Climate Change and Inland Flood Risk in Jamaica

1. PROJECT FUNDED BY CLIMATE DEVELOPMENT KNOWLEDGE NETWORK (CDKN) AND
MANAGED BY CARIBSAVE.
PRINCIPAL INVESTIGATOR : ARPITA MANDAL
LECTURER, DEPARTMENT OF GEOGRAPHY AND GEOLOGY
UNIVERSITY OF THE WEST INDIES, MONA CAMPUS,
KINGSTON, JAMAICA
arpita.mandal@uwimona.edu.jm
CLIMATE CHANGE AND INLAND FLOODING IN JAMAICA – RISK AND
ADAPTATION MEASURES FOR VULNERABLE COMMUNITIES

2. Outline
OBJECTIVES
OUPUTS
STATUS OF KNOWLEDGE PRODUCTS
COMMUNICATION STRATEGY FOR THE PROJECT

3. Specific Project Objectives
The specific objectives of the project are :
To provide a historic overview of the frequency and severity of flooding for the
watersheds under study.
Assess local knowledge, attitudes and practice (KAP) of project communities towards
climate change, increase KAP towards climate change, and institute climate change into
the curriculum of basic and primary schools.
Create downscaled regional climate projections (medium and long term) for the
watersheds of Yallahs and South Negril Orange river using PRECIS Regional Climate
Model.
Creation of flood hazard maps for Yallahs (St Thomas) and South Negril-Orange river
(Westmoreland, Negril) watersheds using HEC and LISFLOOD-FP models. Maps created
for specific storms and 100 yr rainfall event.
Dissemination of results through community workshops, television and radio interviews
and through publication in peer reviewed academic journals.

4. Study Areas
Flood
model
domain
Buildings

5. Outputs
44%
41%
14%
0%
10%
20%
30%
40%
50%
Hurricanes Tropical
Storms
Tropical
Depressions
PERCENTAGEOF
OCCURRENCE
Rainfall and
Hurricanes
show a high R2
with flood
events.
R2= 0.70
R2= 0.73

6. Hazard Evaluation
Categorical
Variables Continuous Variables Binary Variables
ArcGIS Spatial Analyst and
SPSS Statistical Software

7. Tropical Storm Gustav: Results
Maximum flood depth
(m)
HEC-HMS
15-minute
rainfall
LISFLOOD-FP
Generation of flow data for upstream
input and subcatchment inflows
Routing of flood wave along main channel
and across floodplain
1.PASTFLOODEVENT2.RETURNPERIODANALYSIS3.FUTURECLIMATEANALYSISSUMMARYINTRODUCTION
YALLAHS
NEGRIL

8. Topographically
constrained
flooding
Estimation of current 100yr flood depth maps
2.RETURNPERIODANALYSIS1.PASTFLOODEVENT3.FUTURECLIMATEANALYSISSUMMARYINTRODUCTION

9. INTRODUCTION1.PASTFLOODEVENT2.RETURNPERIODANALYSIS4.FUTURECLIMATEANALYSISSUMMARY3.STORMSURGEANALYSIS
Future annual exceedance
probability, surge/ SLR
(high)
Present annual
exceedance probability,
surge
• Buildings at risk:
substantially more affected in
future rainfall/ SLR scenario
• Greatest hazard for buildings
is along the coast
Buildings: probability of inundation Hazard to buildings
Future 100-yr,
surge + SLR (high)
Haz = Depth *
(Velocity+1.5)
(DEFRA, 2003)
Estimation of future flood risk: results

10. Estimation of future flood risk: results
Present annual
exceedance probability
2070-2099 annual
exceedance probability
(ECHAM, B1)
No reduction in
inundation risk
in valley
Lower risk
downstream
Maps of exceedance probability:
Green: 4% (25 year return period)
Blue: 2% (50 year return period)
Red: 1% (100 year return period)
3.FUTURECLIMATEANALYSIS2.RETURNPERIODANALYSIS1.PASTFLOODEVENTSUMMARYINTRODUCTION

11. OUTPUTS

12. STATUS OF KNOWLEDGE PRODUCTS
FLOOD HAZARD MAPS FOR PRESENT AND FUTURE : TO BE REFINED
WITH ONGOING CALIBRATION OF THE MODEL.
CLIMATE PROJECTIONS AND DOWNSCALING HAS BEEN REFINED
AND FINAL MODEL IS IN PROGRESS.
PUBLICATIONS IN PROGRESS.

13. COMMUNICATION STRATEGY FOR THE PROJECT
UPLOAD OF FINAL MAPS THROUGH GEONODE – OPEN SOURCE WEB
PLATFORM : http://cariska.mona.edu
•STAKEHOLDER WORKSHOP CONDUCTED IN MAY 2014
•TRAINING ON FLOOD MODELS CONDUCTED IN MAY 2014
•COMMUNITY MEETINGS AND RADIO TELECAST