灌漑・排水システム工学

Evaluation of Groundwater Suitability for Drinking and Irrigation Purposes in Toba Tek Singh District, Pakistan

Abstract

Muhammad Hasan, Yanjun Shang, Gulraiz Akhter and Weijun Jin

Correlating the physicochemical parameters for assessment of the groundwater quality has emerged as a very useful approach for water use. Taking water samples from the Toba Tek Singh District of Pakistan, this study assess the water quality for drinking and irrigation purposes. A sum-total of 72nos. groundwater samples were collected and analyzed for the purpose of different water quality parameters including sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO- 3), chloride (Cl-), sulphate (SO4 2-), pH, electrical conductivity (EC), total dissolved solids (TDS) and total hardness (TH). The results obtained were, then, compared with the standard desirable limits of physicochemical parameters prescribed by World Health Organization (WHO), Pakistan Standards and Quality Control Authority (PSQCA) and Pakistan Council of Research in Water Resources (PCRWR) for drinking purposes. In order to classify the groundwater suitability for irrigation purpose, parameters such as sodium adsorption ratio (SAR), percent sodium (PS), permeability index (PI), residual sodium bicarbonate (RSBC), Kelly’s ratio (KR), and magnesium adsorption ratio (MAR) were also calculated on the basis of chemical data. After that, the correlation coefficients between different physicochemical parameters were calculated to identify the highly correlated and interrelated parameters for water quality. Different plots like Piper, Durov, Schoeller and Stiff diagrams were drawn to classify the groundwater ability for different purposes. These several classifications show most of groundwater samples falling within the safe limits and thus suitable for drinking and irrigation purposes, except of a few samples with a caution that it may get worse in the future.