Slide 1

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.

Introductionto Hydrogeology Introductionto HydrogeologyHydrology: Processes governing the depletion and replenishment of water resources of land areas of the earth. Dealing with ground waterHydrogeology: Mode of occurrence, distribution, movement and chemistry of water occurring in the subsurface in relation to the geological environment. Geohydrology: Emphasising the hydrologic aspect.

Dealing with surface waterPotamology: Science of surface streamLimnology: Science of LakesCryology: Science of snow and iceDealing with air waterHydrometeorologyClimetologyImportanceEvaluation of surface water- required parameters- precipitation, infiltration, slopeEvaluation of ground water-required parameters-geometry of basin, storage, yield, properties of aquiferMineral prospecting and mining- Sulphide minerals-1ppm ZincEvaluation of sites for geotechnical construction reservoir and dam

Problem related to pollutionProper management of water resource- Problem- excess extraction of ground water depletion of water level, subsidence of land surface---- both by artificial rechargeExcess 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 environmentConstruction of reservoirshallow water tableDeforestation---reduce infiltration and recharge, increase runoff and erosion and evaporationWaste 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 cyclePrecipitationEvaporationTranspirationEvapotranspirationField capacityWilting pointConsumptive useConjunctive useInfiltrationRun 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 precipitationCyclonicConvectiveOrographicForms of PrecipitationDrizzle--.1-.5mmRain-- >.5mmGlazeSleet ice pellets14mmSnowice crystalHail->5mmDew2. Evaporation and transpiration: It is the process by which water is returned to the atmosphere.

Evaporation:Sublimation:Transpiration:

Factors affecting evaporationMeteorologicalRadiation,temperature,humidity,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 tableSoil waterPellicular waterVadose Pearched waterCapillary water

Below water tableFree waterConfined waterFixed waterConnet water

Zone of saturationAquiferAquitardAquicludeAquifugeTypes of aquiferUnconfined or water table or phreaticConfined or artesian or pressureLeaky or semi confined

Piezometric surface