RESPONSE OF SNOWMELT HYDROLOGY TO CLIMATE-CHANGE

In mountainous regions where the accumulation and melt of seasonal sno w cover are important for runoff production, the timing and quantity o f water supply could be strongly affected by regional climate change, particularly altered temperature and precipitation regimes. In this pa per, the hydrological response to climate change scenarios is examined using a semi-distributed snowmelt runoff model. The model represents an improvement over simple temperature-based models, in that it incorp orates the net radiation into the snowpack. Thus it takes into account the basin's topography and slope orientation when computing snowmelt. In general, a warmer climate is expected to shift snowmelt earlier in to the winter and spring, decreasing summer runoff. The effects of oth er potential climate changes (such as precipitation and cloudiness pat terns) are explored. The uncertainties in these predictions are discus sed.