Subject: Cartography : Types of maps, map information, scales, map enlargement and reductions, map construction, visualization, projections, map reading and interpretation, introduction to computer cartography.

1. Climatic Risk Assessment on
Southern Expressway in Sri Lanka
Climatic Risk Assessment on
Southern Expressway in Sri Lanka
BY
S.D. Kelum Priyantha
Thiwanka Jayasiri
MSc in Geoinformatics
IHRA
University of Colombo
28th June 2014

2. • The Southern Expressway,
also known as the Southern
Lanka Distributor is Sri
Lanka's first E Class highway.
• The 126 km long highway
links the Sri Lankan capital
Colombo with Galle and
Matara, major cities in the
south of the island

3. • Rainfall
• Temperature
• Bends
• Flood
• Landslides

4. Average Rainfall (mm)
• Dry zone → < 1,750
• Intermediate zone → 1,750-2,500
• Wet zone → > 2,500
Located in
Wet Zone

5. Geometric Design of road
Vs
Weather

6. Deflection Angle

7. There are lot of bends
associated with
southern expressway
Bend Index are
calculated as follows
(Deflection angle/Bend
length) * 100
If Bend Index is high then risk
also high

8. Rain Fall

9. First Inter Monsoon
March-April

10. Southwest Monsoon
May – September

11. Second Inter monsoon
October-November

12. Northeast Monsoon
December-February

13. Rainfall Trend
(mm/year)

14. Temperature

15. Temperature
January, February
July - December

16. Temperature
March

17. Temperature
April

18. Temperature
May

19. Temperature
June

20. Landslide

21. Landslides
(1947 - 1996)

22. Landslides Risk
DS Divisions

23. Flood

24. Flood Risk
At 1m elevation

25. Flood Risk
At 2m elevation

26. Flood Risk
At 3m elevation

27. Flood Risk
At 4m elevation

28. Flood Risk
At 5m elevation

29. Flood Risk
At 6m elevation

30. Flood Risk
At 7m elevation

31. Flood Risk
At 9m elevation

32. Flood Risk
At 13m elevation

33. Flood Risk
At 20m elevation

34. Risk Analysis Chart for Rainfall
( Risk Barometer )

35. Risk Analysis Chart of Rain Fall
(km)
First Inter monsoon Southwest Monsoon Second Inter monsoon Northeast Monsoon

36. • Premature deterioration of infrastructure
• Damage to roads from buckling and rutting
• Damage to tires of vehicles
• Bridges subject to extra stresses through thermal expansion
and increased movement
Climate Change Impacts on the Highway
System
Change in extreme maximum temperature

37. • If more rainfall, there will be an increased risk of landslides, slope failures, and floods
from the runoff, causing road washouts.
• Increasing precipitation could lead to soil moisture levels becoming too high (structural
integrity of roads, bridges, and tunnels could be compromised leading to accelerated
deterioration)
• Less rain available to dilute surface salt may cause steel reinforcing in concrete
structures to corrode
• Road embankments at risk of subsidence
• Bridges, signs, overhead cables, tall structures at risk from increased wind speeds
Climate Change Impacts on the Highway
System
Greater changes in rainfall levels

38. • Weather phenomenon such as rainfall,
temperature, wind, fog and disaster such as
flood, landslides and extreme weather events
that could in some way affect the operations
of a transportation system or facility.
Findings

39. Findings
• The highway is mainly in the wet zone.
• The drivers faces two main problems due to
climatic conditions. Rain and Fog.
• In addition strong winds may cause specially
on rainy days.
• No street lamps along the road except in main
junctions.

40. Safety Process

41. Safety Precautions
• Identifying the most risky areas along the road and risky seasons using
Risk Analysis Charts ( Risk Barometer )is very important.
• Identify the risky places where should establish sign boards and use
‘Dynamic electronic speed limits sign boards’ according to weather
conditions. Specially in rainy days drive “below” the speed limits.
• Encourage drivers to use fog lights when driving in the fog.
• Use head lights even in day time when driving in rain or fog.
• Make sure of the lights and wipers are in proper order before entering to
the highway.
• Make aware the drivers regarding weather conditions by mentioning on
the ticket of the day before entering to the highway.
• Properly check whether vehicle & driver are in allowed conditions.
• In case of flood, find the solution to make connection between
expressway and general road network
• Make precautions by analyzing of weather trends such as rainfall,
Temperature due to global warming, tsunami, Landslides