The activities and processes led by natural and anthropogenic factors not only change environmental variables upstream (such as land use and land cover, snowmelt, and erosion, among others), they also affect the downstream environment in terms of water availability, floods, and sedimentation. Upstream–downstream linkages (UDL) of land and water management in the Himalayan region have been widely discussed in the literature. In 1989, L. A. Bruijnzeel and C. N. Bremmer published an ICIMOD occasional paper highlighting highland–lowland interactions in the Ganges–Brahmaputra river basins (Bruijnzeel & Bremmer 1989).