The dynamic Remote Sensing monitoring of the east four outlets in Pearl river estuary and its application on offshore engineering
Xu Xiangxiang, Chen Xuelian, Luo Dan
The Scientific Research Institute,
Pearl River Resources Commission,
Min. of Water Resources, China
Abstract
In this paper described are the dynamic monitoring of the flow field suspended sediment distribution beachland resources and its development by means of satellite remote sensing information processed with computer and its qualitative and quantitative interpretation .The recent change of water sediment transport in analyzed through a dynamic comparison of the features in multi time phase images The scoring and silting on the shoals at the outlets are analyzed through a comparison of historical survey data and present remote sensing data The effect of existing works on the water sediment transport and the hydro-dynamics at and out of the outlets is analyzed by means of monitoring the progress of the exclamation projects at the outlets . And proposals are put forward for outlet training reasonable development of the beachland and the optimal time of exploitation.
Introduction
The east four outlets (Humen, Jiaomen, Hongqimen and Hengmen ) and the shallow sea area out of them compose Lingdingyang Bay, which is the biggest estuary bay situated in front of the east part of Pearl River Delta with a trumpet it catches the water and sediment coming from the outlets lets the tidal water come in from and go out to the South China sea. The hydro dynamics is very complex resulting in an active sedimentation which yields rich beach land resources providing conditions for land extension but is unfavorable for flood disposal irrigation drainage and navigation therefore the improvement and development of the east four outlets is an urgent and heavy task .In recent years computer processing and optical processing the multi time phase suspended sediment images we analyze the image feature and their dynamic changes to research the flow field suspended sediment distribution and topography of shoals Some phenomenon and laws difficult to be find in traditional way are revealed and important information is provided for the planning and construction of estuary improvement works. Part of the results in this research work has been adopted by production sectors to adjust the plan of the projects certain social and economic benefit is yielded.
Remote Sensing information and its processing
The remote sensing information used in this research includes color infrared images in 16 time phase from MSS TM and China Land sat in Which TM CCT data and color infrared images taken in 1986 to 1988 are taken for information's about the present situation of the east four outlets while the MSS images taken in 1970's are taken for dynamic comparison information.
Computer image processing is involved in the quantitative analysis and mapping of the remote sensing information and survey data including radiation value rectification geometric rectification linear contrast stretch correlation analysis of remote sensing and field survey data digital enlargement digital mosaic and color composition In addition optical processing method is used in the color enlargement of images at the scales of 1:50000 and 1:100000 with DS 1840 color Enlarger and also in superposing of remote information on geographic information etc.
