Spatial variation on hydrogeochemical parameter in the Hetauda Valley, central Nepal

Water is a requisite source for human survival, facing increasing issues and challenges in terms of both quantity and quality due to exacerbated global populations and urbanization trends. This increased demand has caused a decline in the overall availability and quality of water resources. Hetauda, serving as the administrative center of Bagmati Province, has emerged as a key destination for employment services along with a good potential zone for geotourism closely connected to its diverse geological features and water resources. However, excessive utilization, depletion, and extensive pollution of surface water sources in the region have underscored the importance of exploring groundwater for agricultural, and domestic needs along with decreasing the possibilities for geotourism. As the study area lies in the Hetauda Valley, to address this concern, water samples from 34 different sources such as dug wells, boreholes, and springs were collected. A thorough analysis of physicochemical parameters was conducted to evaluate water quality, revealing notable variations across locations, including the presence of iron and arsenic traces in specific samples. The Weighted Arithmetic Index Method was used to calculatethe Water Quality Index (WQI) showing that certain water sources had very good quality while few weren’t appropriate for human consumption. The Piper diagram indicates the dominancy of calcium ions in cations and chloride in anions. The stiff diagram shows that the ions Na + K > Ca > Mg dominate the composition of the cations, whilst HCO₃⁻ > Cl⁻ > SO₄²⁻ dominates the anions. Besides, the multivariate statistical analysis through Principal Component Analysis was executed to support these hydrochemical findings. In conclusion, this research underscores the critical necessity for sustainable water management strategies in the study area, advocating for the prudent exploration of groundwater while addressing the challenges posed by contaminants, thus ensuring the availability of safe and sufficient water resources in the region.