Optimal Drought Management Using Sampling Stochastic Dynamic Programming with a Hedging Rule

This study develops procedures that calculate optimal water release curtailments during droughts using a future value function derived with a sampling stochastic dynamic programming model. Triggers that switch between a normal operating policy and an emergency operating policy (EOP) are based on initial reservoir storage values representing a 95% water supply reliability and an aggregate drought index that employs 6-month cumulative rainfall and 4-month cumulative streamflow. To verify the effectiveness of the method, a cross-validation scheme (using 2,100 combination sets) is employed to simulate the Geum River basin system in Korea. The simulation results demonstrate that the EOP approach: (1) reduces the maximum water shortage; (2) is most valuable when the initial storages of the drawdown period are low; and (3) is superior to other approaches when explicitly considering forecast uncertainty.

[1]  Jery R. Stedinger,et al.  Reservoir optimization using sampling SDP with ensemble streamflow prediction (ESP) forecasts , 2001 .

[2]  Kirk S. Westphal,et al.  Drought Management Planning with Economic and Risk Factors , 2007 .

[3]  Alessandro Ancarani,et al.  Susceptibility of Water Supply Reservoirs to Drought Conditions , 1998 .

[4]  Jhih-Shyang Shih,et al.  Water supply operations during drought: A discrete hedging rule , 1995 .

[5]  R. Heim.  A Review of Twentieth-Century Drought Indices Used in the United States , 2002 .

[6]  M. Bayazit,et al.  Effects of hedging on reservoir performance , 1990 .

[7]  Wen-Cheng Huang,et al.  A drought early warning system on real‐time multireservoir operations , 2004 .

[8]  Sharon A. Johnson,et al.  Comparison of two approaches for implementing multireservoir operating policies derived using stochastic dynamic programming , 1993 .

[9]  T. R. Neelakantan,et al.  Hedging Rule Optimisation for Water Supply Reservoirs System , 1999 .

[10]  A. Steinemann.  DROUGHT INDICATORS AND TRIGGERS: A STOCHASTIC APPROACH TO EVALUATION 1 , 2003 .

[11]  A. Viña,et al.  Drought Monitoring with NDVI-Based Standardized Vegetation Index , 2002 .

[12]  R. P. Oliveira,et al.  Operating rules for multireservoir systems , 1997 .

[13]  Jared L. Cohon,et al.  A Programming Model for Analysis of the Reliability, Resilience, and Vulnerability of a Water Supply Reservoir , 1986 .

[14]  V. Klemeš.  Value of information in reservoir optimization , 1977 .

[15]  B. Shafer,et al.  Development of a surface water supply index (SWSI) to assess the severity of drought conditions in snowpack runoff areas , 1982 .

[16]  Young-Oh Kim,et al.  Optimizing Operational Policies of a Korean Multireservoir System Using Sampling Stochastic Dynamic Programming with Ensemble Streamflow Prediction , 2007 .

[17]  A. Draper.  Implicit Stochastic Optimization with Limited Foresight for Reservoir Systems , 2001 .

[18]  K. Srinivasan,et al.  Effect of Hedging on Over-Year Reservoir Performance , 1998 .

[19]  Jery R. Stedinger.  Comment on ‘Value of information in reservoir optimization’ by V. Klemeš , 1978 .

[20]  Ximing Cai,et al.  Hedging rule for reservoir operations: 2. A numerical model , 2008 .

[21]  T. McKee,et al.  THE RELATIONSHIP OF DROUGHT FREQUENCY AND DURATION TO TIME SCALES , 1993 .

[22]  B. F. Sule,et al.  Stochastic dynamic programming models for reservoir operation optimization , 1984 .

[23]  Wen-Cheng Huang,et al.  Drought early warning system in reservoir operation: Theory and practice , 2005 .

[24]  Richard N. Palmer,et al.  Value of Seasonal Flow Forecasts in Bayesian Stochastic Programming , 1997 .

[25]  Nien-Sheng Hsu,et al.  Optimization of Reservoir Management and Operation with Hedging Rules , 2003 .

[26]  J. Dracup,et al.  An aggregate drought index: Assessing drought severity based on fluctuations in the hydrologic cycle and surface water storage , 2004 .

[27]  Daniel P. Loucks,et al.  Reliability, resiliency, and vulnerability criteria for water resource system performance evaluation , 1982 .

[28]  J. Stedinger,et al.  Sampling stochastic dynamic programming applied to reservoir operation , 1990 .

[29]  K. Srinivasan,et al.  Evaluation and selection of hedging policies using stochastic reservoir simulation , 1996 .

[30]  Jhih-Shyang Shih,et al.  Water‐Supply Operations during Drought: Continuous Hedging Rule , 1994 .

[31]  Ximing Cai,et al.  Hedging rule for reservoir operations: 1. A theoretical analysis , 2008 .

[32]  J. Lund,et al.  Optimal Hedging and Carryover Storage Value , 2004 .

[33]  Young-Oh Kim,et al.  Combining Rainfall-Runoff Model Outputs for Improving Ensemble Streamflow Prediction , 2006 .