Study On The Inning And Management Of Reclaimed Areas Of The Portside Tidal Flat Of Lianyungang City, Jiangsu Province, China

With the rapid development of social economy, the contradiction between increasing population and decreasing farmland has become a main factor restricting the growth of local economy. Accelerating the exploration and utilization of coastal mudflat resource is of great strategic significance for easing the contradiction and boosting the development of littoral economy.Lianyungang City, located on the west bank of the Yellow Sea, is an important coastal city in China, with abundant tidal mudflat resources. However, most of the coastal mudflat has not been well explored and utilized. To mitigate the contradiction between population and farmland, there is a stronger demand for exploring the tidal mudflat resources. Accordingly, a series of approaches and methods are urgently needed for the design and construction of the sea wall and the process of soft bed. In the meanwhile, an effective pattern and mechanism of exploration and utilization is also needed in order to improve the management of the reclaimed areas, increase the integrated benefits, and attract the wide participation of the local people. This would promote the quick and healthy development of the littoral mudflat areas.Development and utilization of coastal mudflat is a systematic task concerning macro policy, economic condition, environmental impacts, engineering technology, managerial issues, and so on. Based on existing relative works, questionnaire surveys and field investigation, natural condition for inning and management of reclaimed areas of the portside area of the city are studied in the thesis. Methods of sample test, statistical analysis and environmental simulation are employed. The results show that, the mudflat area in question is mostly consisted of fine sediments and prograding slowly. The rate of progradation decreased gradually to about 20m/a in the recent years due to the reduction of foreign sediment sources. Some tidal flats have been reclaimed for aquaculture, but they are under great threats due to the low- standard cofferdam. Considering the conditions of coastal evolution, engineering technology, and the safeguard of lives and property, developing the mudflat by inning may be the best choice. An effective running pattern is proposed as "Manage as a farm, Operate intensively, and Socialize services". This pattern may help extend the cubic aquaculture technology, push the development of leading processing enterprises and win the significant economic benefits. It may also help the lagged area of 30 km2 to jump up quickly.Different from early practices and researches of "strong inning and weak management" which usually led to failure in most of the exploration and utilization of coastal mudflats in the past, this thesis combines both of the aspects organically. Not only scientific inning but suitable post-reclamation management is also taken into account during exploring the tidal mudflat. Of course, the achievement is limited because of the complexity of the issue, the limitation of research ability and energy.Thesis is arranged as follows:Chapter one gives the background of this research, a review of relative studies and a framework.Chapter two describes the natural and social economic conditions of the area in question. Possible risks and favorable prerequisites are advanced, and basic materials are provided for next step study.Chapter three investigates the evolution process of the coast, driving forces and developing tendency of the river mouths, and disciplines of parenthetic coast line developing out side of the seawalls. And a train of thoughts to design favorable tracks and stable structures of seawall is developed as well, based on concrete analysis.Chapter four analyzes the alternatives of suitable tracts of seawall in connection with practical situation of the portside reclamation areas. Designing, construction, and soft mud bed handling of seawall on mudflat are discussed. Safety of the seawalls is analyzed. The control indexes and key technologies during seawall construction are advanced. These results provide scientific foundations for inning engineering and construction of supporting facilities of the other similar tidal flats.Chapter five discusses the operation and management, the integrated efficiency of the reclaimed areas and risks in detail. Centered on scale maximization of high efficiency agriculture, a mode of developing and utilization of tidal mudflat are discussed, that could attract people's activity, increase farmer's or fisherman's income vastly, and lead the reclaimed area to a virtuous circle.Chapter six concludes the thesis. Some countermeasures for dealing with them are proposed. To be sure the reclaimed area could run safely.Utilization of tidal flat may face many risks, such as storm surges, red tide, soft mud bed, flood of river mouths, market fluctuations and so on. Introduction and application of risk evaluation methods are helpful means of improving scientific level of strategic decision. Meanwhile could contribute to improve mission success rate, and could provide new methods for comparing programs and optimizing designs.