Groundwater flow modelling using visual modflow and studies on the effect of saline water intrusion in Tavanur-Ponnani area

Abstract

Groundwater is an important source of water which is drastically declining due to the increased exploitation by human beings. Groundwater models are increasingly used in modelling of groundwater flow problems to develop useful information about groundwater resources. Visual MODFLOW is an efficient groundwater flow modelling software. In this study the MODFLOW model is applied to assess the groundwater flow and availability in Tavanur-Ponnani area of Malappuram district, Kerala. 18 0bservation wells were established in the study area. A conceptual model was constructed based on the topographical, climatic and hydrogeological data of the area along with the field observation data including the water table level in the observation wells. The recharge in the area was taken as 10% of the average rainfall of the area during the period of study. A steady state model was developed on the basis of the average groundwater heads for a 3 year period. The study also includes the calibration of the model, the validation of the model and the prediction of the groundwater conditions of the study area in the succeeding year. The model predicted the flow of groundwater and its velocity in magnitude and direction. The western part of the study area is taken as the constant head boundary and the river boundary is taken along the river bharathapuzha with proper values of river stage and bottom elevations. The model created during our study provides a clear idea of the groundwater characteristics of the Tavanur-Ponnani area and it will help in the future studies and development of the groundwater management in the area. The groundwater modelling using the visual MODFLOW software is well understood by this study. Samples of water were collected from the observation wells established in the study area. Quality analysis of the water sample was done to assess the quality of groundwater and the extent of salt water intrusion the area. A socio-economic survey was done to get an idea about the effects of saline water intrusion on the living status of people in the area. This study helped us to get an overall idea about the quality of water and its effect on people in our study area.