GEOCHEMICAL CHARACTERISTICS OF HIMALAYAN RIVERS: A CASE STUDY FROM SATLUJ AND BEAS RIVERS, INDIA

Abstract

The Himalayan region is known for its unique geological and tectonic features, and notably, its intriguing hydrological aspects, making it a fascinating area for geochemical studies. Himalayan rivers, nestled amidst towering peaks, are more than mere carriers of life-sustaining water; they are repositories of myriad tales and histories, their stories encrypted in geochemical signatures. The prominent Himalayan river system such as the Ganga and Brahmaputra have been extensively studied in geochemical contexts. In contrast, the Indus River system, with its extensive and complex network of rivers spanning four nations: China, India, Pakistan, and Afghanistan, has often been geochemically understudied. Owing to its transboundary nature, the Indus River system has either been overlooked/underrated in scientific studies or has received only fragmentary attention. The limited research available on the Indus’s river system geochemistry offers only a fragmented understanding, despite the river’s significant economic and ecological importance. India is home to five major tributaries of the Indus River system: the Jhelum, Chenab, Ravi, Satluj, and Beas, which either drain completely or partially within the country. Among all these tributaries, the Jhelum river has received considerable scientific attention in the geochemical context. The other tributaries, while important, have not received comparable attention and, consequently, have been less frequently addressed in the published literature. Therefore, in an effort to bridge a segment of the research gap, we have selected Satluj and Beas for our research, the least attended tributaries of the Indus within the Indian border. This selection also enables a detailed examination of the hierarchical tributary relationships, emphasizing the complex and interconnected nature of these water systems within the larger Indus River basin (IRB) framework. Both Satluj and Beas Rivers serve as critical aquatic arteries for the populations of two important Indian states, particularly Himachal Pradesh and Punjab, India, playing an indispensable role in providing fresh water for domestic and agricultural purposes and also supporting the region’s hydroelectric power generation. These rivers are essential for sustaining the region’s agrarian economies, supporting both irrigation and potable water needs, and facilitating hydroelectric power generation. This multifaceted contribution underpins the socio-economic fabric of these areas, integrating natural resources into the core of developmental strategies. Consequently, this research is planned to offer a comprehensive geochemical characterization of these river basins, aiming to deepen our understanding of diverse geochemical facets inherent to this dynamic and complex landscape, and to explore their integration into the broader IRB hydrological and ecological system of the region. Moreover, this insight has implications for the Indo-Himalayan fluvial systems and the millions who rely on these rivers. Through an integrated multi-tracer geochemical and isotopic approach (δ18O, δD and d-excess) applied to the waters of both the Satluj and Beas River Basins, and the riverine sediments of only the Satluj Basin, this research delivers an in-depth analysis of geochemical variability, highlighting their contribution to the broader IRB and shedding light on the hydrochemical intricacies of the Western Himalaya-Plains region. Major emphasis has been placed on the isotopic characterization of the IRB; geochemical & isotopic profiling and streamflow partitioning in the Satluj River Basin (SRB) (major tributary of IRB); detailed evaluation of riverine sediments in the Satluj catchment; and the exploration of spatial variations in hydrochemistry and stable isotopes across the mountainous catchment of the Beas River basin (major tributary of SRB). Consequently, this research systematically investigates the hierarchical tributary relationships, further enriching our understanding of the interconnectedness within the IRB’s aquatic systems. This structured analysis not only elucidates the significant roles these tributaries play within the broader ecosystem dynamics but also contributes to a comprehensive understanding of their geochemical and hydrological contributions to the IRB.