Coastline change detection with satellite remote sensing for environmental management of the Pearl River Estuary, China

The Pearl River delta area in Guangdong Province has one of the highest economic development rates of China. Rapid industrialization and urbanization has resulted in extensive changes in land use, including the construction of harbours and embankments. The lack of sustainable coastal zone management has caused severe environmental problems, such as land subsidence, intrusion of sea water, siltation of river channels and coastal erosion. For the analysis of the changes of the coastlines, multi-temporal Landsat images and a SPOT scene have been used, in combination with topographical and nautical data. From the change analysis, it can be concluded that the largest variations in the position of the coastline over time occurred in the Nansha Development Zone, situated in the Northern part of Lingdingyang bay. Sedimentation and land reclamation was responsible for the growth of the islands in the period 1960 to 2000, which however decreased slightly in the years after. Various large changes occurred also in the East of the bay along the coast of Shekou peninsula, caused by extensive harbour construction and growth of polder systems. Based on the research of the coastline change in recent decades, suspended sediment plume distribution and its sedimentation, it is suggested that the western part of the waterway in the estuary may not be suitable for large number of construction for harbours, due to the sedimentation and fill up. One of the most important impacts of the coastline changes in the Pearl River Estuary is the narrowing down and extension of river channel which results in more floods in the upper part of the river.