Runoff simulation sensitivity to remotely sensed initial soil water content

Abstract

A variety of aircraft remotely sensed and conventional ground-based measurements of volumetric soil water content (SW) were made over two subwatersheds (4.4 and 631 ha) of the U.S. Department of Agriculture's Agricultural Research Service Walnut Gulch experimental watershed during the 1990 monsoon season. Spatially distributed soil water contents estimated remotely from the NASA push broom microwave radiometer (PBMR), an Institute of Radioengineering and Electronics (IRE) multifrequency radiometer, and three ground-based point methods were used to define prestorm initial SW for a distributed rainfall-runoff model (KINEROS; Woolhiser et al., 1990)•at a small catchment scale (4.4 ha). At a medium catchment scale (631 ha or 6.31 km •) spatially distributed PBMR SW data were aggregated via stream order reduction. The impacts of the various spatial averages of SW on runoff simulations are discussed and are compared to runoff simulations using $W estimates derived from a simple daily water balance model. It was found that at the small catchment scale the SW data obtained from any of the measurement methods could be used to obtain reasonable runoff predictions. At the medium catchment scale, a basin-wide remotely sensed average of initial water content was sufficient for runoff simulations. This has important implications for the possible use of satellite-based microwave soil moisture data to define prestorm SW because the low spatial resolutions of such sensors may not seriously impact runoff simulations under the conditions examined. However, at both the small and medium basin scale, adequate resources must be devoted to proper definition of the input rainfall to achieve reasonable runoff simulations. 1. Introduction Passive microwave soil moisture research has focused on the basic questions involved in the data interpretation algorithm [Jackson and Schmugge, 1989]. There have been a number of efforts to develop water balance models that utilize these surface observations [Jackson, 1986; Prevot et al., 1984]; however, these have only considered a single profile and have not considered surface runoff dynamics. Engrnan and Gurney [1991] recently summarized some common viewpoints concerning remotely sensed soil moisture observations and hydrologic modeling. The general conclusion was that in order to fully utilize the information that frequent spatially distributed soil moisture observations might provide, we must reevaluate the hydrologic models themselves. The soil component of many existing models is constructed in such a way to make the model work even though soil moisture has never been available as an input variable. This element of the hydrologic cycle has thus Gurney [1991] noted, actual observations of soil moisture may offer no improvement in runoff estimation because these models do not properly incorporate this variable. This was observed by Jackson et al. [1981] in a study involving a continuous runoff simulation model. In that study they examined how repetitive surface soil moisture observations could be us...

Coupling soil moisture and precipitation observations for predicting hourly runoff at small catchment scale

“…The importance of soil moisture on runoff, infiltration, and evapotranspiration is well recognized in the literature (Goodrich et al, 1994;Merz and Plate, 1997;Scipal et al, 2008;Brocca et al, 2009a, among others). Specific monitoring programs (Merz and Bardossy, 1998;Aubert et al, 2003;Castillo et al, 2003;Brocca et al, 2009a;Matgen et al, 2012;Morbidelli et al, 2012) and modelling studies (Gautam et al, 2000;Anctil et al, 2004;Komma et al, 2008;Berthet et al, 2009;Sheikh et al, 2009;Brocca et al, 2012;Tramblay et al, 2012;Van Steenbergen and Willems, 2013) were carried out to investigate the influence of soil moisture on producing runoff hydrographs.…”

“…Other studies directly used the observations for the assessment of the antecedent wetness conditions through in situ (Meyles et al, 2003;Huang et al, 2007;Tramblay et al, 2010;Zehe et al, 2010) and remotely sensed (Jacobs et al, 2003;Brocca et al, 2009b;Beck et al, 2009) estimates. For instance, Goodrich et al (1994) monitored two sub-catchments of 0.044 km 2 and 6.31 km 2 size in Walnut Gulch experimental watershed of the U.S. Department of Agriculture. They pointed out that a basin-wide remotely sensed average initial soil moisture can be sufficient for rainfall-runoff modelling in semiarid regions provided that the spatial-temporal variability of rainfall is accurately known.…”

A new instrument to measure plot-scale runoff

“…Surface runoff generation can occur at multiple scales, ranging from small pools of excess water that propagate downhill to stream networks that drain large catchments (Horton, 1939;Betson, 1964;Hewlett and Hibbert, 1967;Dunne and Black, 1970;Goodrich et al, 1994;Van de Giesen et al, 2000;Stomph et al, 2001Stomph et al, , 2002aMcDonnell, 2003;Descroix et al, 2007;Blume et al, 2008;McGuire and McDonnell, 2010;Ali et al, 2013;Jones et al, 2013;Radatz et al, 2013;Steenhuis et al, 2013;Blair et al, 2014;Stewart et al, 2014). Runoff is a primary cause of erosion and can drive nutrient losses from watersheds (Aksoy and Kavvas, 2005;Butler et al, 2008;Nearing et al, 2011).…”

Fuzzy Logic for Rainfall-Runoff Modelling Considering Soil Moisture

“…Some studies directly used the soil moisture observations for the assessment of the antecedent wetness conditions through in-situ (Meyles et al 2003;Huang et al 2007;Zehe et al 2010) and remotely sensed (Jacobs et al 2003;Brocca et al 2009b;Beck et al 2010) estimates. Goodrich et al (2004)) pointed out that, when the spatial-temporal variability of rainfall is known, basin-wide remotely sensed average initial soil moisture can be sufficient for RR modelling in semiarid regions. Brocca et al (2009a) stated that the integration of in situ soil moisture observations into a simple event-based RR model can improve the runoff hydrographs predictions.…”

“…The importance of soil moisture on runoff, infiltration, and evapotranspiration is well known in the literature (Goodrich et al 2004;Merz and Plate 1997;Scipal et al 2008;Brocca et al 2009a). Specific monitoring programs (Merz and Bardossy 1998;Aubert et al 2003;Morbidelli et al 2012) and modelling studies (Gautam et al 2000;Anctil et al 2004;Casper et al 2007;Komma et al 2008;Berthet et al 2009;Brocca et al 2012b;van Steenbergen and Willems 2013) were carried out to investigate the influence of soil moisture on runoff hydrographs.…”