Author(s)

Ankit Kandel¹, Kismat Pokhrel¹, Lenin Adhikari¹, Deep Narayan Shah^1,2

¹Goldengate International College, Tribhuvan University, Battisputali, Kathmandu, Nepal.
²Central Department of Environment Science, Tribhuvan University, Kirtipur, Kathmandu, Nepal.

Historically, alluvial rivers have been a desirable source of sediment for various industrial purposes. However, the demand for sand is rapidly increasing, leading to environmental concerns associated with its extraction. The extraction of sediment from riverbeds has both visible and invisible effects. This research aims to investigate the dynamics of the Jhimruk River’s morphology and its impacts by evaluating the river’s quality and studying its changing morphology. To assess morphological changes, satellite images from different years were compared using Geographic Information System (GIS). Physical assessments were conducted by calculating a Habitat score based on various parameters. Water quality assessments involved measuring factors such as pH, temperature, nitrate levels, and alkalinity. A water quality map of the river was generated using color coding to indicate different conditions. The Habitat score demonstrated variations in the data collected from all sites, with factors such as instream cover, bottom substrate stability, riparian vegetation, and aesthetic of the river stretch playing crucial roles in influencing the total score. The Water Quality Index value for the disturbed site indicated moderate pollution, falling under class II. Aquatic macroinvertebrates displayed natural responses to increasing levels of stressors across their life stages, as observed through the analysis of the GRS-BIOS/ASPT index. With the exception of the disturbed site, all other sites were classified under water quality class II, while the disturbed site belonged to class III, indicating a moderate to critically polluted state for most of the Jhimruk River. Furthermore, an increase of 180.87 meters in the river width at the disturbed site provided evidence of morphological changes occurring over the specified period. Mining activities were identified as a significant contributor to the alteration in river morphology.

Alluvial Mining, Physical Assessment, Biological Assessment, Water Quality Assessment, Jhimruk River, Sand Mining

Kandel, A. , Pokhrel, K. , Adhikari, L. and Shah, D. (2023) The Influence of Alluvial Mining on the Morphology and Ecological Health of the Jhimruk River in Pyuthan, Nepal. Journal of Geoscience and Environment Protection, 11, 33-48. doi: 10.4236/gep.2023.118003.