Future Effects of Climate Change on the Dynamics of the Sierra Nevada Snowpack: Conclusions from Cellular Automata Models

Abstract

Water resources (surface water and groundwater) of Alpine basins are conditioned by the spatiotemporal evolution of the snowpack. In turn, the dynamics of the snowpack depends on stationary parameters (altitude, slope, orientation, …) and non-stationary parameters (rainfall, temperature, wind, …). In this work the influence of climate change has been studied considering that the stationary parameters are constant while precipitation and temperature have been modified according to different climate change scenarios. The calculations have been carried out by spatially distributed cellular automata models that describe the dynamics of the snowpack according to state (snow or no snow) transition rules according to the altitude of each cell, the state of neighbor cells and climate indexes that drive the dynamics of the snowpack. This analysis has been applied to the Sierra Nevada mountain range where several Mediterranean alpine basins have their origin. The climatological models predict that, for the time period (2071–2100), there will be a temperature increase of around 30% and a reduction in precipitation of around 27%. This information is used to generate plausible indexes of the climate variables and to study their effect on the snow cover. This kind of analysis is very important in planning and management of water resources (both surface water and groundwater) of Alpine basins that are originated in Sierra Nevada.