Wildﬁres frequently result in natural hazards such as ﬂash ﬂoods (Yates et al., 2001) and debris ﬂows (Cannon et al., 2001a,b; Gabet and Sternberg, 2008). One of the principal causes of the increased risk of post-wildﬁre hydrologically driven hazards is reduced in ﬁltration rates (e.g. Scott and van Wyk, 1990; Cerdà, 1998; Robichaud, 2000; Martin and Moody, 2001). Beyond the reduction in peak inﬁltration rate, there is mounting evidence that the fundamental physics of inﬁltration in wild ﬁre-affected soils is different from unburned soils (e.g. Imeson et al., 1992; Moody et al., 2009; Moody and Ebel, 2012).
Understanding post-wildﬁre hydrology is critical given the increasing wildﬁre incidence in the western USA (Westerling et al., 2006) and elsewhere in the world (Kasischke and Turetsky, 2006; Holz and Veblen, 2011; Pausas and Fernández-Muñoz, 2012). Wildﬁre is a disturbance event with global distribution (Bowman et al., 2009; Krawchuk et al., 2009; Pechony and Shindell, 2010; Moritz et al., 2012), and with increasing populations moving into ﬁre-prone areas, understanding post-wildﬁre inﬁltration is of increasing importance for predicting post-wildﬁre consequences. Runoff is generally controlled by the inﬁltration-excess mechanism in ﬁre-affected soils (e.g. Mayor et al., 2007; Onda et al., 2008; Kinner and Moody, 2010). It is essential that the ﬁre community have conceptual models, physical equations and tools (i.e. numerical models) to predict inﬁltration and thus excess rainfall (after Horton, 1933), which can provide estimates of peak discharge, start of runoff, time to peak and total runoff for hydroclimatic scenarios after wildﬁres. Reductions in saturated hydraulic conductivity Ksat [LT-1] are common for ﬁre-affected soils, and the relatively low values observed explain the elevated ﬂash ﬂood hazards (e.g. Ksat of 1–100 mm h-1 , Robichaud, 2000; Yates et al., 2000; Martin and Moody, 2001; Robichaud et al., 2007; Moody et al., 2009; Neary, 2011; Nyman et al., 2011).
Additional publication details
|Publication Subtype||Journal Article|
|Title||Rethinking infiltration in wildfire-affected soils|
|Series title||Hydrological Processes|
|Contributing office(s)||National Research Program - Central Branch|