Walling Bendangtola, Chaudhary Shushobhit, Dhanya C T, Kumar Arun
Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India.
Environ Monit Assess. 2017 May;189(5):225. doi: 10.1007/s10661-017-5942-2. Epub 2017 Apr 21.
Environmental flows (Eflow, hereafter) are the flows to be maintained in the river for its healthy functioning and the sustenance and protection of aquatic ecosystems. Estimation of Eflow in any river stretch demands consideration of various factors such as flow regime, ecosystem, and health of river. However, most of the Eflow estimation studies have neglected the water quality factor. This study urges the need to consider water quality criterion in the estimation of Eflow and proposes a framework for estimating Eflow incorporating water quality variations under present and hypothetical future scenarios of climate change and pollution load. The proposed framework is applied on the polluted stretch of Yamuna River passing through Delhi, India. Required Eflow at various locations along the stretch are determined by considering possible variations in future water quantity and quality. Eflow values satisfying minimum quality requirements for different river water usage classes (classes A, B, C, and D as specified by the Central Pollution Control Board, India) are found to be between 700 and 800 m/s. The estimated Eflow values may aid policymakers to derive upstream storage-release policies or effluent restrictions. Generalized nature of this framework will help its implementation on any river systems.
环境流量（以下简称Eflow）是指为维持河流健康运行以及养护和保护水生生态系统而需在河流中保持的流量。估算任何河段的环境流量都需要考虑各种因素，如水流形态、生态系统以及河流健康状况。然而，大多数环境流量估算研究都忽略了水质因素。本研究强调在估算环境流量时需要考虑水质标准，并提出了一个在当前以及气候变化和污染负荷的假设未来情景下纳入水质变化来估算环境流量的框架。所提出的框架应用于流经印度德里的亚穆纳河污染河段。通过考虑未来水量和水质的可能变化，确定了该河段沿线不同位置所需的环境流量。发现满足印度中央污染控制委员会规定的不同河流水使用类别（A、B、C和D类）最低质量要求的环境流量值在700至800立方米/秒之间。估算出的环境流量值可能有助于政策制定者制定上游蓄水-放水政策或废水排放限制。该框架的通用性将有助于其在任何河流系统上的实施。
