235
Table 13.4 Calculation of probable peak gauge height for corresponding return period
T
Y t
Ӯn
∂ n
k t
S x
X̄
X t
2
0.37
0.5362
1.1124
−0.1494067
1.35
39.57
39.366634
5
1.5
0.5362
1.1124
0.866415
1.35
39.57
40.737994
10
2.25
0.5362
1.1124
1.5406329
1.35
39.57
41.648188
20
2.97
0.5362
1.1124
2.1878821
1.35
39.57
42.521974
30
3.38
0.5362
1.1124
2.5564545
1.35
39.57
43.019547
50
3.9
0.5362
1.1124
3.0239123
1.35
39.57
43.650615
100
4.6
0.5362
1.1124
3.6531823
1.35
39.57
44.500129
Table 13.5 Return period calculation by Gumble’s extreme value distribution method for
Nutanhat station
Year
Peak gauge
level in metre
(X)
X-X̄
(X-X̄ )
2
Reduced
variate (y)
Return period
in years (T)
Probability of
occurrence [P]
(%)
1987 20.74
1.07
1.1456134 1.41
4.62
21.64502
1988 18.6
−1.07
1.1441868 −0.32
1.34
74.62687
1989 19.7
0.03
0.0009201 0.57
2.32
43.10345
1990 19.33
−0.34
0.1153734 0.27
1.87
53.47594
1991 19.3
−0.37
0.1366534 0.24
1.84
54.34783
1992 19
−0.67
0.4484534 0.00
1.58
63.29114
1993 19.36
−0.31
0.0958934 0.29
1.9
52.63158
1994 20.43
0.76
0.5781068 1.16
3.72
26.88172
1995 22.3
2.63
6.9186534 2.67
14.95
6.688963
1996 19.86
0.19
0.0362268 0.70
2.55
39.21569
1997 20.07
0.40
0.1602668 0.87
2.92
34.24658
1998 19.36
−0.31
0.0958934 0.29
1.9
52.63158
1999 22.89
3.22
10.370547 3.15
23.84
4.194631
2000 23.21
3.54
12.53396 3.41
30.77
3.249919
2001 18.69
−0.98
0.9597468 −0.25
1.38
72.46377
2002 18.96
−0.71
0.5036268 −0.03
1.55
64.51613
2003 18.89
−0.78
0.6078801 −0.09
1.5
66.66667
2004 20.07
0.40
0.1602668 0.87
2.92
34.24658
2005 18.43
−1.24
1.5367734 −0.46
1.26
79.36508
2006 20.49
0.82
0.6729468 1.21
3.88
25.7732
2007 21.37
1.70
2.8911334 1.92
7.33
13.64256
2008 18.44
−1.23
1.5120801 −0.45
1.26
79.36508
2009 20.25
0.58
0.3367868 1.01
3.28
30.4878
2010 17.65
−2.02
4.0790534 −1.09
1.05
95.2381
2011 19.07
−0.60
0.3596001 0.06
1.64
60.97561
2012 18.03
−1.64
2.6885068 −0.79
1.12
89.28571
2013 19.2
−0.47
0.2205868 0.16
1.74
57.47126
2014 18.1
−1.57
2.4638534 −0.73
1.14
87.7193
2015 20.1
0.43
0.1851868 0.89
2.97
33.67003
2016 18.2
−1.47
2.1599201 −0.65
1.17
85.47009
13 Flood Frequency Analysis and Its Management in Selected Part of Bardham…
Table 13.4 Calculation of probable peak gauge height for corresponding return period
T
Y t
Ӯn
∂ n
k t
S x
X̄
X t
2
0.37
0.5362
1.1124
−0.1494067
1.35
39.57
39.366634
5
1.5
0.5362
1.1124
0.866415
1.35
39.57
40.737994
10
2.25
0.5362
1.1124
1.5406329
1.35
39.57
41.648188
20
2.97
0.5362
1.1124
2.1878821
1.35
39.57
42.521974
30
3.38
0.5362
1.1124
2.5564545
1.35
39.57
43.019547
50
3.9
0.5362
1.1124
3.0239123
1.35
39.57
43.650615
100
4.6
0.5362
1.1124
3.6531823
1.35
39.57
44.500129
Table 13.5 Return period calculation by Gumble’s extreme value distribution method for
Nutanhat station
Year
Peak gauge
level in metre
(X)
X-X̄
(X-X̄ )
2
Reduced
variate (y)
Return period
in years (T)
Probability of
occurrence [P]
(%)
1987 20.74
1.07
1.1456134 1.41
4.62
21.64502
1988 18.6
−1.07
1.1441868 −0.32
1.34
74.62687
1989 19.7
0.03
0.0009201 0.57
2.32
43.10345
1990 19.33
−0.34
0.1153734 0.27
1.87
53.47594
1991 19.3
−0.37
0.1366534 0.24
1.84
54.34783
1992 19
−0.67
0.4484534 0.00
1.58
63.29114
1993 19.36
−0.31
0.0958934 0.29
1.9
52.63158
1994 20.43
0.76
0.5781068 1.16
3.72
26.88172
1995 22.3
2.63
6.9186534 2.67
14.95
6.688963
1996 19.86
0.19
0.0362268 0.70
2.55
39.21569
1997 20.07
0.40
0.1602668 0.87
2.92
34.24658
1998 19.36
−0.31
0.0958934 0.29
1.9
52.63158
1999 22.89
3.22
10.370547 3.15
23.84
4.194631
2000 23.21
3.54
12.53396 3.41
30.77
3.249919
2001 18.69
−0.98
0.9597468 −0.25
1.38
72.46377
2002 18.96
−0.71
0.5036268 −0.03
1.55
64.51613
2003 18.89
−0.78
0.6078801 −0.09
1.5
66.66667
2004 20.07
0.40
0.1602668 0.87
2.92
34.24658
2005 18.43
−1.24
1.5367734 −0.46
1.26
79.36508
2006 20.49
0.82
0.6729468 1.21
3.88
25.7732
2007 21.37
1.70
2.8911334 1.92
7.33
13.64256
2008 18.44
−1.23
1.5120801 −0.45
1.26
79.36508
2009 20.25
0.58
0.3367868 1.01
3.28
30.4878
2010 17.65
−2.02
4.0790534 −1.09
1.05
95.2381
2011 19.07
−0.60
0.3596001 0.06
1.64
60.97561
2012 18.03
−1.64
2.6885068 −0.79
1.12
89.28571
2013 19.2
−0.47
0.2205868 0.16
1.74
57.47126
2014 18.1
−1.57
2.4638534 −0.73
1.14
87.7193
2015 20.1
0.43
0.1851868 0.89
2.97
33.67003
2016 18.2
−1.47
2.1599201 −0.65
1.17
85.47009
13 Flood Frequency Analysis and Its Management in Selected Part of Bardham…