Solve the problem using the NRCS method for a watershed located right outside New York City, New York for a 50 year storm event. Assume the soil hydrologic group B (65%), C (25%) and D (10%). Given Am=1.29 sm. Impervious = 6.6 acres, Woods =819 acres. Overland flow: L=100 ft, s=4%, fair; Shallow Concentrated Flow: unpaved L= 2300 ft, s=2.7%, stream flow L=9000 ft, s= 3.4% The Time of Concentration is 20¹ 12' n = 0.035

Solve the problem using the NRCS method for a watershed located right outside New York City, New York for a 50 year storm event. Assume the soil hydrologic group B (65%), C (25%) and D (10%). Given Am=1.29 sm. Impervious = 6.6 acres, Woods =819 acres. Overland flow: L=100 ft, s=4%, fair; Shallow Concentrated Flow: unpaved L= 2300 ft, s=2.7%, stream flow L=9000 ft, s= 3.4% The Time of Concentration is 20¹ 12' n = 0.035

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Hydrology Give me right solution according to the question
3.2 Calculate the time of concentration (I), with the following design inputs: • Hydraulic length = 5000 m • The area mostly consists of moderate grass • Level at the highest point of the catchment = 2500 m above mean sea level (MSL). • Level at the lowest point of the catchment = 1000 m above MSL sea level. • Use the Kerby formula
4. A reservoir has an average area of 50 km over a year. The normal annual rainfall at the place is 120 cm and the class A pan evaporation is 240 cm. Assuming the land flooded by the reservoir has a runoff coefficient of 0.4, estimate the net annual increase or decrease in the streamflow as a result of the reservoir. (Problem 3.3, Subramanya 4th Ed.)
2) Determine time of concentration, tc, for use in the Rational Method for a drainage basin having a hydraulic path described as follows: Overland Flow: average grass, 80' long, 2.5% average slope Shallow Concentrated Flow: 450' long. 4.8% average slope Gutter Flow (Treated as Shallow Concentrated Flow): 200' long, 1.9% average slope.
A stream of 135 L/s was diverted from a canal and 100 L/s were delivered to the field. An area of 1.6hectares was irrigated in 8 hours. The effective depth of root zone was 1.8 m. the runoff loss in the fieldwas 432 m3. The depth of water penetration varied linearly from 1.8 m at the head end of the field to1.2 m at the tail end. Available moisture holding capacity of the soil is 20 cm per meter depth of soil.Irrigation was started at a moisture extraction level of 50 percent of the available moisture. Determine;a. The water conveyance efficiencyb. The water application efficiencyc. The water storage efficiencyd. The water distribution efficiency
Provide the correct answer .
Problem 3. A 50-ha catchment has the following time-area relationship. Estimate the runoff hydrograph (cumecs) using the time-area method for a 30-min rainfall hyetograph given. Time (min) Contributing area (ha) 10 15 20 10 25 30 30 50 Time (min) Average rainfall intensity (cm/hr) 0-5 10 5-10 8. 10-15 15-20 4 20-25 25-30 1
The observed rainfall and discharge of a catchment is given the table. The catchment area is 0.23Km^2. Time (h) 1 2 3 4 5 6 7 8 00 9 10 11 12 13 Rainfall (mm) 0 0 2 6 10 8 2 0 0 0 0 0 0 1. Estimate the base flow. 2. Estimate the surface runoff. 3. Estimate the initial loss 4. Estimate the continuous loss using phi method. Discharge (M3/s) 20 20 20 20 30 50 40 35 25 21 20 20 20
Given the drainage area in above Figure calculate the discharge at the outfall using the rational method. Use the5-year rainfall intensity-duration curve Other data are: •for Area 1, C=0.50, Area = 1.3 acres, and inlet time = 7 mins; •for Area 2, C= 0.40 , area = 2.5 acres , and inlet time 5 mins•for Area 3, C=0.70, area 3.9 acres, and andinlet time = 5 mins.The sewer lines in Areas 2 and 3 are each 500 ft in length; and the average velocity of flow in the sewers may be assumed to be 3.0 ft/sec. (Answer 20 cu ft/sec)
Watershed area = 11.1 acres Average N concentration of inflow = 1.9 mg/L Total Rainfall = 44.75 inches Average N concentration of outflow = 1.4 mg/L Total pond inflow = 330,441 ft3 Average P concentration of inflow = 0.42 mg/L Total pond outflow = 288,492 ft3 Average P concentration of outflow = 0.23 mg/L Total pond volume = 46,893 ft3 (this is the volume to the top of the riser before overflow occurs) Answer the following questions: a) What percentage of the total rainflow flowed into the pond? b) If the pond were completely empty, how much rainfall in inches would be required to fill it to the total pond volume? Use your answer to question A to help answer this. c) What is the total Nitrogen load flowing into the pond in lbs/Acre/Year? d) How many lbs of Nitrogen did the pond remove over the year? e) What percentage of Phosphorous was removed by the pond?
Questions (3.2) Determine using the 'rational formula' with runoff co-efficient equal to 0.80, the peak storm runoff to be carried out by the underground drainage pipeline AB for the drainage basin area of 0.2 ha as shown in the given figure. Take the length of pipeline as 100 m and the level difference between A and B as 0.5 m. Assume initially a pipe diameter of 250 mm. Consider Darcy- Weisbach friction factor f = 0.015. The rainfall duration and rainfall intensity is furnished in tabular form below. Consider time of entry at end A as 2 min. Drainage basin Duration (mins) 2.0 2.5 3.0 3.5 4.0 4.5 A Pipeline Rainfall intensity (mm/hr) 122 108 97 89 82 77 Check whether the pipe size is adequate or not.
B: The direct runoff hydrograph is 64hr and maximum discharge is 30 m/sec. If the observed runoff due to 12hr storm of uniform intensity is 0.5 cm/hr and the catchment area is 120 km². Determine the o index for the basin in cm/hr.