Appraisal of Water Quality Measurements for Canal and Tube Well Water Systems for Agriculture Irrigation in Rechna Doab, Pakistan

Abstract

The present study was an attempt to assess the surface and ground water quality for irrigation suitability in
Rechna Doab. Irrigation water quality at canals and tube well water were analyzed by physicochemical parameters
including pH, Electric Conductivity (EC), important cations such as Calcium (Ca2+) Magnesium (Mg2+), Potassium (K+),Sodium (Na+), important anions such as Chloride (Cl-), Bicarbonate (HCO3 -), Sulphate (SO42-), three heavy metals including Zinc (Zn), Nickel (Ni) and Copper (Cu). Twelve water samples were collected from the main canals (Lower Gogera canal, Jhang branch canal and Rakh branch canal) while fifty water samples were collected from the tube wells. Statistically, data were analyzed by generating correlation coefficients. Canal water quality parameters i.e. Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Sodium Percentage (Na %), Kelly Ratio (KR), Soluble Sodium Percentage (SSP), Residual Sodium Bicarbonate (RSBC), Permeability Index (PI) and Potential Salinity (PS) with their mean values 0.16,38.18, 8.03, 0.08, 10.17, 0.08, 28.34 and 0.024 respectively were calculated. Piper and Durov diagrammatic representations provided the suitability of the canal water regarding ionic composition. Results revealed that the status of the canal water was fit for agriculture. On the contrary, the data about Electric Conductivity (EC), Sodium Adsorption Ratio (SAR) and Residual Sodium Carbonate (RSC) of tube well water (with their maximum values 4.80, 29.65 and 13.60, respectively) was exceeding the FAO limits owing of sodium hazards. Thus, the scenario of groundwater is alarming due to unfit status of tube well water regarding irrigation purposes. Out of total 50 water samples of tube wells, 11 samples were found to be fit. While 39 samples were unfit for crop irrigation. Geo-statistical analysis was performed by using Inverse Distance Weighted (IDW) technique created in Arc map. 

Keywords: Surface and ground water quality, Physiochemical parameters, Irrigation quality indices.