Hydrogeochemical assessment of wetlands of Gurugram, Haryana, India: implications for natural processes and anthropogenic changes

Abstract

Surface water samples (n = 55) from four wetlands (Lost-W1, Sultanpur-W2, Damdama-W3, and Basai-W4) of Gurugram were studied for their hydrogeochemical characterization, quality assessment and suitability for various purposes. The parameters studied were temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), dissolved organic carbon (DOC), major cations, major anions, and trace metals. The results indicate that water samples of all the four wetlands are alkaline. Among studied parameters, pH (8.9), TDS (2233 mg/l), alkalinity (428 mg/l), PO43− (7.05 mg/l), F− (1.88 mg/l), Na+ (597 mg/l), and K+ (32 mg/l) are above permissible limits (PL). BOD and COD are above WHO limits in all the wetlands, except W1. Among ions, HCO3− and Ca2+ are dominant in W1, W2, and W3 which indicate weathering of Ca2+ and HCO3− minerals (carbonate weathering), whereas Cl− and Na+ are dominant in W4, which indicate strong anthropogenic influence. Lower values of the majority of ions in winter as compared to summer indicate the dilution effect. Among metals, Fe (549 mg/l), Cr (90 mg/l), and Ni (117 mg/l) are above PL. Piper diagram revealed the Ca-HCO3 type of water in W1, W2, and W3 and Na-Cl type in W4. Gibbs plot indicated rock-forming minerals are dominantly affecting the water chemistry of all the wetlands. WQI suggested unsuitability of water from W4 (in both seasons) and W3 (in summer) for drinking, as well as irrigational indices (Wilcox, USSL plots, PI, RSC, KI, and MH) suggest unsuitability of W4 water for irrigation. Also, water from W4 is not suitable for cattle drinking. Water from W1, W2, and W3 is suitable for human consumption, irrigation, and cattle drinking except W3 water in summer which is not suitable for human consumption. Hence, it is concluded that, among studied wetlands, W4 is maximally perturbed, whereas W2 and W3 are disturbed to a lesser extent. All these wetlands need continuous monitoring and timely measures.