APPENDIX A: TABLES
TABLE A-1 PROPERTIES OF WATER IN SI UNITS. |
Temperature (°C) |
Specific Gravity |
Density (g/cm3) |
Heat of Vaporization (cal/g) |
Viscosity |
Vapor Pressure |
Absolute (cp) |
Kinematic (cs) |
(mm Hg) |
(mb) |
(g/cm2) |
0 |
0.99987 |
0.99984 |
597.3 |
1.790 |
1.790 |
4.58 |
6.11 |
6.23 |
5 |
0.99999 |
0.99996 |
594.5 |
1.520 |
1.520 |
6.54 |
8.72 |
8.89 |
10 |
0.99973 |
0.99970 |
591.7 |
1.310 |
1.310 |
9.20 |
12.27 |
12.51 |
15 |
0.99913 |
0.99910 |
588.9 |
1.140 |
1.140 |
12.78 |
17.04 |
17.38 |
20 |
0.99824 |
0.998211 |
586.0 |
1.000 |
1.000 |
17.53 |
23.37 |
23.83 |
25 |
0.99708 |
0.99705 |
583.2 |
0.890 |
0.893 |
23.76 |
31.67 |
32.20 |
30 |
0.99568 |
0.99565 |
580.4 |
0.798 |
0.801 |
31.83 |
42.43 |
43.27 |
35 |
0.99407 |
0.99404 |
577.6 |
0.719 |
0.723 |
42.18 |
56.24 |
57.34 |
40 |
0.99225 |
0.99222 |
574.7 |
0.653 |
0.658 |
55.34 |
73.78 |
75.23 |
50 |
0.98807 |
0.98804 |
569.0 |
0.547 |
0.554 |
92.56 |
123.40 |
125.83 |
60 |
0.98323 |
0.98320 |
563.2 |
0.466 |
0.474 |
149.46 |
199.26 |
203.19 |
70 |
0.97780 |
0.97777 |
557.4 |
0.404 |
0.413 |
233.79 |
311.69 |
317.84 |
80 |
0.97182 |
0.97179 |
551.4 |
0.355 |
0.365 |
355.28 |
473.67 |
483.01 |
90 |
0.96534 |
0.96531 |
545.3 |
0.315 |
0.326 |
525.89 |
701.13 |
714.95 |
100 |
0.95839 |
0.95836 |
539.1 |
0.282 |
0.294 |
760.00 |
1013.25 |
1033.23 |
Source: Linsley, R. K. et al. (1982). Hydrology for Engineers. 3d. ed., New York: McGraw-Hill.
|
TABLE A-2 PROPERTIES OF WATER IN U.S. CUSTOMARY UNITS. |
Temperature (°F) |
Specific Gravity |
Density (lb/ft3) |
Heat of Vaporization (Btu/lb) |
Viscosity 1 |
Vapor Pressure |
Absolute (lbs/ft2) |
Kinematic (ft2/s) |
(in Hg) |
(mb) |
(lb/in2) |
32 |
0.99986 |
62.418 |
1075.5 |
3.746 |
1.931 |
0.180 |
6.11 |
0.089 |
40 |
0.99998 |
62.426 |
1071.0 |
3.229 |
1.664 |
0.248 |
8.39 |
0.122 |
50 |
0.99971 |
62.409 |
1065.3 |
2.735 |
1.410 |
0.362 |
12.27 |
0.178 |
60 |
0.99902 |
62.366 |
1059.7 |
2.359 |
1.217 |
0.522 |
17.66 |
0.256 |
70 |
0.99798 |
62.301 |
1054.0 |
2.050 |
1.058 |
0.739 |
25.03 |
0.363 |
80 |
0.99662 |
62.216 |
1048.4 |
1.799 |
0.930 |
1.032 |
34.96 |
0.507 |
90 |
0.99497 |
62.113 |
1042.7 |
1.595 |
0.826 |
1.422 |
48.15 |
0.698 |
100 |
0.99306 |
61.994 |
1037.1 |
1.424 |
0.739 |
1.933 |
65.47 |
0.950 |
120 |
0..98856 |
61.713 |
1025.6 |
1.168 |
0.609 |
3.448 |
116.75 |
1.693 |
140 |
0.98321 |
61.379 |
1014.0 |
0.981 |
0.514 |
5.884 |
199.26 |
2.890 |
160 |
0.97714 |
61.000 |
1002.2 |
0.838 |
0.442 |
9.656 |
326.98 |
4.742 |
180 |
0.97041 |
60.580 |
990.2 |
0.726 |
0.386 |
15.295 |
517.95 |
7.512 |
200 |
0.96306 |
60.121 |
977.9 |
0.637 |
0.341 |
23.468 |
794.72 |
11.526 |
212 |
0.95837 |
59.828 |
970.3 |
0.593 |
0.319 |
29.921 |
1013.25 |
14.696 |
1 To obtain values of viscosity, multiply values shown in Table by 10-5.
Source: Linsley, R. K. et al. (1982). Hydrology for Engineers. 3d. ed., New York: McGraw-Hill.
|
TABLE A-3 FACTOR p IN BLANEY-CRIDDLE METHOD.1 |
Latitude North South |
Jan July |
Feb Aug |
Mar Sep |
Apr Oct |
May Nov |
Jun Dec |
Jul Jan |
Aug Feb |
Sep Mar |
Oct Apr |
Nov May |
Dec Jun |
60° |
0.15 |
0.20 |
0.26 |
0.32 |
0.38 |
0.41 |
0.40 |
0.34 |
0.28 |
0.22 |
0.17 |
0.13 |
50° |
0.19 |
0.23 |
0.27 |
0.31 |
0.34 |
0.36 |
0.35 |
0.32 |
0.28 |
0.24 |
0.20 |
0.18 |
40° |
0.22 |
0.24 |
0.27 |
0.30 |
0.32 |
0.34 |
0.33 |
0.31 |
0.28 |
0.25 |
0.22 |
0.21 |
30° |
0.24 |
0.25 |
0.27 |
0.29 |
0.31 |
0.32 |
0.31 |
0.30 |
0.28 |
0.26 |
0.24 |
0.23 |
20° |
0.25 |
0.26 |
0.27 |
0.28 |
0.29 |
0.30 |
0.30 |
0.29 |
0.28 |
0.26 |
0.25 |
0.25 |
10° |
0.26 |
0.27 |
0.27 |
0.28 |
0.28 |
0.29 |
0.29 |
0.28 |
0.28 |
0.27 |
0.26 |
0.26 |
0° |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
0.27 |
1 p = [(mean daily daytime hours for a given month) / (total daytime hours in a year)] × 100
|
TABLE A-4 FACTOR K IN THORNTHWAITE METHOD.1 |
Latitude |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
60°N |
0.54 |
0.67 |
0.97 |
1.19 |
1.33 |
1.56 |
1.55 |
1.33 |
1.07 |
0.84 |
0.58 |
0.48 |
50°N |
0.71 |
0.84 |
0.98 |
1.14 |
1.28 |
1.36 |
1.33 |
1.21 |
1.06 |
0.90 |
0.76 |
0.68 |
40°N |
0.80 |
0.89 |
0.99 |
1.10 |
1.20 |
1.25 |
1.23 |
1.15 |
1.04 |
0.93 |
0.83 |
0.78 |
30°N |
0.87 |
0.93 |
1.00 |
1.07 |
1.14 |
1.17 |
1.16 |
1.11 |
1.03 |
0.96 |
0.89 |
0.85 |
20°N |
0.92 |
0.96 |
1.00 |
1.05 |
1.09 |
1.11 |
1.10 |
1.07 |
1.02 |
0.98 |
0.93 |
0.91 |
10°N |
0.97 |
0.98 |
1.00 |
1.03 |
1.05 |
1.06 |
1.05 |
1.04 |
1.02 |
0.99 |
0.97 |
0.96 |
0° |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
10°S |
1.05 |
1.04 |
1.02 |
0.99 |
0.97 |
0.96 |
0.97 |
0.98 |
1.00 |
1.03 |
1.05 |
1.06 |
20°S |
1.10 |
1.07 |
1.02 |
0.98 |
0.93 |
0.91 |
0.92 |
0.96 |
1.00 |
1.05 |
1.09 |
1.11 |
30°S |
1.16 |
1.11 |
1.03 |
0.96 |
0.89 |
0.85 |
0.87 |
0.93 |
1.00 |
1.07 |
1.14 |
1.17 |
40°S |
1.23 |
1.15 |
1.04 |
0.93 |
0.83 |
0.78 |
0.80 |
0.89 |
0.99 |
1.10 |
1.20 |
1.25 |
50°S |
1.33 |
1.19 |
1.05 |
0.89 |
0.75 |
0.68 |
0.70 |
0.82 |
0.97 |
1.13 |
1.27 |
1.36 |
1 K = Constant to correct PET for latitudes other than 0° (Eq. 2-46).
|
TABLE A-5 VALUES OF F (z) (AREAS UNDER HALF OF THE NORMAL PROBABILITY DENSITY FUNCTION, Eq. 6-11) VERSUS FREQUENCY FACTOR z
(DOUBLE-ENTRY TABLE). |
z |
0.00 |
0.01 |
0.02 |
0.03 |
0.04 |
0.05 |
0.06 |
0.07 |
0.08 |
0.09 |
0.0 |
0.0000 |
0.0040 |
0.0080 |
0.0120 |
0.0159 |
0.0199 |
0.0239 |
0.0279 |
0.0319 |
0.0359 |
0.1 |
0.0398 |
0.0438 |
0.0478 |
0.0517 |
0.0557 |
0.0596 |
0.0636 |
0.0675 |
0.0714 |
0.0753 |
0.2 |
0.0793 |
0.0832 |
0.0871 |
0.0910 |
0.0948 |
0.0987 |
0.1026 |
0.1064 |
0.1103 |
0.1141 |
0.3 |
0.1179 |
0.1217 |
0.1255 |
0.1293 |
0.1331 |
0.1368 |
0.1406 |
0.1443 |
0.1480 |
0.1517 |
0.4 |
0.1554 |
0.1591 |
0.1628 |
0.1664 |
0.1700 |
0.1736 |
0.1772 |
0.1808 |
0.1844 |
0.1879 |
0.5 |
0.1915 |
0.1950 |
0.1985 |
0.2019 |
0.2054 |
0.2088 |
0.2123 |
0.2157 |
0.2190 |
0.2224 |
0.6 |
0.2257 |
0.2291 |
0.2324 |
0.2357 |
0.2389 |
0.2422 |
0.2454 |
0.2486 |
0.2518 |
0.2549 |
0.7 |
0.2580 |
0.2611 |
0.2642 |
0.2673 |
0.2704 |
0.2734 |
0.2764 |
0.2794 |
0.2823 |
0.2852 |
0.8 |
0.2881 |
0.2910 |
0.2939 |
0.2967 |
0.2995 |
0.3023 |
0.3051 |
0.3078 |
0.3106 |
0.3133 |
0.9 |
0.3159 |
0.3186 |
0.3212 |
0.3238 |
0.3264 |
0.3289 |
0.3315 |
0.3340 |
0.3365 |
0.3389 |
1.0 |
0.3413 |
0.3438 |
0.3461 |
0.3485 |
0.3508 |
0.3531 |
0.3554 |
0.3577 |
0.3599 |
0.3621 |
1.1 |
0.3643 |
0.3665 |
0.3686 |
0.3708 |
0.3729 |
0.3749 |
0.3770 |
0.3790 |
0.3810 |
0.3830 |
1.2 |
0.3849 |
0.3869 |
0.3888 |
0.3907 |
0.3925 |
0.3944 |
0.3962 |
0.3980 |
0.3997 |
0.4015 |
1.3 |
0.4032 |
0.4049 |
0.4066 |
0.4082 |
0.4099 |
0.4115 |
0.4131 |
0.4147 |
0.4162 |
0.4177 |
1.4 |
0.4192 |
0.4207 |
0.4222 |
0.4236 |
0.4251 |
0.4265 |
0.4279 |
0.4292 |
0.4306 |
0.4319 |
1.5 |
0.4332 |
0.4345 |
0.4357 |
0.4370 |
0.4382 |
0.4394 |
0.4406 |
0.4418 |
0.4430 |
0.4441 |
1.6 |
0.4452 |
0.4463 |
0.4474 |
0.4485 |
0.4495 |
0.4505 |
0.4515 |
0.4525 |
0.4535 |
0.4545 |
1.7 |
0.4554 |
0.4564 |
0.4573 |
0.4582 |
0.4591 |
0.4599 |
0.4608 |
0.4616 |
0.4625 |
0.4633 |
1.8 |
0.4641 |
0.4649 |
0.4656 |
0.4664 |
0.4671 |
0.4678 |
0.4686 |
0.4693 |
0.4699 |
0.4706 |
1.9 |
0.4713 |
0.4719 |
0.4726 |
0.4732 |
0.4738 |
0.4744 |
0.4750 |
0.4756 |
0.4762 |
0.4767 |
2.0 |
0.4772 |
0.4778 |
0.4783 |
0.4788 |
0.4793 |
0.4798 |
0.4803 |
0.4808 |
0.4812 |
0.4817 |
2.1 |
0.4821 |
0.4826 |
0.4830 |
0.4834 |
0.4838 |
0.4842 |
0.4846 |
0.4850 |
0.4854 |
0.4857 |
2.2 |
0.4861 |
0.4865 |
0.4868 |
0.4871 |
0.4875 |
0.4878 |
0.4881 |
0.4884 |
0.4887 |
0.4890 |
2.3 |
0.4893 |
0.4896 |
0.4898 |
0.4901 |
0.4904 |
0.4906 |
0.4909 |
0.4911 |
0.4913 |
0.4916 |
2.4 |
0.4918 |
0.4920 |
0.4922 |
0.4925 |
0.4927 |
0.4929 |
0.4931 |
0.4932 |
0.4934 |
0.4936 |
2.5 |
0.4938 |
0.4940 |
0.4941 |
0.4943 |
0.4945 |
0.4946 |
0.4948 |
0.4949 |
0.4951 |
0.4952 |
2.6 |
0.4953 |
0.4955 |
0.4956 |
0.4757 |
0.4959 |
0.4960 |
0.4961 |
0.4962 |
0.4963 |
0.4964 |
2.7 |
0.4965 |
0.4966 |
0.4967 |
0.4968 |
0.4969 |
0.4970 |
0.4971 |
0.4972 |
0.4973 |
0.4974 |
2.8 |
0.4974 |
0.4975 |
0.4976 |
0.4977 |
0.4977 |
0.4978 |
0.4979 |
0.4980 |
0.4980 |
0.4981 |
2.9 |
0.4981 |
0.4982 |
0.4983 |
0.4983 |
0.4984 |
0.4984 |
0.4985 |
0.4985 |
0.4986 |
0.4986 |
3.0 |
0.4987 |
0.4987 |
0.4987 |
0.4988 |
0.4988 |
0.4989 |
0.4989 |
0.4989 |
0.4990 |
0.4990 |
Source: Weatherburn, C. E. (1957). Mathematical Statistics. Cambridge University Press.
|
TABLE A-6 FREQUENCY FACTORS K FOR PEARSON TYPE III DISTRIBUTIONS VERSUS SKEW COEFFICIENT CS AND RETURN PERIOD
T (OR PROBABILITY OF EXCEEDANCE P). |
Skew Coeff. Cs |
Return Period T (y) |
1.05 |
1.11 |
1.25 |
2 |
5 |
10 |
25 |
50 |
100 |
200 |
|
Probability of Exceedance (percent) |
95 |
90 |
80 |
50 |
20 |
10 |
4 |
2 |
1 |
0.5 |
3.0 |
-0.665 |
-0.660 |
-0.636 |
-0.396 |
0.420 |
1.180 |
2.278 |
3.152 |
4.051 |
4.970 |
2.8 |
-0.711 |
-0.702 |
-0.666 |
-0.384 |
0.460 |
1.210 |
2.275 |
3.114 |
3.973 |
4.847 |
2.6 |
-0.762 |
-0.747 |
-0.696 |
-0.368 |
0.499 |
1.238 |
2.267 |
3.071 |
3.889 |
4.718 |
2.4 |
-0.819 |
-0.795 |
-0.725 |
-0.351 |
0.537 |
1.262 |
2.256 |
3.023 |
3.800 |
4.584 |
2.2 |
-0.882 |
-0.844 |
-0.752 |
-0.330 |
0.574 |
1.284 |
2.240 |
2.970 |
3.075 |
4.444 |
2.0 |
-0.949 |
-0.895 |
-0.777 |
-0.307 |
0.609 |
1.302 |
2.219 |
2.192 |
3.605 |
4.398 |
1.8 |
-1.020 |
-0.945 |
-0.799 |
-0.282 |
0.643 |
1.318 |
2.193 |
2.848 |
3.499 |
4.147 |
1.6 |
-1.093 |
-0.994 |
-0.817 |
-0.254 |
0.675 |
1.329 |
2.163 |
2.780 |
3.388 |
3.990 |
1.4 |
-1.168 |
-1.041 |
-0.832 |
-0.225 |
0.705 |
1.337 |
2.128 |
2.706 |
3.271 |
3.828 |
1.2 |
-1.243 |
-1.086 |
-0.844 |
-0.195 |
0.732 |
1.340 |
2.087 |
2.626 |
3.149 |
3.661 |
1.0 |
-1.317 |
-1.128 |
-0.852 |
-0.164 |
0.758 |
1.340 |
2.043 |
2.542 |
3.022 |
3.489 |
0.8 |
-1.388 |
-1.166 |
-0.856 |
-0.132 |
0.780 |
1.336 |
1.993 |
2.453 |
2.891 |
3.312 |
0.6 |
-1.458 |
-1.200 |
-0.857 |
-0.099 |
0.800 |
1.328 |
1.939 |
2.359 |
2.755 |
3.132 |
0.4 |
-1.524 |
-1.231 |
-0.855 |
-0.066 |
0.816 |
1.317 |
1.880 |
2.261 |
2.615 |
2.949 |
0.2 |
-1.586 |
-1.258 |
-0.850 |
-0.033 |
0.830 |
1.301 |
1.818 |
2.159 |
2.472 |
2.763 |
0.0 |
-1.645 |
-1.282 |
-0.842 |
0.000 |
0.842 |
1.282 |
1.751 |
2.054 |
2.326 |
2.576 |
-0.2 |
-1.700 |
-1.301 |
-0.830 |
0.033 |
0.850 |
1.258 |
1.680 |
1.945 |
2.178 |
2.388 |
-0.4 |
-1.750 |
-1.317 |
-0.816 |
0.066 |
0.855 |
1.231 |
1.606 |
1.834 |
2.029 |
2.201 |
-0.6 |
-1.797 |
-1.328 |
-0.800 |
0.099 |
0.857 |
1.200 |
1.528 |
1.720 |
1.880 |
2.016 |
-0.8 |
-1.839 |
-1.336 |
-0.780 |
0.132 |
0.856 |
1.166 |
1.448 |
1.606 |
1.733 |
1.837 |
-1.0 |
-1.877 |
-1.340 |
-0.758 |
0.164 |
0.852 |
1.128 |
1.366 |
1.492 |
1.588 |
1.664 |
-1.2 |
-1.910 |
-1.340 |
-0.732 |
0.195 |
0.844 |
1.086 |
1.282 |
1.379 |
1.449 |
1.501 |
-1.4 |
-1.938 |
-1.337 |
-0.705 |
0.225 |
0.832 |
1.041 |
1.198 |
1.270 |
1.318 |
1.351 |
-1.6 |
-1.962 |
-1.329 |
-0.675 |
0.254 |
0.817 |
0.994 |
1.116 |
1.166 |
1.197 |
1.216 |
-1.8 |
-1.981 |
-1.318 |
-0.643 |
0.282 |
0.799 |
0.945 |
1.035 |
1.069 |
1.087 |
1.097 |
-2.0 |
-1.996 |
-1.302 |
-0.609 |
0.307 |
0.777 |
0.895 |
0.959 |
0.980 |
0.990 |
0.995 |
-2.2 |
-2.006 |
-1.284 |
-0.574 |
0.330 |
0.752 |
0.844 |
0.888 |
0.900 |
0.905 |
0.907 |
-2.4 |
-2.011 |
-1.262 |
-0.537 |
0.351 |
0.725 |
0.795 |
0.823 |
0.830 |
0.832 |
0.833 |
-2.6 |
-2.013 |
-1.238 |
-0.499 |
0.368 |
0.696 |
0.747 |
0.764 |
0.768 |
0.769 |
0.769 |
-2.8 |
-2.010 |
-1.210 |
-0.460 |
0.384 |
0.666 |
0.702 |
0.712 |
0.714 |
0.714 |
0.714 |
-3.0 |
-2.003 |
-1.180 |
-0.420 |
0.393 |
0.636 |
0.660 |
0.666 |
0.666 |
0.667 |
0.667 |
Source: U.S. Interagency Committe on Water Data, Hydrology Subcommitee (1983). "Guidelines
for Determining Flood Flow Frequency," Bulletin No. 17B, issued 1981, revised 1983.
|
TABLE A-7 OUTLIER FREQUENCY FACTORS Kn FOR LOGPEARSON DISTRIBUTIONS. |
Record Length (y) |
Kn |
Record Length (y) |
Kn |
Record Length (y) |
Kn |
Record Length (y) |
Kn |
10 |
2.036 |
45 |
2.727 |
80 |
2.940 |
115 |
3.064 |
15 |
2.247 |
50 |
2.768 |
85 |
2.961 |
120 |
3.078 |
20 |
2.385 |
55 |
2.804 |
90 |
2.981 |
125 |
3.092 |
25 |
2.486 |
60 |
2.837 |
95 |
3.000 |
130 |
3.104 |
30 |
2.563 |
65 |
2.866 |
100 |
3.017 |
135 |
3.116 |
35 |
2.628 |
70 |
2.893 |
105 |
3.033 |
140 |
3.129 |
40 |
2.682 |
75 |
2.917 |
110 |
3.049 |
145 |
3.140 |
Source: U.S. Interagency Committe on Water Data, Hydrology Subcommitee (1983). "Guidelines
for Determining Flood Flow Frequency," Bulletin No. 17B, issued 1981, revised 1983.
|
TABLE A-8 MEAN ȳn AND STANDARD DEVIATION σn OF GUMBEL VARIATE (y) VERSUS RECORD LENGTH n. |
n |
yn |
σn |
n |
yn |
σn |
n |
yn |
σn |
8 |
0.4843 |
0.9043 |
35 |
0.5403 |
1.1285 |
64 |
0.5533 |
1.1793 |
9 |
0.4902 |
0.9288 |
36 |
0.5410 |
1.1313 |
66 |
0.5538 |
1.1814 |
10 |
0.4952 |
0.9497 |
37 |
0.5418 |
1.1339 |
68 |
0.5543 |
1.1834 |
11 |
0.4996 |
0.9676 |
38 |
0.5424 |
1.1363 |
70 |
0.5548 |
1.1854 |
12 |
0.5035 |
0.9833 |
39 |
0.5430 |
1.1388 |
72 |
0.5552 |
1.1873 |
13 |
0.5070 |
0.9972 |
40 |
0.5436 |
1.1413 |
74 |
0.5557 |
1.1890 |
14 |
0.5100 |
1.0095 |
41 |
0.5442 |
1.1436 |
76 |
0.5561 |
1.1906 |
15 |
0.5128 |
1.0206 |
42 |
0.5448 |
1.1458 |
78 |
0.5565 |
1.1923 |
16 |
0.5157 |
1.0316 |
43 |
0.5453 |
1.1480 |
80 |
0.5569 |
1.1938 |
17 |
0.5181 |
1.0411 |
44 |
0.5458 |
1.1499 |
82 |
0.5572 |
1.1953 |
18 |
0.5202 |
1.0493 |
45 |
0.5463 |
1.1519 |
84 |
0.5576 |
1.1967 |
19 |
0.5220 |
1.0566 |
46 |
0.5468 |
1.1538 |
86 |
0.5580 |
1.1980 |
20 |
0.5236 |
1.0628 |
47 |
0.5473 |
1.1557 |
88 |
0.5583 |
1.1994 |
21 |
0.5252 |
1.0696 |
48 |
0.5477 |
1.1574 |
90 |
0.5586 |
1.2007 |
22 |
0.5268 |
1.0754 |
49 |
0.5481 |
1.1590 |
92 |
0.5589 |
1.2020 |
23 |
0.5283 |
1.0811 |
50 |
0.5485 |
1.1607 |
94 |
0.5592 |
1.2032 |
24 |
0.5296 |
1.0864 |
51 |
0.5489 |
1.1623 |
96 |
0.5595 |
1.2044 |
25 |
0.5309 |
1.0915 |
52 |
0.5493 |
1.1638 |
98 |
0.5598 |
1.2055 |
26 |
0.5320 |
1.0961 |
53 |
0.5497 |
1.1653 |
100 |
0.5600 |
1.2065 |
27 |
0.5332 |
1.1004 |
54 |
0.5501 |
1.1667 |
150 |
0.5646 |
1.2253 |
28 |
0.5343 |
1.047 |
55 |
0.5504 |
1.1681 |
200 |
0.5672 |
1.2360 |
29 |
0.5353 |
1.1086 |
56 |
0.5508 |
1.1696 |
250 |
0.5688 |
1.2429 |
30 |
0.5362 |
1.1124 |
57 |
0.5511 |
1.1708 |
300 |
0.5699 |
1.2479 |
31 |
0.5371 |
1.1159 |
58 |
0.5515 |
1.1721 |
400 |
0.5714 |
1.2545 |
32 |
0.5380 |
1.1193 |
59 |
0.5518 |
1.1734 |
500 |
0.5724 |
1.2588 |
33 |
0.5388 |
0.1226 |
60 |
0.5521 |
1.1747 |
750 |
0.5738 |
1.2651 |
34 |
0.5396 |
1.1255 |
62 |
0.5527 |
1.1770 |
1000 |
0.5745 |
1.2685 |
Source: Gumbel, E. J. (1958). Statistics of Extremes. Irvington, New York: Columbia University Press.
|
TABLE A-9 NRCS 24-HR RAINFALL TABLES (AT HALF-HOUR INCREMENTS). |
Time (h) |
Fraction of 24-h rainfall depth |
Type I |
Type IA |
Type II |
Type III |
0.0 |
0.00000 |
0.00000 |
0.00000 |
0.00000 |
0.5 |
0.00871 |
0.01000 |
0.00513 |
0.00500 |
1.0 |
0.01745 |
0.02000 |
0.01050 |
0.01000 |
1.5 |
0.02621 |
0.03500 |
0.01613 |
0.01500 |
2.0 |
0.03500 |
0.05000 |
0.02200 |
0.02000 |
2.5 |
0.04416 |
0.06600 |
0.02813 |
0.02519 |
3.0 |
0.05405 |
0.08200 |
0.03450 |
0.03075 |
3.5 |
0.06466 |
0.09800 |
0.04113 |
0.03669 |
4.0 |
0.07600 |
0.11600 |
0.04800 |
0.04300 |
4.5 |
0.08784 |
0.13500 |
0.05525 |
0.04969 |
5.0 |
0.09995 |
0.15600 |
0.06300 |
0.05675 |
5.5 |
0.11234 |
0.18000 |
0.07125 |
0.06419 |
6.0 |
0.12500 |
0.20600 |
0.0800 |
0.07200 |
6.5 |
0.13915 |
0.23700 |
0.08925 |
0.08063 |
7.0 |
0.15600 |
0.26800 |
0.09900 |
0.09050 |
7.5 |
0.17460 |
0.31000 |
0.10925 |
0.10163 |
8.0 |
0.19400 |
0.42500 |
0.12000 |
0.11400 |
8.5 |
0.21900 |
0.48000 |
0.13225 |
0.12844 |
9.0 |
0.25400 |
0.52000 |
0.14700 |
0.14575 |
9.5 |
0.30300 |
0.55000 |
0.16300 |
0.16594 |
10.0 |
0.51500 |
0.57700 |
0.18100 |
0.18900 |
10.5 |
0.58300 |
0.60100 |
0.20400 |
0.21650 |
11.0 |
0.62300 |
0.62400 |
0.23500 |
0.25000 |
11.5 |
0.65550 |
0.64500 |
0.28300 |
0.29800 |
12.0 |
0.68400 |
0.66400 |
0.66300 |
0.50000 |
12.5 |
0.70925 |
0.68300 |
0.73500 |
0.70200 |
13.0 |
0.73200 |
0.70100 |
0.77200 |
0.75000 |
13.5 |
0.75225 |
0.71900 |
0.79900 |
0.78350 |
14.0 |
0.77000 |
0.73600 |
0.82000 |
0.81100 |
14.5 |
0.78625 |
0.75281 |
0.83763 |
0.83406 |
15.0 |
0.80200 |
0.76924 |
0.85350 |
0.85425 |
15.5 |
0.81725 |
0.78529 |
0.86763 |
0.87156 |
16.0 |
0.83200 |
0.80096 |
0.88000 |
0.88600 |
16.5 |
0.84625 |
0.81625 |
0.89119 |
0.89838 |
17.0 |
0.86000 |
0.83116 |
0.90175 |
0.90950 |
17.5 |
0.87325 |
0.84569 |
0.91169 |
0.91938 |
18.0 |
0.88600 |
0.85984 |
0.92100 |
0.92800 |
18.5 |
0.89825 |
0.87361 |
0.92969 |
0.93581 |
19.0 |
0.91000 |
0.88700 |
0.93775 |
0.94325 |
19.5 |
0.92125 |
0.90001 |
0.94519 |
0.95031 |
20.0 |
0.93200 |
0.91264 |
0.95200 |
0.95700 |
20.5 |
0.94225 |
0.92489 |
0.95844 |
0.96336 |
21.0 |
0.95200 |
0.93676 |
0.96475 |
0.96944 |
21.5 |
0.96125 |
0.94825 |
0.97094 |
0.97523 |
22.0 |
0.97000 |
0.95936 |
0.97700 |
0.98075 |
22.5 |
0.97825 |
0.97009 |
0.98294 |
0.98598 |
23.0 |
0.98600 |
0.98044 |
0.98875 |
0.99094 |
23.5 |
0.99325 |
0.99041 |
0.99444 |
0.99561 |
24.0 |
1.00000 |
1.00000 |
1.00000 |
1.00000 |
Source: Roger G. Cronshey, USDA Natural Resources Conservation Service, Engineering Division, Washington, D.C., June 1988.
|
TABLE A-10 STANDARD NRCS DIMENSIONLESS TEMPORAL RAINFALL DISTRIBUTION FOR EMERGENCY SPILLWAY AND FREEBOARD-POOL DESIGN. |
Fraction of storm duration |
Fraction of storm depth |
Fraction of storm duration |
Fraction of storm depth |
0.00 |
0.0000 |
|
|
0.02 |
0.0080 |
0.52 |
0.7240 |
0.04 |
0.0162 |
0.54 |
0.7420 |
0.06 |
0.0246 |
0.56 |
0.7590 |
0.08 |
0.0333 |
0.58 |
0.7750 |
0.10 |
0.0425 |
0.60 |
0.7900 |
0.12 |
0.0524 |
0.62 |
0.8043 |
0.14 |
0.0630 |
0.64 |
0.8180 |
0.16 |
0.0743 |
0.66 |
0.8312 |
0.18 |
0.0863 |
0.68 |
0.8439 |
0.20 |
0.0990 |
0.70 |
0.8561 |
0.22 |
0.1124 |
0.72 |
0.8678 |
0.24 |
0.1265 |
0.74 |
0.8790 |
0.26 |
0.1420 |
0.76 |
0.8898 |
0.28 |
0.1595 |
0.78 |
0.9002 |
0.30 |
0.1800 |
0.80 |
0.9103 |
0.32 |
0.2050 |
0.82 |
0.9201 |
0.34 |
0.2550 |
0.84 |
0.9297 |
0.36 |
0.3450 |
0.86 |
0.9391 |
0.38 |
0.4370 |
0.88 |
0.9483 |
0.40 |
0.5300 |
0.90 |
0.9573 |
0.42 |
0.6030 |
0.92 |
0.9661 |
0.44 |
0.6330 |
0.94 |
0.9747 |
0.46 |
0.6600 |
0.96 |
0.9832 |
0.48 |
0.6840 |
0.98 |
0.9916 |
0.50 |
0.7050 |
1.00 |
1.0000 |
Source: USDA Natural Resources Conservation Service. (1983). "Computer Program for Project Formulation: Hydrology,"
Tecnical Release No. 20 (TR-20), Engineering Division, Washington, D.C., May.
|
|