Abstract
Snowmelt runoff is a significant component of the hydrological cycle in many regions. Major problems of snowmelt runoff modelling associated with the physiographic and climatic conditions of these regions, and problem solutions being investigated, are reviewed. Problems common to all regions include: (a) definition of the spatial and temporal distribution of model input; (b) measurement or estimation of snow accumulation, snowmelt, and runoff process parameters for a range of applications and scales; and (c) development of accurate short term and long term snowmelt runoff forecasts. Procedures being investigated to solve these problems include: (a) integrating conventional and remote-sensing data to improve estimates of input data; (b) developing snowmelt process algorithms which have parameters that are closely related to measurable basin and climatic characteristics; and (c) updating model parameters and components using measured data or knowledge of past uncertainty. Research needs include development of improved model capabilities and establishment of standardized techniques and measures to evaluate model performance and results.