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ANALYSIS OF bathymetric FEATURES USING SARIMAGE: AN EXAMPLE FROM THE SOUTHERN NORTH SEA

Chinese Journal of Oceanology and Limnology 1998年第2期16卷 128-136页

作者：金梅兵张杰袁业立

This paper presents the authors ’ simulation model of the bathymetric features on SAR image and their inversion model for detecting bathymetric features by SAR image. A function G proportional to the radar backscatter cross section σ0 is defined to simulate the radar image gray tone level based on Yuan (1997). The inversion method is the minimum deviation solution proposed by Jin and Yuan (1997b). Tests with actual data of the Seasat SAR image and the sea chart of the southern North Sea showed that the models could simulate and detect the basic bathymetric features.

关键词： simulation inversion bathymetric feature SAR image

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3D Modal Solution for Tidally Induced Lagrangian Residual Velocity with Variations in Eddy Viscosity and Bathymetry in a Narrow Model Bay

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Journal of Ocean University of China 2019年第1期18卷 69-79页

作者： DENG Fangjing JIANG Wensheng VALLE-LEVINSON Arnoldo FENG Shizuo Physical Oceanography Laboratory/CIMST Ocean University of China and Qingdao National Laboratory for Marine Science and Technology Laboratory of Marine Environment and Ecology Ocean University of China Department of Civil and Coastal Engineering University of Florida

In this study, we examine the results obtained by the Finite-volume Coastal Ocean Circulation Model(FVCOM) regarding the effects of eddy viscosity and bathymetry on the three-dimensional(3 D) Lagrangian residual velocity(LRV) in a narrow bay. The results are cast in terms of two nondimensional numbers: the ratio of friction to local acceleration(δ) and the ratio of the minimum depth over shoals to the maximum depth in the channel(ε). The ratio δ depends on the eddy viscosity and mean depth. For a given eddy viscosity, when ε > 0.5, the along-estuary LRV tends to be vertically sheared and when ε < 0.5, the exchange is laterally sheared. When ε << 1, the structure of the 3 D, depth-integrated, and breadth-averaged LRV changes only slightly as δ increases. For ε values between 0.33 and 0.5, the structure of the 3 D LRV is mainly laterally sheared. In the same ε range, the 3 D and depth-integrated LRV exhibit reversed structures from high to low δ values. In addition, the breadth-averaged LRV weakens the typical twolayered circulation when δ decreases. When ε is 1, the two-layered vertical structure reverses direction, and a three-layered vertical structure develops in the outer bay as δ decreases.

关键词： eddy viscosity bathymetric effects Lagrangian residual velocity 3D narrow bay

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Mitigating the Impact of Climate Change by Reducing Evaporation Losses: Sediment Removal from the High Aswan Dam Reservoir

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American Journal of Climate Change 2017年第2期6卷 230-246页

作者： Emad Elba Brigitte Urban Bernd Ettmer Dalia Farghaly Faculty of Sustainability Sciences Institute of Ecology Landscape Change Division LEUPHANA University of Lüneburg Lüneburg Germany Department of Water and Waste Management: University of Applied Sciences Magdeburg-Stendal Magdeburg Germany

Scientists in Egypt are particularly interested in the sustainable management of water and land resources. Global climate change will have a dramatic impact on the Egyptian water and land resources as well as its coastline and agriculture. Egypt is likely to become one of the most vulnerable countries in the world in the next several decades. Many climate scenarios predict that climate change will severely affect rainfall in the Nile basin and the flow of the Nile River in general and the High Aswan Dam Reservoir (HADR) in particular. Global warming and the higher temperatures will lead to higher evaporation rates, which, in turn, will result in less water availability at the HADR. Egypt’s Ministry of Water Resources and Irrigation predicts that the evaporation losses will, compared to the mean annual evaporation rates for the last 30 years, be approximately 3% to 10% higher by the year 2100. Since the construction of the High Aswan Dam fifty years ago, high sediment loads are a tremendous problem. 6.6 Billion Cubic Meter (km3) of sediments were deposited in the HADR during this period. The sediment has raised the lakebed level as well as the water level and caused a larger surface area. These developments have decreased the storage capacity of HADR and have increased the evaporation rate. The presented paper investigates the impact of lowering the lakebed by removing sediments from the HADR with a distinct emphasis on evaporation losses. A digital elevation model for the HADR was developed to describe the hydrological characteristics and to assess the consequences of removing sediment deposits. The results show that the removal of sediments will reduce evaporation losses by about 1.1 km3 projected for 2100, which represents 6.5% of the total projected evaporation losses.

关键词： bathymetric Survey Climate Change DEM Evaporation Losses GIS Sediments

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Adequate Advance Provided by a Familiar Fluid Dynamic Balance Principle to Tools and Techniques for Water Quality Interpretation: Experienced in Yaoundé(Cameroun) 2<sup>nd</sup>Supply Dam

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Open Journal of Marine Science 2015年第1期5卷 158-168页

作者： Kom Olivia Estelle Mbane Biouele César Laboratory of Earth’s Atmosphere Physics Department of Physics University of Yaoundé IYaoundé Cameroun

In a fluid (liquid or gas) at rest, the isobars are horizontal surface. This fluid dynamic balance theorem provides adequate advance to tools and techniques for Water Quality Interpretation. We deal in this paper, with an effective way of exploiting the familiar communicating containers’ principle. That formally consists on providing water samples from desired depths of rivers, oceans, retention dams, etc. The prevailing limiting factor to achieve this feat is the length of our sampling pipes named Mbane bathymetric Tube (MBT) designed for this purpose when rivers or retention dams are very deep. Providing drinking water to urban growing populations is a challenge that no government can escape. Therefore, improving the tools and techniques for water quality interpretation is an adequate advance for drinking water managerial techniques because this allows the recovery of contaminated water which abounds on the earth by acquiring appropriate wastewater treatment stations. The aim of the manuscript is to provide a brief theoretical description of our designed sampling equipment to allow everyone who is going to use it to solve in advance problems brought by Archimedes’ pressure force when experiencing the sampling pipes. Archimedes’ pressure force acts mainly when moving the sampling pipes to water lower levels and then opening its protective cover which allows the communication with the supply dam.

关键词： Communicating Containers’ Principle Water Samples from Desired Depths of Rivers Mbane bathymetric Tube (MBT) Tools for Water Quality Interpretation

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An Integrated Approach to Hydrographic Surveying of Large Reservoirs—Application to Tarbela Reservoir in Pakistan

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Open Journal of Modern Hydrology 2014年第4期4卷 156-163页

作者： Sarfraz Munir Muhammad Armaghan Arsalan Babrus Water Resources Engineering Program University of Kurdistan Hewler Kurdistan Region Iraq MM Pakistan (Pvt.) Ltd. Lahore Pakistan Water and Power Development Authority Tarbela Dam Project Haripur Pakistan

Hydrographic surveying in reservoirs is a key activity in order to collect data for a variety of purposes like estimation of storage capacity, rate and pattern of sediment deposition, movement of underwater sediment delta and reservoir routing, etc. These parameters play a pivotal role in any planning, management and operation activity of the reservoirs. Traditional approaches to perform hydrographic surveying in Indus Basin are time consuming, laborious, comparatively inaccurate and costly. As water resources are under immense pressure due to a variety of factors, such inefficient methods are not acceptable for efficient water management. In this study, an integrated approach for hydrographic surveying is introduced and evaluated in terms of its efficiency in comparison with the traditional methods of hydrographic surveying. The approach develops an integrated environment of hydrographic surveying comprising human, hardware and software. The process of surveying starts from in-house planning using specialized geo-spatial softwares. Then, on site a combination of computer hardware, echosounder, differential global positioning system (DGPS), survey vessel and survey crew is made. Post-processing is performed after conducting a survey in order to improve quality of data by filtering errors and producing the end product like reservoir underwater terrain, development of reservoir stage-area and stage-storage relationships, etc. The study was applied to Tarbela Reservoir, Pakistan.

关键词： Hydrographic Survey bathymetric Survey Tarbela Reservoir Reservoir Capacity Differential GPS Echosounder

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