The Study Of The Evolution And Degradation Of The Typical Coastal Wetland In Hebei Province

The coastal wetland is the special ecosystem which formed under the interaction between the sea and the land in the coastal zone scope, is one of the wetland ecosystem which most being abundant of bio-diversity, high of productive forces and valuable in the nature. It played an influential role in protecting the bio-diversity, storing water to defend the flood, purifying land source pollution entering the sea, complementing groundwater, regulating the weather aspects etc, simultaneously its natural resource was also the premise which causes the sea fishery, salt industry and salty chemical industry obtains the sustainable development. Therefore it has important influence on the economy development and the living environment of a region, the nation and even the globe, and have become the hotspot region of international society nowadays.Under the interaction between sea and land, the coastal area of Hebei Province grew wetland with abundant resource and various types. However, under people's long-term and high-strength exploitation's influence, the area of natural wetland has a great deal of decrease, which is replaced by man-made wetland. The coastal wetland ecosystem receives the enormous disturbance, is facing serious problem such as the natural wetland to wither, the ecological environment worsening.This paper take the most representative wetland as object of study which includes Qilihai lagoon wetland, Luan river mouth wetland and Nandagang wetland. It choosed many issue of topographic diagrams and the satellite remote sensing images from 1956 to 2005, and applied RS and GIS technologies to the interpretation analysis of the successional variation process of the Hebei typical coastal wetland. Then it analyzed ecological environment effect and influencing factor of coastal wetland evolution in detail. On the basis of it, it valued the degree of action of the factors affecting and the coastal wetland's degree of degeneration, using the synthesis matrix analytic method and jamming intensity model judgment method based on the landscape ecology. With that, we discussed the restoration of governance and the reasonable use countermeasures of typical coastal wetland.The results showed that, (1) By the artificial development operation influence, the Hebei typical coastal wetland is been remarkable day after day, especially by the degree of people's interference is been getting bigger and bigger after the 1980s. Its appearance characteristics has had the very big change and already presented the situation of degenerated evolution development. Its main trend of evolution situation was that the area of the natural wetland was gradually reduced, and the area of man-made wetland was gradually increased. The majority of natural wetland was replaced of man-made wetland such as breed pond, rice paddy, salty field. Its original ecosystem encounters the enormous disturbance and the environment is in the state of deterioration.(2) The human factors such as the cultivation (farmland, salty field, breed pond) and hydraulic engineering (coastal levee, reservoir etc) construction, the excessive use of biological resources and pollution etc with natural factors, which includes the climatic change and the river amount of runoff reduction are the main environment pressure factors of degenerated evolution. The Hebei typical coastal wetland presents the evolution ecological environment effect,which includes the bio-diversity reduction, landscape simplification, natural non-uniformity reduction and ecological environment worsening.(3) The climatic change, excessive use of biological resources, pollution, hydraulic engineering, river amount of runoff reduction, reclamation and other environmental factors impacts on the wetland's degradation was increasing in turn, of which reclamation was the primary factor which creates the typical coastal natural wetland gradually disappeared. Under the human factors and natural factors influence, the human factors, the funtion of which degenerates to the wetland is biggest, is the predominant factor causes the typical coastal wetland degenerated. The typical coastal wetland'intensity of anthropogenic interference is big and the extent of degradation is very high, of which Luan river mouth wetland is biggest, Nandagang coastal wetland next best, Qilihai is situated the third.(4) The restoration mechanical control measures to the typical coastal wetland includes:â‘ The project of drawing back the cultivation to give back to the wetland.â‘¡Water quality betterment work.â‘¢Mixing the basin domestic waters resources reasonably, to construct water source supplies project.