6th International Disaster and Risk Conference IDRC 2016 Integrative Risk Management - Towards Resilient Cities. 28 August - 01 September 2016 in Davos, Switzerland

1. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Community Based Early Warning System for Landslides:
the Case of 04 Gramaniladhari Divisions of Matale District, Sri Lanka
Menake Wijesinghe.
Janathakshan (GTE) Limited,
Sri Lanka,

2. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Landslides in Sri Lanka
• Land Area: km2 65,610,: Population 20,359,439 (2015) density 325/km2. Increased 5,512,689
(37.1%) since 1981 AGR 1.1%.
• Nearly 1/5 of the area is prone to landslides with many hundreds of identified landslide
locations
• Triggered by to hydro-meteorological (two monsoonal rains from South West and North East
and inter-monsoonal rains (non seismic factors)
• Induced by manmade factors such as water management and deforestation; cutting failure is
common
• Vulnerability increased due to land use and inappropriate development measures

3. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Need of a community based landslide EW system
• Annually number of effected is increasing –
Immediate actions needed to save lives
• structural mitigation or relocation of people
– long term measures
• Risk assessment and early warning
• Landslides are isolated events specifically
dependent on unique geo-physical factors of
a given point
• Hence centrally decided EW is least affective
• Local system would be precise method of
risk information decision making
Landslide affected people 1980-2015
Structural mitigation:-
Geo engineering and research
Slope stability and landslide stability
Structural stability for buildings
Relocation of vulnerable communities
Long term (many years) of planning and
funds in millions
Finding suitable lands
Socio economic ‘benefits’ supporting the
risk culture

4. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Risk reduction through community based early
waning
Geographic
vulnerability
(hazard)
Socio economic
vulnerability
• Poverty – not access to
safe lands
• Social bounds
• Education for youth
• Lads used for
livelihoods/economic
benefits
Relocation
Planed rural
and urban
settlements
Preparedness planning with effective Early Warning
-
Communities
living with
landslide risk
Low risk perception
Structural
mitigation
Risk reduction

5. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Method: Introducing a simple early warning method
Instructions for observers
Level 01: Alert: height 75mm to 100mm (colour: green). If
the water level reach 50mm within 24 hours and if the rain
continues
Level 02: Warning: be ready to evacuate if water level
reaches risky level
Height 100 mm to 150mm (colour: yellow) if the water
level passes 100mm within 24 hours and if the rain continues
Level 03: Evacuate for safety
Height 150 mm and above (colour: red) if the water level
passes 150mm within 24 hours and continues to rise or within
one hour water collection is 75mm and if rain continues
• Clusters of houses were using single rain gauge
• Awareness on placing maintenance and observing the rain
gauge was given
• Clusters were parts of an early warning system
• Houses in the clusters were aware of evacuation (how, when
and where to)
Portable plastic rain
gauge – easy to use and
maintain, least cost

6. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Method: preparedness and evacuation exercise
Assumptions when developing the
CBEW
1. Key houses will disseminate the
message to surrounding houses and
the surrounding houses will be in
touch with the key house expecting
a message
2. All houses will participate in the
exercise (given number of cards will
reach the evacuation center)
Findings
People were aware of the evacuation
system and found out that within a fair
amount of time they could reach the
evacuation center
Communities were thorough with the
system and could practice the same in
actual incidences
Community organization for early warning

7. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Findings
1. Arrangement of houses in early warning system established in sample communities
Being a part of EW system Key house Peripheral house
Alugumale 3 7
Kandemada 6 18
Punchi Rattota 5 30
Kandegedara 8 54
2. Preparedness for post landslide early warning action
Evacuation route
and site identified
Member of Early
Warning Cluster
Evacuation
practiced through
drills
Used the system
of EW in real
situations
Number of
households
131 131 117 121
% of households 100.00 100.00 81.68 92.37
3. Experience in evacuation using the EW systems
GN Division Alugumale Kandemada Punchi Rattota Kandegedara
Dates of Evacuation Oct-2010 Oct-2010 Nov-2010 Oct-2010
Jan-2011 Jan-2011 Jan-2011 Jan-2011
Nov-20 13 Nov-2013 Nov- 13 Nov-20 13

8. 6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
In brief …
Technology
• The CBEW system could be developed to provide more specific information by considering
some geophysical factors (soil type, bearing capacity, slope stability and angle and land use
pattern)
- the threshold levels of the portable rain gauge could be adjusted as per local
requirements; a technical tool for calculation could be developed
• Such method could be practically applied together with other supportive risk reduction
methods (hazard mapping, providing appropriate meteorological information etc.)
Policy and development planning
• Structural mitigation and relocation are two best options -but are practically impossible for
many landslide prone communities (due to economy of costs and complex socio-cultural
issues)
• Communities have socioeconomic benefits of being in a risk culture
• Threat from landslides are increasing (especially towards poor communities living in
vulnerable lands) and immediate solution is needed
• Families in sample communities have identified their roles in the community based early
warning systems and to evacuate to pre-identified places following a warning .
• Communities have practiced the early warning system in several occasions; ownership is with
the community