7997

• UCREFRP Catalog Number: 7997
• Author: Nash, L. L. and P. H. Gleick.
• Title: The Colorado River Basin and Climatic Change, The Sensitivity of Streamflow and Water Supply to Variations in Temperature and Precipitation.
• USFW Year: 1993.
• USFW - Doc Type: EPA 230-R-93-009,
• Copyright Material: NO

TABLE OF CONTENTS

ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., ii

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., vii

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 1

Background ............................................................ 1

Scenarios of Climate Change for Impact Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

METHODS OF ANALYSIS I: HYDROLOGIC MODELING ................................. 9

Background ............................................................ 9
Description of the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11

Model Calibration ............................................... . . . . . . .. 14

Application of Climate Scenarios to the NWSRFS Model. . . . . . . . . . . . . . . . . . . . . . . . . .. 17

RESULTS OF HYDROLOGIC MODELING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 21

Annual Runoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21

Seasonal Runoff . . . . . . . . . . . . . . . .-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28

Transient Scenario ...................................................... 32

GCM Runoff Scenarios .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Discussion of Hydrologic Modeling Results .................................... 34

METHODS OF ANALYSIS II: WATER-SUPPLY MODELING .............................. 43
Description of the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
Modeling Assumptions ................................................... 46

RESULTS OF WATER-SUPPLY MODELING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 51

Runoff ............................................................... 51

Reservoir Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ; . . . . . . . ., 54

Depletions and Deliveries ................................................. 62
Hydroelectricity Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 67

Uncontrolled Spills ...................................................... 67

Salinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 68

Time-Shifted Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 71
Summary and Discussion of Water-Supply Modeling Results ....................... 73

STUDY CONCLUSIONS ........................................................ 80

Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 88

REFERENCES ............................................................... 80

APPENDIX A: CALIBRATION RESULTS FROM THE NWSRFS MODEL. . . . . . . . . . . . . . . . . . . . .. A-1
APPENDIX B: THE LAW OF THE RIVER AND CRSS OPERATING PROCEDURES ............ B-1

APPENDIX C: ADDITIONAL RESULTS FROM THE CRSS MODEL. . . . . . . . . . . . . . . . . . . . . . .. C-1

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