Calculation of the amount of siltation and erosion in the Xinqiao Channel of the South Branch of the Changjiang Estuary in China

Supported by GIS,15 pieces of charts of the Xinqiao Channel of the South Branch of the Changjiang Estuary are studied.Digital elevation model of the Chang jiang Estuary is established with Kriging gridding method to research evolution of channel change of coasts,formation and evolution.The different points of views,transverse section,plane and volume changes are considered.The results show that the evolution of the Xinqiao Channel has experienced three stages:in 1861~1926,the Xinqiao Channel area had been eroded at first and then silted;the Xinqiao Channel is for med during 1926~1958 with the channel experiencing persist ence erosion;from 1958 to 2002,the total volume of the Xinqiao Channel keeps stable with the volume of 5.02 10⁸m³.The pattern of 10 m contour has shaped to a certainty in 1926 and 5 m contour of the upper and lower parts of Biandansha has been joined.The change of sections of the Xinqiao Channel reflects its thalweg movement to the North Bank 1.1~2.8 km,its shape changes from Ushape to Vshape and its depth has been deepened.The evolution of the Xinqiao Channel from 1861 to 2002 is predicted that the channel will keep stable for a long time as soon as the Chang jiang Estuary maint ainsits config uration.