An Evaluation of Carbonaceous Metaphytic remains from the Proterozoic Singhora Group of Chhattisgarh Supergroup, India

Chemical quality of surface and groundwater of an area is influenced by the climate, hydrological conditions, soil characteristics and geological formation. Irrespective of their source, all natural waters contain some chemical constituents and their quality changes progressively as they traverse over the land surface or infiltrate downward due to various hydro-geochemical processes. Anthropogenic factors also contribute substantially towards quality change of both surface water and ground water. In the present study an attempt has been made to understand the aquifer vulnerability to pollution, at the regional scale (Goa State), which takes into account the intrinsic hydraulic and hydrogeological parameters and environmental impacts. It is noticed that a variety of activities, such as agricultural, industrial and urban land uses, are carried out in the area, thus exposing the aquifers to a wide range of contaminants. Groundwater quality data of Goa state for the pre-monsoon seasons of 2014 and 2018 were obtained from CGWB (Bengaluru) and analysed statistically. A regional scale approach was developed which is known as ABHESHT (Aquifer type, Boundary conditions, Hydraulic Head representing static water level, Environmental impact, Solute concentration, Head variation (Water Table Fluctuation) during pre-monsoon and post-monsoon seasons and Transmissivity). The method has been applied to Goa State, west coast of India and compared with the observed groundwater quality parameters. It is found that the model has successfully delineated the wells which are prone to pollution. Using GALDIT model, seawater intrusion impact was also assessed. The study revealed that the groundwater of Goa State did not show any significant pollution indicator, however, seasonal variations in water quality parameters were observed. It is also found that the North Goa coast as well as the other tourist spots spread over the entire state show signs of pollution at various locations (Anjuna. Baga, Mapusa. Concona etc). This calls for immediate attention from the concerned authorities.

Goa is drained by several rivers like Terekhol, Mandovi, Zuari, etc. and their tributaries, many of which show tidal influence and related saltwater intrusion. The surface water resources of the state have been assessed at about 8570 Mcum with 1465 Mcum utilizable resources (1125 Mcum surface water, 340 Mcum ground water). Presently, surface storages available are to the tune of 335.87 Mcum in the tanks, diversion structures such as bandharas, weirs, etc. The macro level surveys indicate ground water available is to the tune of 43.83 Mcum and utilization is to the tune of 33% which is considered as safe. Major and medium schemes like Salaulim, Tillari, Anjunem and minor irrigation schemes like Chapoli, Panchawadi, and Amthane irrigation projects cater to the agricultural needs of Goa State. The Sal-Amthane, Salauli-Kalay River Inter Linking Projects in Goa augmented the source to a tune of 156 lakh cubic meter. The paper discusses the water requirement and water resources management of Goa by 2051.

In western India, the states Goa, Gujarat, Maharashtra and Rajasthan having area of 0.11%, 5.97%, 9.36% and 10.41% of India respectively have 0.24%, 6.83%, 13.48% and 4.52% of the total population of the country. The area, except Goa which records high precipitation, receives moderate rainfall. Arid conditions prevail in north Gujarat and major part of Rajasthan. The utilization pattern of ground water is uneven across the region resulting in ground water stressed conditions and over exploitation in some parts, particularly the arid regions and sub-optimal ground water utilization in others. Water level varies widely being very shallow in the southern part and deep to alarmingly deep in the northern part, having deepest water level of the country in Bikaner district of Rajasthan. Water quality is of concern in the major parts. In considerable areas, some chemical constituents exceed the permissible limit for drinking water, and large patches with brackish to saline water are encountered in Rajasthan and Gujarat. Sporadic occurrences of Fluoride and Nitrate in ground water exceeding the permissible limit for drinking water are spread almost throughout the region which necessitates cautious use of ground water in these areas for drinking purposes. The stage of ground water development is 37%, 68% and 54% in Goa, Gujarat and Maharashtra respectively. In Rajasthan, the stage of ground water development is 140% and 164 out of 248 ground water assessment units are overexploited and 23 ground water assessment units in Gujarat are over exploited. This requires immediate judicious intervention without which some areas will not be able to meet even the drinking water needs. Groundwater withdrawal requires to be strictly regulated so that it does not exceed the annual recharge and also that it does not disturb the hydro-chemical balance. Alarming declines in groundwater levels warrant immediate attention for taking-up of recharge schemes to arrest further decline and augment the groundwater resources. In areas of scanty recharge, ground water should be allowed only for drinking water purposes. In other areas, along with water conservation and ground water augmentation measures, demand side management using micro irrigation techniques and change of cropping pattern etc should be religiously adopted.

Air, Solar energy, Land, and Water are the four life support systems of which, only ?Water? is amenable for its development and management to meet human needs of water. Water Resource Development structures had to be compatible to the characteristics of ?Water Resource?. With the advancement of civilization, ingenuity of man prompted him to evolve different types and sizes of infrastructure to meet changing patterns and increasing magnitude of water demand. It also stressed the need to have an integrated approach in such development. Subsequently as a soft option, improvement in management of infrastructure was the next logical step. As the issue of complexities in the competing and conflicting demands on water surfaced prominently, need for taking a holistic approach towards them was thought of and there emerged the viable solution in the form of better governance of water resources. An attempt has been made here in below to present evolution of all these developments by citing a case study of Maharashtra State in the Peninsular India. It mentions at the end a ?Vision Statement? for the future development of the State in the water sector and an outline of future planning and policies which need to be adopted. In conclusion it states a framework of desirable actions to be taken in future, to transform the ?Vision? into a reality.