Impacts of spatially and temporally varying snowmelt on subsurface flow in a mountainous watershed: 2. Subsurface processes

Abstract

The impacts of spatial and temporal variations of snowmelt recharge on subsurface flow in a small mountainous watershed were investigated using field measurements and numerical simulations. A twodimensional, variably saturated flow model (VAM2D) was used to characterize the hillslope aquifer and to delineate subsurface flow mechanisms. Spatially varying snowmelt along a hillslope transect described in the preceding paper were used as input for the subsurface flow analyses. Simulations indicated that the heterogeneous hillslope aquifer provides hydrogeological conditions for confined and unconfined groundwater flow depending on the extent of snowmelt recharge. The spatial and temporal distribution and amount of snowmelt recharge play important roles in determining when flow is governed by confined and unconfined flow. Results showed that the VAM2D model was able to simulate piezometric measurements reasonably using calibrated hydraulic parameters. Sensitivity analyses showed that the flow regime was considerably different when the spatial variation of snowmelt was not considered.

Impacts of spatially and temporally varying snowmelt on subsurface flow in a mountainous watershed: 1. Snowmelt simulation

“…Hourly and daily simulated snow depth and snow cover outflow were compared with measured data. Although not presented here, water loss to sublimation and évapotranspiration were included in the simulations and included in the input to the subsurface flow model in the following paper (Deng et al, 1994) …”

“…Snow depth, density and melt measurements on the watershed were used to validate the model. Based on validations, the model was applied to simulate the spatially and temporally variable snowmelt at points along a hillslope transect for input to the groundwater simulations in the following paper (Deng et al, 1994).…”

The impact of climate change on spatially varying groundwater recharge in the grand river watershed (Ontario)

“…Similar to rainfall, the spatial and temporal distribution of snow accumulation is very complex, and even further complicated by its high sensitivity to temperature and wind velocities (i.e., drifting) (Deng et al, 1994). The presence and extent of a frost layer influences the rate and distribution of the infiltrating snowmelt (Johnsson and Lundin, 1991;Kane and Stein, 1983;Granger et al, 1984;Engelmark, 1988;Black and Miller, 1990).…”

Hydrologic response and recovery to prescribed fire and vegetation removal in a small rangeland catchment

“…Detailed studies of the Upper Sheep Creek Watershed were conducted by the USDA‐ARS NWRC from 1984 through 1994. Numerous investigations were conducted to define the geology of the watershed (Winkelmaier, ; Mock, ; and Stevens, ) and to better understand the processes controlling hydrologic response (Cooley, ; Flerchinger et al ., ; Flerchinger et al ., ; Deng et al ., ; Flerchinger et al ., ; Unnikrishna et al ., ; Flerchinger et al ., ; Luce et al ., ). Chauvin et al .…”

“…Detailed studies of the Upper Sheep Creek Watershed were conducted by the USDA-ARS NWRC from 1984 through 1994. Numerous investigations were conducted to define the geology of the watershed (Winkelmaier, 1987;Mock, 1988;and Stevens, 1991) and to better understand the processes controlling hydrologic response (Cooley, 1988;Flerchinger et al, 1992;Flerchinger et al, 1993;Deng et al, 1994;Flerchinger et al, 1994;Unnikrishna et al, 1995;Flerchinger et al, 1996;Luce et al, 1998). Chauvin et al (2011Chauvin et al ( ) conducted a 24-year (1984Chauvin et al ( through 2007 water balance of the watershed that effectively characterized pre-fire hydrologic response.…”