3 A summary of UNICEF report on THE STATE OF THE WORLD’S CHILDREN 2005 Number of children in the world:2.2 billionNumber of children living in poverty:1 billionNumber of children in developing countries who livewithout adequate shelter640 millionNumber of children who have no access to safe water: one in five400 millionNumber of children who have no access to health services270 millionNumber of children who are out of school121 millionTotal number of children younger than five living in France, Germany, Greece and Italy:Total number of children worldwide who died in 2003 before they were five10.6 millionDaily toll of children in the world who die before their fifth birthday:29,158The number of children who die each day because they lack access to safe drinking water and adequate sanitation:3,900Many technical jumps are desperately needed …………Kurit Kara Consulting Engineers
4 World population from 1000 BC to 2300 BC Kurit Kara Consulting Engineers
6 Key findings of the Climate change report million people across Africa could face water shortages by 2020;More heavy rain events are very likely and more areas are likely to be hit by drought;Crop yields could decrease by up to 30% in Central and South Asia;Agriculture fed by rainfall could drop by 50% in some African countries by 2020;Kurit Kara Consulting Engineers
11 Adaptation Strategies Predict the Climate Change trendsNon-Structural ApproachesStructural ductilityPublic participation and Demand ManagementHolistic, integrated and Creative Approaches
12 Holistic Approach to adaptive design of hydraulic structures (Emami, 1997) Ensure a flexible and adaptive design in view of hydrosystems changes and the inherent uncertainties of water engineering.
13 Holistic Approach to adaptive design of hydraulic structures (Emami, 1997) Establish the interdependence and synergy of structural and non-structural approaches in design.
14 Holistic Approach to adaptive design of hydraulic structures (Emami, 1997) Adapt to the stochastic nature of river flow by integration of seasonal characteristics and river forecasting.
15 Holistic Approach to adaptive design of hydraulic structures (Emami, 1997) Design hydraulic structures to adapt to extreme events far larger than design parameters and remain inherently safe (structural ductility)
16 Holistic Approach to adaptive design of hydraulic structures (Emami, 1997) Enhance safety by 'designing' emergency and crisis management preceding the events and in real time for the structure and downstream population centers
23 CHARACTERISTICS RESULTS OF THE DEVELOPMENTSprotection levels are generally far below the economic optimumserious risk of loss of a large number of lives when an extreme event would occurcosts of only physical solutions are generally unaffordable
24 Protection levels are generally far below the economic optimum
29 Adaptive management Principles (2004) Adaptability (Change Threat to Opportunity)Flexible Decision Making (uncertainties)Monitoring and vigilanceLearning while doingApplication of New knowledge and technologiesKurit Kara Consulting Engineers
30 Adaptive management Principles (2004) Avoiding costly irreversible mistakesUpdating the ObjectivesKurit Kara Consulting Engineers
31 Adaptive management Principles (2004) ResilienceHarmony with Environment (step by step)Passive and Active AMStakeholders ParticipationEnhanced Real time reactionsKurit Kara Consulting Engineers
40 Vanyar Dam Spillway Value Engineering Workshop - 2003
41 VE Proposals and Results Enhanced Reservoir Operation Based on new rule curve, Seasonal forecasting and flood WarningReduced Cost (spillway length form 110 to 40m)Enhanced Dam SafetyDrastic Attenuation of floods in the reservoir
45 ConclusionsBased on experiences of application of AM in several larges projects it can be concluded that:Adaptive flood risk Management is an effective, efficient and versatile tool.AM emphasize of Non-structural approaches enhance adaptability, flexibility and sustainability.
46 Basic Requirements: Efficient and reliable Water Managers and experts Comprehensive and reliable Monitoring SystemPreparedness and Plans for EmergenciesRegulations to ensure flexibility and adaptabilityResources and Training
48 Kurit Kara Consulting Engineers با توجه به عدم قطعيتها بايستي بجاي راهبرد اجتنابي از راهبرد تطبيقي و مقاوم سازي استفاده نمود. در اين راستا مقاوم سازي سدهاي خاكي در مقابل سيلاب و استفاده از سدها و فرازبندي بتني ميتواند بيشترين ايمني را با حداقل هزينه تامين نمايد.Kurit Kara Consulting Engineers
49 Adaptability and Flexibility Description of a Fusegate Free-standing blocks,so called Fusegates,are installedside by sideacross the spillway sillSLIDE 3 – DESCRIPTION FG (1/2)A Fusegate unit is formed by 3 parts: the base, the bucket and the well.Downstream toe abutments prevent Fusegates from sliding, and seals avoid leakage from the reservoir.
50 Description of a Fusegate In such a waythat they forma watertight barrier.SLIDE 4 – DESCRIPTION (2/2)Fusegates are installed side by side on the spillway sill to form a watertight barrier.When water is below Fusegates’ crest, the Fusegates act just like a dam.
51 Working Concept – Normal Operation Common Floods are discharged between the Fusegates crest and the inlet levelsInlet wells are set at different elevationsAt this stage the chamber is emptyToe abutmentDrain holeBallastInlet wellBase chamberSLIDE 5 – NORMAL OPERATIONIn normal operating conditions,moderate floods spill over the Fusegate crest.Note that inlet wells are set at different elevations.
52 Working Concept – Exceptional Floods For exceptional floods only, the reservoir level increases until the water begins spilling over the inlet lips.SLIDE 6 – EXCEPTIONAL FLOODS (1/2)For exceptional floods only,the water spills over the Fusegates and into the well;the drain hole cannot discharge the extra water and uplift pressure increases.Uplift pressure builds up in the chamber.Drain holes can not discharge all the flow.
53 Working Concept – Exceptional Floods Uplift pressure causes the Fusegate to overturn.SLIDE 7 – EXCEPTIONAL FLOODS (2/2)The uplift pressure, combined with hydrostatic pressure, is sufficient to overcome the restraining forces and causes the rotation of the unit off the spillway. The Fusegate is then washed away from the sill.If the water level continues to rise after the first breach, more Fusegates will rotate, according to their well level, which is set to a pre-determined water level.Eventually, no more unit may remain on the sill and the spillway is free to pass the original maximum design flood.
54 Environmental Impacts Progressive release of the flood waterOutflow not exceeding the inflowTip off probability = very low (usually 1 in 100 years and above)Maximum Water Level in the reservoir not raisedGeneral principlesTipping stagesFlood Routing through a Fusegated SpillwayPMFBlue curve: inflow / Red curve: outflowSLIDE 10 – ENVIRONMENTAL IMPACTSFusegates are engineered in such a way that negative impacts of the spillway rehabilitation on river regimes and reservoir elevations are mitigated.The Fusegate solution ensures that there will be no sudden increase in the outflow and that the MWL will never be raised, which is very important for the downstream population.The diagram shows the flood routing hydrograph of a fusegated spillway which has the same degree of reliability as an ungated spillway.
55 Increase Storage Capacity 1. The sill is modified slightly2. Fusegates are used to increase the Full Supply Level3. No increase in Maximum Water LevelNew Full Supply LevelSLIDE 11 – APPLICATION - Increase Storage CapacityThe Fusegate System has a wide range of applications.One of them is to increase the dam storage capacity.First, the sill is modified slightly.Then, we install Fusegates to increase the Full Supply Level without increasing the MWL.
56 Terminus Dam, CA – USA Main characteristics Purpose: Flood attenuation Discharge capacity: 8500 m3/sSpillway length: 93 mFusegate height: 6,50 mNumber of units: 6Former storage capacity: 173 Mm3New storage capacity: 226 Mm3Storage increase: 30%SLIDE 12 – TERMINUSA good example of this type of application is the Terminus Dam in California, owned by the US Corps of Engineers.By using Fusegates for the auxiliary spillway enlargement, the existing storage has been increased by more than 50 Mm3/s.The Fusegate alternative provided 6M dollars of savings on the project.Without the Fusegate option, the project would not have been realized.
57 Increase Discharge Capacity 1. The spillway is not able to pass the design flood below the MWL.2. The spillway sill is lowered in order to pass the design flood.3. The storage capacity of the dam is recovered by installing Fusegates.4. The storage capacity could even be increased by installing higher Fusegates.Full Supply LevelSLIDE 14 – APPLICATION – Increase Discharge CapacityAnother range of application is to increase the discharge capacity of an undersized spillwaywithout lowering the Normal Water Level, in other words, without sacrificing the water storage.The WML is again unchanged.Moreover, it is possible to increase the storage capacity of a dam while rehabilitating its undersized spillway.
58 Shongweni Dam – South Africa Main characteristicsPurpose: RecreationStorage capacity: 6,6 Mm3Spillway length: 125,0 mFusegate height: 6,5 mNumber of units: 10Former discharge capacity: 1245 m3/sNew discharge capacity: 5000 m3/sDischarge capacity increase: 300%SLIDE 15 – SHONGWENI DAMAt Shongweni, the original design flood was approximately 1250 m3/s and has been increased to 5000 m3/s with Fusegates to fulfill safety requirements.1995 Most outstanding Civil Engineering Achievement in Technical Excellence Award
59 Dam Safety Strategy in Switzerland Kurit Kara Consulting Engineers
60 Kurit Kara Consulting Engineers بولتن ICOLD در مورد كاهش ريسـك سدهـا بوسيله روشهـاي غيـر سازهايKurit Kara Consulting Engineers
61 Kurit Kara Consulting Engineers Levees only!Kurit Kara Consulting Engineers