Study Of Topography Evolution Process In Oujiang Estuary And Aojiang Estuary Tideland And Adjacent Seabed

With the rapid development of economy and society in Wenzhou City, the population of Wenzhou is more and more, land contradictions have become increasingly prominent. Wenzhou which is located in the east coast has a large number of tidal flat resources.In order to solve the land problem, in recent years Wenzhou implemented a number of reclamation project. Oujiang Estuary and Aojiang mouth is the main zone where rivers and ocean cross. Oujiang Estuary and Aojiang mouth has a lot of beach resources which is the biggest land resource reserve in Wenzhou. Entered in twenty-first century, in order to alleviate the land shortage problem, Wenzhou along the coastal beach development activities is increasing. There are a series of large completed projects in the South Wenzhou Aojiang and Oujiang estuary, such as dam siltation, reclamation, maintenance of water ways. The implementation of these projects will cause the the terrain changes, and thus generate new seabed evolution. So it is important for the utilization of beach and channel maintenance that study of Oujiang Estuary and Aojiang Estuary project area in opposition to change.Firstly according to the latest Wenzhou coastline,terrain data,hydrologic survey results,we analyzed bathymetric changes and seabed erosion variation in Oujiang Estuary and Aojiang Estuary. Finally, we analyze the causes of changes. The conclusions are as follows:Comparison of Oujiang Estuary different topographic map between 2005 and 2012 year, the results show that the Lingni embankment and shoals in two Pro embankment siltation effect significantly, Lingni embankment lateral and shoal two internal large deposition, deposition rate of about between 1m~2m; other regions scour in the range of 1m, the maximum local scour up to 4m.Based on 2010 observed hydrological and sediment data and four different periods of topographic maps(1963,2003,2005,2011),it is discussed that the recent characteristics of topography evolution in Aojiang estuary.The results show that Aojiang estuary terrain experienced three different states: the slow sedimentation period from 1963 to 2003, the erosion and situation steady period from 2003 to 2005, the slight erosion period in the entire waters.The result of the analysis indicates that the change of Oujiang estuary and Aojiang estuary seabed in recent years is mainly caused by dredging and reclamation. Dynamic environmental changes caused by reclamation projects and sediment reduction also rushed to a certain degree of influence on the seabed.