ISOTOPIC STUDY OF GROUNDWATER AND SURFACE WATER INTERACTION DURING PRE MONSOON SEAAON OF DARLIPALI AREA

Abstract

The area of study is around the Super thermal power plant (STPP) which is located in the Darlipali village in lephripara taluk of Sundargarh district,Odisha.. The site is located between 21 ° 52'57 "N and 22 ° 03'32" N latitude and 83 ° 49'29 "E longitude and 83 ° 57'31" E longitude and is well connected to Sundargarh by road. The field study was conducted in May 2016. In this study, samples of groundwater and surface water were collected for isotope characterization in the 10 km zone of Darlipali STPP. To identify groundwater isotope signatures, samples were collected from open pits, pipe wells and hand pumps, and surface water samples were collected from ponds and rivers. On-site measurements such as sample temperature, pH, conductivity and all other relevant site information were also recorded. Samples were collected and analyzed for isotope composition at the Roorkee National Institute of Hydrology. Oxygen and hydrogen isotope measurements were performed using a dual-input isotope mass spectrometer (GV instruments, UK) with automatic sample preparation units. The overall accuracy based on repeated 10-point repeated measurements of each sample was ± 0.1 for δ 18 O and ± 1 for δD. The enrichment in δ18O and δD observed in river water clearly indicates that surface water is subject to greater enrichment by evaporation. Evaporation in some areas is very high and the lightest isotope evaporates, enriching the mass of water in the heavier isotope. The results allow us to conclude that the groundwater in the area is recharged with rainwater during the pre-monsoon period