Call number:
ZSP-201-76/27
In:
CRREL Report, 76-27
Description / Table of Contents:
In Part I a physically based model was used to predict daily snowmelt on 2000 m sq plots in the Subarctic. The plots had a range of aspects and inclinations in boreal forest and on the tundra. The energy balance, computed for each of the plots, was compensated for differences in radiative and turbulent energy fluxes caused by varied slope geometry and vegetative cover. The turbulent energy fluxes were also corrected for the effects of the stable stratification of the air over the snow surface. The predictions of the model were compared with daily melts derived from runoff measured on the snowmelt plots. The results show that the method is a good predictor of daily amounts of snowmelt, although some uncertainties are introduced by changes in the snow surface during the melt period. In Part II, a physically based model of the movement of water through snowpacks was used to calculate hydrographs generated by diurnal waves of snowmelt on the tundra and in the boreal forest of subarctic Labrador. The model was tested against measured hydrographs from hillside plots that sampled a range of aspect, gradient, length, vegetative cover, and snow depth and density. The model yielded good results, particularly in the prediction of peak runoff rates, though there was a slight overestimate of the lag time. A comparison of predictions against field measurements indicated that, given the ranges over which each of the controls is likely to vary, the two most critical factors controlling the hydrograph are the snow depth and the melt rate, which must be predicted precisely for short intervals of time. Permeability of the snowpack is another important control, but it can be estimated closely from published values.
Type of Medium:
Series available for loan
Pages:
ix, 40 Seiten
,
Illustrationen
Series Statement:
CRREL Report 76-27
URL:
https://hdl.handle.net/11681/9527
Language:
English
Note:
Contents:
Abstract
Preface
Summary
Notation
Scope of the study
Part I. Energy balance computations
Introduction
The experimental sites
Instrumentation
Theoretical
Radiation heat flow Hr
Sensible heat flux Hc and latent heat flux He
The application of the heat flow model
Results and discussion
Conclusions and recommendations
Part II. Comparison of water runoff computations and measurements
Introduction
The runoff model
The unsaturated zone
The saturated layer
The field study
Instrumentation of the plots
Descriptive hydrology
Application of the runoff model
The unsaturated zone
The saturated zone
Discussion and conclusions
Comparison of predicted and observed hydrographs
Factors affecting results
Literature cited
Location:
AWI Archive
Branch Library:
AWI Library
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