Problem 6-1

Given P = 6 in, and CN = 82, find the runoff Q (in). Verify using Online curve number.

Problem 6-2

Given the following 2-h unit hydrograph for a certain catchment, find the 3-h unit hydrograph.

Time (h)	Flow (m3/s)
0	0
1	30
2	80
3	100
4	70
5	30
6	10
7	0

Using this unit hydrograph, calculate the 1-h unit hydrograph. Verify using Online S-hydrograph.

Problem 6-3

The following 2-h unit hydrograph has been developed for a certain catchment:

Time (h)	Flow (ft3/s)
0	0
2	100
4	200
6	70
8	50
10	30
12	0

A 6-h storm covers the entire catchment and is distributed in time as follows:

Time (h)	Total rainfall (in/h)
0-2	1.0
2-4	2.0
4-6	1.5

Calculate the composite hydrograph for the effective storm pattern, assuming a runoff curve number CN = 84. Verify using Online convolution.

Problem 6-4

A certain basin has the following 2-h unit hydrograph:

Time (h)	Flow (m3/s)
0	0
1	5
2	20
3	35
4	65
5	90
6	70
7	55
8	40
9	20
10	10
11	0

Calculate the flood hydrograph for the following effective rainfall hyetograph (CN = 100):

Time (h)	Effective rainfall (cm/h)
0-3	1.3
3-6	2.2

Verify using Online S-hydrograph and Online convolution.