Portfolio
Q1
The annual maximum daily rainfall at a hydropower station is provided below.
a) Estimate the parameters of the log-normal and GEV distributions by the method of moments.
b) Plot the empirical cumulative distribution using Weibull formula.
c) Superimpose on the plot the two fitted distributions.
d) Estimate the quantiles (maximum daily rainfall) corresponding to return periods of 5, 10, 20, 50, 100, 200, 500, 1000 years using both fitted distributions, and show the points on the plot.
e) Use Kolmogorov-Smirnov test to select the preferred distribution.
Table Q1: Maximum daily rainfall data
|
Year
|
Rain
|
Year
|
Rain
|
Year
|
Rain
|
Year
|
Rain
|
|
1917
|
394
|
1942
|
588
|
1967
|
501
|
1992
|
1075
|
|
1918
|
432
|
1943
|
625
|
1968
|
389
|
1993
|
276
|
|
1919
|
403
|
1944
|
553
|
1969
|
406
|
1994
|
325
|
|
1920
|
1153
|
1945
|
491
|
1970
|
465
|
1995
|
423
|
|
1921
|
494
|
1946
|
580
|
1971
|
906
|
1996
|
498
|
|
1922
|
682
|
1947
|
660
|
1972
|
589
|
1997
|
1031
|
|
1923
|
597
|
1948
|
366
|
1973
|
808
|
1998
|
437
|
|
1924
|
884
|
1949
|
932
|
1974
|
415
|
1999
|
623
|
|
1925
|
505
|
1950
|
655
|
1975
|
419
|
2000
|
481
|
|
1926
|
375
|
1951
|
666
|
1976
|
471
|
2001
|
529
|
|
1927
|
614
|
1952
|
520
|
1977
|
463
|
2002
|
485
|
|
1928
|
832
|
1953
|
357
|
1978
|
567
|
2003
|
561
|
|
1929
|
663
|
1954
|
590
|
1979
|
997
|
2004
|
556
|
|
1930
|
332
|
1955
|
467
|
1980
|
513
|
2005
|
942
|
|
1931
|
532
|
1956
|
535
|
1981
|
754
|
2006
|
439
|
|
1932
|
480
|
1957
|
496
|
1982
|
686
|
2007
|
305
|
|
1933
|
503
|
1958
|
668
|
1983
|
530
|
2008
|
473
|
|
1934
|
438
|
1959
|
527
|
1984
|
569
|
2009
|
537
|
|
1935
|
410
|
1960
|
577
|
1985
|
780
|
2010
|
729
|
|
1936
|
344
|
1961
|
447
|
1986
|
867
|
2011
|
377
|
|
1937
|
1062
|
1962
|
961
|
1987
|
671
|
2012
|
844
|
|
1938
|
425
|
1963
|
497
|
1988
|
448
|
2013
|
521
|
|
1939
|
746
|
1964
|
629
|
1989
|
513
|
2014
|
430
|
|
1940
|
456
|
1965
|
404
|
1990
|
723
|
2015
|
559
|
|
1941
|
802
|
1966
|
657
|
1991
|
428
|
2016
|
585
|
Q2
A water resources project is to be located in Weipa (12.6493° S, 141.8470° E). Use ARR2016 to provide the following information.
a) Determine the rainfall depth for 5% AEP of 1 hour duration.
b) Show a table of the 10 temporal patterns for 1-hour duration corresponding to AEP in a).
c) Draw the 10 histograms of 5% AEP design storm.
d) Derive the 5-min Snyder Unit Hydrograph for a 30 km2 catchment where the main stream length is 5 km and the distance from the point on the stream nearest to the centroid to catchment outlet is 2 km. Assume Ct=0.6 and Cp=0.8.
e) Assuming an initial loss of 20 mm and continuing loss of 6 mm/h, prepare a table of net rainfall for the design storms.
f) Route the net rainfall hyetographs to the catchment outlet using the unit hydrograph derived in d).
g) Show the hydrographs on the same plot and indicate the average of the ensemble hydrographs.
Q3
Measured flows at an upstream and downstream section of a river are given below.
a) Select the best combination of Muskingum coefficients of X from the set (0.1, 0.2, 0.3, 0.4, 0.5) and K from the set (30, 35, 40, 45, 50) that best fit the data based on minimum sum of squared residuals.
b) New upstream section flow is given in the table below. Estimate the hydrograph at the downstream section using the optimum X and K values.
c) On the same plot show the upstream and downstream sections' flows of the new data.
Table Q3: Flows
|
Time (min)
|
Upstream Flow (m3/s)
|
Downstream Flow (m3/s)
|
New Upstream Flow (m3/s)
|
|
0
|
10.0
|
10.0
|
10.0
|
|
30
|
10.0
|
10.0
|
10.0
|
|
60
|
25.0
|
12.2
|
13.0
|
|
90
|
45.0
|
23.4
|
15.0
|
|
120
|
31.3
|
35.1
|
20.0
|
|
150
|
27.5
|
32.1
|
25.0
|
|
180
|
25.0
|
28.8
|
30.0
|
|
210
|
23.8
|
26.2
|
35.0
|
|
240
|
21.3
|
24.3
|
45.0
|
|
270
|
19.4
|
22.1
|
40.0
|
|
300
|
17.5
|
20.0
|
38.0
|
|
330
|
16.3
|
18.3
|
32.0
|
|
360
|
13.5
|
16.6
|
25.0
|
|
390
|
12.1
|
14.4
|
20.0
|
|
420
|
10.0
|
12.6
|
18.0
|
|
450
|
10.0
|
11.0
|
15.0
|
|
480
|
10.0
|
10.3
|
13.0
|
|
510
|
10.0
|
10.1
|
10.0
|
|
540
|
10.0
|
10.1
|
10.0
|
|
570
|
10.0
|
10.0
|
10.0
|
|
600
|
10.0
|
10.0
|
10.0
|
Q4
The runoff hydrographs from a site before and after development are given below. The post development detention basin is to be drained by an outflow weir. The elevation versus storage in the detention basin is given below. The weir crest is at elevation 0.0 m, which is also the initial elevation of the water surface in the detention basin prior to runoff. The performance characteristics of the weir is given by
Q = 1.83BH3/2
where Q is the overflow rate in m3/s, B is the crest length in m, and H is the head on the weir in m.
a) Plot the performance characteristics curves of the reservoir and outlet structure required by the PULS Method of reservoir routing.
b) Determine the optimum (most economical) crest length (B, to the nearest 5 mm) of the weir for the detention basin to operate at its full capacity.
Table Q4.1: Before and after hydrographs
|
Time (mins)
|
Runoff
|
|
Before (m3/s)
|
After (m3/s)
|
|
0
|
0.00
|
0.00
|
|
30
|
2.00
|
3.50
|
|
60
|
7.50
|
10.60
|
|
90
|
1.70
|
7.50
|
|
120
|
0.90
|
5.10
|
|
150
|
0.75
|
3.00
|
|
180
|
0.62
|
1.50
|
|
210
|
0.49
|
0.98
|
|
240
|
0.30
|
0.75
|
|
270
|
0.18
|
0.62
|
|
300
|
0.50
|
0.51
|
|
330
|
0.00
|
0.25
|
|
360
|
0.00
|
0.12
|
|
390
|
0.00
|
0.00
|
Table Q4.2: Detention basin elevation versus storage data
|
Elevation (m)
|
Storage (m3)
|
|
0.0
|
0
|
|
0.5
|
11022
|
|
1.0
|
24683
|
|
1.5
|
41522
|
Q5
A stormwater drainage system located in Weipa is to be designed for a new development. The proposed pipeline segments (links) and manholes (nodes) are shown in the figure below.
a) Upload the image of the catchment provided into XPSWMM. Note that the Real World Extents of Top: 6880800 m; Left: 460000 m; Bottom: 6880500 m; Right: 460500 m.
b) Digitise the incremental catchment boundaries, nodes and links using XPSWMM. Attach an image of the digitised information on the background image.
c) Determine the incremental areas and pipe lengths. Prepare two tables with headings below in XPSWMM and export for your report.
Table Q5.1: Sub-catchments
|
Name
|
Node Name
|
Area (ha)
|
|
1
|
|
|
|
2
|
|
|
|
3
|
|
|
|
4
|
|
|
|
5
|
|
|
|
6
|
|
|
|
7
|
|
|
Table Q5.2: Nodes and Links
|
Link Name
|
Upstream Node
|
Downstream Node
|
Length (m)
|
|
1-2
|
|
|
|
|
3-2
|
|
|
|
|
4-2
|
|
|
|
|
2-5
|
|
|
|
|
6-5
|
|
|
|
|
5-7
|
|
|
|
