TY - CHAP
T1 - On the use of satellite passive microwave data for estimating surface soil wetness in the mackenzie river basin
AU - Leconte, Robert
AU - Temimi, Marouane
AU - Chaouch, Naira
AU - Brissette, François
AU - Toussaint, Thibault
PY - 2008
Y1 - 2008
N2 - A method is presented to obtain dynamic estimates of basin wetness (BWI) and fractional water surface (FWS) indices at the scale of the Mackenzie River Basin using SSM/I remotely sensed brightness temperature measurements. The approach accounts for the seasonal evolution of the vegetation state and the basin surface heterogeneity. Results demonstrate that the approach can filter out the vegetation effect and produce reasonable estimates of FWS at the basin scale. However, the low resolution of SSM/I and other passive microwave sensors precludes the use of this approach for monitoring soil wetness at a smaller scale. Also, the FWS cannot distinguish moisture effects from open water bodies from that of soil surface. A methodology based on the combined use of passive microwave and visible data, along with topographic information, has been developed to separate the open water from the soil surface component in estimating the BWI, and to downscale the index at the digital elevation models scale using a topographic index (TI) which is continuously adjusted to account for vegetation growth. When applied to the Peace-Athabasca-Delta area, this method improved the correlation between soil wetness and precipitation measured at a meteorological station, compared to an approach based on a time invariant TI.
AB - A method is presented to obtain dynamic estimates of basin wetness (BWI) and fractional water surface (FWS) indices at the scale of the Mackenzie River Basin using SSM/I remotely sensed brightness temperature measurements. The approach accounts for the seasonal evolution of the vegetation state and the basin surface heterogeneity. Results demonstrate that the approach can filter out the vegetation effect and produce reasonable estimates of FWS at the basin scale. However, the low resolution of SSM/I and other passive microwave sensors precludes the use of this approach for monitoring soil wetness at a smaller scale. Also, the FWS cannot distinguish moisture effects from open water bodies from that of soil surface. A methodology based on the combined use of passive microwave and visible data, along with topographic information, has been developed to separate the open water from the soil surface component in estimating the BWI, and to downscale the index at the digital elevation models scale using a topographic index (TI) which is continuously adjusted to account for vegetation growth. When applied to the Peace-Athabasca-Delta area, this method improved the correlation between soil wetness and precipitation measured at a meteorological station, compared to an approach based on a time invariant TI.
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U2 - 10.1007/978-3-540-75136-6_4
DO - 10.1007/978-3-540-75136-6_4
M3 - Chapter
AN - SCOPUS:84892099604
SN - 9783540749271
VL - 2
SP - 59
EP - 79
BT - Cold Region Atmospheric and Hydrologic Studies. The Mackenzie GEWEX Experience
ER -