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-o~ <br />~yQsuM ~ia-~[an ~~ I ~21az <br />REPRODUCED FROM TABLE 2, LECTURE 2, DAY 2, ACOE 1990 <br />SURFACE N VALUE SOURCE <br />ASPHALT/CONCRETE O. - <br />BAREPACKED SOIL FREE OF STONE <br />FALLOW-NO RESIDUE D.008-OD12 B <br />CONVENTIONAL TILLAGE - NO RESIDUE 0.06 - 0.12 B <br />CONVENTIONAL TILLAGE -WITH RESIDUE 0.16-0.22 B <br />CHISEL PLOW-NO RESIDUE 0.06-0.12 B <br />CHISELPY~OW-WITH RESIDUE 0.10-0.16 B <br />FALLDISKING -WITH RESIDUE 0.30 - 0.50 B <br />NO TILL-NO RESIDUE 0.04-0.10 B <br />NOTILL(20-40 PERCENT RESIDUE COVER) 0.07-0.17 B <br />NO TILL(60-1O0 PERCENT RESIDUE COVER) 0.17-0.47 B <br />SPARSE RANGELAND W1TH DEBRIS: <br />O PERCENT COVER 0.09-0.34 1 B <br />20 PERCENT COVER 0.05-0.25 8 <br />SPARSE VEGETATION 0.053-0.13 F <br />SHORTGRA55PRAIRIE 0.10-0.20 F <br />POOR GRA55 COYER ON MODERATELY 0.30 C <br />ROUGH BARE SURFACE <br />LIGHT TURF 0.20 - ~ A <br />GRASS R O. C <br />DENSE TURF 0.17-0.80 A,C,E,F <br />DENSE GRASS 0.17-0.30 D <br />BERMUDA GRASS 0.30-0.48 D <br />DENSE SHRUBBERY AND FOREST LITTER 0.4 A <br />A) CRAWFORD AND LINSLEY (1966). <br />B) ENGMAN (1986). <br />C) HATHAWAY (1945). <br />D) PALMER (1946). <br />E) RAGAN AND DURU (1972). <br />F) WOOLHISER (1975). <br />'N" values provided in this table pertain to both the <br />SCS TR-55 "To" and FHWA 1984 HEC-12 °To' methods <br />OVERLAND FLOW RESISTANCE FACTOR (N) <br />TABLE `E-1" <br />T1F(' 1994 F_S <br />