- Dona Paula, Goa, India.
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- iiosc2020[at]nio[dot]org
| Abstract Submission No. | ABS-2022-09-0278 |
| Title of Abstract | Investigations on submarine groundwater discharge zones along south Goa, Central west coast of India |
| Authors | R.Prakash*, C.D. Pesso, P.M. Kessarkar, V.J. Loveson, S. Verma, S. Vaz, G. Tirodkar |
| Organisation | CSIR-National Institute of Oceanography |
| Address | Geological Oceanography Division, CSIR-National Institute of Oceanography Dona Paula, Goa, Goa, India Pincode: 403004 Mobile: 8903863610 E-mail: hydroprakash@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Abstract Goa receives average 3300 mm of rainfall within a short span of four months every year. This water is flown to the sea as surface water and part is percolated into bottom soil/rocks as groundwater. The physiography of Goa is dominated by the spread of the Western Ghats to the east followed by the coastal plains. Goa is covered mostly by lateratized soil/rocks that help in percolation of water into the groundwater. South Goa has numerous sandy beaches, one is ~25 km long and others are smaller pocket beaches being enveloped between promontories on two sides. To understand the submarine groundwater discharge (SGD) in the south Goa coastal region, archival data and available information were consulted. In addition, thermal infrared images available from Earth Explorer of United States Geological Survey were downloaded and processed. Sea surface temperature during pre-monsoon and post-monsoon periods of 2018, 2019, 2020, and 2021 were generated for off south Goa. Prepared thermal thematic maps/images showed areas adjacent to the coast with warmer temperature surrounded by colder temperature and vice versa. With reference to the coastal groundwater data and the thermal images, 8 beach sites were selected for the detailed field survey. At these 8 locations, seawater was collected from intertidal zone. Pore water was collected along a transect perpendicular to the coast at 10 m distance, with first sample in the intertidal zone. Groundwater from open/bore wells closest to the coast was also collected. Beach profiling survey was conducted across the beaches and linked to the closest well. The results show that smaller coastal areas bounded by hills on the two sides have significant variations in pore/seawater parameters and beach profiles as compared to the larger sandy beach. The conductivity of pore water in the intertidal areas at 1 m depth was much lower than that of the seawater on beaches bounded by hills suggesting probable SGD zones. Keywords: Submarine groundwater discharge, Thermal infrared images, hydrogeochemistry, and south goa. |