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Table 1-5.7 "n"and "k"Values Used in Time Calculations for Hydrographs <br /> Sheet Flow(initial 300 feet of travel) <br /> Surface <br /> Smooth surfaces(concrete,asphalt,gravel,compacted soil) —� 0•U 1 i <br /> Fallow fields or loose soil 0.05 <br /> Short prairie gross and lawns 0.1? 0. 15 <br /> Dense grasses -0.45- o.Z4 <br /> Bermuda grass -0:24- o,41 <br /> Range(natural) '0.41 o,13 <br /> Woods or forest with light underbrush -0.!3 o•Yo <br /> Woods or forest with dense underbrush -0,40- <br /> Shallow Concentrated Flow(After the initial 300 feet of sheet flow; R=0.1) <br /> Surface k <br /> Forest with heavy ground litter and meadows(n=0.10) i <br /> Brushy ground with some trees(n=0.060) <br /> Fallow or minimum tillage cultivation(n=0.040) ti <br /> High grass(n=0.035) 9 <br /> ( Short grass,pasture and lawns(n=0.030) 11 <br /> early bare ground(n=0.25) 1 1 <br /> Paved and gravel areas(n =0.012) 27 <br /> Intermittent Channel Flow(At lite beginning of visible channels,R=0.2) <br /> Channel Type k <br /> Forested Swale with heavy ground litter(n=0.10) <br /> Forested drainage course/ravine with defined channel bed(n=0.050) 1 <br /> Rock-lined waterway(n=0.035) 15 <br /> Grassed waterway(n=0.030) 17 <br /> Earth-lined waterway(n=0.025) 20 <br /> CMP pipe(n=0.024) 21 <br /> Concrete pipe(n=0.012) — ' 42 <br /> Other waterways and pipe 0.508/11 <br /> Continuous Stream Channel Flow(R=0.4) <br /> Channel Type k <br /> Meandering stream with some pools(n=0.040) 20 <br /> Rock-lined stream(n =0.035) 23 <br /> Grass-lined stream (n=0.030) 27 <br /> !her streams,man-made channels,and pipe 0.807'n <br /> 1-5-34 <br />