C.F. Tolman (1937): Groundwater, McGraw Hill , New York and London.D.K. Todd (1995): Groundwater Hydrology, John Wiley and Sons. F.G. Driscoll (1988): Groundwater and Wells, UOP, Johnson Div.St.Paul. Min. USA. H.M. Raghunath (1990): Groundwater, Wiley Eastern Ltd., H.S. Nagabhushaniah (2001): Groundwater in Hydrosphere (Groundwater hydrology), CBS Publ..K. R. Karanth (1989): Hydrogeology, Tata McGraw Hill Publ..S.N. Davies and R.J.N. De Wiest (1966): Hydrogeology, John Wiley and Sons, New York.
Hydrology: Processes governing the depletionand replenishment of water resources of landareas of the earth.Dealing with ground waterHydrogeology: Mode ofoccurrence, distribution, movement andchemistry of water occurring in thesubsurface in relation to the geologicalenvironment.Geohydrology: Emphasising thehydrologic aspect.
• Dealing with surface water• Potamology: Science of surface stream• Limnology: Science of Lakes• Cryology: Science of snow and ice• Dealing with air water• Hydrometeorology• Climetology
• Importance• Evaluation of surface water- required parameters- precipitation, infiltration, slope• Evaluation of ground water-required parameters-geometry of basin, storage, yield, properties of aquifer• Mineral prospecting and mining- Sulphide minerals-1ppm Zinc• Evaluation of sites for geotechnical construction– reservoir and dam
• Problem related to pollution• Proper management of water resource- Problem-• excess extraction of ground water– depletion of water level, subsidence of land surface---- both by artificial recharge• Excess use of surface water for irrigation– water logging---by conjuctive use
• Groundwater development• Stratigraphy• Petrography• Structural Geology• Geomorphology• ------ Presence of aquifer, type of aquifer, dimension of aquifer, lithofacies variation productivity, quality of water, structure of formation
• Water resource• Ocean- 97%• Ice caps 2%• Deep ground water 0.31%• Fresh water 0.69% (surface water 3%, subsurface 97%)
•Hydrogeology and environment• Construction of reservoir—shallow water table• Deforestation---reduce infiltration and recharge, increase runoff and erosion and evaporation• Waste disposal--- water quality (water pollution)
•Hydrogeological classification of rocks•Consolidated (hard)•Unconsolidated (soft)
• Hydrologic cycle: The circulation of water from the ocean to the atmosphere, atmosphere to the lithosphere and lithosphere to the ocean occurring through complex and independent process including precipitation, runoff, ground water flow, evaporation and transpiration, is called hydrologic cycle.
• The stages of the Hydrological Cycle.
• Hydrologic cycle• Precipitation• Evaporation• Transpiration• Evapotranspiration• Field capacity• Wilting point• Consumptive use• Conjunctive use• Infiltration• Run off
• 1.Precipitation: It is atmospheric discharge of water in the form of the solid, liquid from the earth surface. The distribution of water on the surface and subsurface is governed by duration and intensity of precipitations.
Types of precipitation•Cyclonic•Convective•Orographic
Forms of Precipitation• Drizzle--.1-.5mm• Rain-- >.5mm• Glaze• Sleet –ice pellets—1—4mm• Snow—ice crystal• Hail->5mm• Dew
• 2. Evaporation and transpiration: It is the process by which water is returned to the atmosphere.Evaporation:Sublimation:Transpiration:
Factors affecting evaporationMeteorological— Radiation,temperature,humidi ty,wind, pressurePhysical factors: water quality, shape and size of evaporating surface
• (i) Wilting point: Lowest amount of moisture that is held by soil, not available for transpiration by vegetation, is the wilting point• (ii)Field capacity: The maximum water that the soil can hold against the force of gravity.• Available soil moisture: Difference between field capacity and wilting point
• 1. Transpiration: The part of water reaching the ground is evaporated through the leaves.• 2. Evapo-transpiration:The umulative loss by evaporation and transpiration• (i) Consumptive use: Term includes water used in plant metabolism and evapo-transpiration.
•4. Infiltration: Moving of precipitated water in to subsurface. The rate of infiltration depends on the rain fall intensity, duration and texture of materials.
• Runoff. Runoff is the water discharged through stream consisting wholly, or in part, of water contributed by overland flow (surface runoff) and ground water flow (base flow).
•Vertical distribution of water or kind of ground water• Zone of aeration• Zone of saturation
• Above water table•Soil water•Pellicular water•Vadose•Pearched water•Capillary water
•Below water table•Free water•Confined water•Fixed water•Connet water
•Zone of saturation•Aquifer•Aquitard•Aquiclude•Aquifuge
• Types of aquifer• Unconfined or water table or phreatic• Confined or artesian or pressure• Leaky or semi confined