Sediment Model and the Three Gorges Project

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Sediment Model and the Three Gorges Project

• MPS
• Siu Lan Zhang
• April 30, 1999

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Introduction

• Dams
• Sedimentation in a Reservoir
• Model for Sediment Deposit in the Reservoir
• The Three Gorges Project

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Dams

• Definition
• Structure of dams
• Bottom Outlet
• Spill way

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Sedimentation

• Characteristics
• Deposition
• Flushing
• Sampling

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Sediment Characteristics

• 6 orders of grain size classes
• boulders
• cobbles
• gravel
• sands
• silt
• clay

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Sediment Deposition

• Three main deposit zone
• Four basic type deposit patterns

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Sediment Deposition

• Three main deposit zone
• Topset beds
• foreset deposit
• bottomset beds
• Four basic type deposit patterns

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Sediment Deposition

• Three main deposit zone
• Four basic type deposit patterns
• delta depsoit
• wedge_shaped
• tapering deposits
• uniform depoist

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Sediment Flushing

• Two general categories for flushing Techniques
• Flushing Procedures

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Sediment Flushing

• Two general categories for flushing Techniques
• empty or free-flow flushing
• flood season
• non-flood season
• pressure flushing
• Flushing Procedures

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Sediment Flushing

• Two general categories for flushing Techniques
• Flushing Procedures
• Drawdown
• Erosion
• Refill

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Sediment Sampling

• Suspended sediment sampling
• suspended sediment sampler
• bedload sampler

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Model for Sediment Deposit in a Reservoir

• Parameters
• Model

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The Model
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The Three Gorges Project

• Background
• Yangtze River
• Three Gorges Dam
• Prediction

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Yangtze River

• The third longest river in the world
• 6,300 kilometers from Tibet to the East China sea
• ranks third in volume of flow
• average flow every year is 451 billion cubit
  meter
• The forth sediment river in the world

• average carries 535 million tons sediment every
  year
• mean concentration is 1.19 kg/m3

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Three Gorges Dam

• Began in 1993, and going to finish in 2010
• 1.8 million people need to resettle
• The dam has 183 m height, 2150 m long
• The reservoir is 500-600 km long

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Prediction

• Input data
• Result
• Compare the result to the data from other document

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Acknowledgements

• Professor Carol Shilepsky
• Professor Steven Rae
• Professor Sally Sievers