Groundwater Geophysics – a Tool for Hydrogeology	5
	Contents	7
	Authors	15
	1 Petrophysical properties of permeable and lowpermeable rocks	18
	1.1 Seismic velocities	18
	1.1.1 Consolidated rock	19
	1.1.2 Unconsolidated rock	21
	1.1.3 Clay and till	24
	1.2 Electrical resistivity	25
	1.2.1 Archie´s law – conductive pore fluid and resistive rock matrix	25
	1.2.2 Limitations of Archie´s law – conducting mineral grains	29
	1.3 Electric Permittivity (Dielectricity)	33
	1.4 Conclusions	37
	1.5 References	38
	2 Seismic methods	40
	2.1 Introduction	40
	2.1.1 What type of waves is applied in seismic exploration?	40
	2.1.2 How can seismic waves image geological structure?	41
	2.1.3 How are seismic waves generated and recorded in the field?	44
	2.1.4 What kind of seismic measurements can be performed?	46
	2.1.5 What kind of hydro-geologically relevant information can be obtained from seismic prospecting?	46
	2.1.6 What are the advantages and disadvantages of seismic measurements compared to other methods? How do seismics and other geophysical measurements complement each other?	48
	2.2 Seismic refraction measurements	48
	2.2.1 Targets for seismic refraction measurements	49
	2.2.2 Body wave propagation in two-layer media with a plane interface	50
	2.2.3 Seismic refraction in laterally heterogeneous two-layer media	55
	2.2.4 Consistency criteria of seismic refraction measurements	58
	2.2.5 Field layout of seismic refraction measurements	61
	2.2.6 Near surface layering conditions and seismic implications	63
	2.2.7 Seismic interpretation approaches for heterogeneous subsurface structures	66
	2.2.8 Structural resolution of seismic refraction measurements	75
	2.3 Seismic reflection imaging	80
	2.3.1 Targets for seismic reflection measurements	81
	2.3.2 Seismic reflection amplitudes	82
	2.3.3 Concepts of seismic reflection measurements	84
	2.3.4 Seismic migration	91
	2.3.5 Field layout of seismic reflection measurements	94
	2.3.6 Problems of near surface reflection seismics	96
	2.3.7 Structural resolution of seismic reflection measurements	97
	2.4 Further reading	99
	2.5 References	99
	3 Geoelectrical methods	102
	3.1 Basic principles	102
	3.2 Vertical electrical soundings (VES)	104
	3.2.1 Field equipment	107
	3.2.2 Field measurements	107
	3.2.3 Sounding curve processing	109
	3.2.4 Ambiguities of sounding curve interpretation	110
	3.2.5 Geological and hydrogeological interpretation	114
	3.3 Resistivity mapping	115
	3.3.1 Square array configuration	117
	3.3.2 Mobile electrode arrays	119
	3.3.3 Mise-à-la-masse method	121
	3.4 Self- potential measurements	122
	3.4.1 Basic principles of streaming potential measurements	122
	3.4.2 Field procedures	123
	3.4.3 Data processing and interpretation	124
	3.5 2D measurements	126
	3.5.1 Field equipment	126
	3.5.2 Field measurements	127
	3.5.3 Data Processing and Interpretation	128
	3.5.4 Examples	130
	3.6 References	133
	4 Complex Conductivity Measurements	136
	4.1 Introduction	136
	4.2 Complex conductivity and transfer function of waterwet rocks	137
	4.3 Quantitative interpretation of Complex conductivity measurements	140
	4.3.1 Low Frequency conductivity model	140
	4.3.2 Complex conductivity measurements	142
	4.4 Relations between complex electrical parameters and mean parameters of rock state and texture	147
	4.5 The potential of complex conductivity for environmental applications	155
	4.5.1 Organic and inorganic contaminants	155
	4.5.2 Monitoring subsurface hydraulic and migration processes	158
	4.5.3 Geohydraulic parameters	161
	4.6 References	166
	5 Electromagnetic methods – frequency domain	172
	5.1 Airborne techniques	172
	5.1.1 Introduction	172
	5.1.2 Theory	173
	5.1.3 Systems	179
	5.1.4 Data Processing	182
	5.1.5 Presentation	183
	5.1.6 Discussion and Recommendations	187
	5.2 Ground based techniques	187
	5.2.1 Slingram and ground conductivity meters	187
	5.2.2 VLF, VLF-R, and RMT	191
	5.3 References	193
	6 The transient electromagnetic method	196
	6.1 Introduction	196
	6.1.1 Historic development	196
	6.1.2 Introduction	198
	6.1.3 EMMA - ElectroMagnetic Model Analysis	199
	6.2 Basic theory	199
	6.2.1 Maxwell’s equations	200
	6.2.2 Schelkunoff potentials	201
	6.2.3 The transient response over a layered halfspace	203
	6.2.4 The transient response for a halfspace	205
	6.3 Basic principle and measuring technique	206
	6.4 Current diffusion patterns	208
	6.4.1 Current diffusion and sensitivity, homogeneous halfspace	208
	6.4.2 Current densities, layered halfspaces	211
	6.5 Data curves	213
	6.5.1 Late-time apparent resistivity	213
	6.6 Noise and Resolution	214
	6.6.1 Natural background noise	214
	6.6.2 Noise and measurements	216
	6.6.3 Penetration depth	217
	6.6.4 Model errors, equivalence	218
	6.7 Coupling to man-made conductors	220
	6.7.1 Coupling types	221
	6.7.2 Handling coupled data	222
	6.8 Modelling and interpretation	224
	6.8.1 Modelling	224
	6.8.2 The 1D model	224
	6.8.3 Configurations, advantages and drawbacks	225
	6.9 Airborne TEM	226
	6.9.1 Historical background and present airborne TEM systems.	226
	6.9.2 Special considerations for airborne measurements	228
	6.10 Field example	233
	6.10.1 The SkyTEM system	233
	6.10.2 Inversion of SkyTEM data	236
	6.10.3 Processing of SkyTEM data	236
	6.10.4 The Hundslund Survey	237
	6.11 References	241
	7 Ground Penetrating Radar	244
	7.1 Electromagnetic wave propagation	245
	7.1.1 Electric permittivity and conductivity	245
	7.1.2 Electromagnetic wave propagation	247
	7.1.3 Reflection and refraction of plane waves	249
	7.1.4 Scattering and diffraction	251
	7.1.5 Horizontal and vertical resolution	251
	7.1.6 Wave paths, traveltimes, and amplitudes	252
	7.1.7 Estimation of exploration depth	255
	7.2 Technical aspects of GPR	256
	7.2.1 Overview of system components	256
	7.2.2 Antennas and antenna characteristics	256
	7.2.3 Electronics	258
	7.2.4 Survey practice	260
	7.3 Processing and interpretation of GPR data	262
	7.3.1 General processing steps	262
	7.3.2 Examples for GPR profiling and CMP data	263
	7.4 References	267
	8 Magnetic Resonance Sounding	270
	8.1 Introduction	270
	8.2 NMR-Principles and MRS technique	270
	8.3 Survey at Waalwijk / The Netherlands	278
	8.4 Survey at Nauen / Germany with 2D assessment	282
	8.5 Current developments in MRS	286
	8.6 References	288
	9 Magnetic, geothermal, and radioactivity methods	292
	9.1 Magnetic method	292
	9.1.1 Basic principles	292
	9.1.2 Magnetic properties of rocks.	295
	9.1.3 Field equipments and procedures	297
	9.1.4 Data evaluation and interpretation	299
	9.2 Geothermal method	303
	9.2.1 The underground temperature field	306
	9.2.2 Field procedures	307
	9.2.3 Interpretation of temperature data	308
	9.3 Radioactivity method	309
	9.4 References	311
	10 Microgravimetry	312
	10.1 Physical Basics	312
	10.2 Gravimeters	313
	10.3 Gravity surveys and data processing	315
	10.3.1 Preparation and performance of field surveys	316
	10.3.2 Data processing	319
	10.4 Interpretation	324
	10.4.1 Direct methods	324
	10.4.2 Indirect methods	328
	10.4.3 Density estimation	330
	10.5 Time dependent surveys	331
	10.6 References	333
	11 Direct Push-Technologies	338
	11.1 Logging tools	338
	11.1.1 Geotechnical tools	339
	11.1.2 Geophysical tools	341
	11.1.3 Hydroprobes	343
	11.1.4 Hydrogeochemical tools	345
	11.1.5 Miscellaneous other tools	347
	11.2 Sampling tools	348
	11.2.1 Soil sampling tools	348
	11.2.2 Soil gas sampling tools	348
	11.2.3 Groundwater sampling tools	349
	11.3 Tomographic applications	349
	11.4 Permanent installations	352
	11.5 Conclusions	352
	11.6 References	354
	12 Aquifer structures – pore aquifers	358
	12.1 Pore aquifers – general	358
	12.1.1 Definition	358
	12.1.2 Porosity – a key parameter for hydrogeology	358
	12.1.3 Physical properties of pore aquifers	360
	12.1.4 Geophysical survey of pore aquifers	361
	12.2 Buried valley aquifer systems	365
	12.2.1 Introduction	365
	12.2.2 Geological and hydrological background	367
	12.2.3 Methods	368
	12.2.4 Discussion and Conclusion	376
	12.3 A Large-scale TEM survey of Mors, Denmark	380
	12.3.1 Study area – the island of Mors	380
	12.3.2 Hydrogeological mapping by the use of TEM	382
	12.3.3 Data collection and processing	384
	12.3.4 Results and discussions	386
	12.3.5 Conclusions	396
	12.4 Groundwater prospection in Central Sinai, Egypt	398
	12.4.1 Introduction	398
	12.4.2 Geological and hydrogeological aspects	399
	12.4.3 Field work and interpretation	401
	12.4.4 Groundwater occurrence	407
	12.5 References	408
	13 Aquifer structures: fracture zones and caves	412
	13.1 Hydraulic importance of fracture zones and caves	412
	13.2 Geophysical exploration of fracture zones: seismic methods	414
	13.3 Geophysical exploration of faults and fracture zones: geoelectrical methods	419
	13.4 Geophysical exploration of fracture zones: GPR	429
	13.5 Exploration of faults and fracture zones: Geophysical passive methods (self-potential, gravity, magnetic, geothermal and radioactivity methods)	430
	13.6 Geophysical exploration of caves	435
	13.7 References	437
	14 Groundwater quality - saltwater intrusions	440
	14.1 Definition	440
	14.2 Origin of saltwater intrusions	440
	14.3 Electrical conductivity of saline water	443
	14.4 Exploration techniques	446
	14.5 Field examples	446
	14.5.1 Saltwater intrusions in the North Sea region	447
	14.5.2 Saline groundwater in the Red Sea Province, Sudan	450
	14.6 References	453
	15 Geophysical characterisation of aquifers	456
	15.1 Definition of hydraulic conductivity and permeability	456
	15.2 Hydraulic conductivity related to other petrophysical parameter	457
	15.3 Geophysical assessment of hydraulic conductivity	460
	15.3.1 Resistivity	460
	15.3.2 Seismic velocities	463
	15.3.3 Nuclear resonance decay times	464
	15.4 Case history: Hydraulic conductivity estimation from SIP data	467
	15.5 References	472
	16 Groundwater protection: vulnerability of aquifers	476
	16.1 General	476
	16.2 Vulnerability maps	476
	16.3 Electrical conductivity related to hydraulic resistance, residence time, and vulnerability	480
	16.4 Vulnerability maps based on electrical conductivity	483
	16.5 References	487
	17 Groundwater protection: mapping of contaminations	490
	17.1 The brownfields problem	490
	17.2 Mapping of waste deposits	491
	17.3 Mapping of abandoned industrial sites	493
	17.4 Mapping of groundwater contaminations	497
	17.4.1 Anorganic contaminants	498
	17.4.2 Organic contaminants	500
	17.5 References	502
	Index	506