Flood Forecasting and Hazard Mapping in Jamaica
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Thematic Session “Integrated Flood Risk Management Through Appropriate Knowledge Sharing And Capacity Building Systems” Kobe, Japan January 20, 2004 Flood Forecasting and Hazard Mapping in Jamaica Presenter Andreas Haiduk Water Resources Authority Jamaica 1 Content • The cause and nature of flooding • Flood warning systems/Hazard mapping as risk reduction instruments. • Lessons Learned • Way forward 2/2/2005 2 Jamaica located; 161 km (100 miles) south of Cuba Latitude 17o42′ and 18o31′ N Longitude 76o10′ and 78o22′ W. 2/2/2005 3 Cause of Flooding 9 Jamaica prone to flooding Flood prone areas 9 Topography Housing areas /geology determines the 'W$T'W'W $T $T nature of $T$T 'W'W 'W'W'W'W'W 'W'W 'W$T $T $T$T$T $T'W'W'W'W'W'W$T'W$T 'W 'W'W'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W $T $T $T 'W'W $T 'W$T'W$T 'W 'W'W'W'W'W'W'W 'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W $T flooding 'W$T$T'W$T$T $T $T 'W'W'W'W'W'W'W'W'W'W'W 'W'W'W $T $T $T$T$T'W$T$T $T 'W $T 'W'W'W'W'W 'W'W'W'W'W'W 'W $T$T 'W'W'W$T $T$T$T $T$T$T$T'W $T $T 'W 'W'W'W'W 'W'W $T$T 9 Climate also 'W'W$T'W'W$T$T$T'W$T'W$T'W$T$T$T$T$T$T $T $T$T 'W 'W'W 'W'W'W 'W 'W$T$T$T$T$T$T 'W$T 'W$T'W $T$T$T$T$T$T$T $T $T $T 'W'W 'W $T$T$T $T$T$T $T $T'W 'W$T$T$T 'W'W'W'W'W'W'W 'W 'W'W'W'W'W'W'W'W'W'W $T impacts 'W$T 'W'W'W'W 'W'W'W'W'W'W'W 'W 'W $T$T 'W$T 'W$T$T'W'W$T 'W'W $T $T'W'W$T 'W'W 'W'W'W'W'W'W'W'W'W'W'W'W 'W 'W'W 'W'W$T $T'W'W'W$T'W'W$T $T 'W 'W $T 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W 'W$T$T 9 Man’s impact 'W'W'W 'W $T'W'W'W'W'W'W'W 'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W 'W 'W'W 'W'W'W'W'W'W'W'W'W 'W'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W$T'W'W'W'W'W'W$T'W'W'W$T'W'W'W$T'W$T$T $T $T$T $T 'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W$T$T $T'W'W'W'W$T 'W$T$T'W$T'W'W'W'W$T'W'W$T $T$T aggravate the 'W'W 'W 'W'W'W'W'W'W'W'W 'W'W'W'W'W$T 'W 'W'W'W'W$T 'W'W $T$T'W$T 'W$T'W$T$T$T$T'W$T 'W'W $T $T 'W'W'W'W$T'W'W'W 'W'W$T'W'W'W'W'W'W'W flooding $T$T$T$T$T'W$T'W'W$T$T$T$T$T $T$T$T 2/2/2005 4 Nature of the flooding • Groundwater induced • Depression • Riverine • Storm Surge • Urban Runoff 2/2/2005 5 Minimising the Flood Risk What is the Jamaican Experience ? 2/2/2005 6 Existing early warning systems in Jamaica 1992-NF 1999-D 1993-F 1992-year established NF- not functioning F- functioning D-development stage 2/2/2005 7 Future Early Warning Systems Pencar River 2/2/2005 8 Cave River 2/2/2005 9 Flood Forecast table 2/2/2005 10 Flood Forecasting 20 Rainfall 18 Stage Hydrograph 16 14 12 Flood Stage 10 8 Potential additional 6 Warning time 4 2 0 Preparedness Flood Flooding Recovery Preparedness plan plan Recognition Warning time at stage 2/2/2005 11 Community Based Early Warning Systems in Jamaica FLOOD GAUGES Blue = Watch mode Orange = Alert mode Red = Critical 2/2/2005 12 Value FEWS to Community Communities Reliability Loss Is System Reduction still being used Rio Rivoli 97% yes 97% yes 100% Cobre Thompson 93% yes 100% yes 98% Pen Cave River (Aenon 44% yes 28% yes 60% yes Town) 16% no 39% no 6% no ODPEM Field Survey February 2004 2/2/2005 13 RECOMMENDATIONS Get local govt involved and designate a Lead Agency Revive communication process within communities Improve equipment and monitoring Institute annual drills Upgrade /Maintenance of systems Dedicated Budget Strengthen institutional capacity 2/2/2005 14 Flood Plain Mapping •Flood plain mapping Project, WMO 1980s •Hydrologic Support Unit Project UNDP 1990s •Community Disaster based management Projects UNDP, USAID, DIPECHO, 2000s - to date 1 6 1 Rio Grande 3 2 Yallahs River 4 2 3Hope River 5 4Rio Cobre 5 Rio Minho 6 Black River 2/2/2005 15 Overview of the Mapping Process ArcView ArcView Input Data Flood DEM plain maps HEC-RAS HEC-HMS Water Flood surface discharge profiles Rio Cobre Flood Plain Map 2/2/2005 17 Problems with usage 1. No guidelines for their interpretation and use. 2. No national standard for regulatory flood 3. No national guideline prohibiting/permitting flood plain uses. 4. No national standard for the level of protection – depth/or flow velocity 5. Very limited number of flood plain maps available. 6. No flood zoning done - hence need for rigorous analysis to assess cumulative impacts 2/2/2005 18 Legislative Amendments •Amendment of the Water Resources Act 1995 •Repeal of the Floodwater Control Act 1958 The Water Resources (Amendment) Act, 2003 has been drafted. - Floodwater Control Areas - Floodwater Control Plans for those areas. Flood Control Policy to be implemented (regulatory flood, usage regulation, zoning, etc) 2/2/2005 19 THE END THANK YOU FOR YOUR ATTENTION 2/2/2005 20.