Study On The Method For Delimiting Sea-land Demarcation Line In Estuary Areas

Estuary area possesses fruitful resources as well as ideal environment. Along with social development, estuary is gradually under an integrated exploration by several management sections. The effect from human beings is getting heavier and the negative consequence, such as environmental pollution, destroying of ecosystems, coastal erosion and so on, is also more and more obvious. To solve such problems, it is urgent to enhance the coastal scientific management and carry out sustainable development. By far, definite sea-land demarcation lines in most Chinese river estuary areas have not been delimited yet, which has resulted in the undefined authority and responsibility of relevant departments and is unfavorable to solve the environmental problems in the estuarine coast area. There is a pressing need to delimit definite sea-land demarcation lines in the river estuary area.Based on projects like "Sea-land Demarcation Research", "Marine Delimitation" and nature environment information, this paper systemically analyzes the category and characters of China's main estuaries. Considering the coast geomorphology, sedimentology, wave and current condition, ecology and other sea-land delimitation index, it is found that estuary areas possesses complicated changes of wave and current conditions as well as ecological characters. There a lot disadvantages lie in the current boundary such as inordinate zigzag, unclear locating, little temporal-space changes, and hard to be managed. Thus, a demarcation method based on the geometric and geomorphologic characters would be simple, clear and practical in most estuary areas. As for boundaries settled by management rules, agreement and with no disputes, they can be still used.Totally 18 estuaries such as the month areas of Long River, Qiantang River, Yellow River, Zhujiang River as well as Liaohe River, Luanhe River and Haihe River are selected and analyzed in this paper with their respective demarcation schemes, which could sever as a reference for sea-land demarcation research and relevant management sections.