Transcript Vellar Climate
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
•
Physiography :7521 sq. km :Kalvanrayan Hills in north and Kollimalai Pachchamalai 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
Maximum Elevation Ranges of Elevation Minimum elevation
RELIEF MAP
: 1266 m (Kalvarayan Hills-South slope) : 110 m to 1183 m In the northwestern part of Vellar Basin :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 Northwest monsoon Rainfall Vellar River basin Southeast monsoon Rainfall
RASIPURAM
1600.0
1400.0
1200.0
1000.0
800.0
600.0
400.0
200.0
0.0
ANNUAL RF IN mm 5 YEARS MOV. AVE.
Year
ANNUAL AVG.
Linear (ANNUAL RF IN mm)
SENDAMANGALAM
1400.0
1200.0
1000.0
800.0
600.0
400.0
200.0
0.0
ANNUAL RF IN mm 5 YEARS MOV. AVE.
Year
ANNUAL AVG.
Linear (ANNUAL RF IN mm)
ATHUR
2500.0
2000.0
1500.0
1000.0
500.0
0.0
ANNUAL RF IN mm 5 YEARS MOV. AVE.
Year
ANNUAL AVG.
Linear (ANNUAL RF IN mm)
CHIDAMBARAM
3000.0
2500.0
2000.0
1500.0
1000.0
500.0
0.0
ANNUAL RF IN mm 5 YEARS MOV. AVE.
Year
ANNUAL AVG.
Linear (ANNUAL 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