FEMA 480 Exam LATEST VERSION COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+

FEMA 480 Exam LATEST VERSION COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+ Watershed - Answer- Also termed basin or catchment area. Area that drains into body of water. Channels - Answer- Features on ground that carry water through and out of watershed. Ex. Rivers, creeks, streams, ditches Riverine flooding - Answer- Flooding occurring along the channel. Too much water caused overflow to banks and flood plains Topography flooding - Answer- - flat area: may remain covered with shallow, slow-moving floodwater for days to weeks - hilly/mountainous areas: flooding can happen minutes after rain — flash flooding prone 3 major flood catagories - Answer- 1. Riverine 2. Coastal 3. Shallow Overbank flooding - Answer- Most common flooding in US. Occurs when downstream is blocked or inundated with larger amounts of water. Overloaded channels and flow into floodplain Measures of floods - Answer- Velocity (ft/sec) Regional flood warnings - Answer- - downstream in larger watershed warning can be given hours-days before - mountainous regions may have little to no warning Flood depth and duration - Answer- Larger the river the deeper the flooding and longer likelihood of lasting - hilly regions can still pose deep flooding even tho smaller order streams Flash floods - Answer- - Regions with steep slopes and narrow stream valleys are more prone. - banks of small tributary streams more vulnerable -impervious surface on urban areas escalated flash flooding -dam failures, release of ice-jams and collapse of debris dams increase likelihood - #1 cause of flood related deaths in US Riverine erosion - Answer- -Channel banks and bottoms (Thalweg) receive more force in flooding with inc vel Features of river affected by flow - Answer- 1. Meander (channel curve) : outsides more prone to erosion with insides receiving more sediment deposits Coastal flooding - Answer- Receive added hazards of coastal storms, coastal erosion, and in pacific and Caribbean, tsunamis. Hurricanes and severe storms are main sources of flooding (like noreasterns) Sandy coastal flood plains more unstable. Storms at high tide cause more flooding than low tide. Wind and waves influence dunes, bluffs, and barrier islands Coastal erosion - Answer- Long-term is natural process, shaping shorelines Natural influences: sand sources, sand size and density changes in water level, effects of waves, current, tides, wind — factors influence likelihood of shorelines recede or accrete Human influences: construction of groins or sea walls, dredging of channels, sandbags — alters natural transport of sand storm surge - Answer- Persistent high wind and changes in air pressure push water toward shore. Raises level large water body by several feet. Waves moving inland can be highly destructive. Tsunamis - Answer- Also called tidal wave Caused by underwater earthquakes or volcanos Pressure wave raising waters up to 15 ft Open ocean has more depth and therefore less energy and lift— closer to shore allows compression of energy and more lift Occur in pacific and can flood Caribbean Lake flooding - Answer- Similar to coastal flooding — severe stores produce waves and shoreline erosion Shallow Flooding - Answer- Happen in flat areas with lack of channels for drainage Three catagories: 1. Sheet flow 2. Ponding 3. Urban drainage sheet flow - Answer- Somewhat uniform depth of shallow flooding Occur post intense/prolonged rainfall when ground can not soak