certain vistas of geoinformation technology for water

JOURNAL OF APPLIED HYDROLOGY Vol. XXV No. 3&4, July & Dec., 2012, pp. 1-8

CERTAIN VISTAS OF GEOINFORMATION TECHNOLOGY FOR WATER RESOURCES MANAGEMENT C.J. Kumanan Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli-620023 Email: [email protected] ABSTRACT Importance of water resources has been felt deeply by the Government and the people all over the world. Scientists from different parts have made plans to prospect, conserve, and manage both surface and groundwater resources by integrated approach using the fast emerging Geoinformation technology through continuous monitoring, mapping, surface and subsurface data base generation and 2D and 3D modelling them in order to better understanding of terrain conditions, accurate planning and decision making for future. Geoinformation technology has been a boon for Earth Scientists and has got every proven tool to handle any such situation mentioned above with all capabilities of handling huge spatial and non-spatial data. In case of water resources, the immense credibility of Geoinformation technology are exploited through various research studies conducted in Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli in various dimensions and activities such as, Surface Water Resources Targeting, Quantity Estimation of both runoff and static water and forecasting of their daily availability, Budgeting, Pollution Monitoring, Reservoir Siltation and Management. Similarly, using Remote Sensing and Digital Image Processing techniques for deriving terrain information, and GIS which is an important tool in incorporating field data and conducting spatial analyses, several studies have been conducted and derived quick and easy methodologies for groundwater targeting in hard rock and sedimentary aquifers, understanding of aquifer functions and its modelling, groundwater flow movement monitoring, numerical modelling of natural recharge, suitable site selection and mechanism detection for artificial recharge, and estimation of volume of subsurface rechargeable containers. This key paper describes both the integrated methodologies adopted in such research studies conducted in our Centre and the capabilities of Geoinformation technology in water resources prospecting, management and conservation for attaining sustainable development. Introduction Life in this world exists since it has held Water in it. Water is one of the highly essential things for all living beings. Because of this, all-living beings had and having their habitats in and around water sources. Ever since, the demand for water increased due to over population in all living beings. Amongst all, the humans started depleting in an unplanned and unscrupulous manner by exploiting the groundwater through various conventional methods. Later he started using the advanced technologies such as Remote Sensing and Geophysical technologies and very recently the GIS technology. Though the exploitation has become inevitable for humans, he should have simultaneously planned for replenishing this renewable resource. Now, since the situation reached very critical stage, the surface water body restoration and the groundwater recharge programmes have taken important placement in Government sector in general and each and every human activity in particular. One such programme is the Roof top Harvesting of Rainwater. Under this we had developed and practicing lot more conventional methods for groundwater recharge by pushing the rainwater into the ground (aquifer) by constructing various types of artificial recharge structures. 1

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This paper deals with some findings arrived out of research studies carried out at Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli on surface and groundwater management using Geoinformation technology. Surface Water Resources Surface Water Targetting Remote Sensing satellite images are most useful in targeting the surface water in every season accurately. The standard FCC images are clearly depicting the surface water availability in tanks, reservoirs and rivers distinctly in blue shades based on the absorption characteristics of water column of varying thickness in visible and IR spectrum (Kumanan, C.J. and Ramasamy, SM., 2001). If the thickness of water column is less along the upper fringes of tank, then there will be reflectance from the sand and clay from the tank bed lead to light blue shades in FCC. As the water column thickness increases towards the inner side and bund side of the tank, then the light ray entering the water body will get absorbed and the shades of dark blue and black will be the result as it deepens. Hence, it is easy to classify such tanks that are heavily silted and hence having reduced storage capacity, moderately silted, less silted and unsilted or desilted tanks having full storage capacity for different seasons and maps can be generated showing the availability status of water bodies for drinking, agriculture, industries, etc. Surface water quantification and Budgetting Accordingly, it is also possible to quantify the surface water available in terms of millions of cubic meters. For the same, it is important to bringout the bottom topography of water bodies such as tanks and reservoirs. Tank bed topography can be constructed using elevation data collected from topographic sheets, by conducting GPS survey, or from satellite data such as Cartosat, ASTER, etc., in GIS platform. Once the tank bottom topography is established well, then it is possible to declare the quantum of water available in each and every tank periodically by using the water spread area of all water bodies from temporal satellite data (Kumanan, C.J. and Ramasamy, SM., 2001). Based on the surface water requirement of the area by including the usages such as drinking, domestic, agriculture, industry, etc., and the water availability in surface water bodies, it is possible to generate overall surface water budget of the area. Surface water pollution Surface water pollution monitoring has been effectively done using satellite data for many areas in Tamil Nadu in general and Cauvery river in Tiruchirappalli region in particular (Ramasamy, SM, 1993 and Ramasamy, SM, et al., 1996). . Based on the reflectance property of river water, it is possible to delineate the pollutant source such as point discharge from industries / domestic sewage, or light sediment that are floating on the surface, etc., and movement of polluted water in river course. Surface water management Based on the percentage of siltation, each water body can be prioritized for periodic desiltation of them so as to keep them with fullest water storage capacity before monsoon. In order to arrest the silt in the catchment itself, it is important to understand the terrain controlling paramaters of soil erosion and construct check dams, grassed water ways, paved chutes, etc., to retain the soil in the catchment itself (Ramasamy, SM, et al., 1997). Further, in the entry point of the tank and reservoir, silt trap can be constructed in suitable place to filter the silt in the upstream area. Similarly, the supply canals and tank bunds need to be strengthened and all encroachments along water ways need to be removed and maintained periodically.

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Certain Vistas of Geoinformation Technology for Water Resources Management

Ground Water Resources Groundwater Targetting The unscrupulous mining of groundwater reservoirs has led to uncontrolled fall of water table all over the world. For the past nearly three decades, man has started using technologies like Remote Sensing and Geophysics and recently the Geographic Information System for groundwater targetting and management. While such hunting of groundwater targets has been comparatively easy in sedimentary aquifer systems, it has ever remained a challenging problem in the hard rock aquifer systems because of their heterogenic nature owing to poly phase metamorphism and multiple deformations. However, Remote Sensing has provided a possibility to locate the fracture systems, which only act as the master conduits for the groundwater flow as well as act as storage cabins in hard rocks (Ramasamy, SM., and Bakliwal, P.C., 1989). So, in the initial phase of the Remote Sensing era, especially during 1970-1985, the Geoscientists have started mapping all fractures as water bearing but when they found appreciable failure rate, they started thinking more on the fracture dynamics and morphology so as to distinguish the water bearing fractures from that of water barren. Subsequently, when the GIS technology was born, the geoscientists have started using it in codifying and amalgamating huge amount of multivariate geo scientific data for groundwater targeting in the hard rock aquifer systems too. For quick groundwater targeting in hard rock aquifer systems, various aquifer characteristic data need to be generated, especially on transmissivity, permeability, storage co-efficient and water level (Kumanan, C.J., and Ramasamy, SM., 2001, Ramasamy, SM, et al., 2001, Palanivel K., 2008). By analyzing the above aquifer parameters individually we can locate possible ground water locales in the areas of high transmissivity, high permeability, high storage co-efficient and in the areas of minimum water level. To get a better groundwater prospect area we can integrate these individual prospect areas through GIS and demarcate where all the positive areas of all the above aquifer parameters have coinciding and have influence. Aquifer Function Modelling Ground water occurs in various conditions in the underground. In general, it is either controlled by rock types or structure (Palanivel, K. and Ramasamy, SM 2002 and Nagappan, N. and Ramasamy, SM.2005), or geomorphology or sub surface lithology (thickness of top soil, weathered zone, fracture zone etc). In order to identify the controls of aquifer the GIS image showing groundwater targets need to be generated first followed by GIS images showing maxima of various aquifer controlling parameters. The groundwater target image has to be overlaid with all the other GIS images on controlling parameters and the entire area will be fragmented into number of aquifer systems according to the combinations of controlling parameters (Usha, K., et al., 1989, Vasudevan, S. and Ramasamy, SM. 1997, and Palanivel, K. and Ramasamy, SM, 2003). But, in hard rock the groundwater is generally controlled by the fractures. The aquifer function analysis between ground water and fracture so for carried out revealed that fractures of different chronology have got variable controls over groundwater (Ramasamy, SM., and Jayakumar 1993, Palanivel, K., Vasudevan, S., et al 1997, Ramasamy, SM, 2000, Kumanan C.J., and Ramasamy SM 2003 and Palanivel K and Ramasamy SM 3

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2005). For this study very detailed fracture mapping is essential for which the remote sensing data is very much useful. Fracture verses the ground water analysis can be more effectively carried out through GIS. Natural Recharge During the rainy seasons, immediately after the rain, in some areas the water level raises up to 50cm and in some areas 1 to 5 mts. These variance is due to the variability of geological and terrain conditions. Once these controlling parameters are understood spatially then those can be motivated. Brief Methodology

 Demarcate natural recharge zones from the 30-50 years of pre monsoon and post monsoon water level i.e. demarcate areas with varying increase of water level after the rain.

 Prepare various thematic maps on aquifer controlling geological parameter such as lineaments, fracture density, thickness of top soil, thickness of weathered zone, thickness of fracture zone, depth to bed rock, drainage density, slope, land use land cover etc. Both natural recharge map and the various thematic maps can be studied together in i) Through mathematical model (factor varimax analysis) by assigning numerical grades for various thematic maps, to find out one to one mathematical relationship between natural recharge and controlling parameters. ii) Spatial overlay through GIS technology to fragment the area into number of polygons (pieces of land) where natural recharge of varying depth is controlled by various parameters and its combinations. Once the controlling parameters are identified for various natural recharge conditions through both mathematical and spatial analysis we can very well suggest suitable scientific recharging methodology for each and every piece of land. For example: By this above mathematical analysis if you find a piece of land where the parameters such as thickness topsoil (TTS), thickness of weathered zone, (TWZ), depth to bedrock and slope are in required level, but the other variables such as thickness fracture zone (TFZ), and water level (WL) are not in the required level to have 5 mts of water level raise (recharge) during rainy season. So, to have 5 mts of water level increase during rain in this particular area, these two parameters, TFZ and WL must be modified by increasing the thickness of subsurface fracture to the required level by hydro fracturing and the existing water level must be kept at favorable depth (by suitably pumping out excess water just before the rain) so that the subsurface geological system allows increase of 5 mts water level during rainy season (Ramasamy, SM, et al., 1997, Ramasamy, SM, et al., 2000 and Ramasamy, SM, et al., 2005). Artifical Recharge The artificial recharge scheme is a ticklish art to understand its complexity many scientific criterions will have to be studied in detail. This involves identification of suitable site, deduction of site specific mechanism, estimation of allowable recharge, estimation of available surface water resources etc, then only such artificial recharge scheme can be fully viable and effective. Site selection: Selection of suitable site has become foremost and mandatory requisite in any artificial recharge scheme. This warrants detailed studies on various geological, geomorphological (Anbazhagan,

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S., and Ramasamy, SM., 1997a), sub surface geological (Anbazhagan, S., and Ramasamy, SM., 1997b) and subsurface hydrological characters. Evaluation of geological parameters: The geological parameters such as rock soil contacts, folded structures, lineament density, soil types are the essential components and they play vital role in the selection of suitable sites for artificial recharge. For example as for as folded structures are concerned the areas of synformal folds and basinal folds are favorable areas for recharge whereas the areas of domal and antiformal folds are unfavorable. Similarly the lineament/ fracture density maxima zone is highly favorable whereas in the soil type the highly porous soil is much suitable for recharge (Ramasamy, SM, et al., 1996). Finally the above favorable zones i.e. the soil area from rock soil contact maps, the zones of synformal and basinal structures in fold style maps, the lineament maxima zone from lineament map and the zones of porous soil from soil type map can be buffered out, integrated together and the areas of coincident of all the above themes can be taken as the favorable areas for recharge as for as geological parameters are concerned. Evaluation of Geomorphology: The regions of null slope, drainage density minima, the zones of colluvial fills, levees, avulted drainages, paleo channels, bazadas, covered pediments etc are the favorable areas for recharge as for as the geomorphology is concerned. The buffered areas of above characters can be integrated and the areas where all these characters coincide can be demarcated as favorable areas for recharge as for as the Geomorphology is concerned. Evaluation of subsurface geology: Similarly, in the case of subsurface geology the maxima zones of thickness of topsoil, thickness of weathered zone, thickness of fracture zone and depth to bed rock are the favorable zones. The areas where all the above maxima zones coincide in the integration, those areas are highly favorable as far as the subsurface geology is concerned. Evaluation of subsurface hydrology: The zones of deeper water level indicate, maximum thickness of unsaturated zones and hence, forms suitable sites for recharge. Finally, such favorable recharge areas demarcated from the above geological, geomorphological, subsurface geology, subsurface hydrology can be integrated and wherever all the above four themes are coinciding, those areas can be considered as priority area I. Detection of Site Specific Mechanism: Different types of artificial recharge mechanisms, which are mostly site-specific in nature such as flooding and dentritic furrowing, percolation ponds, pitting etc. Hence, these mechanisms will have to be selected depending upon the site’s exact ground conditions (Ramasamy, SM. 2002 ). The following are some of the suitable site-specific artificial recharge mechanisms.

 Dendritic furrowing and flooding can be in the areas of null slope areas.  Percolation ponds can be in the areas where the slope is less than 5% with appropriate catchments and porous subsurface media.

 Pitting can be in the areas where drainage density is more which indicate clayey topsoil.  En- echelon damming can be along the wide rectilinear drainages etc. Estimation of volume of rechargeable formations: Estimation of volume of rechargeable formations is very important so as to design suitable recharge schemes according to the volume of such rechargeable containers. This includes the estimation of 5

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· Aerial extent of rechargeable zones · Average width of rechargeable zones · Thickness of unsaturated zones · Volume of rechargeable formations there from and · Actual allowable recharge. The areas of rechargeable formation can be estimated by multiplying the aerial extent, average width and thickness of unsaturated zones. Finally the actual allowable recharge can be estimated from the storage coefficient of the aquifer area. Estimation of surface water potential : It is also essential to work out the available water potential so that only this water can be pushed into the above estimated rechargeable formations. To work out this we need to estimate the surface run-off by taking considerations such as daily rainfall, slope, hydrological soil group, land use / landcover etc (Anbazhagan, S., et al., 2005). Conclusion Thus any ground water targeting attempt and designing of any recharge scheme needs detailed scientific analysis of the aquifer condition itself, then only we may be able to achieve fruitful result. To achieve a quick and more precise evaluation / study can be carried out through Remote Sensing and Geographic Information System. References Anbazhagan, S., and Ramasamy, SM., 1997a. Role of Remote Sensing in Geomorphic Analysis for Water Harvesting Structures. Proc. Vol. of National Seminar on Water Harvesting, REC, Trichy, pp.264 - 273. Anbazhagan, S., and Ramasamy, SM., 1997b. Geophysical Resistivity Survey and Potential Site Selection for Artificial Recharge in Central Tamil Nadu. Proc. of Int. Sym. on Engineering Geology and the Environment (IAEG), Athens, Greece, (1997), pp.1169-1173. Anbazhagan, S., Ramasamy, SM., and Edwin Moses, S., 1997. Artificial Recharge Studies through Remote Sensing in Central part of Tamil Nadu, India, IGARSS ’97. pp 29 -31. Anbazhagan, S., Ramasamy, SM., Dasgupta S., 2005. Remote Sensing and GIS for Artificial Recharge Study. Runoff Estimation and Planning in Ayyar Basin, Tamil Nadu, India, Environmental Geology, Vol. 48. pp: 158 – 170. Kumanan, C.J., and Ramasamy, SM., 2001. Groundwater Targetting in Kambam Valley, South India with the aid of satellite imagery. Escap Water Resources Journal, Bangkok, pp. 63- 73. Kumanan, C.J. and Ramasamy, SM., 2001. Surface water Forecasting Modelling: Using Satellite Infra-Red data. (Ed) R.P. Singh and Vinod Tare, Spec. Vol. of the Indian Society of Remote Sensing on “Spatial Technology for Natural Hazards Management”, pp.270-279. Kumanan C.J., and Ramasamy SM., 2003. Fractures and the transmissivity behaviour of the hard rock aquifer systems in parts of Western Ghats, Tamil Nadu, India. Escap Water Resources Journal, Bangkok (June), pp 53-59.

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Nagappan, N. and Ramasamy, SM., 2005. GIS Mapping of Fractured Aquifer Systems, Central Tamil Nadu, India. (Ed) SM.Ramasamy et al, Spec. Vol. on “Geospatial Technology for Developmental planning”, Allied Publisher, Chennai, pp. 225-232. Palanivel, K. and Ramasamy, SM., 2000. GIS and Hardrock Aquifer Function Modelling in Western Ghats Region, Tamil Nadu, India. Proc. Vol. of National Conference on Geoinformation 2000, PSG College of Technology, Coimbatore (2000), pp. 205-207 & 221-225 Palanivel, K. and Ramasamy, SM., 2002. Functions of Groundwater Flow in Folded Aquifer System Westernghats Region, South India (Ed) SM.Ramasamy et al, Proc. Vol. of National Conference on “IT Enabled Spatial Data Services” (GEOMATICS 2002), 18-20 September 2002, pp. 204-209. Palanivel, K. and Ramasamy, SM., 2003. “Space and Spatial technology in Hard Rock Aquifer Function modeling in Precambrian Tract of South Western of Tamil Nadu, India. Annual Convention of ISRS and National Conference on Remote Sensing, CESS, Trivandrum, December 2003 (in CD, 7 pages) Palanivel K and Ramasamy SM., 2005. GIS and Hardrock Aquifer Function Modelling in Western Ghats Region, Tamil Nadu, India. SM.Ramasamy (Ed.). Remote Sensing in Water Resources. Rawat Publishers, Jaipur. pp. 160-167. Palanivel K, Gunasekaran S, Ramasamy SM and Kumanan C.J., 2008. Geomatics Modelling of Geosystems for Groundwater Targetting, Pudukkottai District, Tamil Nadu, India. (Ed. Vol.) Asian Conference on Remote Sensing 2008. Pp. 1- 6. Ramasamy, SM., 1993. Pollution of Cauvery River using Remote Sensing. (Ed) Shankara Pitchaiah, Inland Water Resources India, Nagarjuna University. pp 361 - 377. Ramasamy, SM., 2002. Designing of Artificial Recharge Schemes in Hard Rock Aquifer Systems, Journal of Indian Water Works Association, pp.141-147 Ramasamy, SM., and Bakliwal, P.C., 1989. Groundwater Targetting of Banded Gneissic Complex, Rajasthan, through Remote Sensing. Proc. Vol. on National Symposium on Remote Sensing in Development and Management of Water Resources, SAC, ISRO, Ahmedabad, 1989, pp.277-284 Ramasamy, SM., and Jayakumar, R., 1993. Behaviour of the Aquifer Systems in Complexly Folded and Fractured Precambrian Regimes of Southern Indian Peninsula. Proc. Vol. on 19th Thematic Conference in Geol. Remote Sensing Exploration, Environment and Engineering ERIM California, 8 - 11, Feb, pp 597 - 608. Ramasamy, SM., Athithan, D.S.P., Jayakumar, R., and Vasudevan, S., 1996. Groundwater Quality Monitoring through Remote Sensing - A Mathematical Approach. (Ed) SM.Ramasamy, Trends in Geological Remote Sensing, Rawat Publishers, Jaipur, pp 217 - 230. Ramasamy. SM., Anbazhagan. S., and Moses Edwin. J., 1996. Control of Fracture Systems in Artificial Recharge with Special Reference to Crystalline Aquifer System in Tamil Nadu. (Ed) SM.Ramasamy Trends in Geological Remote Sensing, Rawat Publishers, Jaipur, pp.274 – 280. Ramasamy, SM., Kumanan, C.J. and Palanivel, K., 1997. New Techniques for improving the efficiency of Natural Recharge in Hard Rock Aquifer Systems. Proc. Vol. of Int. Con. on Management of Drinking Water Resources, CLRI, Chennai (1997), pp. 162-167.

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Ramasamy, SM., Vasudevan, S., Sindhanaivalavan, A., Kumanan, C.J., and Visveswaran, V.R., 1997. Reservoir Siltation Prevention by Catchment Treatment Models - A GIS Study, Proc. Vol. on Nat. Seminar on Application of GIS for Solving Environmental Problems 6 - 8, Aug. Technical Teachers Training Institute (TTTI), Chennai, pp.84-89. Ramasamy, SM., Pugalenthi, P.L., Saravanavel, J.,Gunasekaran, S. and Anandan, C., 2000. Nourishment of Aquifer Systems Through Natural Recharge Using GIS. Proc. Vol. of National Conference on Geoinformation 2000, PSG College of Technology, Coimbatore (2000), pp. 211-217. Ramasamy, SM., Kumanan C.J. and Palanivel. K., 2001. Remote Sensing and GIS Applications in Rapid groundwater appraisals in hardrock aquifer systems of Tamil Nadu, India. Proc. Vol. of ICORG 2001, on Remote Sensing and Geographical Information Systems, BS Publications, Hyderabad, pp.170-177. Ramasamy SM, Kumanan C.J and Palanivel, K., 2005. Certain New Tech-niques for Improving the Efficiency of Natural Recharge in Hard Rock Aquifer Systems. SM.Ramasamy (Ed.). Remote Sensing in Water Resources. Rawat Publishers, Jaipur. pp. 175-184. Usha, K., Ramasamy, SM., and Subramanian, S.P., 1989. Fracture Pattern Modelling for Groundwater Targetting in Hard Rock Terrain - A Study Aided by Remote Sensing Technique. Proc. Vol. on International Workshop on Appropriate Methodologies for Development and Management of Groundwater, 28 Feb – 4 Mar, 1989, NGRI, Hyderabad, pp.319-328. Vasudevan, S. and Ramasamy, SM., 1997. Evaluation of Groundwater Functions in Vellar Tamil Nadu using GRAM - GIS. Information Studies, Vol. 3, No. (3). pp 180 - 185.

Basin,

Vasudevan, S., Ramasamy, SM., Venkatachalam, P. and Suri, J.K., 1997. Detection of Ground water Barrier in Vellar Basin Using Remote Sensing and GIS. Proc. Vol. of Int. Con. on Remote Sensing and GIS (ICORG), Hyderabad (1997), pp.141-145.

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