Hello -
I have two questions from the NCEES 2008 Book, Water Resources Afternoon Questions.
1) For Problem 508 - The question is "A rain event has an intensity of 1.5 in/hour for the first hour followed by 0.7 in/hr for the second hour. The 1 hour unit hydrograph for the watershed is given as Q = 0.5 (T = 1 hour), 1.2 (T=2 hours) and 0.4 (T= 3 hours). Neglecting infiltration, the discharge (CFS) from the watershed during the second hour is most nearly: 2.64, 2.15, 1.44 or 1.20." The books answer has the solution as 1.5 in/hour x 0.5 cf/in + 0.7 in/hr x 1.2 cf/in. = 2.15 cfs. I do not understand how they go this answer, especially because the units do not add up.
2) For Problem 509 - The question is "Assume that you are evaluating an agricultural watershed. The soil is classified as clay with a high swelling potential. The watershed is a pasture that has 65% ground cover and is not heavily grazed. The potential maximum retention (in) after runoff begins (also called the soil storage capacity) is most nearly." How can you tell from this problem whether you use straight row, contoured, or contoured and terraced in Table 20.5 of the Lindenburg book?
If anyone can help with these questions I would greatly appreciate it.
Thanks.
I have two questions from the NCEES 2008 Book, Water Resources Afternoon Questions.
1) For Problem 508 - The question is "A rain event has an intensity of 1.5 in/hour for the first hour followed by 0.7 in/hr for the second hour. The 1 hour unit hydrograph for the watershed is given as Q = 0.5 (T = 1 hour), 1.2 (T=2 hours) and 0.4 (T= 3 hours). Neglecting infiltration, the discharge (CFS) from the watershed during the second hour is most nearly: 2.64, 2.15, 1.44 or 1.20." The books answer has the solution as 1.5 in/hour x 0.5 cf/in + 0.7 in/hr x 1.2 cf/in. = 2.15 cfs. I do not understand how they go this answer, especially because the units do not add up.
2) For Problem 509 - The question is "Assume that you are evaluating an agricultural watershed. The soil is classified as clay with a high swelling potential. The watershed is a pasture that has 65% ground cover and is not heavily grazed. The potential maximum retention (in) after runoff begins (also called the soil storage capacity) is most nearly." How can you tell from this problem whether you use straight row, contoured, or contoured and terraced in Table 20.5 of the Lindenburg book?
If anyone can help with these questions I would greatly appreciate it.
Thanks.
