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<br />9 <br /> <br />water repellency in the soil causing it's infiltration rate to be reduced by 66% (Campbell et aI., <br /> <br />1977). Dyrness (1976) measured infiltration rates in a lodgepole pine forest in Oregon and <br /> <br />/' <br /> <br />indicates that soils in unburned areas absorb water at a rate which is roughly three times faster <br /> <br />than soils in burned areas. <br /> <br />Other features of the fire contribute to lower infiltration rates which leads to higher <br /> <br />overland flow generation. The removal of a litter layer on the surface and removal of growing <br /> <br />vegetation allow raindrops to fall to the soil surface with little reduction in kinetic energy. The <br /> <br />potential storage of water within the vegetation and litter layer that is lost, and also the reduction <br /> <br />in evapotranspiration demands, will lead to greater runoff. Plant roots also provide increased <br /> <br />permeability, allowing intense rainfall to be quickly absorbed. The compounding effect of <br /> <br />decreased infiltration capacity and decreased storage at the surface create an environment where <br /> <br />,/ <br /> <br />short, intense rainfall events can lead to destructive flash flooding. Depth to bedrock in the <br /> <br />Buffalo Creek area ranges from 8 to 29 This characteristic also allows water to run off <br /> <br />soon after the initiation of intense precipitation events, <br /> <br />,"~1h ; <br />vr"cY1J,~' <br /> <br />1:i <br /> <br />Runoff along the Front Range of Colorado can be highly variable. High discharge <br /> <br />amounts occur in the foothills of the Rocky Mountains primarily due to exposed bedrock, steep - <br /> <br />slopes, and soil characteristics which give way to higher rates of flood runoff (Jarrett 1993). Soil <br /> <br />depths of 8-20 inches characterize the Buffalo Creek basin with soils (unburned) consisting <br /> <br />mainly of excessively drained gravelly sands with a high rate of water transmission (SCS, 1993)_ <br /> <br />Slopes of 10-80% are found in the Buffalo Creek area, <br /> <br />Camp'bell et al. (1977) found an 800% increase in stream flow and a 450% increase in <br /> <br />/' <br /> <br />runoff efficiency from a catchment in Arizona in the first wet season following a fire. Scott and <br /> <br />VanWyk (1990) also found peak flow rates from a pine vegetated catchment in South Africa to <br />