The observed rainfall and discharge of a catchment is given the table. The catchment area is 0.23Km^2. Time (h) 1 2 3 14 5 6 7 8 19 a 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

The observed rainfall and discharge of a catchment is given the table. The catchment area is 0.23Km^2. Time (h) 1 2 3 14 5 6 7 8 19 a 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

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

Q1. Based on 14 days runoff data given in TABLE Q1, determine the unit hydrograph for the catchment if the area is 4500 km2. Separate the baseflow by using appropriate method. TABLE Q1 Runoff Hydrograph Time (days) Runof(m's Time (days) Runoff(m's 1 II 2 10 4 4 2 15 12 2 6 18 13 7 16 14
Problem 1. The following are the ordinates of the hydrograph flow from a catchment area of 770 km2 due to a 6-hr rainfall. a. Derive the ordinates of the 6-hr unit hydrograph. Assume that the graph of the baseflow is linear with respect to time. b. Plot the direct runoff hydrograph. c. Determine the rainfall excess in terms of (i) volume in m3 and (2) depth in cm. d. Plot the unit hydrograph. Time from the beginning of the storm (hr) 0 6 12 18 24 30 36 42 48 54 60 66 72 Discharge (cumecs) 40 65 215 360 400 350 270 205 145 100 70 50 42
Sample Problem Given the following observed flows from a storm of 3-hr duration on a watershed with a drainage area of 10 sq. km. Assume that the base flow at the end of the runoff period is 6.0 cubic meters per second. TIME Q (hours) (m³/s) 1 6.0 2 15 3 25 4 21 5 13 6 6.0 1. Determine the direct runoff hydrograph by separating the baseflow. 2. Derive the unit hydrograph (for 1 centimeter of direct runoff) for the 3-hr rainfall.
Recorded flow data from a 7 sq. km. catchment due to a 1 hour rainfall event is given in Table 2. The base flow is 0.14 m³/s. Assume that the uniform rainfall over the catchment area was 39 mm. If the o-index of the catchment area is 21 mm/hr, calculate the ordinates of 1 hour unit hydrograph in Table 2. Table 2: Data for Question 2(b) (Draw the Table on a Page and Solve the Problem) Time Flow (hr) (m³/s) 0.5 1 3.0 2 7.5 3 6.0 4 4.5 5 3.0 2.1 7 1.5 8 1.1 9 0.8 10 0.5 11 0.2
Question 4 The time of concentration of a 5.8ha catchment has been estimated as 33 minutes. Estimate the peak rate of runoff for a storm with an intensity of 49mm/hr and a duration of 22 minutes. Assume the coefficient of runoff as 0.61 and the time-area relationship to be linear. Present the result in the unit of m³/s and keep two decimal points (i.e to the accuracy of 0.01). Your Answer: Answer need it ASAP question 4
The average rainfall values over a catchment in three successive 2-hour intervals are 3, 5 and 2 cm, respectively. The index for the catchment is taken as 0.2 cm/hour. The 2 hour unit hydrograph ordinates are given in table below. Time in hrs. Discharge m 0 2 4 m³/sec 0 10 40 6 14 16 70 50 20 10 6 0 Base flow can be taken as 7 m³/sec at the beginning of the storm linearly increasing to 9 m³/sec at 10 Hrs. after the beginning and then linearly decreasing to 8 m³/sec at 4 Hrs. after the end of direct run off. Compute the resultant flood hydrograph. 8 10 12
QUESTION 3 10 A storm with 10 cm precipitation produced a direct surface runoff of 5.8 cm in the equivalent depth unit. The time distribution of the storm is given in Table below. Estimate the @-index of the storm and the excess rainfall hyetograph. Time from start (hr) Incremental 0.4 rainfall in each hr (cm) 4 6. 0.9 1.5. 3.3 T.7 1.6 1.0 0.5
Compute the diameter (cm) of the outfall required to drain storm water from the watershed described in figure below. Use rainfall intensity = 4 cm/hr. Average velocity of flow is 1 m/s. Other data are for: Area 1: C=0.5, area=0.005 km2. Area 2: C=0.4, area =0.01 km2. Area 3: C=0.7, area=0.015 km2.
You have been given a 1-hour unit hydrograph (1 unit = 1 cm) and have been asked to use it to derive the surface runoff hydrograph for a 2-hour storm for which the total depth of rainfall excess was X cm and the intensity was constant. To derive it, you can: Multiply the ordinates of the 1-hour unit hydrograph by X/2 Find the 2-hour unit hydrograph and then multiply its ordinates X/2 Consider the storm as having two 1-hour periods of depth X/2 , multiply each 1-hour UH by X/2, lag them by 1 hour, and then add their ordinates. Multiply the ordinates of the 1-hour unit hydrograph by 2X
10-min unit hydrograph for a catchment is given in Table 1 below. Table 1: 10-min Unit Hydrograph Time (min) 05 10 15 20 25 30 35 40 45 50 1.75 1.95 2.0 1.8 1.25 0.6 Flow (m³/s) 0 0.5 1.0 1.4 0 a. What is the area of the catchment? b. Construct a storm hydrograph resulting from the 40-min rainfall event. The rainfall excess depths are provided in Table 2. Determine the peak discharge resulting from this 40-min rainfall event. Table 2: Rainfall Excess Depths Rainfall Excess (mm) Time (min) 0-20 4 20-40 6
Q2) Annual rainfall and runoff values of a catchment for a period of 10 years are given below. Analyze the data to (a) develop a non-linear correlation equation to estimate annual runoff volume for a given annual rainfall value, (b) Estimate r values for the equation, (c) Estimate the runoff depth when the rainfall depth is (i) 350 mm (ii) 600 mm. 2010 2011 2017 2018 2019 Year Annual 2012 2013 2014 2015 2016 Rainfall 361 408 217 324 510 488 275 392 296 420 (mm) Annual Runoff (mm) 145 160 90 130 205 195 110 157 120 165
Estimate ∅-index for a watershed having an area 5 acres. The runoff volume caused by the rainfall is 56000 ft^3. Round off your answer to the nearest whole number. Indicate the unit. Plot the hyetograph and superimpose the final ∅-index. (1 acre = 43560 ft^2) * Using the rounded-off ∅-index, estimate the volume of infiltration losses in cubic feet. *