CE322 Basic Hydrology
Jorge A. Ramirez
Homework No.7
Assigned on: Monday,
April 3, 2000
Due on: Friday,
April 7, 2000
1. Obtain a Unit Hydrograph for a basin of
282.6 km2 of area using the rainfall and streamflow data tabulated
below.
|
Time (h) |
Observed Hydrograph (m3/s) |
|
0 |
160 |
|
1 |
150 |
|
2 |
350 |
|
3 |
800 |
|
4 |
1200 |
|
5 |
900 |
|
6 |
750 |
|
7 |
550 |
|
8 |
350 |
|
9 |
225 |
|
10 |
150 |
|
11 |
140 |
|
Time (h) |
Gross Precipitation (GRH) (cm/h) |
|
0 - 1 |
0.25 |
|
1 - 2 |
2.75 |
|
2 - 3 |
2.75 |
|
3 - 4 |
0.25 |
In this process: use the horizontal
straight-line method to separate baseflow.
2. For the basin of Problem 1, predict the
total streamflow hydrograph that would be observed as a result of a storm whose
effective rainfall is tabulated below. Use the same value of baseflow as for
Problem 1.
|
Time (h) |
Effective Precipitation (ERH) (cm/h) |
|
0 - 1 |
1.0 |
|
1 - 2 |
1.0 |
|
2 - 3 |
1.5 |
|
3 - 4 |
1.5 |
|
4 - 5 |
0.75 |
|
5 - 6 |
0.75 |
|
6 - 7 |
0.25 |
|
7 - 8 |
0.25 |
3. Use the 1-h Unit Hydrograph tabulated
below to predict the total streamflow hydrograph that would be observed as a
result of a storm whose effective rainfall is also tabulated below. Use the
same value of baseflow as for Problem 1. Obtain the solution using the
S-Hydrograph method.
|
Time (h) |
1-H Unit Hydrograph (m3/s/cm) |
|
1 |
0.00 |
|
2 |
40.00 |
|
3 |
130.00 |
|
4 |
210.00 |
|
5 |
150.00 |
|
6 |
120.00 |
|
7 |
80.00 |
|
8 |
40.00 |
|
9 |
15.00 |
|
10 |
0.00 |
|
Time (h) |
Effective Precipitation (ERH) (cm/h) |
|
0 - 3 |
1.0 |
|
3 - 6 |
2.0 |
|
6 - 9 |
1.5 |
4. The table below presents the recession
limb of a total streamflow hydrograph from a basin. Use the tabulated data to
obtain the groundwater recession constant k
for this basin. Use the following model for the recession:
|
Time (h) |
Streamflow Hydrograph (m3/s) |
|
10 |
2500 |
|
11 |
2300 |
|
12 |
2010 |
|
13 |
1645 |
|
14 |
995 |
|
15 |
600 |
|
16 |
370 |
|
17 |
220 |
|
18 |
135 |
|
19 |
80 |
|
20 |
50 |