Dr. S.N. Rai

Department of Earth SciencesIndian Institute of Technology Roorkee

Roorkee- 247667

Ex-Chief ScientistCSIR-National Geophysical Research Institute

Hyderabad-500 007

E-mail: snrai_ngri@yahoo.co.in

Dept. of Hydrology, IITR, Sept, 17, 2014

Groundwater management in hard rock area

using geophysical methods

Sustainable

Development

Delineation &

Development

GovernanceManagement

Sustainable development rejects all policies and practices that

leads to depleting the resource base by fulfilling present needs

and leaving future generation unable to meet their demands.

General four electrode array of resistivity survey

C1 P1 P2 C2

A M N B

BNANBMAM

K

I

VKa

1111

12

Electrode configurations (or arrays)

A

Vaa

2

I

V

l

lLa

2

22

Dipole-Dipole configuration

naa aC2 P2P1C1

Pole- Dipole configuration

aP2C1∞ P1na

Pole-Pole configuration

a P2C1∞ ∞

Four 160-m

multiconductor

cables with 16 takeouts

at 10-m spacing

4×64 channel relay

switching unit

High-resolution

Voltmeter with current

amplifier and active

booster interface

Terrameter Imaging System

Lay out of 4 multi-electrode cables with Terrameter, Electronic

switching unit, and laptop computer

2-D Inverse modeling and interpretation

• RES2DINV program automatically creates a 2D model by

dividing the subsurface into rectangular blocks

• Calculates the apparent resistivity values of the model blocks

using either a finite difference or finite element method

• Compares these to measured data. The resistivity of the model

blocks is adjusted iteratively until the calculated apparent

resistivity values of the model agree with the actual

measurements.

• The final output displays the 2-D variation of true formation

resistivity which is interpreted in terms of hydro-geological

form.

Case studies

Chandrabhaga river basin, Nagpur district,

Vidarbha region, DVP

Tawarja river basin, Latur district, Marathwada

region, DVP

Hot springs of Chiplun Taluk, Ratnagiri district,

DVP

In and around Hyderabad, Granitic terrains

Tadkeshwar lignite mines, Surat district, DVP

Chandrabhaga river basin (Deccan Traps),

Nagpur district, Vidarbha region- case study

25 km in North-West of Nagpur city

Between 78o42’ to 79o East Longitudes and

21o11’ to 21o20’ North Latitudes

Geophysical Investigation details :

Vertical Electrical Soundings :45 sites

Electrical Resistivity Tomography : 56 sites

Investigated area :

~500 sq. km encompassing 50 villages spread over

in parts of Katol, Kalmeshwar and Rural Nagpur taluks

Regional stratigraphy of the region (Mehta, 1989)

Recent to Quaternary

-----------------------------------------

Alluvial, Black cotton soil

and weathered formation

--------------------------------------

Deccan basalt lava flow

(Cretaceous to Eocene)

Vesicular and

Massive basalt layers with

intervening intertrappeans

------------------------------------------------------------------------------------

Lameta beds(Infratrappeans) Thin sedimentary sequences

-------------------------------------------------------------------------------

Gondwana Sandstone of upper Kamthi

Group

1 10 100 1000

1

10

100

1000

Current Electrode Spacing (AB/2) in m

Computed

Observed

S 41

n h

37.5 0.8 91.1 2.9 25.2 22.4 94.2 15.0 26.1 3.5184.0 36.0 60.1

Resis

tivity(

) in

Oh

m -

m

S42

S41

S 42

nh

6.2 0.5 14.5 9.0140.7 27.6 52.2 4.9127.5 10.4 34.5

S43

S44S45

S 43

n h

3.3 3.5 25.4 9.8 46.6 32.6124.5 10.2 20.3

S 44 n h

4.3 5.4 23.5 9.3 42.5 31.6112.6 12.2 21.0

S 45 n h

5.0 2.3 33.8 4.6109.2 25.4126.1 23.0242.0 12.4 20.6

S40

S 40

n h

7.8 6.5 14.8 7.2113.6 24.8217.1 16.9 15.8

Alluvial, Black cotton soil and Bole bed : 5-10 Ohm m

Weathered/fractured/ vesicular basalt saturated

with water : 20-45 Ohm m

Moderately weathered/fractured/vesicular basalt : 40-70 Ohm m

saturated with water Massive basalt : >70 Ohm m

Water saturated Lameta bed : < 10 Ohm m

Water saturated Gondwana sand stone : < 30 Ohm m

Resistivity ranges for different lithos unit (CGWB web site)

Ubali S 41

Rock samples of S2 Site at 3.33 m intervals (10 ft)

Kotwlbardi S10

Raulgaon; S 38

Societal Benefit:

Distribution of true resistivity with depth and Lithologs of borewell

P1 – Ghogali, (E 78o52’9.6” N 21o 14’ 19.2” )

(a) Distribution of true resistivity with depth and borewell location at Khairi, Kalmeshwar

Taluk, Nagpur district

(b) Lithologs obtained from borewell drilling

P21 – Khairi (E 780 50’ 39.7” N 210 12’ 46.9”)

W E

P-13 Samundari

E W

P14-Wathoda

N 21017’09.8”, E78049’36.0”

N 21016’56.8”, E78050’38.9”

P17-Waroda

P8-Waroda

N 21016’25.6”, E78054’20.1”

N 21015’45.4”, E78053’40.8”

Tawarja Basin (Deccan Traps), Latur District, Marathwada

NNN

Geothermal exploration

ofilesERTandhotspringsofLocations Pr

NW SEF

F

NW SENW SEF

F

2D Resistivity model near Unhavare hot spring along L1 profile

2D Resistivity model near Unhavare hot spring along L2 profile

E W

F

FE W

F

F

F

FF

F

S NF

F

F

F

S NS NF

F

F

F

S N

F

F F

FF

F

2D Resistivity model near Tural hot spring along L3 profile

2D Resistivity model near Tural hot spring along L4 profile

Granitic formation

Tadkeshwar lignite mine, Surat district, Gujarat

Development & Management

WEES, Jan. 12-16, 2009

Well hydrographs for

Piezometer upstream,

T(u) and downstream,

T(d) of Tandlam

subsurface dam (after

Raju et al 2006)

Subsurface check

dam, Swarnamukhi

river (after Raju et al.

2006)

Perforated casing of bore well

The Hindu, April 19, 2013

Drilling holes in the Thirst Economy, P. SAINATH

WATER PLUNDER:The owner of this brand new bore well rig says that all told it cost him Rs.14 million. But he can

recover that in six months by drilling just two wells a day

Roof top rainwater harvesting

Conclusions:

Scarcity of water supply is not because of non-availabilty of

groundwater but due to scarcity of proper scientific investigations.

Scientific investigations should be followed by development of

infrastructures like bore wells, and structures like ponds, check

dams for managing aquifer recharge.

Sharing of scientific findings with stakeholders to facilitate

implementation of development schemes to achieve the preset

objectives of development and management.

A substantial amount of scientific projects should be allocated for

development of groundwater resources in a form useful for society.

Acknowledgements

• Dr. S. Thiagarajan

• Dr. Dewashish Kumar

• Mrs Y. Ratnakumari

• Dr. V. Anand Rao

• M. Bulliabai

• Shri G.B.K. Shankar

• Mr. M. Sateesh Kumar

Related literature

•Dewashish Kumar, Rai, S.N., Thiagarajan, S. and Ratnakumari, Y., 2014. Current Science,

vol 107.

•Rai, S.N., Thiagarajan, S., Dewashish Kumar, Dubey, K.M., Rai, P.K., Ramchandran, A. and

Nithya, B., 2013. Current Science, vol. 105 (10), 1410-1418.

•Rai, S.N., Thiagarajan, S., Ratnakumari, Y., Anand Rao, V. and Manglik , A. 2013.

Journal of Earth System Sciences. 122(1), 29-41.

•Rai, S.N., Thiagarajan, S., Ratnakumari, Y and Kumar, D. 2012. J. of Applied Hydrolgy, XXV

(3&4), 85-94.

•Ratnakumari, Y., Rai, S.N., Thiagarajan, S. and Dewashish Kumar, 2012. Current Science,

102(1), 61-69

•Rai, S.N., Thiagarajan, S. and Ratnakumari, Y., 2011. Current Science, 101(9), 1198-1204.

•Kumar, D, Thiagarajan, S. and Rai, S.N., 2011. Journal of Geol. Soc. India, 78, 541-548

•Thiagarajan, S., Rai, S.N., Dewashis Kumar and Ratna Kumari, Y. (2013). J. of Earth System

Science (communicated).

•Rai, S.N., Thiagarajan, S., Kumar. D. and M. Bulliabai, 2011. Hydrogeological investigations

in Tadkeshwar Lignite mine of Gujarat Mineral Development Corporation (GMDC) Ltd.,

Technical Report No. NGRI-2011-GW-766, p. 29.

The Earth has provided adequate natural

resources to meet our needs but not greed

Thank you