Hydro-chemical characterization and quality assessment of a Western Himalayan river, Munawar Tawi, flowing through Rajouri district, Jammu and Kashmir, India

Studies on river water quality in the Indian Himalayas are limited to a few larger ones; the smaller ones, although vital for a large section of people, mostly remain untouched. Therefore, Munawar Tawi a tributary of Chenab flowing through Rajouri district of Jammu region, Western Himalayas was selected for the study. Fifty-four water samples from 27 sites from Rajouri town and its upstream and downstream locations were collected during January and June 2014. Fourteen water quality parameters that include major cations and anions were analyzed. Water quality indicators such as SAR, %Na, RSC, MAR, KI, and PI were also calculated to determine suitability of water for irrigation. Piper plots identified four water types, of which Ca2+–Mg2+–HCO−3 was the dominant type in both the seasons. While in January, water samples varied across all the four types, in June only two types were seen (i.e. Ca2+–Mg2+–HCO−3 and Ca2+–Mg2+–Na+–HCO−3). Ludwig-Langelier plot also showed Ca2+–Mg2+–HCO−3 type as the dominant water type. Wilcoxon signed-rank test showed most of the parameters, except TDS, significantly high in January than in June. Kruskal-Wallis test showed significant variation in concentration among most of the parameters from upstream to the town and towards downstream. The water, with respect to the set standards (WHO, ISI, UNESCO), in both January and June, is found suitable for drinking and irrigation.