Part A Flood Risk Management in Yellow River Delta1 Introduction 3
1.1 The Yellow River 3
1.2 Yellow River Delta 4
1.3 Socio-economic development in Delta 5
2 Main problems on flood risk management 6
2.1 Relatively instability of the river course 6
2.2 Continuous sedimentation and imperfect flood defense works 7
2.3 Storm surge hazard and disintegrated defense system 7
2.4 Land loss 8
2.5 Competition between different interests in terms of land use and management 9
3 Analysis of the problems 10
3.1 The characteristics of water and sediment 10
3.2 The sedimentation in the Lower Yellow River and the delta area 11
3.3 Decrease of water and silt inflow to delta in recent years 13
3.4 Regional development and land use changes 14
3.5 Flood risk in the Lower Yellow River and the delta area 17
3.6 Risk analysis of storm surge hazard 19
4 Possible solutions 23
4.1 Sediment reduction 23
4.2 Alternatives of extending the running life for current course 29
4.3 Spare course plan 37
Reference 40
Part B Flood Risk Management in Rhine River Delta 40
1 Introduction 43
1.1 The Rhine 43
1.2 The Rhine Delta 44
2 Main problems on flood risk management 45
2.1 Increasing flood risk 45
2.2 High cost in defense maintenance 48
3 Analysis of flood risk 48
3.1 Characteristics of Rhine 48
3.2 Flood defense standard(Rhine):design discharge and water level 54
3.3 Floods and causes of the river 58
3.4 Storm surge hazard 63
3.5 Expectation of sea level rise and river discharge increase 69
3.6 Flooding and measures taken 71
3.7 Flood defenses system and safety 75
4 Possible solutions 82
4.1 Reduction of the flow of water to the Rhine Branches 82
4.2 Storage of water along the Rhine Branches 84
4.3 Discharge of water via the Rhine Branches 87
Reference 94
Part C Flood Risk Management in Mississippi River Delta 94
1 Introduction of Mississippi River Delta 99
1.1 Mississippi River system 99
1.2 The forming of Mississippi River Delta 100
1.3 Physical conditions 102
1.4 Socio-economic devemopment 103
2 Problems identification 105
2.1 Flood threat from the Mississippi River 105
2.2 Frequent hurricane and tropical storm and imperfect hurricane protection system 106
2.3 Tremendous coastal erosion 109
2.4 Land subsidence 110
2.5 Insufficient institutional attention and imperfect management 111
3 Analysis 112
3.1 Climate change in Coastal Louisiana 112
3.2 Flood protection system in the Lower Mississippi River 113
3.3 The impacts of intervention of human on the river 118
3.4 The causes and distribution of the wetland loss 120
3.5 Coastal defense 122
3.6 The impact of Hurricane Katrina 124
4 Possible solutions 129
4.1 Make a Master Plan for coastal protection and restoration 129
4.2 Block the openings of hurricane protection in New Orleans 132
4.3 A New Approach to Levee Building 133
4.4 Land use management for smart development and minimizing risk 134
4.5 Relocation of freshwater and sediment for wetland restoration 136
References 137
Part D Comparison and Recommendations 141
1 Comparison 141
1.1 Physical condition 141
1.2 Socio-economic aspects 142
1.3 Main problems 144
1.4 Human intervention on the river system and impacts 146
1.5 The roles of the institutions in flood management 148
1.6 Flood defense system and flood risk management 151
1.7 Non-structural measures for flood mitigation 152
1.8 Flood incident management 153
2 Recommendations 156