Environmental Geology PRINCIPLES AND PRACTICE Fred G. Bell Department of Geology and Applied Geology University of Natal, Durban, South Africa b Blackwell Science
Preface, ix 1 Introduction, 1 1.1 Planning and geology, I 1.2 Conservation, restoration and reclamation of land, 5 1.3 Geological hazards and planning, 6 1.4 Risk assessment, 8 1.5 Hazard maps, 10 1.6 Morphological maps, 11 1.7 Engineering geomorphological maps, 17 1.8 Environmental geological maps, 19 1.9 Engineering geological maps, 23 1.10 Geographical information systems, 29 2 Volcanic activity, 34 2.1 Introduction, 34 2.2 Volcanic form and structure, 34 2.3 Types of central eruption, 38 2.4 Volcanic products: volatiles, 40 2.5 Volcanic products: pyroclasts, 41 2.6 Volcanic products: lava flows, 44 2.7 Mudflows or lahars, 46 2.8 Volcanic hazard and prediction, 48 2.8.1 Methods of prediction, 48 2.8.2 Assessment of volcanic hazard and risk, 50 2.8.3 Dealing with volcanic activity, 56 3 Earthquake activity, 58 3.1 Introduction, 58 3.2 Intensity and magnitude of earthquakes, 60 3.3 Ground conditions and seismicity, 63 3.4 Effects of earthquakes, 66 3.5 Methods of seismic investigation, 70 3.5.1 Earthquake prediction, 70 3.5.2 Assessment of movements along faults, 72 3.5.3 Aseismic investigation, 72 3.5.4 Accelerographs, 73 3.6 Seismic hazard and risk, 74 3.7 Seismic zoning, 76 3.8 Induced seismicity, 78 Mass movements, 83 4.1 Soil creep and valley bulging, 83 4.2 Causes of landslides, 84 4.3 Classification of landslides, 88 4.3.1 Falls, 88 4.3.2 Slides, 90 4.3.3 Flows, 91 4.4 Landslides in soils, 93 4.5 Landslides in rock masses, 94 4.6 Monitoring slopes, 97 4.6.1 Monitoring movement, 97 4.6.2 Monitoring groundwater, 98 4.6.3 Monitoring acoustic emissions or noise, 99 4.7 Landslide hazard, investigation and mapping, 99 4.8 Methods of slope control and stabilization, 106 4.8.1 Rockfall treatment, 106 4.8.2 Alteration of slope geometry, 107 4.8.3 Reinforcement of slopes, 107 4.8.4 Restraining structures, 108 4.8.5 Drainage, 110 River activity, 114 5.1 The development of drainage systems, 114 5.2 Fluvial processes, 120 5.2.1 River flow, 120 5.2.2 River erosion, 122 5.2.3 River transport, 123 5.2.4 Deposition of sediments, 125 5.3 Floods, 126 5.4 Hazard zoning, warning systems and adjustments, 131 5.5 The design flood and flood control, 134 Marine activity, 139 6.1 Waves, 139 6.1.1 Force and height of waves, 140
6.1.2 Wave refraction, 141 6.2 Tides, 142 6.3 Beach zones, 143 6.4 Coastal erosion, 144 6.5 Beaches and longshore drift, 147 6.6 Storm surges and marine inundation, 151 6.7 Protective barriers, 153 6.8 Stabilization of longshore drift, 157 6.9 Tsunamis, 159 7 Arid and semi-arid lands, 163 7.1 Introduction, 163 7.2 Wind action, 163 7.3 Desert dunes, 166 7.4 Stream action in arid and semi-arid regions, 169 7.5 Flooding and sediment problems, 173 7.6 Movement of dust and sand, 174 7.7 Sabkha soil conditions, 180 7.8 Salt weathering, 183 7.9 Desertification, 188 7.10 Irrigation, 190 8 Glacial and periglacial terrains, 199 8.1 Introduction, 199 8.2 Glacial erosion, 199 8.3 Glacial deposits: tills and moraines, 203 8.4 Basic properties of tills, 209 8.5 Compressibility and strength of tills, 212 8.6 Fluvio-glacial deposits; stratified drift, 213 8.7 Other glacial effects, 219 8.8 Glacial hazards, 220 8.9 Frozen ground phenomena in periglacial environments, 221 8.10 Construction in permafrost regions, 227 8.11 Frost heave, 228 9 Water resources, 233 9.1 The hydrological cycle, 233 9.2 Reservoirs, 234 9.3 Dam sites, 239 9.4 Geology and dam sites, 243 9.5 Groundwater, 246 9.6 A note on basement aquifers, 248 9.7 Springs, 249 9.8 Water budget studies, 250 9.9 Hydrogeological properties, 251 9.10 Groundwater exploration, 254 9.11 Assessment of permeability and flow in the field, 257 9.12 Water quality and uses, 260 9.13 Wells, 265 9.14 Safe yield, 270 9.15 Artificial recharge, 271 9.16 Groundwater pollution, 272 9.16.1 Landfill and groundwater pollution, 274 9.16.2 Saline intrusion, 275 9.16.3 Nitrate pollution, 277 9.16.4 Other causes of groundwater pollution, 277 9.17 Groundwater monitoring, 279 9.18 Conjunctive use, 281 10 Soil resources, 285 10.1 Origin of soil, 285 10.2 Soil horizons, 286 10.3 Soil fertility, 287 10.4 Pedological soil types, 288 10.5 Basic properties of soil, 292 10.5.1 Particle size distribution, 293 10.5.2 Consistency limits, 294 10.6 Soil classification, 298 10.7 Shear strength of soil, 300 10.8 Consolidation, 301 10.9 Soil erosion, 307 10.10 Estimation of soil loss, 311 10.10.1 The Universal Soil Loss Equation, 311 10.10.2 Soil erosion by wind, 313 10.11 Erosion control and conservation practices, 313 10.11.1 Conservation measures for water erosion, 314 10.11.2 Conservation measures for wind erosion, 316 10.12 Assessment of soil erosion, 316 10.13 Soil surveys and mapping, 323 10.14 Soils as a construction material, 324 10.14.1 Gravels and sands, 324 10.14.2 Clay deposits, refractory materials and bricks, 326 10.14.3 Fills and embankments, 328 11 Problem soils, 335 11.1 Quicksands, 335 11.2 Expansive clays, 338 11.3 Dispersive soils, 341 11.4 Collapsible soils, 345 11.5 Quickclays, 348 11.6 Soils of arid regions, 350 11.7 Tropical soils, 352 11.8 Peat, 357
12 Rock masses, their character, problems and uses, 362 12.1 Rock types, 362 12.1.1 Igneous rocks, 362 12.1.2 Metamorphic rocks, 362 12.1.3 Sedimentary rocks, 365 12.1.4 Deformation and strength of rocks, 367 12.2 Description of rocks and rock masses, 368 12.3 Discontinuities, 375 12.3.1 Description of discontinuities in rock masses, 376 12.3.2 Strength of discontinuous rock masses and its assessment, 378 12.3.3 Discontinuities and rock quality indices, 379 12.3.4 Discontinuity surveys, 381 12.4 Weathering, 384 12.4.1 Mechanical weathering, 385 12.4.2 Chemical and biological weathering, 386 12.4.3 Engineering classification of weathering, 387 12.5 Igneous and metamorphic rocks, 388 12.6 Mudrocks, 395 12.7 Carbonate rocks, 399 12.8 Evaporitic rocks, 404 12.9 Building, roofing and facing stones, 406 12.10 Crushed rock, 408 12.10.1 Concrete aggregate, 408 12.10.2 Road aggregate, 410 12.11 Lime, cement and plaster, 41 I 13 The impact of mining on the environment, 415 13.1 Introduction, 415 13.2 Metalliferous mining and subsidence. 415 13.2.1 Mining methods, 415 13.2.2 Stabilization of old workings, 41 ~ 13.2.3 Mining and sinkhole development, 41 ~ 13.3 Pillar workings, 41 8 13.4 Old mine workings and hazard zoning. 421 13.5 Measures to reduce or avoid subsidence effects due to old mine workings, 423 13.6 Old mine shafts, 424 13.7 Longwall mining and subsidence, 426 13.8 Measures to mitigate the effects of subsidence due to longwall mining, 430 13.9 Surface mining, 431 13.9.1 Strip mining and opencasting, 431 13.9.2 Open pit mining, 433 13.9.3 Blasting and vibrations, 434 t 2 u.1 i^-.>.l,,:.,:«.. 435,1 1 c 13.9.4 Dredge mining,' 13.10 Subsidence Subsit" associated with fluid abstraction, 437 13.11 Waste materials from mining, 441 13.11.1 Spoil heaps and their restoration. 441 13.11.2 1.1.1 I./, Waste waste disposal in tailings igs dams, 444 13.12!. 12 The] problem of acid mine drainage, 446 13. i. 13 Waste waters and effluents from coal minimi. mining, 450 450 13.14 Heap leaching, 45_ 13.15 Other impacts, 453 14 Waste and its disposal, 459 14.1 Introduction, 459 14.2 Domestic refuse and sanitary landfills, 459 14.2.1 Design considerations for a landfill, 461 14.2.2 Degradation of waste in landfills. 466 14.2.3 Attenuation of leachate, 466 14.2.4 Surface and groundwater pollution. 468 14.2.5 Landfill and gas formation. 470 14.3 Hazardous wastes, 4"" I 14.4 Radioactive waste, 4 "4 14.5 Contaminated land,4~8 14.6 Remediation of contaminated land, 4X2 14.6.1 Soil remediation, 48 > 14.6.2 Groundwater remediation. 4X4 15 Environmental geology and health, 487 15.1 Introduction. 48" 1 5.2 The occurrence of elements, 49(1 1 V i Geochcmical surveys and maps. 49<s 1 5.4 Some trace elements and health. 498 15.4.1 Arsenic. 498 1 5.4.2 Cadmium, 500 1 5.4.3 Mercury, Mil 15.4.4 le.id. 501 15.4.5 Iodine, 50? 1 5.4.h Fluorine, 506 1 5.4." Selenium, 50" 15.4.8 Zinc. 508 15.4.9 Molybdenum. 508 1 5.4.10 Some other trace elements and health. 509 15.5 Mineral dusts and health, 51 1
viii 15.6 Radon, 512 15.7 Environmental geology and chronic disease, 516 16 Land evaluation and site assessment, 524 16.1 Introduction, 524 16.2 Remote sensing, 525 16.2.1 Infrared line scanning, 525 16.2.2 Side-looking airborne radar, 526 16.2.3 Satellite imagery, 527 16.3 Aerial photographs and photogeology, 528 16.3.1 Types of aerial photograph, 528 16.3.2 Photogeology, 530 16.4 Terrain evaluation, 531 16.5 Land capability studies, 532 16.6 Site investigation, 535 16.6.1 Desk study and preliminary reconnaissance, 535 16.6.2 Site exploration, 536 16.6.3 Subsurface exploration in soils, 537 16.6.4 Sampling in soils, 541 16.6.5 Subsurface exploration in rocks, 542 16.7 Geophysical exploration, 546 16.7.1 Seismic methods, 546 16.7.2 Resistivity methods, 547 16.7.3 Electromagnetic methods, 551 16.7.4 Magnetic and gravity methods, 552 16.7.5 Drill-hole logging techniques, 554 16.7.6 Cross-hole seismic methods, 556 16.8 In situ testing, 556 Index, 563