UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM - - PowerPoint PPT Presentation

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UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM USING PROBABILISTIC OPERATION AND MODELLING APPROACH

Research Fellow: Mulugeta Bereded Zelelew Supervisor: Associate Prof Knut Alfredsen Department of Hydraulic and Environmental Engineering October 28, 2008

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CONTENTS

1. STATUS 2. BRIEF BACKGROUND AND RESEARCH OBJECTIVES 3. SHUFFLED COMPLEX EVOLUTION (SCE-UA), GENERAL PURPOSE GLOBAL OPTIMIZATION ALOGORITHM 4. IMPLEMENTATION OF THE SCE-UA FOR HBVPINE HYDROLOGICAL MODEL 5. WHAT IS NEXT? 6. COMMENT

Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM…

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• 1. STATUS:
• The final plan of the research was approved in June 2008

by the Doctoral committee “UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM USING PROBABILISTIC OPERATION AND MODELLING APPROACH”

Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM…

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2. OBJECTIVES OF THE RESEARCH:

• The general objective of the research is to investigate the key

processes, interactions, inputs and interpretation of the system outputs

• The specific objectives of the research are:
• Investigate inflow estimation techniques
• Investigate sources of uncertainty, the significance and

propagation in operational hydrology

• Bring the issue of risk into the operation of multipurpose

water resource projects

• Investigate approaches to improve the operation of water

resources systems to ensure infrastructural sustainability, dam safety and operational reliability

• To get an overview of uncertainty propagation and risk in
• perations of water resources systems

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• 3. SHUFFLED COMPLEX EVOLUTION ALGORITHM (SCE-UA):
• A shuffled Complex Evolution algorithm has been

implemented for HBVPINE hydrological model, which will be applied for the research

• SCE-UA was Developed by Qingyun Duan at the

Department of Hydrology and Water Resources, University

• f Arizona, 1991
• It combines the strength of CRS algorithm with concept of

competitive evolution

• General purpose global optimization program

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• Shuffled Complex Evolution (SCE) Algorithm (Duan et al

(1992): A method for finding Global Optimum Random Parameter Sets as a starting point and then allowed to ‘evolve’ over successive iterations (Simplex Method) Ranking and Shuffling Containing ‘better’ and ‘worse’ points (New parameter Set) The shuffling in SCE allows Global information about the response surface to be shared which makes the algorithm responsive to the presence of multiple local optima. The procedure continues until a Global Optimum fitness is reached; Figure SCE

Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM…

7 x10 x9 x8 x7 x6 x5 x4 x3 x2 x1 x9 x7 x5 x3 x1 x10 x8 x6 x4 x2

Figure-2-1: Flow chart of SCE-UA Method, Source: Duan Q.Y., et al, 1992

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Figure-2-2: Flow chart of the Competitive Complex Evolution (CCE) strategy, Source: Duan Q.Y., et al, 1992

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Reflection Expansion Contraction Shrinking

Simplex Procedure:

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SCE-UA

• Setting initial P. value
• Parameter Sampling
• Triggering the HM
• Sorting SP
• Partitioning
• Evolving
• Sorting & Replacing

Model Parameters Model Outputs Convergence Criteria Global Optimum Model Parameters

Yes No Figure-3: Flow Chart-Implementation of SCE-UA for HBVPINE

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• 4. Implementation of SCE-UA Algorithm for HBVPINE:

Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM… HYDROLOGICAL MODEL (HM)

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i. Global Parameter and Parameter Space – Initial Simulation without screening Figure-4: Output from HBV-SCE tool (17 Parameters)

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• ii. Parameter Space – Simulation with screening

Figure-5: Output from HBV-SCE tool

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• iii. Global Optimum Parameter Value

Figure-6 : Output from HBV-SCE tool

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Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM…

• iv. Parameter Interaction and Correlation Studies

Figure-7: Output from HBV-SCE tool

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• 5. What is Next?
• Extensive study of the regional pattern of model

parameters

• Develop approaches for transferring model

parameters to Ungauged catchments

• Investigate the nature and propagation of uncertainty
• n the model output
• 6. Comment:
• The SCE-UA algorithm is a general purpose global
• ptimization procedure, could be useful for similar

problems

• The implementation is relatively easy
• Has been used widely , has research outputs and

references

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THANK FOR YOUR ATTENTION!!

Mulugeta, UNCERTAINTY PROPAGATION AND RISK ANALYSIS IN WATER RESOURCE SYSTEM…