Sanjaya Shah 1

8/17/2019 Sanjaya Shah 1

1/14

Assignment

of

Engineering Hydrology

Assignment no: 01

SUBMITTED TO:

SUMBITTED BY:

Mr. Bharani Dharan

Sanjaya Bikram Shah

Dept. of CE B-

Tech Civil 7th sem

AP!"#!"!!$"%%


2/14

Q.No.2.13

Following are the data of storm as recorded in the self-recording rain gage rain gage at station:

!ime from

the

"eginningof #torm

$%in&

10 20 30 '0 (0 (0 )0 *0 +0

,mlati

e ainfall

$mm&

1/ '1 '+ )+ /1 12' 1(2 1)0 1))

a& lot the hyetograh of the #torm. "& lot the maimm intensity-dration cre of the #torm.

#oltion:

a& !he ntensity of the rainfall at arios time dration is calclated as shown "elow:

!ime since

start $min&

10 20 30 '0 (0 )0 *0 +0 /0

,mlatie

ainfall $mm&

1/ '1 '+ )+ /1 12' 1(2 1)0 1))

ncremental

deth of

ainfall in

interal $mm&

1/ 22 * 20 23 33 2+ + )

ntensity

$mm4hr.&

11' 132 '2 120 13+ 1/+ 1)( '+ 3)


3/14

!" $" %" &" '" (" 7" )" #""

!""

$""

%""

"

!!& !%$

&$

!$" !%)!#) !()

&) %(

hyetograph of storm

Time since start *min+

,ainfall ntensity *mmhr+

"& !he maimm ntensity-dration cre of the storm is:

ncremental deth of rainfall $mm& in arios drations

5rations$min&

!ime

$min&

,m.

ainfall$mm

&

10 20 30 '0 (0 )0 *0 +0 /0

0 0 0

10 1/ 1/

20 '1 22 '1

30 '+ * 2/ '+

'0 )+ 20 2* '/ )+(0 /1 23 '3 (0 *2 /1

)0 12' 33 () *) +3 10( 12'

*0 1(2 2+ )1 +' 10' 111 133 1(2

+0 1)0 + 3) )/ /2 10) 11/ 1'1 1)0

/0 1)) ) 1) '2 *( /+ 112 12( 1'* 1))

And6

5ration

in min.

10 20 30 '0 (0 )0 *0 +0 /0

%a.

deth

$mm&

33 )1 +' 10' 111 133 1(2 1)0 1))

%a.

ntensity

$mm4hr.&

1'+ 1+3 1)+ 1() 133.2 133 130.3 120 110.*


4/14


5/14

ncremental 1epth of rainfall *mm+ in vario/s 1/rations

D/ration in min Time*Mi

n+

C/m.

,ainf

all

*mm+

!" $" %" &" '" (" 7" )" #"

" "!" ) )

$" !' 7 !'%" $' !" !7 $'

&" %" ' !' $$ %"

'" &( !( $! %! %) &((" '' # $' %" &" &7 ''

7" (" ' !& %" %' &' '$ (")" (& & # !) %& %# %# '( (&

#" (7 % 7 !$ $! &$ &$ &$ '# (7

And6

D/ratio

n *min+

!" $" %" &" '" (" 7" )" #"

Ma0.

1epth

!( $' %! &" &7 '' (" (& (7


6/14

" !" $" %" &" '" (" 7" )" #" !"""

!"

$"

%"

&"

'"

("

7"

)"

!(

$'

%!

&"

&7

''

("(&

(7

Ma0 Depth-1/ration c/rve

time *min+

ma0 septh *mm+

Q.No. 2.1(

!he mass cre of the rainfall in a storm of total dration /0 mintes is gien "elow.

a& lot the hyetograh of the storm at 10 mintes ste. "& lot the maimm intensity dration

cre for this storm. c& lot the maimm deth dration cre for the storm.

!ime

$%intes&

0 10 20 30 '0 (0 )0 *0 +0 /0

,mlati

e rainfall

$mm&

0 2.1 ).3 1'.( 21.* 2*./ 33.0 3(.1 3).2 3*.0


7/14

#oltion:

a+ The ntensity of the rainfall at vario/s time 1/ration is calc/late1 as sho4n 3elo45

Time since

start *min+

!" $" %" &" '" (" 7" )" #"

C/m/lative

,ainfall*mm+

$.! (.% !&.' $!.7 $7.# %% %'.! %(.$ %7."

ncremental

1epth of

,ainfall in

interval

*mm+

$.! &.$ ).$ 7.$ (.$ '.! $.! !.! ".)

ntensity

*mmhr.+

!$.( $'.$ .$ &%.$ %7.$ %".( !$.( (.( &.)

!" $" %" &" '" (" 7" )" #""

!"

$"

%"

&"

'"

("

!$.(

$'.$

.$

&%.$

%7.$

%".(

!$.(

(.(&.)

hyetograph of storm

time 1/ration in min/tes

,ainfall ntensity *mmhr+

3+ an1 c+

ncremental 1epth of rainfall *mm+ in vario/s 1/rationsD/ration in min

Time*Mi

n+

C/m.

,ainf

all

*mm+

!" $" %" &" '" (" 7" )" #"

" "!" $.! $.!


8/14

$" (.% &.$ (.%%" !&.' ).$ !$.& !&.'&" $!.7 7.$ !'.& !#.( $!.7'" $7.# (.$ !%.& $!.( $'.) $7.#(" %% '.! !!.% !).' $(.7 %".# %%7" %'.! $.! 7.$ !%.& $".( $).) %% %'.!)" %(.$ !.! %.$ ).% !&.' $!.7 $#.# %&.! %(.$#" %7 ".) !.# &." #.! !'.% $$.' %".7 %&.# %7."

And6

D/ration

*min+

!" $" %" &" '" (" 7" )" #"

Ma0. 1epth

*mm+

).$ !'.& $!.( $(.7 %".# %% %'.! %(.$ %7

Ma0.ntensity *mmhr.+ .$ &(.$ &%.$ &"."' %7.") %%." %".") $7.!' $&.(7

" !" $" %" &" '" (" 7" )" #" !"""

!"

$"

%"

&"

'"

("

.$&(.$

&%.$&"."'

%7.")%%

%".")$7.!'

$&.(7

ma0 intensity 1/ration c/rve

Time in min/tes

Ma0. ntensity in mmhr


9/14

" !" $" %" &" '" (" 7" )" #" !"""

'

!"

!'

$"

$'%"

%'

&"

).$

!'.&

$!.($(.7

%".#%%

%'.! %(.$%7

Ma0. 1epth 1/ration c/rve

Time in min/tes

Ma0. Depth in mm

Q.N7. 2.1)

!he record of annal at a lace is aaila"le for 2( years .lot the cre of recrrence interal s

annal rainfall magnitde and "y sita"le interolation estimate the magnitde of rainfall at the

station that wold corresond to a recrrence interal of $a&(0 years8 and $"&100 years

9ear Annal ainfall

$cm&

9ear Annal ainfall

$cm&

1/(0 113.0 1/)3 )+.)1/(1 /'.( 1/)' +2.(

1/(2 *).0 1/)( /0.*

1/(3 +*.( 1/)) //.+

1/(' /2.* 1/)* *'.'

1/(( *1.3 1/)+ )).)

1/() **.3 1/)/ )(.0

1/(* +(.1 1)*0 /1.0

1/(+ 122.+ 1/*1 10).0

1/(/ )/.' 1/*2 102.0

1/)0 +1.0 1/*3 +*.0

1/)1 /'.( 1/*' +'.01/)2 +).3


10/14

#oltion:

,alclation of retrn eriod $N2( year&

m Annal ainfall $cm& ro"a"ility

m4$N;1&

etrn eriod

!14

1 122.+ 0.03+ 2)

2 113 0.0*) 13

3 10).+ 0.11( +.))*

' 102.2 0.1(3 ).(

( /+.+ 0.1/2 (.2

) //.( 0.230 '.333

* /' 0.2)/ 3.*1'

+ /2.* 0.30* 3.2(

/ /1 0.3') 2.++

10 /0.* 0.3+' 2.)

11 +*.( 0.'23 2.3)

12 +* 0.')1 2.1))13 +).3 0.( 2.00

1' +(.1 0.(3+ 1.+(*

1( +' 0.(*) 1.*33

1) +2.( 0.)1( 1.)2(

1* +1 0.)(3 1.(2/

1+ **.3 0.)/2 1.'''

1/ )/.' 0.*30 1.3)+

20 *'.' 0.*)/ 1.3

21 *1.3 0.+0* 1.23+

22 )/.' 0.+') 1.1+1

23 )+.) 0.++' 1.1302' )).) 0./23 1.0+3

2( )( 0./)1 1.0'


11/14

! !" !"""

$"

&"

("

)"

!""

!$"

!&"

f*0+ 6 !7.!' ln*0+ 7".7

,ec/rrence interval 8s Ann/al ,ainfall

,et/rn perio1 T in years

Ann/all ,ainfall in cm

Form the grah6

1*.1(ln $!& ; *0.)//

A) For T=50 year 1*.1(ln $(0& ;*0.)//

13*.*/ cm

"& For !100 year

1*.1(ln $100& ;*0.)//

1'/.)** cm


12/14

Q.N7: 2.1*

!he annal rainfall ales at a station for a eriod of 20 years are as follows:

9ear Annal ainfall$cm&

9ear Annal ainfall$cm&

1/*( 120.0 1/+( 101.0

1/*) +'.0 1/+) 10/.0

1/** )+.0 1/+* 10).0

1/*+ /2.0 1/++ 11(.0

1/*/ 102.0 1/+/ /(.0

1/+0 /2.0 1//0 /0.0

1/+1 /(.0 1//1 *0.0

1/+2 ++.0 1//2 +/.0

1/+3 *).0 1//3 +0.0

1/+' +'.0 1//' /0.0

5etermine

$a& !he ale of annal rainfall at with a recrrence interal of 1( years.

$"& !he ro"a"ility of occrrence of an annal rainfall of magnitde 100 cm at station .$c& *(< deenda"le annal rainfall at the station.

#oltion:

,alclation of retrn eriod $N2( year&

m Annal ainfall $cm& ro"a"ility

m4$N;1&

etrn eriod

!14

1 120 0.0'* 21.2*

2 11( 0.0/( 10.(2

3 10/ 0.1'2 *.0'2

' 10) 0.1/0 (.2)

( 102 0.23+ '.201

) 101 0.2+( 3.(0+

* /( 0.3+0 2.)31

+ /2 0.'*) 2.100

/ /0 0.(*1 1.*(110 +/ 0.)1/ 1.)1(

11 ++ 0.))* 1.'//

12 +' 0.*)1 1.31'

13 +0 0.+0/ 1.23)

1' *) 0.+(* 1.1))

1( *0 0./0' 1.10)

1) )+ 0./(2 1.0(


13/14

! !" !"""

$"

&"

("

)"

!""

!$"

!&"

f*0+ 6 !!.#' ln*0+ )'.%

Ann/al rainfall 8s ret/rn perio1 chart

,et/rn perio1 in T years

Ann/al ,ainfall in Cm

9rom the a3ove chart

p6!(.$7'ln *T+ 7(.))

a+

the val/e of p at rec/rrence interval of !' years5

P6!(.$7'ln *!'+ 7(.))

P6!$".# cm

3+

Pro3a3ility of occ/rrence of an ann/al rainfall of ma2nit/1e !"" cm at station P is

P 6 !(.$7'ln *T+ 7(.))

!"" 6 !(.$7'ln *T+ 7(.))

*!""-7(.))+!(.$' 6 ln *T+

T 6&.") year

c+

9or pro3a3ility of e0ce1ence 6 ".7'

T6 !p6!".7'6!.%%% year

3y /sin2 the e:/ation from the 1erive1 tren1 line


14/14

pr 6!(.$7'ln *!.%%%+ 7(.))

6 )).'( cm

Q.N7: 2.20

A one-day rainfall of 20.0 cm at a lace at a lace = was fond to hae a eriod of 100 years.

,alclate the ro"a"ility that a one-day rainfall of magnitde e>al to or larger than 20.0 cm:

a& ?ill not occr at station = dring the net (0 years.

"& ?ill occr in the net year.

#oltion:

Here8

141000.01

Q $1-& 1-0.010.//

i&

r8n Qn $1&n

08(0 0.//(0 0.)0(year

ii&

1822 !

1 !∗2! @0.012@0.//2-1

0.01

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