A comparative study of ground water and surface water quality in the Jia – Bharali river basin, Assam, India with reference to Physico - Chemical characteristics

Abstract

A comparative assessment of the hydrological quality of the shallow aquifers and surface water sources in the Jia Bharali River basin and adjoining areas of the Himalayan foothills has been made in this work. Six set of seasonal samples were analysed with respect to the common physicochemical parameters including major anions (carbonate-bicarbonate, chloride, sulphate, fluoride, nitrate and phosphate), and cations (calcium, magnesium, sodium, potassium). 74 % of the aquifers had higher TDS and 88 % had higher hardness in the wet seasons. The major cations were in the ranges of Ca: 7.1 -43.9 mg/L, Mg: 2.1 -25.9 mg/L, Na: 3.8 -40.8 mg/L, and K: 2.1 -22.7 mg/L. The total alkalinity was almost entirely due to the presence of bicarbonate. The aquifers are rich in chloride (5.6 -110.7 mg/L) and sulphate (3.1 -83.1 mg/L) with nitrate (BDL to 0.72 mg/L) and phosphate (BDL -1.27 mg/L), the latter being significantly high for some aquifers. In case of surface water sources, the major ions show wide variability (Ca: 1.56 -45.45 mg/L; Mg: 0.56 -14.56 mg/L; Na: 3.10 -14.30 mg/L; K: 1.0 -11.50 mg/L). The surface water rich in chloride (2.28 -38.45 mg/L) and sulphate (0.38 -29.45 mg/L), is also contains the nutrients, nitrate (BDL -1.45 mg/L) and phosphate (BDL -1.48 mg/L).

Assessment of water quality in and around Jia-Bharali river basin, North Brahmaputra Plain, India, using multivariate statistical technique

“…The wet season values (Wet) and dry season values (Dry) of all the parameters are presented by taking the averages of three wet seasons and three dry seasons values, respectively. In the present work, the GW samples had pH from 5.6 to 7.6 (mean value 6.7) in the wet seasons and from 5.9 to 7.4 (mean value 6.7) in the dry seasons (Khound et al 2012). The pH difference between wet and dry season was insignificant.…”

“…18% of the wells in wet seasons and 24% of the wells in the dry seasons were found to have acidic pH, while majority of the wells in both seasons had pH in guideline range (6.5-8.5) proposed by WHO (2011) for drinking purposes. The SW samples were found slightly alkaline in nature during both the seasons with the averages being in the range of 6.1-7.4 (mean value: 6.7) in the wet seasons and from 6.3 to 8.0 (mean value 6.8) in the dry seasons (Khound et al 2012). The water sources were thus found suitable for irrigation purposes with respect to pH, i.e., there was no alkalinity hazard.…”

“…A few of the TDS values were very large during the wet seasons indicating considerable input through the surface runoff. The TDS values of SW sources varied in a wide range of 55-130 mg/L (mean value: 86 mg/L) in the wet seasons and 70-170 mg/L (mean value: 103 mg/L) in the dry seasons (Khound et al 2012). The dry season values (86%) were observed higher than those of wet season mainly to reduction in water volume.…”

“…For this purpose, the concentrations of the principal cations and anions were calculated in milliequivalents per Fig. 1 The selected ground and surface water sampling points of the study area (Khound et al 2012) Applied Water Science 2018 liter. The two should be equal to one another and the ratio should be equal to 1.0 since the water as a whole is electrically neutral (Hem 1985).…”

“…Based on the pH measurement, the water sources of the basin could be classified as belonging to four pH-zones, (1) < 6.0, (2) 6.0-6.5, (3) 6.5-7.0 and (4) > 7.0 as shown in Table 3. The alluvial dug wells presented a large variation in TDS from 63 to 349 mg/L with a mean value of 168 mg/L during the wet seasons and from 79 to 285 mg/L with a mean value of 121 mg/L during the dry seasons (Khound et al 2012). A few of the TDS values were very large during the wet seasons indicating considerable input through the surface runoff.…”