ABSTRACT

The present study aims to understand the water quality of four urban wetlands of Delhi-NCR (Sanjay lake, Okhla bird sanctuary, Indira Gandhi stadium lake and Bhalswa lake). Several surface water samples from these wetlands were studied in two seasons (winter and summer) for various physico-chemical properties (temperature, pH, dissolved oxygen, biological oxygen demand, chemical oxygen demand, electrical conductivity, alkalinity, major cations and anions) including trace metals. Water from all these wetlands are alkaline and show seasonally varying chemical composition. Hydrogeochemistry (Piper plot and Gibb’s diagram) indicates that water from Bhalswa lake is $\mathrm{N}{\mathrm{a}}^{+}-{\mathrm{S}\mathrm{O}}_4^{2-}$ type and shows an evaporation dominance regime, whereas water from the other three wetlands is $\mathrm{N}{\mathrm{a}}^{+}-{\mathrm{S}\mathrm{O}}_4^{2-}$ and $\mathrm{C}{\mathrm{a}}^{2+}-\mathrm{M}{\mathrm{g}}^{2+}-{\mathrm{S}\mathrm{O}}_4^{2-}$ type, and show a dominance of rock-water interaction. The water quality index reveals that water from all the wetlands is poor to unsuitable for drinking. Concerning irrigation water quality, water from Bhalswa lake is unsuitable, whereas water from other wetlands is marginal to suitable. Both drinking and irrigational water quality deteriorate during summer. In light of the immense ecological importance of these wetlands, urgent measures are required to arrest their deteriorating health.

摘要

本研究旨在了解德里-NCR的四个城市湿地（桑杰伊湖，奥赫拉鸟类保护区，英迪拉·甘地体育场湖和巴尔斯瓦湖）的水质。在两个季节（冬季和夏季）对这些湿地的几个地表水样品进行了各种理化特性（温度，pH，溶解氧，生物需氧量，化学需氧量，电导率，碱度，主要阳离子和阴离子）的研究。痕量金属。来自所有这些湿地的水都是碱性的，并显示出季节性变化的化学成分。水文地球化学（Piper图和吉布图）表明，巴尔斯瓦湖的水是$\mathrm{ñ}{\mathrm{一种}}^{+}-{\mathrm{小号}\mathrm{Ø}}_4^{2-}$ 类型，并显示出蒸发占优势的状态，而来自其他三个湿地的水为 $\mathrm{ñ}{\mathrm{一种}}^{+}-{\mathrm{小号}\mathrm{Ø}}_4^{2-}$ 和 $\mathrm{C}{\mathrm{一种}}^{2+}-\mathrm{中号}{\mathrm{G}}^{2+}-{\mathrm{小号}\mathrm{Ø}}_4^{2-}$类型，并显示出岩水相互作用的优势。水质指数表明，所有湿地的水都很差，不宜饮用。关于灌溉水的质量，Bhalswa湖的水是不合适的，而其他湿地的水则很少。夏季，饮用水和灌溉水的质量都会下降。鉴于这些湿地的巨大生态重要性，需要采取紧急措施来阻止其恶化的健康。