Assessment of seasonal and spatial water quality variation in a cascading lake system in Chennai, India

Xiuming Sun; Daniel Rosado; Georg Hörmann; Zhenyu Zhang; Lukas Loose; Indumathi Nambi; Nicola Fohrer

doi:10.1016/j.scitotenv.2022.159924

Assessment of seasonal and spatial water quality variation in a cascading lake system in Chennai, India

Sci Total Environ. 2023 Feb 1;858(Pt 3):159924. doi: 10.1016/j.scitotenv.2022.159924. Epub 2022 Nov 8.

Authors

Xiuming Sun¹, Daniel Rosado², Georg Hörmann³, Zhenyu Zhang³, Lukas Loose⁴, Indumathi Nambi⁵, Nicola Fohrer⁴

Affiliations

¹ Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, 24118 Kiel, Germany; Indo-German Centre for Sustainability, Indian Institute of Technology Madras, Chennai 600036, India. Electronic address: xsun@hydrology.uni-kiel.de.
² Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, 24118 Kiel, Germany; Indo-German Centre for Sustainability, Indian Institute of Technology Madras, Chennai 600036, India; Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India.
³ Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, 24118 Kiel, Germany.
⁴ Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, 24118 Kiel, Germany; Indo-German Centre for Sustainability, Indian Institute of Technology Madras, Chennai 600036, India.
⁵ Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India.

PMID: 36356775
DOI: 10.1016/j.scitotenv.2022.159924

Abstract

Water quality and scarcity are among the most severe problems humans have been facing in the last decades. India, as a fast-developing country, is not an exception. The surface water quality has deteriorated due to anthropogenic activities. Another factor which impacts the water quality is the heavy rainfall during monsoon season. To maintain the quality and the sustainability of water resources, there is the need to study how human activities impact water quality. We hypothesized that the water quality can be impacted by the spatial land use types and by the seasonality. In the present study, seasonal and spatial water quality regarding physical, chemical, and biological parameters from a lake cascading system was assessed monthly from July to December 2019. Land use/cover data was produced by Impact Observatory, Microsoft, and Esri based on the 10-m Sentinel-2 images. Redundancy analysis was applied to investigate the relationship between land use/cover data and water quality in the riparian of 500 and 1000 m to the lakes. Our results showed clear temporal and spatial variation of water quality in 2019, with better water quality in rainy season (Oct.-Dec.) and downstream lakes while relatively worse water quality was recorded in dry season (Jul.-Sep.) and upstream lakes. The water quality variation was explained 27.8 % and 42.7 % by the land use types within 500 m and 1000 m buffer widths, respectively. The outlet of the catchment showed exceptional results due to the impact of a dumpsite. Our findings indicate that the water quality is highly impacted by human-induced land use/cover. The land use/cover types, such as crops, woodland and urban area, show negative impacts and relate to the high level of nutrient concentrations. In opposite, grass land shows positive effects and leads to better water quality. Our study confirms that the lake water quality is distinguished in both spatial and seasonal aspects. Monsoon season improves the water quality.

Keywords: Anthropogenic impacts; Lake water quality; Land use/cover; Seasonal and spatial variation; Topographical information.

MeSH terms

Humans
India
Water Quality*