The presentation includes the technical knowledge had in the past in Sri Lanka at various level of development and most of them can be used with some modifications at present

1. Sri Lankan Traditional Knowledge in
adaptation to climate change
Systems of knowledge are many.
Among these, modern science is only one, though
the most powerful and universal.
Rural people’s knowledge is in contrast ‘situated’,
differing both by locality and by group and
individual, and differing in its modes of
experimenting and learning: different people know
different things in different places, and learn new
things in different ways.
– Robert Chambers, 1994
Dharmasena, P.B., Presentation made at the Workshop on ‘Conservation and utilization of local
varieties, traditional knowledge associated with genetic resources and agriculture’ held on 9-10
January 2017 at Oak Ray Regency Hotel, Deveni Rajasinghe Mawatha, Gatambe, Kandy.

2. Pre-Vijaya History (3000 BC – 600 BC)
Queen Devayani Sister Mandratha
Prince Tharaka
(Kelaniya)
Prince Soorapadma
(Thissamaharama)
Prince Singhemukha
(Lankapura)
Prince Kuwera
(Alakamanda)
King Ravana
(2554 – 2517 BC
Chithrakuta)
King Vibhishana
(Kelaniya)

3. Kevesastha
Upulwangiri
Rakungiri
Mahagiri
Chalaka
Neelagiri Kawasthalabha
Dhumaka Kaddeera Indra
Agni

4. Kevesastha (Northern)
Upulwangiri (Kala Oya)
Rakungiri (Malwathu Oya)
Mahagiri (Samanala mountain
area) – Kelani, Kalu, Walawe,
Mahaweli
Chalaka (Mi Oya)
Neelagiri (Modaragam Aru)
Kawasthalabha (Yan oya)
Dhumaka Kaddeera (Deduru Oya)
Indra (Maduru Oya,
Mundeni Aru, Gal oya)
Agni (Kumbukkan
Oya, Menik Ganga,
Kirindi Oya

5. Ancient Regional
Divisions of Sri Lanka
Based on Major River
Systems - C.M. Madduma
Bandara (2009)

6. Proposed New
Regions/Provinces of Sri
Lanka based on River
Basins
(Madduma Bandara, 1992)
After Madduma Bandara 1992
Anuradhapura

7. Advantages of New Provinces
• Neutral basis for boundary demarcation of
provinces – no ethnic, religious, linguistic or any
other extreme criteria
• Every Province has a sea-frontage with the coast
and oceanic resources.
• Development of water resources – no “inter-
provincial rivers”.
• Under the 13th Amendment to the Constitution -
Provincial Rivers will be developed and managed
by the Provincial Councils
• Natural disaster such as floods and droughts could
be managed from a long-term perspective.
• No unwelcome social barriers such as Up-country
- Low Country Divisions
• The sharing of power with regard to development
would be more tangible and reasonable between
the centre and the periphery.

8. River basins – Deduru Oya, Kala Oya,
Malwathu Oya and Yan Oya
River Basin Total Basin
Area (Km2)
Total Rainfall
(million M3)
Drainage to
Sea (million
M3)
%
drainage
to Sea
Deduru Oya 2,616 4,794 1,608 34.0
Kala Oya 2,772 4,424 587 13.0
Malwathu Oya 3,246 4,592 568 12.0
Yan Oya 1,520 2,269 300 19.0

9. Post - Vijaya History: Hydraulic Civilization
(600 BC – 1200 AD)
• Inter-river basin water
resources management
– Dambulu Oya -
Malwathu Oya
diversion canal (860
AD)
– Malwathu Oya -
Kanadara Oya
diversion canal (860
AD)
– Yoda Ela -
Nachchduwa feeder
canal (540 AD)
Mahakanadarawa
Nachchaduwa
Kalawewa-Balaluwewa
Dambulu oya
Malwathu oya
Kanadara oya
Kala Oya

10. Post - Vijaya History: Hydraulic Civilization
(600 BC – 1200 AD)
• Intra-river basin water
resources management
– Kalawewa -
Thisawewa Yodha Ela
(470 AD)
– Nachchaduwa -
Nuwarawewa feeder
canal (290 AD)
– Balaluwewa -
Siyambalangamuwa
feeder canal (290 AD)
– Basawakkulama -
Maha Vilachchiya
feeder canal (470 AD)
Kalawewa-Balaluwewa
Thisawewa
Siyambalangamuwa
Nachchaduwa
Nuwarawewa
Mahavilachchiya
Basawakkulama
Malwathu oya
Thalawa oya
Kala oya

11. Network of tanks
and streams
No flood and no
drought

12. Nachchaduwa
Kanadarawewa
Vilachchiya
Kalawewa and
Balaluwewa
Huruluwewa
Main factors:
1. Morphology (landscape)
• Lower elevation,
• Moderate undulation
2. Rainfall
• Bimodality
• ~1500 mm/ year
3. Soil and geology
• Regolith aquifers
• Low infiltration
• RBE – LHG
Network of tanks and streams in the form of cascades

13. Flood situation avoided Drought effect minimized
Opportunities for rich bio-diversity
Food security through
diverse farming
Cyclone forces
diluted

14. Total No. of tanks: 11
Tanks with settlements (Wew gammana): 02
Tanks without settlements (Olagam wew): 02
Tanks to trap sediments (Kayan wew): 03
Forest tanks (Kuluwew): 04

15. Sanitary places of
women and kids
Sanitary places of men
Faeces as a nutrient source to paddy fields
Tank-village system will be declared soon as a
Globally Important Agriculture Heritage System (GIAHS) by UN
A Sustainable System to adapt Climate Change scenarios

16. Chena
Landa
Thisbambe
Gangoda
Godawala
Kattakaduwa
Kiul-ela
Streams
Perahana
Gasgommana
Iswetiya
Chena

17. Godawala
Perahana
Gasgommana
Iswetiya
Tank water – no pollution, no sedimentation: safe drinking water, good storage

18. Landa
Thisbambe
Gangoda
Kattakaduwa
Kiul-ela
Paddy field - no salinity, good fertility: High productivity

19. What does climate change mean
in Sri Lanka?
• The number of rainy days has decreased (except Nuwara
Eliya)*.
• The total annual rainfall has not decreased in many areas*.
• Annual rainfall variability has increased*.
• Annual mean air temperature is increasing**.
• Extreme events (drought and flood) are possible.
* - Manawadu and Fernando, 2008.
** - Premalal, 2009, Chandrapala , 2009.

20. Traditional Agricultural Practices in adaptation to
climate change
• ‘Bethma’ practice during drought periods
– It is a practice that temporarily redistributes plots of land among
shareholders (paddy landowners) in part of the command area
(territory) of a tank (reservoir) during drought periods
• ‘Pangu’ method – Regular maintenance to avoid disasters
– The tank had to be maintained properly to avoid breach, leak, and
excess seepage. Repair and desiltation of tanks and cleaning of
canals during dry periods are shared tasks assigned to each farmer
proportionately to land ownership.
• ‘Kekulama’ if the low rainfall maha is expected
– Farmers advance the cultivation time using early seasonal rains
whenever they feel that tanks would not get enough water to
cultivate the command area. They have the experience that if
September (2nd inter-monsoonal) rains are high, the total seasonal
rainfall is not adequate to fill the tank.

21. 600
650
700
750
800
850
900
950
1000
0 50 100 150 200 250 300 350
September rainfall (mm)
September Vs. October-February rainfalls
(Mahailluppallama 1905 – 2003)
October-Februaryrainfalls(mm)

22. Traditional Agricultural Practices in adaptation to
climate change
• ‘Bethma’ practice during drought periods
– It is a practice that temporarily redistributes plots of land among
shareholders (paddy landowners) in part of the command area
(territory) of a tank (reservoir) during drought periods
• ‘Pangu’ method – Regular maintenance to avoid disasters
– The tank had to be maintained properly to avoid breach, leak, and
excess seepage. Repair and desiltation of tanks and cleaning of
canals during dry periods are shared tasks assigned to each farmer
proportionately to land ownership.
• ‘Kekulama’ if a low rainfall maha is expected
– Farmers advance the cultivation time using early seasonal rains
whenever they feel that tanks would not get enough water to
cultivate the command area. They have the experience that if
September (2nd inter-monsoonal) rains are high, the total seasonal
rainfall is not adequate to fill the tank.
• ‘Thawalu Govithena’ during extremely dry situation
– Tank bed cultivation using little rains constructing a main soil bund
between deep phase and shallow phase of the tank bed

23. Four strata of tank water body
Madakaluwa – dead storage area
Wewpitiya – deep water area
Waangilma – area between FSL and HFL
Wewthaula – shallow water area
Master bund in Thawulu Govithena to
prevent tank sedimentation

24. Summary
River basin level
Inter-River basin level
Intra-River basin level
Cascade level
Village level
Field
level

25. 25