Modelling impacts of climate change on snowmelt runoff generation and streamflow across western US mountain basins: a review of techniques and applications for water resource management

The western US region is heavily reliant on spring snowmelt for much of its annual water supply. However, rising temperatures across the region over the latter half of the twentieth century have reduced snowpack accumulation, snowmelt timing and magnitude, especially at lower elevations. Water resource planners must be prepared to understand and counter the possible consequences resulting from a continuation in rising air temperatures on snowmelt and streamflow into the twenty-first century. This review aims to thoroughly analyse what tools and techniques are available to monitor and plan for such changes. A historical analysis of snowmelt trends in response to increasing air temperatures is followed by a review of methods used to forecast the effects of future changes in air temperature on snowmelt processes along with both general approaches to snowmelt modelling and different snowmelt models themselves. The techniques and methods to be ultimately employed will depend greatly upon data availability and on the scale at which they are to be applied.