Asce 7 10 Chapter 30 Pdf Creator
Within This Page • • • • • • • Flooding is the overflow of excess water from a water body onto adjacent lands. FEMA more specifically defines a flood as a general and temporary condition of partial or complete inundation of normally dry land areas from (1) the overflow of inland or tidal waters or (2) the unusual and rapid accumulation or runoff of surface waters from any source.
One or more water bodies can contribute to flooding at a given site—a river, stream, ocean, bay, lake, pond, storm water retention/detention area, etc.—depending on local topography and hydraulic/hydrologic conditions. Flooding can damage buildings and their contents in many ways, but the most common flood damages arise from: • direct damage during a flood from inundation, high velocity flow, waves, erosion, sedimentation and/or flood-borne debris, • degradation of building materials, either during the flood or sometime after the flood, and • contamination of the building due to flood-borne substances. The likelihood and impacts of these damages can be minimized through the use of siting, design, construction and maintenance practices appropriate to floodplain areas. In the United States, these practices are based largely on the and its regulations governing land management and use (). The Special Flood Hazard Area is the area known as the 100–year floodplain, or the area subject to flooding during the Base Flood. The Base Flood Elevation (BFE) is the water surface elevation associated with the 100–yr flood, and has a one-percent chance of being equaled or exceeded in any year. The SFHA is more precisely defined as the floodplain associated with a flood that has a 1–percent annual chance of being equaled or exceeded in any given year.
ASCE 7: Minimum Design Loads for Buildings and Other.
Therefore the SFHA is not associated with a flood event that happens once in a hundred years, it is associated with a flood event that has a one percent chance of occurring each and every year. The SFHA is usually divided into flood hazard zones beginning with the letter 'A' or 'V' (see Flood Hazard Zone Table): • 'V' zones are those areas within a coastal floodplain where high velocity wave action can occur during the Base Flood. • 'A' zones are those areas within the 100–yr floodplain where high velocity wave action is not expected during the Base Flood. 'A' zones can be mapped in inland or coastal floodplains. 'V' zones are mapped exclusively in coastal floodplains.
The most hazardous floodplain areas will generally be close to coastal shorelines (zone V, also called the coastal high hazard area—CHHA), floodways (areas closest to the centerline of major streams and rivers—see illustration below), and alluvial fans. Special siting and design restrictions and requirements exist for each of these areas. NFIP Flood Hazard Zones Special Flood Hazard Area (SFHA) Zone A The 100–year or base floodplain. There are seven types of A Zones: A The base floodplain mapped by approximate methods, i.e., BFEs are not determined.
This is often called an unnumbered A Zone or an approximate A Zone. A1–30 These are known as numbered A Zones (e.g., A7 or A14). This is the base floodplain where the FIRM shows a BFE (old format). AE The base floodplain where base flood elevations are provided. AE Zones are now used on new format FIRMs instead of A1–A30 Zones.
AO The base floodplain with sheet flow, ponding, or shallow flooding. Base flood depths (feet above ground) are provided. Download torrent nero 9 ita + crack.
AH Shallow flooding base floodplain. BFEs are provided. A99 Area to be protected from base flood by levees or Federal Flood Protection Systems under construction. BFEs are not determined. AR The base floodplain that results from the decertification of a previously accredited flood protection system that is in the process of being restored to provide a 100–year or greater level of flood protection. Zone V and VE Zone V The coastal area subject to a velocity hazard (wave action) where BFEs are not determined on the FIRM.