Modelling of sea water intrusion with Hele–Shaw model: a case study around Surat City, Gujarat

Abstract

Sea water intrusion along the seacoast is getting accelerated because of excessive pumping in coastal areas. In this paper, the sea water intrusion around Surat City for three zones—Zone I containing Hazira; Zone II containing Jahangirpura, Piplod and Dumas; and Zone III containing Rander and Amroli—is studied with help of the Hele–Shaw model. The total dissolved solids (TDS) are also determined to learn the extent of deterioration of groundwater quality. The observation well data were used to quantify the parameters required for the formulation of the model. The results obtained from the study show that for the without-recharge condition, the sea water intrusion was 19.91 km inside the coastal area from the sea shore, and with the two rates of recharge of 2.175 × 10⁻³m³/s/m and 10.73 × 10⁻³m³/s/m by increasing the level of fresh water in the Hele–Shaw model (recharge well method), the intrusion was 90% and 50% of the original intrusion length. However, the average TDS value of fresh water over the study area is higher than 500 mg/l and is unsuitable for drinking.

Keywords:

• sea water intrusion
• Hele–Shaw model
• water quality