Use of Landsat Digital Data for Snow Cover Mapping in the Upper Saint John River Basin, Maine PDF Download

Author: C. J. Merry
Publisher:
ISBN:
Category : Hydrologic models
Languages : en
Pages : 84

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Book Description
Measurements of snow depth and its water equivalent were obtained at 11 snow courses in the Allagash, Maine, area in conjunction with acquisition of five Landsat-2 and -3 images during the 1977-78 and 1978-79 winters. To test a hypothesis that Landsat reflected radiance values on a regional scale do change, histograms of the Landsat MSS band 7 reflected radiance values for a 300- x 300-pixel (420 sq km) area near Allagash were evaluated to quantify the change. A statistical description (skewness and kurtosis) of the histogram for each scene was developed and and then correlated with ground measurements of snow depth. The Lansat date were then re-examined and corrections were made for solar elevation and MSS sensor calibration. Reflected radiance from open areas showed a consistent increase in intensity with increasing snow depth. Forested land cover classes did not change with snow depth. Digital imagery data acquired 31 May 1978 when the land was snow-free was used to classify land cover categories. Ground truth measurements of water equivalent of the snow cover were are-weighted using the land cover classification to derive regional values on each of the five Lansat winter scenes. The 1 March 1978 snow measurement of 19.46 cm of water equivalent was used as an input value to the SSARR model. The SSARR prediction for the 1 March-31 May 1978 period was within 78% of the measured runoff for the initial baseflow period and within 66% measured for the spring melt recession period. Keywords: Hydrologic modeling.