Future snow projections in a small basin of the Western Himalaya.

Snow is a crucial component of the hydrological cycle in the Western Himalaya. Water from snowmelt is used in various sectors in downstream regions, thus playing a critical role in securing the livelihoods of millions of people. In this study, we investigated the future evolution of snow cover and snowmelt in the Panjshir catchment of Afghanistan, a sub-basin of the Indus, in the Western Himalaya. We applied a three-step approach to select a few global climate model (GCM) simulations from CMIP5 climate datasets for RCP4.5 and RCP8.5, which showed reasonable performance with ERA5-Land dataset for the chosen historical period (1981-2010). The selected model simulations were then segregated into two groups: those projecting a cold-wet climate and those projecting a warm-dry climate by the end of the 21st century (2071-2100). These GCMs were downscaled to a higher resolution using empirical statistical downscaling. To simulate the snow processes, we used the distributed cryospheric-hydrological J2000 model. The results indicate that the model captures well the snow cover dynamics for the historical period when compared with the daily MODIS-derived snow cover. The J2000 model was then forced by climate projections from the selected GCMs to quantify future changes in snow cover area, snow storage and snowmelt. While a 10-18% reduction in annual snow cover area is projected in the cold-wet models, a 22-36% reduction is projected in the warm-dry models. Similarly, the snow cover area is projected to decrease in all elevation bands under climate change. At the seasonal scale, across all models and scenarios, the snow cover in the autumn and spring seasons are projected to reduce by as much as 25%, with an increase in winter and spring snowmelt and a decrease in summer snowmelt. The projected changes in the seasonal availability of snowmelt-driven water resources are likely to have direct implications for water-dependent sectors in the region and call for a better understanding of water usage and future adaptation practices.

Developing a science-based policy network over the Upper Indus Basin.

The Upper Indus Basin's (UIB) unique geographical positioning and its ecosystem contributions to the downstream basin in the form of water and energy are of critical importance. UIB is also among the most vulnerable water towers in the world vis-a-vis climate as well as a host of environmental and socio-economic changes. The paucity of ground observations and their associated unknowns make it imperative to study and highlight the grey areas for attention and action by policy planners and basin government and management at different levels in order to improve the management and the governance structures for better water resource management. As this river basin is shared between countries, enhanced co-creation of knowledge can provide greater understanding of the challenges to stakeholders so that they can make better decisions regarding the development of the region. With this in view, the UIB network, comprising four national chapters (Afghanistan, China, India and Pakistan) linked strategically at regional level, was conceived to provide better understanding of the critical issues associated with the UIB. The network strives for a resilient and empowered UIB region through science-based regional cooperation, which promotes coordination and collaboration among organizations working in the UIB to ensure improved understanding of present and future water availability, demand and hazards and to develop gender sensitive solutions for all stakeholders. The special issue is one of such efforts from the network in knowledge generation, exchange, and dissemination to contribute towards an enhanced understanding of climate change impacts in the Indus. The paper presents a time-wise evolution of the network to highlight the importance of cross boundary knowledge and the relevance of such networks. Such a science-based network can provide important information for science-backed policies for the basin countries. It also details the achievements of the network, lessons learnt from such knowledge networks, and the potential for future contributions to basin countries taking into consideration the transboundary nature of the UIB.