TY - JOUR
T1 - Dynamic estimation of free water surface coverage from a basin wetness index of the Mackenzie River basin using SSM/I measurements
AU - Temimi, M.
AU - Leconte, R.
AU - Brissette, F.
AU - Chaouch, N.
PY - 2007
Y1 - 2007
N2 - This work is an investigation to obtain dynamic estimates of free water surface (FWS) coverage in the Mackenzie River basin in northwest Canada. The method used in this study is based on the basin wetness index (BWI), which is computed using the brightness temperature of remotely sensed special sensor microwave imager (SSM/I) data in the 19, 37, and 85 GHz channels. In its basic formulation, the BWI uses two empirical parameters that are constant in time, but they may vary in space depending on the surface type. Hence, a preliminary classification exercise is necessary to apply the BWI. The temporal evolution of the vegetation state and the basin heterogeneity suggest that these parameters could vary in both time and space. An alternative approach is therefore proposed that allows for a reassessment of the empirical constants at the reception of each new image. This approach allows the preliminary classification step to be eliminated. The variability of the parameters over time will account for the evolution of the vegetation cover and improve the BWI sensitivity to the surface wetness. The index was computed for each pixel (625 km2) on a daily basis for the summer seasons from 1997 to 2000 over the entire surface of the Mackenzie River basin (1.8 × 106 km2), which makes up roughly 20% of the area of Canada. The FWS was computed based on the BWI estimates. The reliability of this approach is assessed by analyzing the agreement of the FWS variability with the fluctuations of the climatological and hydrological conditions.
AB - This work is an investigation to obtain dynamic estimates of free water surface (FWS) coverage in the Mackenzie River basin in northwest Canada. The method used in this study is based on the basin wetness index (BWI), which is computed using the brightness temperature of remotely sensed special sensor microwave imager (SSM/I) data in the 19, 37, and 85 GHz channels. In its basic formulation, the BWI uses two empirical parameters that are constant in time, but they may vary in space depending on the surface type. Hence, a preliminary classification exercise is necessary to apply the BWI. The temporal evolution of the vegetation state and the basin heterogeneity suggest that these parameters could vary in both time and space. An alternative approach is therefore proposed that allows for a reassessment of the empirical constants at the reception of each new image. This approach allows the preliminary classification step to be eliminated. The variability of the parameters over time will account for the evolution of the vegetation cover and improve the BWI sensitivity to the surface wetness. The index was computed for each pixel (625 km2) on a daily basis for the summer seasons from 1997 to 2000 over the entire surface of the Mackenzie River basin (1.8 × 106 km2), which makes up roughly 20% of the area of Canada. The FWS was computed based on the BWI estimates. The reliability of this approach is assessed by analyzing the agreement of the FWS variability with the fluctuations of the climatological and hydrological conditions.
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U2 - 10.5589/m07-016
DO - 10.5589/m07-016
M3 - Article
AN - SCOPUS:35748949578
SN - 0703-8992
VL - 33
SP - 121
EP - 129
JO - Canadian Journal of Remote Sensing
JF - Canadian Journal of Remote Sensing
IS - 2
ER -