The Controlled Flood in Grand Canyon

Title Page......Page 3
Copyright......Page 4
Contents......Page 5
Foreword......Page 7
Preface......Page 9
1. INTRODUCTION......Page 11
2.3. Riparian Vegetation......Page 14
3.1. The Colorado River drainage......Page 15
3.3. Sediment  Data Colfeclion......Page 16
4.2. River Discharge......Page 17
4.3. Aggradation of Debris  Fans......Page 18
4.4. Sediment Mass Balance and Bed  Scour......Page 19
4.5. Sand-Bar Erosion......Page 20
4.7. Temperature, Clarity, and Aquatic Productivity......Page 23
4.8. Adaptation of  Native Fish Populations to the Post-Dam River......Page 25
REFERENCES......Page 26
1. INTRODUCTION......Page 32
2. THE  EVOLUTION OF ADMINISTRATIVE OPINIONS  ABOUT THE ROLE OF FLOODS INSTRUCTURING THE RIVER ECOSYSTEM......Page 33
3.1. Physical Resources......Page 35
4. THE INTERFACE BETWEEN EMERGING SCIENTIFIC UNDERSTANDING AND PUBLIC POLICY BETWEEN 1988 AND 1996......Page 37
5. PRELUDE TO THE FLOOD  OF 1996......Page 38
6. PURPOSES AND OBJECTIVES  OF  THE FLOOD......Page 39
8. THE FLOOD AS IT OCCURRED......Page 41
REFERENCES......Page 43
1. INTRODUCTION......Page 46
2. METHODS......Page 48
2.3. Particle-Size Distributions, Constrictions, and Stream Power......Page 50
3.2. Armoring of the Distal Margins of  Debris  Fans......Page 53
3.3. Constriction, Water-Surface Fall, and  Stream Power......Page 54
3.4. Changes in Navigability  of Rapids......Page 55
4. DISCUSSION AND CONCLUSIONS......Page 56
REFERENCES......Page 60
1. INTRODUCTION......Page 61
2.3. A New Method For Estimating Fd/Ws......Page 62
2.4. Velocities and Drag Coefficients......Page 64
3.3. Field Measurements at 127.6 mile and Lava Falls Rapid......Page 65
3.4. Particle tracking at Lava Falls Rapid......Page 66
4.3. Entrainment of Particles at Lava Falls  Rapid......Page 68
4.5. Entrainment and Transport of Particles on Other Debris Fans......Page 70
5. DISCUSSION AND CONCLUSIONS......Page 73
APPENDIX I - EQUATIONS USED TO CALCULATE INCIPIENT MOTION FOR SLIDING WITHOUT ROTATION ON ONE ARBITRARILY ORIENTED PLANAR SURFACE......Page 76
REFERENCES......Page 77
1. INTRODUCTION......Page 79
2. PRE- AND POST-DAM  SEDIMENT SUPPLY......Page 80
4.1. Grand Canyon Gage Reach......Page 81
5.1. Grand Canyon Gage Reach......Page 83
5.2. 122-Mile Eddy......Page 85
5.3. Mechanics of Suspended- Sediment Concentration Decrease and Coarsening......Page 86
6.1. Deposits of the 1996 Flood......Page 100
6.2. Deposits of Pre-Dam Floods and Other Unsteady High Flows......Page 101
7. CONCLUSIONS......Page 103
8. IMPLICATIONS FOR RIVER MANAGEMENT......Page 104
REFERENCES......Page 105
1. INTRODUCTION......Page 107
2. MEASUREMENT PROGRAM......Page 108
3.1. Topography......Page 110
3.2. Velocity Field......Page 111
3.3. Suspended Sediment......Page 118
4. SUMMARY AND CONCLUSIONS......Page 122
REFERENCES......Page 123
1. INTRODUCTION......Page 124
1.1. Morphology of Fan-Eddy  Complex......Page 126
2.1. Selection of Study  Eddies......Page 127
2.2. Bathymetric Surveys......Page 128
4. TOPOGRAPHIC EVOLUTION OF EDDY SAND DEPOSITS......Page 129
4.1. Spatial Pattern of Scour and  Fill......Page 130
4.2. Mass Movements of Sand  Bar Deposits......Page 134
5. CONCLUSION......Page 135
REFERENCES......Page 136
1. INTRODUCTION......Page 138
3. MODEL......Page 139
4. HYDRAULIC PARAMETERIZATION AND BOUNDARY CONDITIONS......Page 142
5. MODEL RESULTS......Page 143
6. SUMMARY AND CONCLUSIONS......Page 150
REFERENCES......Page 151
1. INTRODUCTION......Page 153
1.2. Geomorphology Associated with Grand  Canyon Campsites......Page 154
1.3. Historical Changes to Grand Canyon  Campsites......Page 156
2.2 Reconnaissance Analysis of Changes in Campsite Area Immediately After Flood......Page 158
3.1. Inventories of Campsites......Page 159
3.2. Reconnaissance Analysis of Changes in Campsite Area Immediately  After Flood......Page 160
4. DISCUSSION......Page 161
REFERENCES......Page 164
1. INTRODUCTION......Page 166
2.2. Recent Topographic Surveys......Page 167
3.2. Data Collection......Page 168
3.3. Data Analysis......Page 170
4.1. Overview of Changes, February-April 1996......Page 171
4.2. Responses at Specific  Bars, February-April 1996......Page 172
4.3. Post-Flood Changes, April 1996-September 1997......Page 177
5.2. Depositional Trends and Accommodation Space......Page 180
5.4. Channel-Stored Sediment......Page 183
7. CONCLUSIONS......Page 186
REFERENCES......Page 187
1. INTRODUCTION......Page 189
2. FAN-EDDY COMPLEXES......Page 190
3. THE STUDY REACHES......Page 191
4.1. Mapping  of Sand  Deposits......Page 194
4.2. Measuring Topographic Change of  Sand Deposits......Page 197
4.3. Analysis of Error in Determining Erosion and Deposition......Page 198
5.2. Spatial Characteristics  of Fine-Grain  Flood Deposits......Page 199
5.3. Variation in the Area of Flood Deposits and  the Areas  of Significant  Erosion and  Deposition......Page 201
6. DISCUSSION AND CONCLUSIONS......Page 203
REFERENCES......Page 206
1. INTRODUCTION......Page 208
2. METHODS......Page 209
2.6. pC02 Calculations......Page 210
3.1. pH and 02 Concentration......Page 211
3.2. Flow Velocity......Page 212
3.5. Stoichiometry......Page 213
4. DISCUSSION......Page 215
4.1. Greatest Dally Ranges Not Measured at the Downstream Station......Page 216
4.2. The Peaks of the Daily Ranges at the Downstream Station Occurred Long After Sunset......Page 217
REFERENCES......Page 218
1. INTRODUCTION......Page 219
2.2. Sample Collection and Metabolism Measurements......Page 220
3. RESULTS AND DISCUSSION......Page 221
REFERENCES......Page 224
1. INTRODUCTION......Page 226
2. THE HYPORHEIC ZONE AND RIPARIAN GROUND WATER NUTRIENT AVAILABILITY......Page 227
2.1. Nutrient Availability in  the Colorado River in Grand Canyon......Page 228
3.1. Field and Laboratory Analyses......Page 229
4.1. Flood Deposition Patterns......Page 231
4.2. Short-Term Biogeochemical Responses  to  Flooding......Page 235
4.3. Post-Flood Seasonal Changes in Groundwater Compositions......Page 236
4.4. Statistical Analysis of Temporal Changes in Composition......Page 237
4.5. Changes Following Flooding in Surface-Water Compositions......Page 239
5. SUMMARY AND CONCLUSIONS......Page 241
REFERENCES......Page 242
1. INTRODUCTION......Page 244
3.2. Backwater Sediment Composition......Page 245
3.4. Sediment/Benthic Invertebrate Correlations......Page 246
4. DISCUSSION......Page 247
5. CONCLUSIONS......Page 249
REFERENCES......Page 250
1. INTRODUCTION......Page 252
2.2. Macroinvertebrates......Page 253
3.1. Periphyton and Aquatic Macrophytes......Page 254
3.4. Rainbow trout......Page 255
4. DISCUSSION......Page 256
4.1. Periphyton and Aquatic Macrophytes......Page 257
4.3. Rainbow trout......Page 258
REFERENCES......Page 259
1. INTRODUCTION......Page 262
3.1. Physico-Chemical Measurements......Page 263
3.3. Organic Drift Collections......Page 264
3.4. Source of Organic  Drift During the Experimental Flood......Page 265
4.1. Physico-Chemical Analyses......Page 266
4.2. Patterns in Benthos......Page 267
5. DISCUSSION......Page 269
REFERENCES......Page 273
1. INTRODUCTION......Page 276
2. METHODS......Page 277
3.1. Effects on Fish Distribution......Page 280
3.2. Effects on  Fish Abundance......Page 281
3.3. Effects  on Habitat  Use......Page 282
3.4. Recovery......Page 283
4. DISCUSSION......Page 284
REFERENCES......Page 289
1. INTRODUCTION......Page 291
2.3. Movement......Page 292
3.2. Movement......Page 293
4. DISCUSSION......Page 295
REFERENCES......Page 296
1. INTRODUCTION......Page 298
2.3. Radiotelemetry......Page 299
3.1. Movement......Page 300
3.3. Diet......Page 301
4. DISCUSSION  AND CONCLUSIONS......Page 302
REFERENCES......Page 306
1. INTRODUCTION......Page 309
1.2. Flooding and riparian vegetation......Page 310
2. METHODS......Page 311
2.2. Flood Effects on Vegetation......Page 312
2.3. Physical habitat features......Page 313
3.1. Flood Effects on Vegetation......Page 314
3.2. Soil seed bank comparisons......Page 316
3.3. Physical habitat effects......Page 319
4.1. Flooding and Vegetation......Page 320
4.2. Flooding and Litter......Page 322
4.3. Flooding and Substrates......Page 323
5. MANAGEMENT RECOMMENDATIONS......Page 324
REFERENCES......Page 325
1. INTRODUCTION......Page 328
4. THE STATUS OF PHYSICAL RESOURCES IMMEDIATELY AFTER THE  FLOOD......Page 329
5. THE STATUS OF PHYSICAL RESOURCES 6MONTHS AFTER THE FLOOD......Page 330
6.1. Mainstem Sediment Transport, Computation  of Sediment Budgets, and the Training of Restoration Floods......Page 331
6.2. The Appropriate Duration of Restoration  Floods......Page 333
6.3. Large-Scale Erosion during the  Flood......Page 334
6.5. Longitudinal Patterns of Change in Eddy Bars......Page 336
7. SAND  BALANCE......Page 337
8. IMPLICATIONS FOR  FUTURE RESEARCH......Page 338
REFERENCES......Page 340
1. INTRODUCTION......Page 341
2.1. Nutrient Composition......Page 342
2.4. Riparian Vegetation......Page 343
2.6. Fish Populations......Page 344
3. IMPLICATIONS  FOR FUTURE  FLOODS......Page 345
3.1. Timing  Of Controlled  Floods......Page 346
REFERENCES......Page 347
2. BACKGROUND  AND SETTING......Page 349
5. DAM OPERATIONS DURING  WATER YEAR 1996......Page 350
6.1. Analysis Approach......Page 351
7. RESULTS......Page 353
9. CONCLUSION......Page 354
REFERENCES......Page 355
1. INTRODUCTION......Page 356
1.1. What Science Can, and  Cannot, Do......Page 357
7.2. Processes and Time Scales: Toward a new View of Science and River Management in Grand Canyon......Page 359
1.3. The Glen Canyon Dam Environmental-Impact-Statement Process: Focus for Science and Management......Page 360
1.4. Science and the  Flood Experiment......Page 361
2.1. Scientific Implications of the Flood Experiment......Page 362
2.3. The Implications of the Economics of Hydropower Production for Science-Based Management......Page 363
REFERENCES......Page 364