Water quality and land use/cover changes in the Phewa Watershed, Gandaki Province, Nepal

Authors

  • Kiran Bishwakarma Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
  • Ramesh Raj Pant Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal.
  • Khadka Bahadur Pal Tri-Chandra Multiple Campus, Tribhuvan University, Nepal
  • Archana Ghimire University of Chinese Academy of Sciences, Beijing 100049, China; Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
  • Lal B Thapa Central Department of Botany, Tribhuvan University, Nepal
  • Prem Saud Kailali Multiple Campus, Tribhuvan University, Nepal
  • Susan Joshi Central Department of Chemistry, Tribhuvan University, Nepal
  • Khim Prasad Panthi Tri-Chandra Campus, Tribhuvan University, Nepal

DOI:

https://doi.org/10.3126/njes.v7i0.34473

Keywords:

Drinking water quality, Irrigational quality indices, Land use pattern, Phewa Lake

Abstract

Knowledge and understanding of land use and water quality nexus is an important precursor for assessing the human-water interactions and sustainable freshwater management. In this study, the land use/cover change (LUCC) and water quality assessment with respect to drinking and irrigational purposes were carried out in Phewa Lake, Nepal. A total of 20 water samples were collected during the winter and summer seasons in 2017 and were analysed for major hydrochemical variables. The water quality index of Phewa Lake was found to be 5.15 and 2.57 during the winter and summer, respectively, indicating the suitability of water for drinking purposes. The results revealed that the electrical conductivity, sodium percentage, and sodium adsorption ratio were found to be 38.80 µS/cm, 16.99, and 0.10, respectively in the summer and 85.06 µS/cm, 14.68, and 0.15, respectively in the winter. Similarly, permeability index, Kelly’s ratio, magnesium hazard, cation ratio of soil structural stability, and Wilcox diagram exhibited that the water was suitable for irrigation in both seasons with relatively better quality in the summer. The dynamic pattern of LUCC in the Phewa watershed exhibited an increase in the spatial extent of forest, shrub-land, grassland, and built-up area, whereas decreasing trend of agricultural land, barren land, and water bodies. Irrespective of the seasonality, the LUCC-water quality nexus showed elevated concentrations in the proximity of the urban settlements. The present study could be helpful for the restoration of water quality by sustainable land-use practices in the Himalayan region.

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Published

2019-12-31

How to Cite

Bishwakarma, K., Pant, R. R., Pal, K. B., Ghimire, A., Thapa, L. B., Saud, P., Joshi, S., & Panthi, K. P. (2019). Water quality and land use/cover changes in the Phewa Watershed, Gandaki Province, Nepal. Nepal Journal of Environmental Science, 7, 31–39. https://doi.org/10.3126/njes.v7i0.34473

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Section

Research Articles