CLIMATIC CHANGES AND ITS CONTROL
ON WATER RESOURCES IN VELLAR
RIVER BASIN
by
Mr. K. Santhanam, Dr. R. Kannan and Dr. NethajiMariappan
Research and Development
Sathyabama University,
Chennai -119
Vellar River Basin
One of the 17 major river basins of Tamil Nadu
Index map showing Vellar Basin
• Administrative boundaries
:Dharmapuri, Salem, Viluppuram,
Cuddalore, Namakkal, Perambalure and
Tiruchi Districts
• Total Geographical area
:7521 sq. km
• Physiography
:Kalvanrayan Hills in north and KollimalaiPachchamalai hills in the south
• Regions
:Western hilly terrain
Central Hill valley complex terrain
Eastern deltaic plain and coastal region
Administrative and Sub basin boundary map
Drainage Map of Vellar basin
Tributaries
-Vasista Nadhi
-Swetha Nadhi
-Chennar River
-Anaivari Oodai
-Manimutha Nadhi
-Gomukhi Nadhi
-Periya Ooadi
Vellar River basin drainage Map
RELIEF MAP
Maximum Elevation
: 1266 m (Kalvarayan Hills-South slope)
Ranges of Elevation
: 110 m to 1183 m In the northwestern part of
Vellar Basin
Minimum elevation
:20 to 40 m (Chidambaram)
Relief map of Vellar basin
GEOLOGY
Western part of the basin – Archean Group of rocks
( Magnetite Quartzite, charnockite,
Granulite and Amphibolite)
Eastern part
- Sedimentary formations of
Cretaceous
Argillaceous sand stone
Calcareous sand stone
Shale and Lime stone
Tertiary
sand stone , lignite, clay and shale
Quaternary
Beach, sand dunes, black clay, flood plians and
alluvium
Vellar River Basin Geology Map
Vellar River Basin satellite image mosaic
Vellar River basin Geomorphology Map
Vellar River basin Southeast monsoon
Rainfall
Vellar River basin Northwest monsoon
Rainfall
A NNUA L RF IN mm
5 Y EA RS MOV . A V E.
A NNUA L A V G.
Ye a r
Linear ( A NNUA L RF IN mm)
2002- 03
2001- 02
2000- 01
1999- 00
1998- 99
1997- 98
1996- 97
1995- 96
1994- 95
1993- 94
1992- 93
1991- 92
1990- 91
1989- 90
1988- 89
1987- 88
1986- 87
1985- 86
1984- 85
1983- 84
1982- 83
1981- 82
1980- 81
1979- 80
1978- 79
1977- 78
1976- 77
1975- 76
1974- 75
1973- 74
A NNUA L A V G.
1972- 73
1971- 72
5 Y EA RS MOV . A V E.
A N N U A L R F in m m
A NNUA L RF IN mm
2002- 03
2001- 02
2000- 01
1999- 00
1998- 99
1997- 98
1996- 97
1995- 96
1994- 95
1993- 94
1992- 93
1991- 92
1990- 91
1989- 90
1988- 89
1987- 88
1986- 87
1985- 86
1984- 85
1983- 84
1982- 83
1981- 82
1980- 81
1979- 80
1978- 79
1977- 78
1976- 77
1975- 76
1974- 75
1973- 74
1972- 73
1971- 72
A N N U A L R F in m m
R A S IP U R A M
1600.0
1400.0
1200.0
1000.0
800.0
600.0
400.0
200.0
0.0
Ye a r
Linear ( A NNUA L RF IN mm)
S E N D AM AN GAL AM
1400.0
1200.0
1000.0
800.0
600.0
400.0
200.0
0.0
A NNUA L RF IN mm
5 Y EA RS MOV . A V E.
A NNUA L A V G.
2003- 04
2002- 03
2001- 02
2000- 01
1999- 00
1998- 99
1997- 98
1996- 97
1995- 96
1994- 95
1993- 94
1992- 93
1991- 92
1990- 91
1989- 90
1988- 89
1987- 88
1986- 87
1985- 86
1984- 85
1983- 84
1982- 83
1981- 82
1980- 81
1979- 80
1978- 79
1977- 78
1976- 77
1975- 76
1974- 75
1973- 74
A NNUA L A V G.
1972- 73
1971- 72
5 Y EA RS MOV . A V E.
A N N U A L R F in m m
A NNUA L RF IN mm
2003- 04
2002- 03
2001- 02
2000- 01
1999- 00
1998- 99
1997- 98
1996- 97
1995- 96
1994- 95
1993- 94
1992- 93
1991- 92
1990- 91
1989- 90
1988- 89
1987- 88
1986- 87
1985- 86
1984- 85
1983- 84
1982- 83
1981- 82
1980- 81
1979- 80
1978- 79
1977- 78
1976- 77
1975- 76
1974- 75
1973- 74
1972- 73
1971- 72
A N N U A L R F in m m
AT H U R
2500.0
2000.0
1500.0
1000.0
500.0
0.0
Ye a r
Linear ( A NNUA L RF IN mm)
3000.0
C H ID A M B A R A M
2500.0
2000.0
1500.0
1000.0
500.0
0.0
Ye a r
Linear ( A NNUA L RF IN mm)
TECHNICAL CONCLUSIONS
Western part of Vellar river basin receives more rainfall
during south west monsoon
Due to elevation (1300 m) and Compactness of hard
rock, surface water goes as runoff to the eastern
sedimentary formation
Due to compactness recharge is not possible in the
western and central portions as geological conditions and
geomorphological conditions are not favourable
Year by year rainfall quantity is decreasing
TECHNICAL CONCLUSIONS
In the eastern part Northeast monsoon rainfall is
predominant
In addition to south west monsoon rainfall, water from
western part is also recharging the sedimentary aquifer
Hence Aquifer is fully saturated in south west monsoon
During North East monsoon rainfall water goes as
surplus water to sea and heavy flood is caused in
Chidambaram and Cuddalore Taluks
RECOMMENDATIONS
In the upstream side of western part of the river basin
more artificial recharge structures like check dams
percolation ponds, recharge pits have to be constructed
in order to retain water in upstream side so that south
west monsoon water will not go to down stream side.
In Eastern side water level may be lowered for
irrigation purposes so that Northeast monsoon rain
water will reach the aquifer and gets recharged
By these procedures the surplus water running to the
sea can be prevented. Heavy water logging in the coastal
region can be avoided