A Preliminary Study On Wetland Ecosystem Of The Water-level-Fluctuating Zone In The Three Gorges Reservoir

Building dams in rivers to intercept the rivers water massively (electricity generation, irrigation, control flood and so on), is one of the most remarkable, widespread, and serious events that the rivers ecological environment has been affected by human being. After the Three Gorges Project finishes there will form Wetland ecosystem of the Water-level-Fluctuating Zone which have the height of 30 meters between normal store water level 175m and flood prevention control water level 145m, The wetland ecosystem of the Water-level-Fluctuating Zone in the Three Gorges Reservoir is the important part of the ecosystem of Three Gorges region. It plays vital role in contacts with land ecosystem and the water ecosystem of Three Gorges reservoir. The wetland ecosystem of is important Subsystem of Ecology function protectorate of Three Gorges reservoir. Based on the Ecological environment characteristic in the region of the Water-level-Fluctuating Zone and hydrology process characteristic of the Three Gorges Reservoir, Has forecast the wetland ecosystem evolution tendency in Water-level-Fluctuating Zone. And has made the discussion to type division of the wetland ecosystem in order to improve the ecological environment and maximize ecosystem function.The article is divided into five parts.The first part is prolegomenon. This part including the definition and importance of wetlands, wetlands status and progress of the study, the status of wetland resources in our country and the background of research of Water-level-Fluctuating Zone research.The second part is the formation of the Water-level-Fluctuating Zone. This part including the operational programmers of the Three Gorges Reservoir, the formation of the Water-level-Fluctuating Zone in the Three Gorges Reservoir, the area of the Water-level-Fluctuating Zone and its distribution.The third part analyzes the characteristic of wetland ecosystem of the Water-level-Fluctuating Zone in the Three Gorges Reservoir, including the Ecological environment condition before the Water-level-Fluctuating Zone come into being and the evolution tendency of wetland ecosystem of the Water-level-Fluctuating Zone after the reservoir stores water. When the Three Gorges Project finishes, the bank of the reservoir will remolds because of the change of cycle and range of water level fluctuation. The bank shape, material composition, structure and geologic structure condition are intrinsic factors of remolds, and the water fluctuation is exterior factor, on the whole, the arbor, boscage and hassock will die and be replaced by hygrophilous vegetation because of the changes of condition.The fourth part is the type division of wetland ecosystem of Water-level-Fluctuating Zone. Take the height or slope of the bank of the reservoir as major index, which has important influence to the wetland ecosystem evolution tendency, character, the function of ecosystem and problem of environment, has divided the Wetland ecosystem of the Water-level-Fluctuating Zone in the Three Gorges Reservoir into four types: cutbank, upside, middle part and substrate;Then has gone a step further to divide it into four subgroups: canyon type, non-canyon type, slope type and mild slope type.The fifth part is epilogue and discuss.