Laserfiche WebLink
<br />,I <br /> <br />d, Input Data <br /> <br /> <br />Most of the input data relates to how the model operates, the output it generates, or <br /> <br /> <br />is non-controversial in nature (Le, topographic data), This data will not be presented <br /> <br /> <br />in this report. The data which most effects the results of the modeling effort are <br /> <br /> <br />presented herein, <br /> <br />For this study 6,508 nodes were established at a spacing of 100 feet. The amount <br /> <br /> <br />of area over the entire basin that is available to store water and allow water <br /> <br /> <br />infiltration is 80%, The study assumes that impervious objects (i.e. trees, rocks, <br /> <br /> <br />buildings, etc.) occupy a significant portion of the basin (20%), The study also <br /> <br /> <br />assumes that the maximum Froude Number for flow down steep slopes is 0,9. <br /> <br /> <br />NOAA precipitation maps provided estimates of the 100-year, I-hour rainfall event <br /> <br /> <br />and the 10-year, I-hour rainfall event. The CUHP program then converted these <br /> <br /> <br />precipitation amounts to 2-hourquantities and developed the rainfall distribution that <br /> <br /> <br />was used in the FLO-20 model. <br /> <br />Surface detention and abstraction was assumed to be 0,025 inches, Foruse inFLO- <br /> <br /> <br />20, the study assumed that the soil type was the same over the entire basin, The <br /> <br /> <br />porosity was 0.4 feet per feet, and the initial and final saturation contents were 0,9 <br /> <br /> <br />and 1,0, respectively, The hydraulic conductivity of the soil was assumed to be 0.3 <br /> <br /> <br />inches per hour and the capillary suction was 4,8 inches, This wouldassumethatthe <br /> <br /> <br />soil was a loam. <br /> <br />The peak sediment concentration used in the inflow hydrographs was 0.45, The <br /> <br /> <br />model was run for a range of values varying between 0.35 and 0.48, A <br /> <br /> <br />concentration of 0.45 allowed the flow to just enter the Roaring Fork River during <br /> <br /> <br />a 100~ year event, <br /> <br />14 <br /> <br />1 <br /> <br />.._J <br />