Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Pradeep Raj ¹, L. Nandulal ¹, G. K. Soni ¹

Affiliations
1 Nanakram Bhagwandas Science College, Charkaman, Hyderabad - 500002, IN

Abstract

Hydrogeological studies in the granitic terrain in parts of Mahabubnagar district, Andhra Pradesh, indicate a fairly thick and well distributed weathered zone, linear zones of fractures and deep water levels. The higher yields of some of the bore wells are due to the presence of N-S or E-W fractures. Pumping tests on 23 dug wells and three bore wells drilled within the weathered zone indicate a lower transmissivity values when compared with the pumping tests conducted on four bore wells which encountered fractured zones.

The gross ground water extraction per unit area hardly varies in sampled areas that form sman second order basins, irrespective of well density or type of wells. The number of dug wells drying-up in parts of the area is proportional to the success of the bore wells in the area. It suggests that new and deeper wells are only replacing the older, shallower dug wells and that the deeper fractured zone aquifer and shallower weathered zone aquifer are well connected.

This study also shows that the limiting factor for ground water development is not the nature of the aquifer but the quantum of recharge to it. Hence, artificial recharge structures must be planned to improve availability of ground water in the area.

Keywords

Hydrogeology, Aquifer, Peninsular Gneiss, Andhra Pradesh.

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T. Narasimha Reddy ¹, Pradeep Raj ²

Affiliations
1 Ground Water Department, Government of Andhra Pradesh, Hyderabad, IN
2 Department of Geology, Nanakram Bhagwandas Science College, Charkaman, Hyderabad-500002, IN

Abstract

Ground water in study area underlain by peninsular Gneissic complex occurs in unconfined conditions in weathered zones and semi-confined to confined conditions in fractured zones. Productive fractured zones define narrow linear tracts closely corresponding to surface drainage. Fluoride content of ground water is low mostly in topographic highs and to lesser extent in tank beds or tank commands and in areas where fractures are not connected with fluoride bearing granites. For potability, most wells were drilled in topographic highs and some around tanks.

The aquifer is highly complex (anisotropic and heterogeneous) needing critical analysis to assess performance of wells, as recently yields of a large number of borewells drilled in granitic terrains of Andhra Pradesh are reported to have declined. This is attributed mostly to direct interference with other wells, improper construction of wells leading to silting and general decline in water levels due to various reasons. But rarely, it is realised that these aquifers are laterally limited. In this study pumping tests for 500 to 1000 minutes i.e., 2 1/2 to 3 log cycles of time were carried out and the data was analysed using graphical methods of Cooper and Jacob and Theis recovery method. [n four cases the test data was analysed by a micro processor based simulation technique. Optimum discharges were calculated keeping in view the effects of 'no-flow' boundaries, effective available drawdown and other field parameters. This has indicated that the optimum discharges of the wells are in· general between 60% to 80% of the yields recorded during drillng.

Keywords

Hydrogeology, Granite-Terrain, Nalgonda Dt., A.P.

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Pradeep Raj ¹, V. Raghu ², D. V. J. Sastry ², K. Mruthyunjaya Reddy ²

Affiliations
1 Ground Water Department, 37 LIC Colony, Opp Indira Park, Lower Tank-bund Road, Hyderabad -500 080, IN
2 A P State Remote Sensing Applications Centre, Hyderabad-500 004, IN

Abstract

No Abstract.

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Pradeep Raj ¹

Affiliations
1 1-2-606/80/37, Quarter No. 37, LIC Colony, Opp. Indira Park, Hyderabad - 500 080, IN

Abstract

No Abstract.

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Pradeep Raj ¹, P. D. Sreedevi ²

Affiliations
1 Ground Water Department, 37 LIC Colony, Opp: Indira Park, Lower Tank-bund Road, Hyderabad 500 080, IN
2 National Geophysical Research Institute, Hyderabad, IN

Abstract

No Abstract.

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B. N. Prasad ¹, Pradeep Raj ¹

Affiliations
1 8th floor, BRKR building, Ground Water Department, Hyderabad, IN

Abstract

The reported rise of water levels in some of the wells in AP is noted days after the 26 December 2004 earthquake and the accompanied tsunami events. It is found to be due to seepage from sewerage, paddy fields, deliberate filling up of the wells, etc. Classic signature of an earthquake on water levels is missed by all the 1017 piezometers in the state. None of the piezometers show any abnormal change that coincides with the reported changes in water levels of some of the wells. Thus confirming that the earthquake (tsunami) raised false alarms about water table rise. In coastal areas, quality of the groundwater is affected due to direct inundation of the wells and percolation of sea water that inundated the lands and entered far inland through the estuaries.

Keywords

Tsunami After Effects, Groundwater, Andhra Pradesh.

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Pradeep Raj ¹, B. S. Sukhija ², D. V. Reddy ², P. Nagabhushanam ², M. V. Nandakumar ²

Affiliations
1 Ground Water Department, 37 LIC Colony, Opp Indira Park, Lower Tank-Bund Road, Hyderabad - 500 080, IN
2 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

No Abstract.

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Pradeep Raj ¹

Affiliations
1 1-2 606/80/37, LIC Colony Opp Indira Park Hyderabad 500 080, IN

Abstract

No Abstract.

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Pradeep Raj ¹

Affiliations
1 Ground Water Department, Andhra Pradesh State, Hyderabad, IN

Abstract

High frequency (i.e., continuous record set at 6 hours interval) groundwater level monitoring was started in early 1998 in Andhra Pradesh under the National Hydrology Project. Well hydrographs in the hardrock terrain during the monsoon period show erratic rising trends interspersed with flatter or declining trends, indicating that monsoon recharge occurs in short bursts. The hydrographs during the non-monsoon period show linear recession limbs. However, some hydrographs exhibit a slow-down in rate of recession as the non-monsoon period advances, thereby causing the trend to become curvilinear and fitting into exponential or geometric curve. Curvilinear trends are due to the effect of a complex aquifer system that exhibits double porosity, boundary effects as well as anisotropic and heterogeneous behaviour. Coefficients of recession (R²) in recession limbs of all the hydrographs are nearly equal to 1, indicating that there are no irregular abstraction rates or irregular surges of recharge in non-monsoon period, which would help in predicting nonmonsoon water levels. Diurnal fluctuations within both the rising limbs and recession limbs, do not show any appreciable difference except at the precise time of recharge surge. Exponential recession coefficient of the hydrograph at the end of recession period, when only the aquifer parameters influence the data i.e. the decline in water level, indicate approximate specific yield values of 0.009 to 0.038. However, apparent specific yields obtained using water table fluctuation from the well hydrographs in hydrologic budget equation and commonly adopted value (10%) of rainfall infiltration factor (r.i.), are abnormally low (0.003 to 0.022). This is partly explained by the deep water table (>12 m), and also suggests higher rainfall infiltration factor.

Keywords

Groundwater Monitoring, Piezometers, Hard Rocks, Rainfall Infiltration, Groundwater Recharge, Andhra Pradesh.

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S. Das ¹, Pradeep Raj ²

Affiliations
1 18 Madhusudan Nagar, Unit 4, Bhubaneswar - 751 001, IN
2 Ground Water Department, Flat 6, Suman Apts. 1-3- 183/40/46/1, Gandhinagar, Hyderabad - 500 080, IN

Abstract

No Abstract.

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