Groundwater Modelling in Arid and Semi-Arid Areas

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
Contributors......Page 8
Preface......Page 11
Acknowledgements......Page 13
1.2 Groundwater resources and modelling needs in arid and semi-arid areas......Page 15
1.3 The book content and structure......Page 16
1.4 Conclusions......Page 17
References\r......Page 18
2.2 Hydrological processes in arid areas......Page 19
2.2.1 Rainfall......Page 20
2.2.2 Rainfall-runoff processes......Page 24
2.2.3 Wadi bed transmission losses......Page 25
2.2.4 Groundwater recharge......Page 26
Spatial variability of groundwater recharge......Page 27
2.3 Hydrological modelling and the representation of rainfall......Page 28
2.4 Integrated modelling for groundwater resource evaluation......Page 29
2.5 Conclusions......Page 32
References\r......Page 33
3.1 Introduction......Page 43
3.2 Methods of investigation......Page 44
3.4 Rainfall chemistry......Page 46
3.5 The unsaturated zone......Page 48
3.5.2 Stable isotopes......Page 49
3.5.5 Reactive tracers and water-rock reactions in the unsaturated zone......Page 50
3.5.7 Spatial variability......Page 51
3.6.2 Reactions and evolution along flow lines......Page 54
3.6.3 Redox reactions......Page 55
3.7.1 Data requirements......Page 56
References\r......Page 57
4.1.1 Modelled phenomena......Page 61
4.1.2 What are models built for?......Page 62
4.2.1 Mass conservation......Page 63
4.2.3 Solution by finite difference......Page 64
4.3.1 Conceptualisation......Page 66
4.3.2 Discretisation......Page 68
4.3.4 Model selection......Page 69
4.4.1 Importance of geology......Page 70
4.4.2 Geostatistics......Page 71
Kriging......Page 72
Conditional simulation......Page 73
Facies simulation methods......Page 74
4.4.3 Upscaling......Page 75
Equivalent parameters......Page 76
4.5 Calibration......Page 77
4.5.1 Least squares and maximum likelihood......Page 78
4.5.2 Global optimisation......Page 79
4.6 Uncertainty propagation......Page 80
References\r......Page 82
5.2 The theory of regionalised variables: geostatistics......Page 85
5.3.1 Theoretical aspects......Page 87
5.3.3 Model fabrication......Page 88
5.4 A case study from the Maheshwaram watershed, Andhra Pradesh, India......Page 89
5.5 Conclusions......Page 94
References\r......Page 96
6.2.1 Introduction......Page 97
Intrinsic vulnerability......Page 99
6.2.3 Matrix methods......Page 101
6.2.4 Applications of vulnerability methods in arid and semi-arid regions......Page 102
6.3.1 Definition......Page 103
6.3.2 Evaluation......Page 104
6.3.4 Arid and semi-arid zone applications......Page 105
References......Page 106
7.2 Importance of variable density flow......Page 109
7.4.1 Overview......Page 111
7.4.3 Dimensionless numbers......Page 112
7.4.4 The use of equivalent freshwater head in variable density analyses......Page 113
SUTRA processes......Page 114
SUTRA governing equations......Page 115
SUTRA numerical methods......Page 116
7.5.2 Testing variable density aspects of variable density numerical codes......Page 117
7.5.3 Future challenges for numerical modelling......Page 120
Background......Page 122
Numerical models......Page 123
Future challenges......Page 125
Offshore fresh and brackish palaeo-groundwater......Page 126
Numerical modelling......Page 127
Importance of aquifer storage and recovery (ASR)......Page 128
Choice of model......Page 129
When can density effects be ignored?......Page 130
Importance of variable density flow in fractured rock aquifers......Page 131
Verification of variable density flow in fractured rock......Page 132
Importance of chemical reactions in variable density flow......Page 133
Development and applications of numerical models......Page 134
References\r......Page 135
8.2 Definition of sustainable water management......Page 141
8.3.2 Example The northwest Sahara aquifer system......Page 142
8.4.2 Example The Okavango delta......Page 144
8.5.1 General situation......Page 146
8.5.2 Example The Yanqi basin in Xinjiang, China......Page 147
8.6 Pollution of water bodies of large residence time with persistent or recyclable pollutants......Page 148
8.7 Tools for decision support......Page 149
8.8 The connection to decision makers......Page 150
References\r......Page 151
Index......Page 153