THE DISTRIBUTED PATTERN OF COASTAL WETLANDS IN TANGSHAN AND ITS CONTROLLING FACTORS

Both natural and human-made wetlands are distributed along the coast of Tangshan in a zonal pattern paralleling to the coastline. The formation of the wetland is controlled by active neotectonic movement in the study area, which causes rapid land subsidence, changes in surface water system and its distribution pattern. Natural factors, such as precipitation, evaporation and seasonal and annual variation of climate conditions also play important role, in addition to sedimentary environment, geological background and groundwater occurrence. However, due to the large-scale industrial and agricultural construction and urbanization recently carried out in the research areas, human factors has become the main cause of coastal wetlands degradation, environmental pollution and the shrinkage of wetland areas. And the ecological function of wetland is decreasing. The Tangshan coastal wetlands are products of joint actions of neotectonic movement, climate evolution and environmental changes, and also the consequence of modern industrial and agricultural development.