Chemometric approach to evaluate the chemical behavior of rainwater at high altitude in Shaune Garang catchment, Western Himalaya.

ABSTRACT: The present research has been performed to analyze the chemical behavior of rainwater of the Shaune Garang catchment (32.19° N, 78.20° E) in the Baspa basin, located at a high elevation (4221 m above mean sea level) in the Himachal Himalaya, India. During the study period, sixteen rainwater samples were collected from the Shaune Garang catchment at five different sites. The volume-weighted mean (VWM) pH value of rainwater ranged between 4.59 and 6.73, with an average value of 5.47 ± 0.69, indicating the alkaline nature of rainfall. The total ionic strength in the rainwater ranged from 113.4 to 263.3 µeq/l with an average value of 169.1 ± 40.4 µeq/l. The major dominant cations were Ca²⁺ (43.10%) and Na⁺ (31.97%) and anions were Cl^- (37.68%), SO₄^2- (28.71%) and NO₃^- (23.85%) in rainwater. The ionic ratios were calculated among all the ions. The fraction of (NO₃^-  +Cl^-) with SO₄^2- was measured as 2.3, which specifies sour faces of rainwater due to HNO₃, H₂SO₄, and HCl. A multivariate statistical assessment of rainwater chemistry through Principal Component Analysis (PCA) shows the significance of four factors controlling 78.37% of the total variance, including four-component (PC1 explained 27.89%, PC2 explained 24.98%, PC3 explained 14.64%, PC4 explained 10.85%). However, the individual contribution of Factor 1(PC1) explains 27.89% of the total variance (78.37%) and displays a strong optimistic loading for Ca²⁺ and Cl^-. Further, high loading of Ca²⁺ and NO₃^- and moderate loading of SO₄^2- signify the contribution of burning fossil fuel and soil dust. Anthropogenic and natural pollutants influence the composition of rainwater in the pristine Himalayas due to local and long-distance transportation. The study area receives precipitation from the West and North-West, transporting dust and fossil fuel emissions from the Thar Desert and Northwestern countries.

SUBMITTER: Kumar R 

PROVIDER: S-EPMC9329433 | biostudies-literature |

REPOSITORIES: biostudies-literature