Dynamic monitoring of Yellow River estuary based on remote sensing in the recent ten years and analysis of correlation with flow and sediment condition

摘要

The Yellow River is well-known for its highest sediment contents of all rivers in the world. Due to the huge sediment to the coast, the Yellow river Delta is the youngest land of China, and still in a state of continuous dynamic change. The evolution of the coastline of Yellow River delta is closely related to the environment change of the flow and sediment in the Yellow River Estuary. In recent 10 years, Environment of flow and sediment in the Yellow River Estuary has been changed a lot. At first, in 1996, the riverway into the sea had been artificially changed; secondly, since 1999, Water resources unified collocation has been carried out in the whole basin; and thirdly, since 2002, water and sediment regulation has been carried out in the downstream of Yellow river. Change of flow and sediment condition resulted in change of coastline, land area, land cover and environment. The environment evolution of the Yellow River Delta chiefly lies on the change of the coastline. As a kind of monitoring method, Remote Sensing technology are combined with Geographic Information System (GIS), which is a very useful tool for studying the dynamic change monitoring. Under this background, the study on the recent evolution of the coastline there through the integration of Remote Sensing and GIS can not only provide the foundation to evolution analysis but also serve for the sustainable development of the Delta. In this paper, multi-phase and many kinds of remote sensing images are used to monitor the coastline change that happened in the Yellow River estuary since 1999. The directly extracted information from these images include coastline, land area and their increase or decrease between each two periods along time series. Furthermore, the relation between the changes and the main Affecting factors are also analyzed. Based on the ten years of hydrological data, the flow and sediment feature of the Lijin station that is the last one along the Yellow River from 1996 to 2006 by mon-th was analyzed. Then the relation between it and changes of coastline, land area, landuse are analyzed. The result shows that: though the land area of the Yellow River estuary decreased sometimes, the general of it in recent years increased especially after 2003. It is nearly related to the changes of flow and sediment condition. It is clear that these changes are favorable but it is far from the perfect.