Suitability evaluation of groundwater for irrigation purposes: A study on tea garden belts villages of Golaghat District, Assam, India

摘要

A study was carried out to assess the quality of underground water for irrigation purposes in the tea garden belts of Golaghat district of Assam, India. A total of 30 groundwater samples were analyzed for pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Chloride Fluoride, Hydrogen Carbonate, Nitrate–Nitrogen, Sulphate, Phosphate, Sodium, Potassium, Calcium, Magnesium, Boron and Iron. In addition to assess the water quality for irrigation purposes sodium adsorption ratio (SAR), soluble sodium percentage (SSP) and residual sodium carbonate (RSC) were calculated using standard equations. The concentration of Ca, Mg, Na, K, Cl-, F-, NO3-N, SO4 2-, HCO3 - and Fe in water samples were within the permissible range of drinking purposes. The calculated kurtosis values for Ca, Mg, Na, K, B, Fe, Cl-, F-, NO3 - -N, SO4 2-, HCO3 - and PO4 3- are less than 3 (β23). For pH kurtosis was found in normal distribution curve (β2=3) whereas for EC the curve is mesokurtik (β2 3). The SAR value ranges from 1.02 to 24.14. Out of 30 sampling stations 26 station’s SAR are found excellent for irrigation (SAR10), two station falls in good class (SAR=10-18) and other two falls in medium class. The study revealed that more than 50% water samples are not suitable for irrigation purposes (RSC 1.25). The range of SSP% was recorded 6.78-70.07. SSP% for ten stations found in excellent category (SSP% 20), fifteen stations in good category (SSP%= 20-40) and others are medium to vary bad category.