The investigations contained in this body of work detail a viable proof-of-concept model for monitoring seasonal snow pack propensity for melt release based on time-variant snow surface optical and thermal properties. The model has been called the Near Surface Moisture Index- (Snow) (NSMI). The NSMI was developed based on time-variant snow surface optical and thermal properties. This research achieved three primary objectives: 1).development of theoretical foundation and surface moisture sensitive algorithm used to track both surface melt and pack discharge potential; 2.) time-dependent phases of coupling and decoupling between snow surface properties and melt discharge were characterized through analysis of long-term surface and sub-surface state variables; 3.) and sensitivity of optical satellite systems specifically, EOS TERRA-MODIS, to melting were was examined through radiative transfer simulations. Simulated at-sensor radiance was produced for various grain size changes to determine MODIS capacity to track melt onset. MODIS wavelengths greater than 667nm were sensitive to large changes in grain sizes, particularly bands with coarse spatial resolution (1000m). Longer wavelengths showed greater sensitivity to small changes in smaller grains than to small changes in larger grains. Shorter wavelengths at 500m spatial resolution appeared less effective overall for monitoring changes in grain size. NMSI feature space using Normalized Difference Snow Index (NDSI) on the abscissa and brightness temperature (Tb) on the ordinate was simulated. Simulated NDSI as a function of grain radius saturated approximately around 400-450 μm. ASTER derived NSMI demonstrated behavior consistent with simulations with deviations due to topography, vegetation, and regional heterogeneity. We examined NSMI performance during an entire melt season through tracking phases of coupling between snow surface properties and propensity for melt using two ground-base approaches; one with higher snow surface spectral information and low temporal resolution, the other with high temporal resolution and coarse spectral information. Phases of decoupling exhibited within ground-based time varying simulated NSMI were regulated by the temporal resolution specified to construct the feature space. Coarser temporal intervals on surface optical/thermal variables correlated the NSMI feature space various components of surface radiative variability. Coarser temporal optical and thermal resolution will tend to reduce variability within the NSMI feature space due to specific snowfall events.

Title: Application of the Snowmelt Runoff Model for snow accumulation and snowmelt modelling in experimental catchments Bystřice and Zlatý Brook in the Krušné Mountains Modelling of hydrological processes is a dynamically developing part of hydrology. The Snowmelt Runoff Model (SRM) was applied for modelling the runoff in two experimental catchments Bystřice and Zlatý Brook. The aim of this thesis is to set up and calibrate SRM model and to evaluate methods and procedures used for runoff simulations. The SRM model was used for modelling snow accumulation and snowmelt in two selected catchments in the Krušné Mountains. The snow depths and snow water equivalents are measured since 2009 at selected locations situated in catchments. Calibration and validation of the model was based on continual time series of precipitation, air temperature and discharge measured 2009. Hydrological years 2009 and 2010 were used for model calibration and hydrological years 2011 and 2012 were used for model validation. Sensitivity analysis, which quantifies the effect of individual model parameters on the simulating proces, was carried out based on results. Recession coefficient and runoff coefficient belong to the most sensitive parameters with highest impact on runoff simulations. Model calibration was successful, which...

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Utilising extensive field observations and physically-based simulations of forest-snow processes, the impacts of needleleaf forest-cover on radiation and snowmelt dynamics were investigated in an eastern Rocky Mountain headwater catchment. At low-elevation pine forest sites, the sparse canopy-cover allowed for substantial shortwave transmittance to snow, giving topography-influenced snow radiation balances and snowmelt timing. By comparison, the denser high-elevation spruce cover minimised shortwave radiation to snow, resulting in snowmelt dominated by longwave radiation gains, and close synchronisation in melt timing across opposing mountain slopes. Field observations were used to direct and evaluate physically-based simulation models describing radiation-snow exchanges in needleleaf forests. This included the estimation of shortwave irradiance transfer through sparse needleleaf canopies with explicit account for differing shortwave transmittance properties of trunks, crowns, and gaps within highly structured mountain pine stands. Improved representation of sub-canopy longwave irradiance to mountain snow was also made through the determination of added longwave emissions from shortwave heated canopies. From model simulations, forest-cover effects on radiation to snow were found to vary substantially with both topography and seasonal meteorological conditions. In general, forest-cover increased radiation during the mid-winter by reducing longwave losses from snow. However, with greater shortwave irradiance into the spring, forest-cover effects on radiation to snow became increasing influenced by topography, with greater radiation under more open canopies on south-facing slopes and under more closed canopies on north-facing slopes. Drawing upon past field investigations and modelling exercises, a physically-based simulation model was constructed to represent snow accumulation and melt processes in needleleaf forest environments. By means of an objective evaluation, the model well represented differences in snow accumulation and melt in paired forest and clearing sites of varying location and climate. The model was subsequently applied to examine forest-cover impacts on mountain snowmelt, revealing that forest-cover removal substantially increased total snowmelt and sizeably expanded the spring melt period through a de-synchronisation of melt contributions from south-facing and north-facing landscapes. These results demonstrate the potential for altering the magnitude and timing of mountain snowmelt through topographic-specific changes in mountain forest-cover.

Utilising extensive field observations and physically-based simulations of forest-snow processes, the impacts of needleleaf forest-cover on radiation and snowmelt dynamics were investigated in an eastern Rocky Mountain headwater catchment. At low-elevation pine forest sites, the sparse canopy-cover allowed for substantial shortwave transmittance to snow, giving topography-influenced snow radiation balances and snowmelt timing. By comparison, the denser high-elevation spruce cover minimised shortwave radiation to snow, resulting in snowmelt dominated by longwave radiation gains, and close synchronisation in melt timing across opposing mountain slopes. Field observations were used to direct and evaluate physically-based simulation models describing radiation-snow exchanges in needleleaf forests. This included the estimation of shortwave irradiance transfer through sparse needleleaf canopies with explicit account for differing shortwave transmittance properties of trunks, crowns, and gaps within highly structured mountain pine stands. Improved representation of sub-canopy longwave irradiance to mountain snow was also made through the determination of added longwave emissions from shortwave heated canopies. From model simulations, forest-cover effects on radiation to snow were found to vary substantially with both topography and seasonal meteorological conditions. In general, forest-cover increased radiation during the mid-winter by reducing longwave losses from snow. However, with greater shortwave irradiance into the spring, forest-cover effects on radiation to snow became increasing influenced by topography, with greater radiation under more open canopies on south-facing slopes and under more closed canopies on north-facing slopes. Drawing upon past field investigations and modelling exercises, a physically-based simulation model was constructed to represent snow accumulation and melt processes in needleleaf forest environments. By means of an objective evaluation, the model well represented differences in snow accumulation and melt in paired forest and clearing sites of varying location and climate. The model was subsequently applied to examine forest-cover impacts on mountain snowmelt, revealing that forest-cover removal substantially increased total snowmelt and sizeably expanded the spring melt period through a de-synchronisation of melt contributions from south-facing and north-facing landscapes. These results demonstrate the potential for altering the magnitude and timing of mountain snowmelt through topographic-specific changes in mountain forest-cover.

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The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and fissures. Snowmelt is a function of many meteorological variables and future years of observation will create a better understanding of the interaction of these variables with landslide initiation.

Modelling the energy exchange between the snowpack and the atmosphere is critical for many hydrological applications. Of the terms present in the snow energy balance, the turbulent fluxes of sensible and latent heat are the most challenging to estimate, particularly within mountain environments where the hydrological importance is great. Many of the flux estimation techniques, such as the bulk transfer method, are poorly adapted for use in complex terrain. In order to characterize the turbulence and to assess the suitability of flux estimation techniques, eddy covariance flux measurements and supporting meteorological data were collected from two mountain valley forest openings in Kananaskis Country, AB. These sites were generally calm, however wind gusts were frequently observed which markedly affected the turbulence characteristics and increased the rates of momentum and heat transfer. In order to successfully apply the bulk transfer technique at these sites, it was necessary to use environment-specific transfer coefficients to account for the effect of the surrounding complex terrain. These observations were compared with data collected on a treeless alpine ridge near Whitehorse, YT, where it was found that many of the turbulence characteristics were similar to flat sites. However, the boundary layer formed over the alpine ridge was very thin and the site was poorly suited for estimating surface fluxes. The mountain results were further contrasted with data collected over a homogeneous and flat prairie site located near Saskatoon, SK. This site included measurement of all of the snow energy terms, permitting an estimate of the energy balance closure obtainable over snow surfaces. The observed energy balance residual was very large, indicating that the eddy covariance technique was unable to capture all of the turbulent energy. It was concluded that an unmeasured transfer of sensible heat was occurring which was strongly correlated with the long-wave radiation balance. Mechanisms for this relationship were hypothesized. Two snow energy balance models were used to investigate the energy imbalance, where it was observed that the flux terms could be suitably simulated if effective parameters were used to augment the sensible heat transfer rate. The results from this thesis contribute to the understanding of heat transfer processes over snow surfaces during mid-winter conditions and improve the ability to model turbulent heat and mass fluxes from snow surfaces in complex environments.

The intra-basin variability of snowmelt and meltwater runoff hydrology in an 8 km2 subarctic alpine tundra catchment was examined for the 2003 melt period. The catchment, Granger Creek, is within the Wolf Creek Research Basin, Yukon which is typical of mountain subarctic landscapes in north-western Canada. The study catchment was segmented into nine internally uniform zones termed Landscape Units (LUs) based on their similar hydrological, physiographic, vegetation and soil properties. Snow accumulation exhibited significant variability among the LUs, with greatest snow water equivalent in areas of tall shrub vegetation. Melt began first on southerly exposures and at lower elevations, yet average melt rates for the study period varied little among LUs with the exception of those with strong aspects. In LUs with capping organic soils, meltwater first infiltrated this surface horizon, satisfying its storage capacity and then percolated into the frozen mineral substrate. Infiltration and percolation into frozen mineral soils was restricted where melt occurred rapidly and organic soils were thin; in this case meltwater delivery rates exceeded the frozen mineral soil infiltration rate, resulting in high runoff rates. In contrast, where there were slower meltrates and thick organic soils, infiltration was unlimited and runoff was suppressed. The snow water equivalent had a large impact on runoff generation as soil storage capacity was quickly surpassed in areas of deep snow, diverting the bulk of meltwater laterally to the drainage network. A spatially distributed water balance indicated that snowmelt freshet was primarily controlled by areas with tall shrub vegetation that accumulate large quantities of snow and by alpine areas with no capping organic soils. The intra-basin water balance variability has important implications for modeling freshet in hydrological models.

The intra-basin variability of snowmelt and meltwater runoff hydrology in an 8 km2 subarctic alpine tundra catchment was examined for the 2003 melt period. The catchment, Granger Creek, is within the Wolf Creek Research Basin, Yukon which is typical of mountain subarctic landscapes in north-western Canada. The study catchment was segmented into nine internally uniform zones termed Landscape Units (LUs) based on their similar hydrological, physiographic, vegetation and soil properties. Snow accumulation exhibited significant variability among the LUs, with greatest snow water equivalent in areas of tall shrub vegetation. Melt began first on southerly exposures and at lower elevations, yet average melt rates for the study period varied little among LUs with the exception of those with strong aspects. In LUs with capping organic soils, meltwater first infiltrated this surface horizon, satisfying its storage capacity and then percolated into the frozen mineral substrate. Infiltration and percolation into frozen mineral soils was restricted where melt occurred rapidly and organic soils were thin; in this case meltwater delivery rates exceeded the frozen mineral soil infiltration rate, resulting in high runoff rates. In contrast, where there were slower meltrates and thick organic soils, infiltration was unlimited and runoff was suppressed. The snow water equivalent had a large impact on runoff generation as soil storage capacity was quickly surpassed in areas of deep snow, diverting the bulk of meltwater laterally to the drainage network. A spatially distributed water balance indicated that snowmelt freshet was primarily controlled by areas with tall shrub vegetation that accumulate large quantities of snow and by alpine areas with no capping organic soils. The intra-basin water balance variability has important implications for modeling freshet in hydrological models.