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<br />. <br /> <br /> <br />@ <br /> <br />Determining Flood <br />Discharges <br /> <br />Discharge-Drainage Area Curves <br />Regression Equations <br />. published by USGS. Appendix 4 <br /> <br />Rational Method <br />. QzOA <br />. C..runofTcoefTklent <br />.I_ralnfalllntfnslly(hthlr) <br />. A..drafnagearea(acres) <br /> <br />. Other detailed methods <br />- TR-5S, TR.20, HEC.] <br /> <br /> <br />. <br /> <br />. <br /> <br /> <br />QUICK-2 <br /> <br />FEMA model which will run on a PC <br /> <br />Used to compute <br /> <br />. normal depth <br /> <br />. critical depth <br /> <br />. cross section capacity <br /> <br />. step-backwater <br />computations <br /> <br />Data requirements <br />. cross sectional geometry <br />. channel slope <br />. estimate of Manning's n <br />. discharge <br /> <br /> <br /> <br />Hydraulics <br /> <br />. Water surface elevations that occur <br />during a flood <br /> <br />. 100 year base flood elevations (BFE) <br />. Manning equation (Q= 1.49* A *R67*S"/n) <br /> <br />. Step-backwater model (HEC-2, <br />WSPRO) <br /> <br />. Quick-2 <br /> <br />HydraulIc methods <br />Normal depth hand calculations <br />. Plot the cross sedion obtained from the topographic <br />information on graph paper <br />. Select left and right channel bank stations <br />. Select appropriate Manning's n values for the channel <br />,,:. and overbanks <br />',' 0:-;' . Compute the cross sedional area, welled perimeter <br />and hydraulic radius for at least 3 elevations <br />. Compute the discharge using Mannlngs equation <br />. Add the discharges for each cross section at the same <br />elevation to obtain the total dlscbarge <br />. Plot the total discharge vs, the elevations <br />. Determine the BFE from the graph using the <br />discharge computed for the site <br /> <br /> <br />7 <br />