Presentation made at the Inception Workshop held on 20th September 2019 at National Agriculture Information & Communication Centre, Peradeniya, Sri Lanka for the Project 'Healthy Landscapes - Healthy People UNEP-GEF Project on Healthy Landscapes:Managing agricultural landscapes in socio-ecologically sensitive areas to promote food security, well-being and ecosystem health in Sri Lanka. The presentation argues that human health can be ensured by improving the ecosystem health

1. Healthy Landscapes - Healthy People
UNEP-GEF Project on Healthy Landscapes:
Managing agricultural landscapes in socio-ecologically sensitive areas
to promote food security, well-being and ecosystem health in Sri Lanka
Presentation made at the Inception Workshop held on 20th September 2019
at National Agriculture Information & Communication Centre, Peradeniya,
Sri Lanka.
P.B. Dharmasena,
Ecosystem and Human Health: Issues and Capacity Consultant
HUMAN HEALTH AND ECOSYSTEM HEALTH

2. Natural
disasters
Malnutrition Low Total
Fertility Rate
Non
Communicable
Diseases
Communicable
Diseases
Causal factors of human health in Sri
Lanka

3. Rich in
biodiversity
Regulating
services
Cultural
services
Supporting
services
Provisioning
services
Healthy Ecosystems
drought
flood
flood
Cyclone
Epidemics
nutrients
habitats
food
fruits
vegetables
timber
Fuel wood
medicine
recreation
mental
health
physical
health
knowledge
aesthetic
beauty
human
needs
Pest
control
Water
purification
soil health

4. Human health can be ensured by improving the ecosystem health

5. Agricultural landscape selected for the project:
Tank cascade ecosystem in Sri Lanka
Why?
• Ecosystem service values – High but not yet
evaluated
• Damages to environment – needs to be
recovered
• Threats to human health – can be reduced
through landscape management

6. Tank clusters or cascades
Hydrology based definition
• A ‘cascade’ is a connected series of tanks organized within a micro-catchment (meso
catchment) of the dry zone landscape, storing, conveying and utilizing water from
an ephemeral rivulet’. – Madduma Bandara, 1985
Ecology based definition
• Tank cascade is an ecosystem,
where water and land resources
are organized within the micro-
catchments of the dry zone
landscape, providing basic needs
to human, floral and faunal
communities through water, soil,
air and vegetation with human
intervention on sustainable basis’.
– Dharmasena, 2017

8. Ecosystem service values – High but not
yet evaluated
• Study location: Kalaoya river basin
• Year reported 2013
• Total annual tank service value: 2,972 US $/ha
• Annual value of paddy cultivation: 161 US$/ ha (5.4 %)
• The remaining amount 94.6% is derived from the
utilization of tank water and tanks for:
– vegetable, banana and coconut cultivation,
– fishery,
– the utilization of lotus roots and flowers, and
– The extraction of domestic, livestock and commercial
water.

9. Value of Tank Cascade Ecosystem
Services
• This is only from tank water. How about the
total value of entire ecosystem?

10. Tanks Cascade – A Unique System
to Sri Lanka
1. Over 80% of the small tanks are organized as
cascading systems within micro- and meso-
catchments in the Dry undulating landscape.
2. It addresses natural disasters (drought, flash floods,
cyclones and epidemics)
3. It reduces deforestation, soil erosion, salinity
development, tank sedimentation
4. It enhances biodiversity

11. Why cascade systems again?
1. Drought and flood events can be expected more due to
climate change
2. High prevalence of poverty in tank cascade areas
3. Mal-nutrition can be greatly reduced by tank fishery and
animal husbandry
4. Better land use under cascade principles – addresses
ecological issues such as clearance of village forests,
unsustainable land use etc.
5. Improve living conditions
6. Health issues ? – drinking water, contamination of agro-
chemicals and heavy metals leads to kidney failures, malaria
etc.
7. Most importantly ……….

12. • A rainwater harvesting technology;
• A soil moisture and groundwater maintaining technology;
• A soil erosion and siltation control technology;
• A technology that ensured the maintenance of ecological
balance;
• A technology that promotes social cohesion and needs for
community leadership;
• A system that accommodates spiritual development which
promotes egalitarian (equally treated) attitudes especially during
droughts;
• A system that nurtured the development of drought insurance
through animal husbandry
………It is an answer to drought hazards

13. Distribution of tank
cascades in Sri Lanka
Soils: Mainly RBE and
LHG soils and some on
RYP and IBL
Landscape:
Undulating with
dendritic drainage
pattern
Rainfall: Annual 800-
2000 mm

14. Decline in forest
cover in Tank
cascade system
areas - 1992

15. Decline in forest
cover in Tank
cascade system
areas - 2010

16. CKDu spreads
over all tank
cascade zones

17. Poverty (head
count ratio) is
low to moderate
in Tank cascade
system areas -
2015

19. Regulating Services
Drought – water
storage, reduced
seepage and
evaporation, clean
water
Flood – rainwater
absorption, excess
water drainage,
flow regulatory
mechanism
Cyclone –
gasgommana,
kattakaduwa, tis-
bambe, forest
Epidemics –
malaria, water
purification, waste
recycling

20. Supporting Services
Nutrients – tis-
bambe, gan-goda
landa, mee tree
Habitats–
kattakaduwa,
gasgommana
perahana, wew
thawula

21. Provisioning Services
Cottage
industry –
materials from
kattakaduwa
Consumables – food,
fruits, vegetable from
kattakaduwa,
gasgommana and wewa
Materials – timber, fuel
wood, farm implement,
household implement
Others – medicine,
bio-pesticides,
animal feed

22. Cultural Services
Recreation and
mental and physical
health - Agricultural
landscapes recreational
opportunities
Aesthetic appreciation
and inspiration for
culture, art and design
Spiritual experience and
sense of place - Natural
heritage, spiritual sense of
belonging, traditional
knowledge, and associated
customs.
Tourism -Farm
tourism allowing
urbanites to reconnect
with nature.

23. Human health can be ensured by improving the ecosystem health