Submitted to: Journal Hydrologic Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 31, 2011
Publication Date: January 1, 2012
Citation: Nayak, A., Marks, D.G., Chandler, D., Winstral, A.H. 2012. Modeling interannual variability in snow-cover development and melt for a semiarid mountain catchment. Journal Hydrologic Engineering. 1:74-84. Interpretive Summary: The spatial distribution and melting of the seasonal snowcover is simulated for five individual years (1984, 1986, 1987, 2001 and 2006) representing the historic range of climatic variance. These simulations show that a physics-based snow model can accurately simulate snow conditions over a broad range of conditions without relying on calibration or adjustment for climate trends. This approach will lead to improvements in water supply forecasting.
Technical Abstract: Observed changes in mid-elevation snowcover and duration have raised concerns over future impacts of global warming on snowpack dependent water resources and ecosystems. However, predictions of future changes in snow hydrology over mountain basins are complicated by natural variability in climate conditions and interactions among topography, energy balance and snowpack occurrence. In this study, inter-annual variability in snow cover development, snowmelt, and runoff is assessed for a range of precipitation and temperature conditions typical of a mountain catchment in Idaho, USA. A spatially distributed energy and mass balance snow model, Isnobal, coupled with a wind field and snow redistribution model, is used to continuously simulate snow accumulation and melt for five individual water years (1984, 1986, 1987, 2001 and 2006) representing the historic range of climatic variance. The modeling results compare well with the field measurements for all simulation years (Nash-Sutcliffe model efficiency coefficient of 0.81 to 0.97). This study demonstrates the current state of the art for modeling spatial and temporal variability in snowcover development and melt processes in complex mountain terrain, which are critical for the water resources management of the region.