Exploration for Gold and Associated Base Metal Mineralisation in Bhukia Area, Banswara District, Rajasthan

Palghar, Thane, Raigad, Ratnagiri, Sindhudurg and Greater Mumbai districts of Maharashtra form the Konkan Coastal belt of Maharashtra. In the coastal areas the immediate effect of high groundwater development is often sea water intrusion. Although there were sporadic studies by earlier workers (Umrikar et al., 2007, Gupta et al. 2010) into some reported isolated cases of seawater intrusion in the coastal areas, this has been a maiden attempt to decipher the extent of seawater intrusion in the entire coastal tract of Maharashtra.The area is underlain by Dharwarian meta-sediments (Lower Precambrian age), Deccan Trap lava flows (Upper Cretaceous to Lower Eocene age), Laterites (Pleistocene age) and Coastal alluvial deposits (Recent to Sub-Recent age). Groundwater occurs under phreatic condition in the Coastal and riverine alluvium, laterites and weathered/fractured rocks. The area has been covered by systematic hydrogeological surveys, reappraisal Surveys and groundwater monitoring by CGWB. in these formations depth to water levels range from 0.6 m bgl to 8.07 m bgl. Groundwater is mildly alkaline with pH range of 6.9 to 9.0. Electrical conductivity ranges from 61 to 29370 ?S/cm at 25?C. Only two Samples from Dapoli in Raigad district show EC values higher than 3000 ?S/cm at 25?C. In general, water quality is good and suitable for domestic use and irrigation. In order to confirm the sea water intrusion, ionic ratios like Na:Cl, and Cl:CO3 + HCO3, were computed. From the analysis it is found that about 2 to 10 km wide coastal belt and the inland tidal backwaters are affected by salinity intrusion. It is revealed that about 55% of the analysed samples have indicated salinity ingress. The extent of sea water intrusion is more in the southern part progressively diminishing towards northern area. The maximum effect is observed in Sindhudurg district followed by Ratnagiri, Raigad, Palghar and Greater Mumbai.Over-exploitation of groundwater in pockets and diminishing seaward freshwater flow in the rivers are the major reasons for sea water ingression. Regulation of groundwater development in the coastal area and areas adjacent to estuaries, maintaining adequate stream flow, stopping of riverbed sand mining, construction of tidal regulators at suitable places and creation of fresh water barrier through rainwater harvesting and groundwater recharge are essential to control further sea water intrusion in the area.

CGWB (1997) Master Plan for Goa state. Central Ground Water Board, Faridabad. CGWB (2009-2011) Basic Data reports of Piezometers. Hydrology Project-II in North and South Goa Districts, Goa State, Central Ground Water Board, 2011. CGWB (2013) Report on Ground Water Exploration in Goa State. Technical Report of Central Ground Water Board, Faridabad, 2013. CGWB (2015) State Report of Goa (Hydrochemistry), Central Ground Water Board, Faridabad, 2015. DPSE (2009) Statistical Handbook of Goa. Directorate of Planning, Statistics and Evaluation, Panaji, Goa, 2009. DOWR (2012) Ground Water in Goa. Department of Water Resources, Govt. of Goa, 2012. DPSE (2011) Goa at a glance. Directorate of Planning, Statistics and Evaluation, Panaji, Goa. 2011. Gopalakrishnan, Gukul, A.R., Srinivasan (1985) Stratigraphy and Structure of Goa, Earth Resources for Goa?s Development (publication), Geol. Surv. India, 1985. Gukul, A. R. (1985) Structure and Tectonic of Goa, Earth Resources for Goa?s Development (publication), Geol. Surv. India, 1985. Subburaj, A. and Davithuraj, J. (2019) State Report of Goa (Hydrogeology), Central Ground Water Board, Bangalore, 2019. Subramanian, P.R., Sahoo, K.B. Bhatnagar, S.K (1997) Results of Ground water exploration in hard rock areas of Vidarbha Region, Maharastra, Proceedings of National seminar on Hydrogeology of Precambrian Terrains and Hard Rock Areas, Karnatak University, Dharwad.

Rajasthan is the largest state of India covering an area of 3,42,239 sq.km and represents 10.5% of the country?s geographical area. On the other hand it has only 1.15% of total surface water and 2.6% of dynamic groundwater resources of the country?s resources due to arid climatic conditions. Surface water availability is restricted to command areas of canal system; hence groundwater is the only dependable source in major part of the state. Groundwater quality deterioration with depth coupled with low and erratic rainfall has generated constraints as regards availability and development potential of groundwater resources. Over exploitation of groundwater has caused mining of groundwater, which has set in declining trend in water level and threatening depletion of limited available fresh groundwater resources at an alarming rate. Management of groundwater resources in this context is an extremely complex proposition. The highly uneven distribution of groundwater and its utilization make it impossible to have single management strategy for Rajasthan as a whole. Any strategy for scientific management of groundwater resources should involve a combination of supply side and demand side measures depending on the regional setting and local geology and also on use of saline water. There are saline water tracts in various parts of the state. Recently conservation of water through crop diversification and use of saline water in several parts of the state has gained momentum.

Madhya Pradesh is endowed with sufficient surface water. This water is available to the state thorough perennial rivers Narmada, Son, Tapti, Chambal, and Wainganga. These rivers also have numerous perennial tributaries. The total surface water availability in the Chambal, Betawa, Ken catchment is 45 cubic km; 29.29 cubic km in the Son catchment; 52.43 cubic km in the Mahanadi river catchment; 40.83 cubic km in the Narmada catchment and 4.53 cubic km in Wainganga and Pench catchment. Madhya Pradesh received erratic precipitation during the last five years . So it does not have sufficient surface water. The need is for proper management of available surface water resources including systematic monitoring and water conservation techniques. Involvement of Panchayats and other stakeholders is essential to augment surface water bodies through tanks and other rainwater impounding structures. It is time that the stake holders should be aware of the availability of resources for future use, and benefits of conjunctive use of surface and groundwater.

The high reliability of rural and urban settlements on groundwater in India and the individualistic nature of groundwater usage make groundwater management and governance extremely challenging. Groundwater resources development in India, even today, has progressively become synonymous with increasing the accessibility of the resource through more and more sources and meeting the growing demand through the infrastructure of distribution. Management of groundwater becomes selflimiting when the focus is on exploration for new sources, without understanding resource behaviour. On the other hand, experience has shown that bringing aquifers to the centre stage of groundwater management is important. The concept of aquifers changes the way in which communities begin to perceive groundwater and becomes the first step in developing socioecological resilience to groundwater-related vulnerability. Building resilience to groundwater-related vulnerability further includes developing a governance mechanism that strikes a balance between supply management and demand regulation through an understanding of the resource, i.e., the aquifer.Aquifer systems in India are highly diverse and complex because of the variation in their inherent properties such as storativity, transmissivity and groundwater quality. Aquifer vulnerability is a consequence of not only how the rampant exploitation and contamination of groundwater occur, but also how different aquifers react to these fluxes. Moreover, irrespective of the scales of groundwater accumulation and movement, micro-level analysis of aquifers becomes imperative because of the atomistic nature of groundwater access and use. A systematic hydrogeology-based approach that requires delineating aquifers, understanding the dynamics of groundwater and mapping the demand and dependence of community on the resource holds the key to decentralized groundwater governance in India. Such an approach can be undertaken through participatory monitoring, decision support and action.The inherently heterogeneous nature of aquifers and communities in western and central India demand a strategic application of mapping, characterizing and managing local aquifers through a participatory groundwater management protocol. This nuanced approach beginning with aquifers as both a resource and a system, ensures equitable, efficient and hence, the sustainable management and governance of aquifers in this region.