Clayton Gillian E, Richards Laura A, Fox Bethany G, Thorn Robin M S, Bowes Michael J, Read Daniel S, Tipper Holly J, Khamis Kieran, Dutta Tapan K, Kumar Arun, Hazra Moushumi, Howard Ben, Schneidewind Uwe, Armstrong Linda K, Nicholls David J E, Davies Helen, Hannah David, Nel Holly A, Ghosh Ashok, Joshi Himanshu, Gooddy Daren C, Polya David A, Krause Stefan, Reynolds Darren M
Centre for Research in Sustainable Agri-Food & Environment, School of Applied Sciences, College of Health, Science and Society, University of the West of England, Bristol, BS16 1QY, UK.
Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, UK.
Water Res. 2025 Jun 15;278:123374. doi: 10.1016/j.watres.2025.123374. Epub 2025 Feb 25.
The Ganga River (known internationally as the Ganges) is one of the world's most prominent rivers, running from the Himalayas to the Bay of Bengal and supporting the livelihoods of > 40 % of India's 1.4 billion population. The Ganga River is regionally and globally important, supporting agriculture and industry, yet faces potentially detrimental water quality challenges arising from runoff and discharge from increasing urbanization, industry and agriculture. A ∼ 2700 km longitudinal survey of the nutrient and microbial water quality, including phytoplankton composition, of the Ganga River was undertaken in November 2019. The aim was to investigate if and how anthropogenic activities (e.g. urbanisation, industry, and agriculture) and tributary convergence (potentially reflecting both human activity and flow influences) affect and shift physicochemical, nutrient, and microbial water quality parameters along the river continuum. Segmented regression identified four zones of distinct nutrient/microbial characteristics along the Ganga River, with breakpoints located near Kanpur, Varanasi and downstream of the Farakka Barage, at distances of ∼ 1020, ∼ 1500 and ∼ 2350 km downstream from the Himalayan Ganga source. Population density, land use and urban cover were associated with selected water quality parameters in parts of the catchment, with elevated nutrient, microbial and chemical concentrations likely associated with agriculture, industry, and sewage inputs. Some urban areas (e.g. Kanpur and Varanasi), converging tributaries (e.g. Yamuna and Varuna) and barrages (e.g. Farakka) were associated with changes in nutrient availability, microbial activity/abundance and modelled discharge, likely driving apparent water quality changes in the relevant locations. Downstream shifts in nutrient and microbial water quality parameters were observed throughout the ∼ 2700 km Ganga River continuum. This information can help prioritize locations for targeted monitoring and/or remediation interventions and has illustrated an approach to quantify impacts of anthropogenic inputs on major river systems, such as the Ganga River.
恒河（国际上称为冈底斯河）是世界上最著名的河流之一，发源于喜马拉雅山脉，流入孟加拉湾，为印度14亿人口中40%以上的人口提供生计。恒河在区域和全球都具有重要意义，支撑着农业和工业，但面临着因城市化、工业和农业不断发展导致的径流和排放所带来的潜在有害水质挑战。2019年11月，对恒河进行了约2700公里的纵向调查，内容包括营养物质和微生物水质，以及浮游植物组成。目的是调查人为活动（如城市化、工业和农业）以及支流汇聚（可能反映人类活动和水流影响）是否以及如何影响和改变沿河流连续体的物理化学、营养物质和微生物水质参数。分段回归确定了恒河沿岸四个具有不同营养/微生物特征的区域，断点分别位于坎普尔、瓦拉纳西附近以及法拉卡大坝下游，距离喜马拉雅恒河源头下游约1020公里、约1500公里和约2350公里处。流域部分地区的人口密度、土地利用和城市覆盖与选定的水质参数相关联，营养物质、微生物和化学物质浓度升高可能与农业、工业和污水排放有关。一些城市地区（如坎普尔和瓦拉纳西）、汇聚的支流（如亚穆纳河和瓦鲁纳河）以及大坝（如法拉卡大坝）与营养物质可用性、微生物活动/丰度和模拟流量的变化有关，可能导致相关地点明显的水质变化。在约2700公里的恒河连续体中，观察到营养物质和微生物水质参数向下游转移。这些信息有助于确定进行有针对性监测和/或修复干预的优先地点，并展示了一种量化人为输入对主要河流系统（如恒河）影响的方法
