Abstract:
Rapidly growing human populations with its attendant needs for water
and food supplies have resulted in global exploitation of available water and land
resources. Over exploitation of groundwater has become a common issue along the
coastal areas of Batticaloa district and consequently, many coastal regions in the district
experience extensive saltwater intrusion in aquifers resulting deterioration of the quality
of groundwater resources. Therefore, this study was conducted during the period
between July to August 2009, with a view of assessing irrigation water quality with
pumping duration at the farmers field of Kaluthawalai coastal village. The irrigation
water samples were collected from wells in different locations at 30 minutes time
interval. Collected water samples were analyzed for pH, Electrical Conductivity (EC),
Total Dissolved Solids (TDS), cation concentrations (Na, Ca and Mg) and Sodium
Adsorption Ratio (SAR). Then the results were statistically analyzed to find the
correlation between water quality parameters and pumping duration.
Correlation study revealed that EC (r = 0.317, pO.05) and TDS (r = 0.308,
p<0.05) of irrigation water showed significant positive correlation whereas, sodium (r =
0.087, p > 0.05), magnesium (r = 0.106, p > 0.05) and sodium adsorption ratio (r =
0.090, p > 0.05) of irrigation water showed non-significant positive correlation with
pumping duration. Calcium (r - -0.083, p > 0.05) and pH (r = -0.074, p > 0.05) showed
non-significant negative correlation with duration of pumping. Further, this study
reveals that, EC and TDS concentrations are increasing with the pumping duration in
study site and it will affect the crop yield by deteriorating the soil in long run.
Therefore, proper management practices such as improve the drainage, intermittent
irrigation practices and the use of drip irrigation method might be the solutions for the
existing water quality problem in the study area.
