Remote Sensing and Water Resources (eBook)

Contents 6
1 Foreword: International Space Science Institute (ISSI) Workshop on Remote Sensing and Water Resources 8
References 11
2Modelling Freshwater Resources at the Global Scale: Challenges and Prospects 12
Abstract 12
1Introduction 13
2Approaches for Modelling Global Hydrology 14
3Challenges 15
3.1Modelling Human Water Use 15
3.2Uncertain Climate Input 16
3.2.1Uncertainties in Historic Climate Information and Their Impact on Simulating Water Resources 17
3.2.2Uncertainties in Global and Regional Climate Projections and Their Impact on Simulating Future Water Resources 19
3.3Quantification of the Role of Active Vegetation Under Changing Climate and CO2 Concentrations 21
3.4Understanding of Why GHMs (Including Global Irrigation Models) Respond Differently to Changed Climate Input 22
3.5Modelling of Monthly Time Series of River Discharge and Human Water Use to Support More Meaningful Indicators of Water Stress for Both Humans and Ecosystems 24
3.6 Simulation of Groundwater–Surface Water Interaction and Capillary Rise by Gradient-Based Groundwater Modelling 25
3.7Detection and Attribution of Observed Changes in Freshwater Systems 27
4Prospects 28
4.1Multi-criteria Validation Against River Discharge and Geodetic/Remote Sensing Observations 29
4.2Multi-criteria Calibration and Data Assimilation 29
4.3Hyperresolution Global Hydrological Modelling 32
5Conclusions 32
Acknowledgments 32
References 33
3On the Use of Hydrological Models and Satellite Data to Study the Water Budget of River Basins Affected by Human Activities: Examples from the Garonne Basin of France 39
Abstract 39
1Introduction 40
2The Water Balance at the Scale of the Entire Garonne Basin 42
2.1Climate and Physical Properties 42
2.2Anthropization, Environmental Change due to Human Actions 43
2.3Hydrological Regime of the Garonne Basin: Trends and Variability 45
3Interest of Fine Scale Data to Validate or Constrain Models 47
3.1Snow Cover 47
3.2Crop Sowing Date 49
4Explicit Modeling of Human Activities at the Scale of the Basin Using a Multi-agent Simulation Platform 51
4.1 MAELIA: A Multi-agent Platform of Social–Ecological Systems 51
4.1.1Agricultural Processes 52
4.1.2Hydrological Processes 53
4.1.3Water Management 53
4.1.4Other Socioeconomic Processes 54
4.1.5Calibration of the Model 54
4.2Evaluation and Impact of Changes in the Spatial Allocation of Cropping Systems in the Aveyron Sub-basin 54
4.2.1Studied Area and Methodology 54
4.2.2Evaluation of the MAELIA Instance 55
4.2.3Impact Assessment of Crop Rotation Changes 56
5Conclusions 58
Acknowledgments 59
References 59
4On Creating Global Gridded Terrestrial Water Budget Estimates from Satellite Remote Sensing 64
Abstract 64
1Introduction 65
2Data and Methodology 67
2.1Utilized Data 67
2.2Product Merging and Water Budget Closure 68
2.3Design of the Budget Closure Experiments 69
3Results and Discussion 69
3.1Roles of Non-satellite Sources in Closing the Water Budget 69
3.2Roles of In Situ Precipitation Observations in Water Budget Closure 72
3.3 Effects of Different Remote Sensing ET Products in the Water Budget Closure 73
3.4Roles of CKF in Constraining the Water Balance 74
3.5Runoff Validation Against GRDC Data at the Basin Scale 77
4Conclusions 81
Acknowledgments 82
References 82
5Lake Volume Monitoring from Space 84
Abstract 84
1Introduction 85
2Satellite Altimetry 88
2.1Introduction 88
2.2Basics of Satellite Altimetry 88
2.3Past, Present, and Future Satellite Altimetry 89
2.4Combination of Multi-Satellite Data 93
2.5Accuracy of Satellite Altimetry Over Lakes 94
3Satellite Imagery 96
4Storage Change Calculation 102
5Case Study: The Tibetan Plateau 103
6Results 106
7Conclusions 113
Acknowledgments 115
References 115
6The SWOT Mission and Its Capabilities for Land Hydrology 121
Abstract 121
1SWOT Mission Overview 122
1.1The Needs for a Global Water Surface Mission and Its Requirements 122
1.2Characteristics of the KaRIn Instrument 123
1.3SWOT Measurements over Terrestrial Surface Waters 127
1.4SWOT Spatiotemporal Coverage 129
2River Studies 132
2.1Rivers Seen by SWOT 132
2.2Instantaneous Direct River Discharge Estimations 134
2.3Data Assimilation and Optimal Interpolation 137
3Lake/Reservoir Studies and Other Land Hydrology Applications 140
3.1Lakes and Reservoirs 141
3.2Other Land Hydrology Applications and Synergistic Land Sciences 144
4Conclusions and Perspectives 146
Acknowledgments 147
References 147
7Toward a High-Resolution Monitoring of Continental Surface Water Extent and Dynamics, at Global Scale: from GIEMS (Global Inundation Extent from Multi-Satellites) to SWOT (Surface Water Ocean Topography) 152
Abstract 152
1Introduction 153
2The Potential and Limitation of Satellite Techniques for Surface Water Estimation 154
2.1Visible (VIS) and Near-Infrared (NIR) Observations 154
2.2Active Microwave Observations 155
2.3Passive Microwave Observations 157
3A Multi-satellite Methodology for Global Surface Water Estimation 158
3.1The Global Inundation Extent from Multi-satellites (GIEMS) 158
3.2Downscaling of GIEMS 160
3.2.1Downscaling Based on High-Resolution Satellite Observations 161
3.2.2Downscaling Based on Topography Information 162
4The Future with SWOT 162
5Conclusions and Perspective 165
Acknowledgments 165
References 166
8Assessing Global Water Storage Variability from GRACE: Trends, Seasonal Cycle, Subseasonal Anomalies and Extremes 169
Abstract 169
1Introduction 170
2Data 171
2.1GRACE Data 171
2.2Filtered Grids of Atmospheric Reanalysis 173
3Methods 173
3.1Signal Decomposition 173
3.1.1Background and Previous Approaches 173
3.1.2Seasonal Trend Decomposition Using Loess (STL) 174
3.2Monthly Averaging of the Daily Decomposed Forcing Time Series 175
3.2.1Limitations of the Arithmetic Mean for the Comparison of High-Frequency Anomalies 175
3.2.2.Comparing Flux and State Variables at Different Temporal Resolutions 176
3.2.3Weights Based on Integrated Exponential Decay Functions 177
3.2.4Shape and Properties of the Weighting Function 178
3.3Significance Testing and Correlation Analysis 179
3.3.1Linear Trends 179
3.3.2Inter-Annual Anomalies 180
3.3.3Seasonal Cycle 180
3.3.4Subseasonal Residuals 180
3.4Identifying Droughts in the GRACE Record 180
4Global Hydrological Variability in the GRACE Data 181
4.1Distribution of GRACE Variance Among Temporal Components 181
4.2Linear Trends 182
4.3Inter-Annual Anomalies 184
4.4Seasonal Cycle 186
4.5Subseasonal Residuals 189
4.6Droughts 193
5Conclusions 195
Acknowledgments 196
Appendix 1: STL for Unevenly Spaced Time Series 197
Locally Weighted Regression (Loess) 197
Inner Loop 198
Outer Loop 198
Choosing the Parameters 199
Appendix 2 200
Analytical Integration of the Weighting Function 200
References 201
9Groundwater Storage Changes: Present Status from GRACE Observations 208
Abstract 208
1Introduction 209
2Groundwater Depletion from GRACE 210
2.1Groundwater Depletion in North West India 213
2.2Groundwater Depletion in the California Central Valley 215
2.3 Groundwater Depletion in Southern Murray–Darling Basin 217
2.4Groundwater Depletions in Other Regions 218
3Major Challenges in Monitoring Groundwater Change Using GRACE 220
3.1Uncertainty of SSS Water Storage Changes 220
3.2Uncertainties in GRACE TWS Storage Changes 220
4Summary 224
Acknowledgments 226
References 226
10Modeling Groundwater Depletion at Regional and Global Scales: Present State and Future Prospects 229
Abstract 229
1Introduction 229
2Human Water Use and Groundwater Pumping 231
3Global and Regional Assessments of Groundwater Depletion 235
4Groundwater Depletion and Sea-Level Rise 242
5Future Projections of Groundwater Depletion 244
6A Way Forward 251
6.1Quantifying the Sustainable Yield with Use of Satellite Observations and Integrated Modeling Framework 251
6.2Assessing Food Security 252
6.3Assessing Regional Mitigation Strategies on Food Security 252
Acknowledgments 252
References 252
11What Can be Expected from the GRACE-FO Laser Ranging Interferometer for Earth Science Applications? 262
Abstract 262
1Introduction 263
2Simulation Assumptions and Strategy 265
3Results in the Spectral and Spatial Domain 268
4Regional Applications Using Simulated MWI and LRI Data 272
5Error Analysis 273
6Summary and Conclusions 276
7Acknowledgments 277
References 278
12Subsurface Hydrology of the Lake Chad Basin from Convection Modelling and Observations 280
Abstract 280
1Introduction 281
2Description of the Lake Chad Basin 283
2.1Hydrology of Lake Chad 283
2.2Geology of the Chad Basin 284
2.3Hydrogeology of the Basin 286
2.4Potential Permeability Field of the Basin 286
32D Convective Model 288
4Discussion 295
4.1Relations Between the Deep Convective Circulation and Thermal Data 296
4.1.1Subsurface Thermal Data 296
4.1.2Surface Thermal Data 297
4.2Relation Between Deep Convective Circulation and Hydrogeology 299
4.2.1Evolution of the Water Composition 299
4.2.2Comparison Between Convective Velocity and Transient Variations of the Piezometric Level: Inference on Water Mass Changes 300
5Conclusions 302
Acknowledgments 304
Appendix 1: Governing Equations, Parameters and Equations of State 304
Appendix 2: Parameter values 305
Appendix 3: Method and Boundary Conditions 305
Appendix 4: Evaluation of the Hydrological and Thermal Characteristics of Our Model 306
References 309
13 Water and Food in the Twenty-First Century 312
Abstract 312
1Where Does the Water We Use Today Come From? 313
1.1Freshwater Stocks 313
1.2The Water Cycle 314
1.3Virtual Water, Example of Tunisia 316
2Scenarios for Food Production in 2050 319
3Climate Change 326
4Risk of Droughts 327
5Conflicts 328
6Conclusions 330
Acknowledgments 332
References 332