This paper develops a conceptual and generic framework design for the study of upstream-downstream linkages (UDL) in the Hindu Kush Himalaya (HKH) region. The framework application will to define changing upstreamdownstream linkages (UDL) and likely impacts on downstream regions. The results of such applications will be useful for policy makers, planners, decision makers, and researchers. It also addresses actors involved in Integrated Land and Water Resources Management (ILWRM) challenged by changing UDL processes, triggered by broader environmental changes such as climate change and human activities. This framework document defines the upstream downstream relationship. It describes the issues related to UDL mainly around land use and land cover (LULC) changes, erosion and sedimentation, climate change and infrastructure, which affect the availability of water in downstream areas.