Karnataka, India

JECET; March 2016- May 2016; Sec. A; Vol.5. No.2, 153-166.

E-ISSN: 2278–179X

Journal of Environmental Science, Computer Science and Engineering & Technology An International Peer Review E-3 Journal of Sciences and Technology Available online at www.jecet.org Section A: Environmental Science Research Article

Geomatics Application on Climate Change and Its Impact on Groundwater Table Fluctuation in Parts of Upper Cauvery Basin (Mysuru and Chamarajanagara Districts), Karnataka, India *Basavarajappa H.T, Dinakar S and Manjunatha M.C Department of Studies in Earth Science, Centre for Advanced Studies in Precambrian Geology, University of Mysore, Manasagangothri, Mysore-570006, India Received: 09 April 2016; Revised: 22 April 2016; Accepted: 25 April 2016

Abstract: Analyses of season-wise rainfall variations have been analyzed using 31 years (1971-2001) rainfall data. Rainfall trend alters the hydrological cycle and directly affects the surface & sub-surface water conditions. The spatial variability of mean annual precipitation depends upon the topographic factors like exposure of station to the prevailing wind, elevation, orientation and slope of the mountain. 13 years of Groundwater level has been recorded to study its fluctuation from 1990-2002. The average and mean rainfall & subsurface water level over the area are calculated using Arithmetic mean, Thiessen polygon and Iso-hyetal methods. Average rainfall, water level is the simple arithmetic mean measured in the area; while Iso-hyetal method has been adopted for rainfall & groundwater fluctuation analysis. Rain gauge stations are plotted 153

JECET; March 2016- May 2016; Sec. A; Vol.5. No.2, 153-166

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on a base map with their respective amount of rainfall and then the contours of equal rainfall (isohyets) are drawn using Surfer software and same groundwater levels. The different in rainfall & groundwater intervals obtained (area between the two adjacent lines) are helpful in understanding the variation of rainfall; groundwater over the study area. The final results highlight the impacts of climatic change over groundwater table fluctuation in parts of Upper Cauvery basin in Karnataka state, which is a suitable model in similar geological conditions. Keywords: Climate change, Groundwater table fluctuation, part of Upper Cauvery basin, Geomatics.

INTRODUCTION Rain is a form of precipitation, snow, sleet, hail and dew. The precipitation occurs when separate drops of waterfalls on the earth’s surface from clouds, however some evaporates while falling through dry air, a type of precipitation called virga1. Rise in temperature increases the evaporation of surface water and transpiration in wetlands2 resulting in low precipitation amounts, timings and intensity rates, which impacts on surface; subsurface water bodies and direct changes in major long-term climate variables such as air temperature, moisture content, precipitation & evapo-transpiration. Four conditions are necessary for the production of the observed amount of rainfall3 such as Mechanism to produce cooling of the air, Mechanism to produce condensation, Mechanism to produce growth of cloud droplets and Mechanism to produce accumulation of moisture of sufficient intensity to account for observation for rainfall. The precipitated water percolates to deeper zones to be stored as groundwater and its distribution is controlled by the nature of rock formation, geological structure, geomorphological and hydrometerological conditions4. Clouds dispel greater amounts of moisture over highland areas, due to a phenomenon known as “orographic lifting”. Orographic effects cause much higher volumes of precipitation to accumulate at higher elevations, while rainfall “shadows” develop in areas downwind of these same highlands. The shadow zones may receive as little as a quarter or less of the highland precipitation (David Rogers http://web.umr.edu). In the study area, low lying areas have relatively little precipitation due to the effect of a barrier such as a Biligiri-Rangan hill range that causes the prevailing winds to lose their moisture before reaching it. Groundwater resources in hard rock terrain are limited, which need to be planned scientifically for a better management and development of water resources5. Estimation of groundwater recharge requires proper understanding on the recharge; discharge process and their inter-relationship with geological, geomorphological, land use, soil and climatic factors6. Groundwater potential of an area mainly depends on rainfall and the amount of rainfall in any area varies from year to year. The representative rain gauge stations provide continuous data of rainfall, intensity and duration which is usually expressed in cm (centimeter) or mm (milimeter).

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STUDY AREA It lies in between 11°45’ to 12°15’ N latitude and 76°45’ to 77°15’ E longitude with total areal extent of 3,011 Km2 (Fig.1). The study area includes parts of 9 taluks of Karnataka state and a small patch of Tamil Nadu region (Sathyamangalam) in the southern and southeastern part. The present study is a part of Biligiri-Rangan hills of Karnataka, which belong to a typical hard rock terrain. The eastern portion of the study area forms a hilly terrain with lofty mountains (Biligiri-Rangan hill ranges) raising about 1677m above MSL, run approximately towards North-South direction with thick vegetation.

Fig.1: Location map of the study area

Fig.2: Rain gauge stations map of the study area

METHODS AND MATERIALS 1. Methods: Iso-hyetal method has been adopted for rainfall analysis in the present study. Rain gauge stations are plotted on a base map with their respective amount of rainfall and contours of equal rainfall (isohyetes) are drawn using ArcView1. The average rainfall between the successive isohyets taken as the average of the two isohyetal values is weighed with the area between the isohyets5. The different rainfall intervals obtained (area between the two adjacent lines) are helpful in understanding the variation of rainfall over the study area. Annual normal rainfall iso-hytel map is used for integration purpose6. For the generation of Iso-groundwater table fluctuation, the same methodology has been used and final results of fluctuation are generated in meters2. 2. Materials: i. Topomaps: 57D/16, 57H/4, 58A/13 and 58E/1 of 1:50,000 scale. 155


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Source: Survey of India (SoI), Dehradun. ii. Season-wise Rainfall (1971 to 2001 - 31 years) and Groundwater table data (1990 to 2002 - 13 years). Source: Field survey, Ground Truth Check (GTC) and Meteorological Department, Pune. iii. GIS Software’s: ArcGIS v10. iv. GPS: A handheld GPS (Garmin 12) is used to record the exact location of Rain gauge station & Observation well points of the study area during Ground Truth Check (GTC). v. Methods adopted: Arithmetic mean, Thiessen polygon and Iso-hyetal methods. RAINFALL Rainfall is the source for both surface & subsurface water storage conditions and essential aspects of hydrogeological study. Its seasonal distribution, normally and reliability will give an idea as to how the local recharge by rain would influence the groundwater1. The average annual rainfall recorded is 786.8 mm (2004) with a major contribution of South-West monsoon (44.45%). The annual minimum rainfall is found to be 558.07mm (Kavalande rain-gauge station) while the maximum is 1455.43mm (BiligiriRangan temple rain-gauge station). 31 years (1971-2001) Season-wise rainfall data of all available raingauge stations (Table.1; Fig.2) in the study area were collected & analyzed to understand the characteristics of rainfall5. 1. Seasonal distribution of rainfall: Precipitation over the Cauvery basin has been studied by Subrahmanyam and Venkatesh7 and reported that South-West monsoon contributes the major portion of annual rainfall. Seasonal rainfall data is very important for many instances such as agricultural activities as well as from the groundwater point of view6. The rainfall over the study area in a year is divided into three seasons as Pre-monsoon, Monsoon (South-West) and Post-monsoon (North-East) according to the State Meteorological Report (Bureau of Economics and Statistics, GoK). Pre-monsoon season starts from January to May, Monsoon from June to September and Post-monsoon from October to December. During pre-monsoon period, study area receives very low amount of rainfall, whereas during monsoon & postmonsoon periods the study area receives most of the annual rainfall (Table.1)5. 2. Spatial distribution of rainfall: The spatial variability of mean annual precipitation depends upon the topographic factors like exposure of the station to the prevailing wind, elevation, orientation and slope of the mountain8, 9. Arthmetic method is the simplest objective methods of calculating the average rainfall over an area. The simultaneous measurements for a selected duration at all rain gauges are summed and the total is divided by the number of gauges5. In 1911, the thiessen polygon method devised by an American engineer10, the rainfall measurements at individual gauges are first weighted by the fractions of the catchment area represented by the gauges, and then summed. On a map of the catchment with the rain gauge stations plotted, the catchment area is divided into polygons by lines that are equidistant between pairs of adjacent stations. Iso-hyetal method of rainfall assessment is the most convenient method as it views the continuous spatial variation of rainfall area1. In this method drawing lines of equal rainfall amount (isohyets) using observed amounts at stations11. The average depth is then determined by 156


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computing the incremental volume between each pair of isohyets, adding these incremental amounts and dividing by the total area. Average rainfall is the simple arithmetic mean rainfall measured in the area6. 3. Season wise analysis of rainfall: 3.1 Pre-Monsoon: The rainfall in this season ranges from 132.46 mm (Bilagere) to 263.34 mm (BiligiriRangan temple) accounting approximately 23.48% and 18.09% to the annual rainfall respectively with an average of 196.91 mm. The iso-hyetal map of pre-monsoon season depicts that the rainfall is decreasing from East towards North-Western parts of the study area5. 3.2 Monsoon: The average rainfall recorded is about 349.73 mm accounting approximately about 44.45% which is the maximum contribution for normal annual rainfall. It ranges from 221.95 mm (Kavalande) to 773.11 mm (Biligiri-Rangan temple) contributing about 39.77% and 53.12% of the annual rainfall respectively. The iso-hyetal map for monsoon season depicts that the rainfall is decreasing from East to Western parts of the study area5.

Table 1: Rain gauge station-wise rainfall data of the study area (1971-2001) Sl no

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

Premonsoon (mm) Kavalande 156.87 Terakanambi 181.38 Haradanhalli 174.74 Bilagere 132.46 Udigala 189.08 Ummattur 184.98 Kuderu 205.95 Mangala 184.37 Muguru 190.42 Chamrajnagar 218.39 Mudigunda 193.78 Lokkanahalli 161.39 Kunturu 219.95 Kollegal 207.05 Tirumakudal Narsipur 187.89 Bailur 221.25 Hunsur 242.95 Yelandur 225.12 Biligiri-Rangan temple 263.34 Average 196.91 Location

Percentage 28.11 25.79 26.69 23.48 27.36 26.63 27.91 26.59 25.58 27.34 25.88 20.98 27.09 24.60 23.87 23.73 28.49 24.76 18.09

Monsoon Post- monsoon Annual Percentage Percentage (mm) (mm) (mm) 221.95 270.92 273.64 275.11 276.2 299.22 301.3 303.44 320.17 336.65 349.53 354.84 359.68 370.24 370.79 381.44 392.66 414.15 773.11 349.73

39.77 38.53 41.79 48.76 39.96 43.08 40.84 43.76 43.02 42.15 46.68 46.12 44.30 43.99 47.10 40.90 46.04 45.55 53.12

179.23 250.87 205.7 156.83 225.9 210.38 230.54 205.54 233.72 243.72 205.47 253.11 232.32 264.4 228.6 329.85 217.25 269.95 418.97 240.12

32.12 35.68 31.42 27.80 32.68 30.29 31.25 29.64 31.40 30.51 27.44 32.90 28.61 31.41 29.04 35.37 25.47 29.69 28.79

558.07 703.18 654.74 564.2 691.2 694.58 737.8 693.36 744.3 798.76 748.79 769.35 811.96 841.7 787.28 932.55 852.81 909.23 1455.43 786.8

3.3 Post-Monsoon: Most of the rainfall during post-monsoon is closely associated with the westward passage of storms and depressions that are remnants of low pressure systems moving into the Bay of Bengal12. The average rainfall in this season is 240.12 mm, which contribute 30.15% to normal annual rainfall. It ranges from 156.83 mm (Bilagere) to 418.97 mm (Biligiri-Rangan temple) contributing about 157


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27.80% and 28.79% of the annual rainfall respectively. The iso-hyetal map of post-monsoon season depicts that the rainfall is decreasing from East towards North-Western parts of the study area.

Fig.3: Pre-monsoon isohyets rainfall map (mm)

Fig.5: Post-monsoon isohytes rainfall map (mm)

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Fig.4: Monsoon isohytes rainfall map (mm)

Fig.6: Annual isohytes rainfall map (mm)


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Table 2: 31 years of Rainfall data in mm (1971-2001)

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Sl. No

Year

Pre-monsoon

Monsoon

Post-monsoon

Annual

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.

1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

259 267 245 253 271 119 243 183 248 312 167 177 158 223 211 156 108 256 143 221 187 117 133 271 239 143 182 267 163 159 143

234 187 141 201 223 81 183 143 267 107 234 88 179 133 171 139 157 217 168 115 213 221 135 109 231 318 132 38 126 257 158

237 188 143 203 228 281 189 147 271 108 237 191 183 139 173 141 157 219 171 119 217 227 139 113 227 322 136 42 131 259 157

243 214 176 219 241 160 205 158 262 176 213 152 173 165 185 145 141 231 161 152 206 188 136 164 232 261 150 116 140 225 153


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Fig.7: Line graph depicting Season-wise Rainfall fluctuation in mm (1971-2001)

Fig.8: Line graph depicting Annual Rainfall fluctuation (1971-2001) WATER TABLE The zone of groundwater, or phreatic water, is divided from the capillary fringe by the water table which is a theoretical surface approximated by the elevation of water surface in wells which penetrate only a short distance into the saturation zone13. Unconfined aquifer is not overlined; but underlained by a confining layer at its bottom and is saturated with water and the upper surface of the saturation is termed as water table, which is under atmospheric pressure. Groundwater resources can be classified as static and dynamic. The static resources can be defined as the amount of groundwater available in the permeable portion of the aquifer, below the zone of water level fluctuation. The dynamic resources can be defined as the amount of groundwater available in the zone of water level fluctuation5). The usable groundwater resource is essentially a dynamic resource, which is recharged annually or periodically by rainfall, irrigation return flows, canal seepage and influent seepage, etc. The magnitude of the water table fluctuation also depends on climatic factors, drainage, topography and geological conditions. Water table also declines due to the heavy withdrawal of groundwater by pumping wells4. Near streams, the water table fluctuates in response to the change of level in river stage. Cauvery and Kabani are the two major rivers flowing in the study area and Kabini is also a tributary of river 160


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Cauvery6 There are various methods in use for the quantitative evaluation of groundwater recharge14 viz., (a) Groundwater level fluctuation and specific yield method, (b) Rainfall infiltration method, and (c) Soil moisture balance method. Groundwater recharge depends not only on specific yield of the aquifer material, but also on many other factors viz., soil properties, geomorphic units and land use (Saraf et al., http.//www.gis development.net). Groundwater recharges in the study area observed mainly by direct infiltration of meteoric water5. However, in some places adjacent to the river and canal system, considerable extent through infiltration of irrigation application leads to recharge of groundwater4.

Fig.9: Observation well points map of the study area (MGD, Mysuru) 1. Groundwater fluctuation: In the present study, 22 representative observation well points have been identified to study the fluctuation in water table from season to season (Fig.14). Once in a month water level in all observation well points are recorded1. Overall, 13 years subsurface water level data (19902002) have been collected and analyzed for seasonal and annual fluctuations (Table.3 & 4). The subsurface water table level ranges from 2.19m (Bilagere) to 25.10m (Yediyur observation well). Ferdowsian15 presented a new approach called HARTT (Hydrograph Analysis: Rainfall and Time Trends) for statistically estimating groundwater levels. Their method differentiates between the effect of rainfall fluctuations and the underlying trend of groundwater levels over time5. 1.a Pre-monsoon groundwater table fluctuation: During pre-monsoon season, the groundwater table fluctuates from 3.54m to 23.37m with an average of 11.81m. Groundwater table fluctuation map (Fig.10) indicates that the water table depth is high in the southern, central and western part of study area occurring as isolated patches, while low in northeastern and northwestern parts5.

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1.b Monsoon groundwater table fluctuation: The average water table during monsoon is about 13.55m and its variation from 3.54 to 25.10m (Fig.11). The water table depth is high in southern, central and western parts; in which exploitation of groundwater are noticed to be very high in central part of the study area. 1.c Post-monsoon groundwater table fluctuation: In this season, the water table ranges from 2.19 to 22.38 m with an average of 11.58m. The spatial variation in depth of water table follows the general trend of the previous season. Groundwater table fluctuation map (Fig.12) indicates the rise in water table when compared to the other seasons1. Generally, it rises at the end of the rainy season and as the summer season advances get lowered progressively and reaches the lowest level. 1.d Annual groundwater table fluctuation: It depicts that the water table depth is high in southern, central, eastern and western part of the study area. The North-Eastern and North-Western parts are fortunate by Cauvery and Kabani Rivers for groundwater recharge1. However, gneissic rocks are highly weathered, slope varies from nearly level to very gentle slope and good agriculture activities are noticed due to the water table availability ranging from 5 to 11 m below ground level (Fig.13)5.

Table 3: Observation well point-wise Groundwater level data in mts (1990-2002) Sl. No Location 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

Dhanagere Kollegal Lokkanahalli Uttamballi Bannahallihundi Hemmige Mugur Biligere Hanumanapura Thagadur Kavalande Terakanambi Bisalavady Chamrajnagar Devalapura Haradanahalli Harave Kagalavady Masagapura Yanagahalli Yedapura Yediyur

Pre-monsoon (m) 6.90 11.52 18.45 5.94 8.22 4.01 5.63 3.54 11.22 20.39 11.33 14.01 21.59 14.87 5.28 11.76 14.37 11.58 15.60 9.03 11.31 23.27

Monsoon (m) 7.88 13.25 19.42 6.69 8.41 3.89 6.14 3.54 13.30 19.71 15.14 17.78 24.46 17.77 5.17 22.56 13.32 14.54 17.38 10.07 12.65 25.10

Post-Monsoon (m) 6.13 10.38 16.79 4.72 6.38 2.80 4.57 2.19 12.03 18.53 13.01 13.75 21.34 15.18 3.64 22.38 11.58 10.80 18.44 8.04 10.29 21.97

Average Annual Water table (m) 7.03 11.84 18.16 5.88 7.80 3.69 5.63 3.20 12.37 19.69 14.18 16.33 22.77 15.99 4.83 20.95 14.39 12.43 18.53 9.13 11.50 23.05

Though the rainfall is very high in Biligiri-Rangan hill rain gauge station, but ground water table is high due to its topography, steep slopes and high runoff 4. On other hand, ground water table remains constant 162


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in northeast and northwestern part in all the season due to the Perennial rivers6.Aquifer recharge occurs in nature by rainfall, seepage from canals and reservoir and return flow from irrigation. The geomorphic features like alluvial plains, pediplains, old stream channels and the deep seated interconnected fractures are the indicators of subsurface water accumulation16.

Fig.10: Pre-monsoon Groundwater isohytes map

Fig.11: Monsoon Groundwater isohytes map

Fig.12: Post-monsoon Groundwater isohytes map

Fig.13: Annual Groundwater isohytes map

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Table 4: 12 years Groundwater level data in mts (1990-2002) Sl No 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

Year 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Pre-monsoon 12.12 12.39 9.68 10.17 9.97 10.31 9.83 10.37 10.09 10.73 13.59 12.19 15.92

Monsoon 12.21 12.39 9.87 10.17 9.91 10.29 9.94 11.29 11.04 10.78 13.82 13.31 15.81

Post-monsoon 13.17 9.61 9.37 9.26 9.71 9.57 9.64 9.51 9.19 9.45 9.73 11.11 15.89

Annual 12.5 11.46 9.64 9.86 9.86 10.05 9.8 10.39 10.1 10.32 12.38 12.2 15.87

Fig.14: 12 years of Season-wise Groundwater table fluctuation in mts (1990-2002)

Fig.15: 12 years of Annual Groundwater table fluctuation in mts (1990-2002) 164


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CONCLUSIONS Physiography of the terrain in particular depicts two separate regions i.e., the high land area and low land area. The high land area forms a hilly terrain with lofty mountains ranging to 1677m above mean sea level in the eastern part, whereas low land with an average elevation of 686m with minor undulation in the western part. Representatively there are 31 observations well points have been identified to study the fluctuation in water table from season to season. The rainfall values of the study area ranges from 558.07 mm (Kavalande) to 1455.43 mm (Biligiri-Rangan temple) with an average of 786.80 mm; South-West monsoon rainfall contributes to a large extent (44.45%) to the normal annual rainfall. The iso-hyetal map of 31 years normal rainfall of the study area indicates that all decreases from East towards North-Western parts of the study area. The impact of land use in the prevailing surface and sub-surface hydrologic condition is remarkably high in the study area. Once in every month, the subsurface water levels in all observation wells are recorded. The water table in the study area has a wide variation between 2 and 30m. The low lying area shows least, while the drainage dividing areas show maximum fluctuations. The lowest fluctuation (3 m) is observed at Haradanahalli and highest fluctuation of 12m at Kavalande. Groundwater discharges are noticed primarily through artificial heavy withdrawal of water from most of the observation well points and to a lesser extent through lateral flow to the lower section contributing to the base flow in streams and rivers. The groundwater table is almost constant in the North-Eastern and North-Western parts of the study area due to presence of Perennial Cauvery and Kabani Rivers. Maximum withdrawal of groundwater is observed in central part. Wells at higher elevation show maximum fluctuation, while those at lower elevations particularly noticed on alluvium plains have the least fluctuation. At present summer season (April-2016), the average annual temperature is 370C and may rise up to 420C in the coming years, representing the Global Warming (?) impact in the study area. ACKNOWLEDGMENT The authors are indepthly acknowledged to Prof. K.G. Asha Manjari, Chairman; DoS in Earth Science, CAS in Precambrian Geology, University of Mysore, Mysore-06; Dr. M.V Satish, Rolta India Ltd, Mumbai; Nagesh, MGD, Govt. of Karnataka for their support in GIS work and UGC, New Delhi for financial support. REFERENCE 1. H.T. Basavarajappa, K.N. Pushpavathi and M.C. Manjunatha, Climate Change and its impact on Groundwater Table Fluctuation in Precambrian rocks of Chamarajanagara district, Karnataka, India using Geomatics technique, International Journal of Geomatics and Geosciences, 2015, 5, 4, 510-524. 2. M.C. Manjunatha, H.T. Basavarajappa and L. Jeevan, Climate Change and its Impact on Groundwater Table Fluctuation in Precambrian Terrain of Chitradurga District, Karnataka, India using Geomatics Application, International Journal of Civil Engineering and Technology (IJCIET), 2015, 6, 3, 83-96. 3. Gilman and S. Charles, Handbook of applied hydrology compendium of water resources technology, Mc Graw-Hill Book Company, New York, 1964, 9-68. 165


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4. H.T. Basavarajappa, S. Dinakar, M.V. Sathish, D. Nagesh, A. Balasubramanian and M. C. Manjunatha, Delineation of Groundwater Potential Zones in Hard Rock Terrain of Kollegal Shear Zone (Ksz), South India Using Remote Sensing and GIS, International Journal of Earth Sciences and Engineering (IJEE), 2013, 6, 5(1), 1185-1194. 5. S. Dinakar, Geological, Geomorphological and land use/land cover studies using Remote Sensing and GIS around Kollegal Shear Zone, South India, Unpub. thesis, University of Mysore, 2005, 1-191. 6. K.N. Pushpavathi, Integrated, Geomorphological study using Remote Sensing and GIS for development of wastelands in Chamarajanagar district, Karnataka, India, Unpub. Thesis, University of Mysore, Mysuru, 2010, 1-201. 7. V.P. Subramanyam and H. Venkatesh, Hydrometeorology of Kavery river basin – A climatic study of rainfall and potential evapotranspiration. Proceedings of the seminar on ‘Hydrology’, Osmania University, Hyderabad, 1983, 95-100. 8. A. Basist and G. D. Bell, Statistical relationships between topography and precipitation patterns; Journal of Climate, 1994, 7, 1305-1315. 9. A. Simon and K. Mohan Kumar, Spatial Variability and Rainfall Characteristics of Kerala, Proceedings of the Indian Academy of Science (Earth Planetary Sciences), 2004, 113, 211-221. 10. A.H. Thiessen, Precipitation for large areas, Monthly Weather Rev., 1911, 39, 1082-1084. 11. W.G. Reed and J.B. Kincer, The preparation of precipitation chart, Monthly Weather Rev., 1917, 45, 233-235. 12. P.K. Das, The monsoons, National book trust of India, 1995, 88. 13. S. N. Davis and R. J. M. DeWiest, Hydrogeology. John Wiley and Sons Inc., New York, USA. 1970. 14. C.W. Thornthwaite and J.R. Mather, Instructions and tables for computing potential evapotranspiration and the water balance. Publications in Climatology, Laboratory of Climatology, 1957, 10, 3, 185- 311. 15. R. Ferdowsian, D.J. Pannell, C. McCarron, A. Ryder and L. Crossing, Explaining Groundwater Hydrographs, Separating Atypical Rainfall Events from Time Trends, Australian Journal of Soil Research, 2001, 39, 861-875. 16. L. Mukherjee and D. Das, A study on the development of basins and their hydrogeomorphic features in and around Ajodhya Plateau, Eastern India, Proc. International Symposium on Intermontane Basins: Geology and resources, 1980, 409417.

Corresponding Author: *Basavarajappa H.T Department of Studies in Earth Science, Centre for Advanced Studies in Precambrian Geology, University of Mysore, Manasagangothri, Mysore570006, India

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