Assignment 2 (Last date of submission 13 July 2012)
Ques 1) Name the
device that is used to collect and measure rainfall and also give its
classification.
Ques 2) The
average annual precipitation data of six rain gauge stations in a catchment
area during 1991-2000 are as follows:
Station
|
A
|
B
|
C
|
D
|
E
|
F
|
Year
|
Precipitation (mm)
|
|||||
1991
|
608
|
704
|
378
|
768
|
576
|
544
|
1992
|
663
|
768
|
402
|
837
|
628
|
593
|
1993
|
611
|
707
|
388
|
722
|
519
|
548
|
1994
|
704
|
815
|
433
|
889
|
668
|
629
|
1995
|
606
|
702
|
374
|
766
|
575
|
543
|
1996
|
722
|
836
|
446
|
913
|
685
|
646
|
1997
|
647
|
748
|
402
|
815
|
612
|
578
|
1998
|
797
|
924
|
717
|
1007
|
756
|
713
|
1999
|
721
|
835
|
700
|
913
|
683
|
646
|
2000
|
686
|
794
|
680
|
865
|
649
|
612
|
The data observed at station C were doubtful because of some
topographical changes there. Verify whether the data observed at C is
consistent and correct it, if necessary.
Ques 3) Following
figure shows a typical layout of a catchment area ABCDF, Six rain gauge
stations are established at A, B, C, D,
E and F.The precipitation observed at these six stations in july 2004 is as
follows:
Station
|
A
|
B
|
C
|
D
|
E
|
F
|
|
Precipitation (mm)
|
100
|
120
|
130
|
180
|
125
|
150
|
|
| ||||||||||||||||||||||||||||||||||||
Find the average precipitation over the catchment during
July 2004 by Thiessen’s polygon method.
Ques 4) For a
drainage basin of 600 km2, isohyetals drawn for a storm gave the
following data:
Isohyetals interval (cm)
|
15--12
|
12 -- 9
|
9--6
|
6--3
|
3--1
|
Inter-isohyetal area (km2)
|
92
|
128
|
120
|
175
|
85
|
Estimate the average depth of precipitation over the
catchment.
Ques 5) Estimate
the constant rate of withdrawal from a 1375 ha reservoir in a month of 30 days
during which the reservoir level dropped by 0.75 m in spite of an average
inflow into the reservoir of 0.5 million
m3 per day. During the month the average seepage loss from the
reservoir was 2.5 cm, total precipitation on the reservoir was 18.5 cm and the
total evaporation was 9.5 cm.
Ques 6) A
catchment has four sub-areas. The annual precipitation and evaporation from
each of the sub-areas are given below. Assume that there is no change in the
groundwater storage on an annual average (i)
precipitation, and (ii) evaporation.
What are the annual runoff coefficients for the sub-areas and for the total
catchment taken as a whole?
Sub-area
|
Area
|
Annual precipitation
|
Annual evaporation
|
||||
Mm2
|
mm
|
mm
|
|||||
A
|
10.7
|
1030
|
530
|
||||
B
|
3
|
830
|
438
|
||||
C
|
8.2
|
900
|
430
|
||||
D
|
17
|
1300
|
600
|
No comments:
Post a Comment