19 VB82063 VCB3053 HYDROLOGY.pdf

8/17/2019 19 VB82063 VCB3053 HYDROLOGY.pdf

1/12

UNIVERSTTI

TEKNOLOGI

COURSE

DATE

TIME

VB82063

/ VCB3Os3-HYDROLOGY

27

DECEMBER

2013

(FR|DAY)

9.00

AM

-

12.A0

NOON

(3

hours)

INSTRUCTIONS

TO

CANDIDATES

1.

2.

3.

4.

5.

Answer

ALL questions

in

the

Answer

Booklet.

Begin

EACH

answer

on

a

new

page.

lndicate

clearly

answers

that

are

cancelled,

if

any.

where

applicable,

show

clearly

steps

taken

in

arriving

at

the solutions

and

indicate

ALL

assumptions,

if

any.

Do

not

open

this

Question

Booklet

until

instructed.

Note

:

There

are

TWELVE

(rzr

pages

in

this

euestion Bookret

including

the

cover

page

and

Appendices.

Graph

paper

will

be

provided.

Universiti

Teknologi

PETRONAS

I

PETRONAS

FINAL

EXAMINATION

SEPTEMBER

2013 SEMESTER


2/12

vB82063A/C83053

d-

.

FIGURE

Q1a

shows

i.

Name

the

rain

the

side

view

of

a

rain

gauge.

gauge.

lt

[1

mark]

Describe

the

operational

procedures

for

the

measurement

of

precipitation

depth using

the rain

gauge.

[2

marks]

ilt

Appraise

the

efficiency

of

the

rain

gauge

in rainfall

measurement.

[2

marks]

FIGURE

Qla


3/12

b.

FIGURE

Q1b

shows

a

set

of

rain

gauge

rainfall

depths

in

a

catchment

area.

The

orographic,

influences

are

negligible.

vBB2063A/C83053

stations

with

the respective

catchment

is

flat

and

the

FIGUREQI

b

The

average

rainfall

depth

over

the

catchment

area

can

be

estimated

by

Arithmetic,

Thiessen,

and lsohyetal

methods.

which

method

do

you

think

that

provides

the

best estimate

for

the average

rainfall depth? Why?

i l0

mm \ --*r

133

¡orn

XX


4/12

il

vBB2063A/C83053

Estimate

the average

rainfall

depth

of

the

catchment

area

using

Arithmetic

method.

Estimate

the

average

rainfall

of

the catchment

area

using

Thiessen

method.

For

a

5%

error

in

the

estimation

of

the mean

rainfalt,

evaluate'tf

the

number

of

stations

within

the catchment

is

adequate.

tv.


5/12

vBB2063A/C83053

2. a. The

evaporation

observed

from

an

evaporation

pan

has to be corrected

by

a

pan

coefficient

so

as

to compensate

the limitation

of the

pan.

What

are

the limitations

that can

be

corrected

by the

pan

coeffìcient?

[2

marks]

b.

A

reservoir with

a

surface

area

of

50

ha

has

the

following

parameters

during

a week:

.

Water

temperature: 29

C

.

Relativehumidity:45%

.

Wind velocity

at2

m

above

the

ground:

20

km/h

.

Coefficient

accounting

for water

conditíon,

Ku=

0.50

Estimate

the volume

of

water

evaporated

from

the

reservoir during

the

week

using

Meyer's

formula.

[5

marks]

c.

Differentiate

between

field

capacity

and infiltration

capacity.

[2

marks]


6/12

vBB2063A/C83053

d.

Provide

a

sketch

to relate

the infiltration

rate

of

the

following

soils

with

the

infiltration

time:

i.

Dry

sandy

loam

¡i.

Dry

clay

loam

¡i¡.

Wet

clay

loam

[3

marks]

e.

The mass

curve

of

a rainfall

of

duration

100

min

is

given

in

TABLE

e2.

TABLE

Q2

¡.

lf

the

catchment

had

a

findex

of

0.6

cm/hr, estimate

the

total

infiltration

and

the total

surface

runoff

from

the catchment.

[6

marks]

ii.

criticize

the

use

of

findex

in

the estimation

of infiltration

rate.

[2

marks]

Time

from

start

of

rainfall

(min)

0

20

40

60 80

100

Cumulative

rainfall

(cm)

0

1.2

2.6

3.3

3.5


7/12

a.

.

b.

vBB2063A/C83053

lllustrate

the

procedures

involved

in a river

gauging

operation.

[4

marks]

TABLE

Q3b

shows

the data

pertaining

to

a river

gauging

operation

at

a

gauging

site.

The

rating

equation

of

the

current meter

is

v

=

0.3i/

+

0.05

m/s, where

v and

N

are stream

velocity

and

revolutions

per

second

of the

current

meter,

respectively.

Estimate

the

river

discharge

by using

mean-section

method.

[6

marks]

TABLE

Q3b

Distance

from

left

water

edqe

Water

depth,

d

(m)

Current

meter

readinos

o.6d

o.2d

0.8d

Rev

Sec Rev

Sec

Rev

Sec

0

0

3

1.4

12

50

b

3.3

38

52

23 55

o

5.0

40

58

30 54

12

9.0

48 60

34 58

l5

5.4

34

52 30

50

18

3.8

35

52

30

54

21

1.8

18

50

24

0


8/12

vBB2063A/C83053

4.

a.

Describe

the

THREE

(3)

components

of

runoff.

[6

marks]

Draw

typical

annual

hydrograph

of

a

perennial

stream

and show

the base

flow

(groundwater

flow)

in

the

hydrograph.

[4

marks]

The

maximum

length

of

travel

of

water

in a s00-ha

catchment

area is

3000

m

and

the

elevation difference

between

the

highest and

the

outlet

point

is 25

m.

The

land

use/cover

and

the corresponding

runoff coefficient

are

given

below.

The

maximum

intensity

duration frequency

relationship

of the

catchment

area

is

given

by

l=

6.311

7

0 1s23

(D

+

0.50

)0e45

t4min)

:

0.

0

I 947

L0'77s-0'38s

where,

i

-

rainfall

intensity

in

cm/hr,

T

-

return

period

in

year,

D

=

duration

of

storm

in

hr.

that

is equivalent

to time

of

concentration

in hr

(r ¡.

Estimate

the

25-year

peak

runoff

(Qp)

from

the catchment

area.

b.

c.

Land

Use

/ Cover

Area

(ha)

Runoff

Coefficient

Forest

250

0.10

Pasture

50

0.1'1

Cultivated

Land

200

0.30

[10

marks]


9/12

vBB2063A/C83053

5. a.

Discuss

FOUR

(4)

structural

methods

of

flood control

[8

rnarks]

b. TABLE

Q5

contains

the inflow

hydrograph

of

a river

reach. At

the start

of

the inflow,

the

outflow

discharge

is 15

m3/s. For

the

river

reach,

K= 12hr

and

x

=

O.25.

TABLE

Q5

Time

(hr)

0

6

12 18

24 30

36

42

lnflow

lm3ls¡

15

45

55 50

40

30

22

15

i.

Route

the flood

through

the

river reach

using

the Muskingum

method

and

generate

the

inflow

and

outflow

hydrograph

in

a single

plot.

['10

marks]

¡i.

Calculate

the lag

and

attenuation

of

the

flood.


10/12

vBB2063A/C83053

6. a.

Differentiate

between

i.

confined

and

unconfined

aquifers

[2

marks]

ii.

specific

yield

and

specific

retention

[2

marks]

b.

A

20

cm

diameter

well

completely

penetrates

aR unconfined

saturated

aquifer of

thickness

30

m.

under

a steady

pumping

rate

of

2100

Lpm,

the

drawdown

at

two

observation

wells

'10

and

100

m from

the well are

7.5

and

0.5 m, respectively.

DetermÍne

i.

The

coefficient

of

permeability

and

transmissibility

of the aquifer.

[4

marks]

¡i.

Distance

from

the

wellwhere

the

drawdown

is ínsignificant.

[2

marks]

-END

OF PAPER-

10


11/12

vBB2063AIC83053

Cz=

Qz =

Qt

+

Ct(lt-Qt)

11


12/12

e=ox(hi-t'i)

vBB2063A/C83053

tnL

\

12

Documents

19 VB82063 VCB3053 HYDROLOGY.pdf