| The Yellow River Estuarine Wetlands, located in the Dongying City, Shandong Province, which is one of the most complete, wide and young estuarine wetlands in the Warm Temperate Zone of the world, fulfill many important ecological service functions, such as seawater intrusion prevention, regulation climatic, pollution degradation, carbon fixation, as the habitats of the wildlife and so on. Under the impact of the nature and the human activities, the shortage of the freshwater resource in the Yellow River Estuarine Wetlands leads to a serious of eco-environmental problems, for example the change of the estuarine wetlands'structure and function, natural wetlands'area lessening, ecosystem degeneration, water pollution, soil salinization and so on, which seriously restricts the sustainable development in the estuarine wetlands. According to the increasingly serious eco-environmentalproblems mentioned in this thesis, the eco-hydrological process in the Yellow River Estuarine Wetlands is simulated, and the ecological water requirement in the wetlands is calculated, based on the target of the zoology protection, and finally the hydrological regulation model is proposed, in order to achieve the ecosystem's health and safety in the Yellow River Estuarine Wetlands. The conclusions are as followed:(1) The basic information database about the Yellow River Estuarine Wetlands is set up, based on the Remote Sensing and Geographic Information System, and the sensitive parameters of the model are verified, and the eco-hydrological model suited to the simulation of eco-hydro logical process in the Yellow River Estuarine Wetlands is built. The runoff coefficients simulated of the rivers is close to the annual average runoff coefficient in this area, which is basically meeting the requirements.(2) The average precipitation, evaporation and infiltration in the Yellow River Estuarine Wetlands is 570mm,545mm and 336mm from 1980 to 2010a, respectively, and the inter-annual variations is consistent. The annual average runoff of Shenxiangou river, Xiaodao river and Zhangzhen river is 0.322×108m3,0.115×108m3 and 0.115×108m3, respectively. The annual average runoff and sediment of the Yellow River is 309.88×108m3,6.23×108t according to the measured data of Lijin station, respectively, and decrease significantly. The area of the Yellow River Estuarine Wetlands is changing and the dynamic balance of the Yellow River Estuarine Wetlands'area while the runoff is 158.0×108m3 every year. There is positive correlation between the NDVI and the accumulated precipitation in the Yellow River Estuarine Wetlands.(3) The major ecological protection objectives of the Yellow River Estuarine Wetlands are defined as Reed (Phragmites australis), Seepweed (Suaeda heteroptera), Red-Crowned Crane (Grus Japonensis) and Saunders'Gull (Larus Saundersi) by means of the analysis of the wetland ecological system's functions. During the growing periods from April to October, the ecological water requirement of the reed community and the seepweed community is mainly about the water volume determined by the suitable water level for the growth of the reed and the water volume used to leach salt, respectively, and the water expended by the evapotranspiration also is concluded. During the Non-growing periods from November to the next March, the ecological water requirement is mainly about the water volume determined by the suitable water level for the habitat of the birds. The results show that the annual ecological water requirement of the reed community and the seepweed community in the Yellow River Estuarine Wetlands is 5.48×108m3 and 5.43×108m3, respectively.(4) The ecological water shortage of the Yellow River Estuarine Wetlands is 9.51×108m3,9.87×108m3 and 10.17×108m3, and the usable water volume is 90.57×108 m3,98.08×108 m3 and 51.46×108 m3 in the rainy year, the normal precipitation year and the scanty precipitation year, respectively, but the seasonal distribution of the usable water volume is uneven. From November to the next March, the Yellow River runoff is greater than the wetland water replenishment, and the supply water volume is 0.698×108-0.705x×108m3,0.67×108-0.68×108m3, to the wetlands in the Yiqianer Nature Reserve and in the Huanghekou and Dawenliu Nature Reserve—three parts of the Yellow River Delta national nature reserve, respectively. And from June to October, it increases to 0.22×108-0.48×108m3,1.46×108-1.86×108m3, respectively. However, from April to May, the Yellow River runoff is less than the ecological water requirement of the estuary and offshore, which means it can not supply to the wetlands. The volume of water shortage is 0.76×108-0.81×108m3, 0.72×108-0.79×108m3, of the wetlands in the Yiqianer Nature Reserve and in the Huanghekou and Dawenliu Nature Reserve, respectively. |
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