhalong Wetland quickly, the LandsatTM satellite image of the United States covering the scope of Zhalong Wetland in different period of 12 years are collected and explained combined GIS database. From them the parameters are distilled, which including the area of the lake and reservoir, clear marsh, bulrush marsh and so on, them are needed for calculating the quantity of the eco-environmental water requirement of Zhalong Wetland. The variety of the area of the land use types of Zhalong Wetland in different period are analyzed.With the calculating methods about the quantity of the eco-environmental water requirement of the wetland and the parameters including the area of the lake and reservoir, clear marsh, bulrush marsh and so on, the quantity of the eco-environmental water requirement in the area of the lake and reservoir, clear marsh, bulrush marsh are calculated. On the basis of calculation about all kinds it, the suitable quantity of the eco-environmental water requirement,the minimum quantity of the eco-environmental water requirement and the process of the quantity of the eco-environmental water requirement are calculated and analyzed. It is concluded that the quantity of the eco-environmental water requirement in the whole Zhalong Wetland varies from 521 millions m~3 to 592 millions m~3 and it in the core area of the Zhalong Wetland varies from 208 millions m~3 to 235 millions m~3 in the period that from 1986 to 2002. The suitable quantity of the eco-environmental water requirement is 505 millions m~3 , the minimum quantity of the eco-environmental water requirement that its probability is 75% is 256 millions m~3, the minimum quantity of the eco-environmental water requirement that its probability is 95% is 289 millions m3 .