Sustainable land reclamation in coastal area

Many land reclamation projects have been carried out worldwide for many years to create new land from oceans, seas, riverbeds or lakebeds for several purposes. Historically, agriculture was the first drive for land reclamation, followed by urbanization and industrialization. Recent worldwide globalization has enhanced international trading and promoted many land reclamation projects in coastal areas. Land reclamation requires a large amount of relatively high-quality fill soil, which is used to obtain from mountains, rivers and seabeds. For this purpose, many land reclamation projects have been carried out together with other projects, such as dredging projects at rivers and coastal areas and/or the development of mountainous areas. Recently, it has become difficult to obtain such soil at reasonable cost because of restricted environmental protection, which requires the use of lower-quality soil as a reclamation material. Reclaimed land and sea walls are highly susceptible to ground instability, ground settlement and soil liquefaction, which can amplify the amount of damage to buildings and infrastructure there. Various ground improvement techniques have been developed to assure the stability of the sea wall and reduce and accelerate the ground settlement of reclaimed land. As environmental issues have become very critical in recent years, it is necessary to develop sustainable land reclamation techniques to promote the beneficial use of dredged soil and waste, minimize the environmental impact and create a rich natural environment. In this manuscript, the history of land reclamation in the Tokyo Bay area is briefly introduced, and current technologies regarding ground improvement and preservation of environmental conditions are presented to determine the future trends of sustainable land reclamation technologies.