NATURAL FACTORS FOR DETERIORATION OF COASTAL WETLAND IN THE YELLOW RIVER DELTA

The area reduction and function deterioration of the coastal wetland in the Yellow River Delta, as a response to climate change, is basically controlled by natural factors. Water and sediment from the Yellow River are the fundamental materials for the survival of the coastal wetland. The rate of increment of coastal wetland has slowed down as the water and sediment discharges of the Yellow River decreased since last seventies. The joint action of the factors, such as wave, tide, storm surges, land subsidence and sea level rise has led to area loss and the negative growth of the wetland in the last decade. Owing to water shortage, soil salinization and the drought frequently happened in the coastal wetland, the diluted water from the Yellow River is nearly disappeared. It results in the increase in salinity and decrease in surface water temperature in the offshore water, the damage of environment and the reduction in biodiversity.