Cold region hydrologic models and applications

Over the recent decades, the warming in Arctic has affected changes in the terrestrial hydrologic processes. Unfortunately, the number of hydrometeorological observing stations in the region has decreased. To reduce the limitation in observation, a number of process-based and distributed models have been developed for simulating the hydrological processes in a changing climate. The current generations of models are able to reasonably reproduce the prominent cold region hydrologic processes, such as degrading permafrost, decreasing snow extent, increasing river discharge and evapotranspiration, and increasing streamflow temperature. These models enhance our understanding of the response of Arctic terrestrial processes to climate change and variation. However, the model representations for some of the Arctic hydrological processes are still not yet sufficient and need further improvements. This chapter provides an overview of changes in key processes and conditions of the Arctic terrestrial hydrology based on a synthesis of observations and model simulations, and presents recommendations for further development and improvement of cold region hydrologic models.