Understanding Hyporheic exchange flows around a meandering section of pristine Himalayan headwaters

River systems, such as the Himalayan, consist of three zones: source (high mountains, glaciers), transition (lower mountains, agriculture), and floodplain. About 800 million people in the highlands and Indo-Gangetic plains depend on the Himalayas, hence called the "Water towers of Asia," for freshwater (Kulkarni et al., 2021). While the transition zone contains lower mountains and sustains agricultural activities, the source zone has severe gradients, high peaks, and deep valleys (Nepal et al., 2014). Hence, it is imperative to understand the river systems. It is important to explore methods that have the potential to increase the water quality by inherent natural processes of lotic systems that can assimilate contaminants. One such process is Hyporheic exchange (HE). Keeping in mind the expenses associated with field testing and with the goal of facilitating the development of a deeper understanding over a greater spatial extent, a cost-effective approach is sought. Thus, my study aims to develop a preliminary understanding of hyporheic exchange in the pristine Himalayan headwaters over a meandering section of the Ringali gad stream flowing through the Mussoorie Wildlife Sanctuary. Wherein mini drive point piezometers were used to measure vertical hydraulic gradient (VHG) variations in response to rainfall events over a period of 30 days, and it is observed that the downwelling zones that were giving VHG values of around -0.1 also converted to upwelling zones with VHG values of around +0.1.