Flood Risk and Vulnerability Analysis Project - Atlantic Climate ...

TABLE OF CONTENTS
PAGE
EXECUTIVE SUMMARY .............................................................................................................................. II
SUMMARY .................................................................................................................................................... II
RECOMMENDATION SUMMARY ............................................................................................................... X
1. OVERVIEW ...................................................................................................................................... 1
1.1 Project Objectives ............................................................................................................... 1
1.2 Definitions ........................................................................................................................... 2
2. TASK B – UPDATED FLOOD EVENTS INVENTORY ................................................................... 5
2.1 Data Sources ...................................................................................................................... 5
2.2 Description of Inventory Data .............................................................................................. 8
2.3 Data Summaries ............................................................................................................... 12
2.3.1 Cost of Floods ...................................................................................................... 12
2.3.2 Weather Events - Annual Occurrence ................................................................. 17
2.3.3 Storm Events - Seasonal and Monthly Occurrence ............................................. 19
2.3.4 Causes of Flooding .............................................................................................. 22
2.3.5 Flooded Communities .......................................................................................... 23
2.4 Summary ........................................................................................................................... 27
2.5 Recommendations for Update of the Flood Events Inventory .......................................... 29
3. TASK C – ASSESS EXISTING FLOOD RISK MAPS .................................................................. 31
3.1 C1 – Compile GIS Base Maps .......................................................................................... 32
3.1.1 Digitization of Flood Plain Data ............................................................................ 32
3.2 C2 – Delineate Community Flood Watersheds ................................................................. 33
3.3 C3 - Land Cover Classification ......................................................................................... 34
3.3.1 Introduction .......................................................................................................... 34
3.3.2 Imagery and Data Sources .................................................................................. 34
3.3.3 Land Cover Classification .................................................................................... 38
3.3.4 Results ................................................................................................................. 42
3.3.5 Recommendations for Remote Sensing and Land Cover Classification ............. 47
3.4 C4 – Assess Climate Change Impacts ............................................................................. 47
3.4.1 Introduction .......................................................................................................... 47
3.4.2 Intensity Duration Frequency (IDF) Curves ......................................................... 57
3.4.3 Hurricanes and Tropical Storms .......................................................................... 59
3.4.4 Sea Level Rise ..................................................................................................... 70
3.4.5 Ocean Currents and Oscillations ......................................................................... 73
3.4.6 Worst Case Scenario Analysis ............................................................................. 79
3.4.7 Summary and Conclusions .................................................................................. 88
3.4.8 Recommendations for Assessment of Climate Change Impacts ........................ 92
3.4.9 Acknowledgements .............................................................................................. 93
4. TASK D – ASSESS NEED FOR NEW / UPDATED FLOOD RISK MAPPING ............................ 94
4.1 Prioritization Parameters ................................................................................................... 94
4.1.1 Age of flood study ................................................................................................ 94
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