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HYDROLOGY

HYDROLOGY. Source: map drawn my M.W. Brown. Source: Taylors historic map of New Orleans. London ave canal. Orleans canal. 17 th canal. Source: Times Picayune. 1965 Proposed levee protection system. Expected to take 10-15yrs to complete pre-katrina. Now expected to be finished in 2015.

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HYDROLOGY

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  1. HYDROLOGY

  2. Source: map drawn my M.W. Brown

  3. Source: Taylors historic map of New Orleans

  4. London ave canal Orleans canal 17th canal Source: Times Picayune

  5. 1965 Proposed levee protection system Expected to take 10-15yrs to complete pre-katrina Now expected to be finished in 2015 Image from Times-Picayune

  6. Flooding from hurricane Betsy in 1965 Pontchartrain park was inundated pontilly Source: USACE 1965

  7. Source: FEMA

  8. Aquents, dredged Allemands Muck, drained Schriever Clay Cancienne Silt Loam Urban Land Soil Types Concerns associated with these types of soil: ~ Subsidence ~ Flooding ~ Depth to Saturation Zone ~ Shrink-Swell Source: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx

  9. Soil Texture ~ Soil texture influences water-retention and water-transmission traits ~ Clay soils have the finest texture and the smallest sized particles (graded to less than 0.002mm) ~ Finest texture soils are often found in backswamp areas 53-75% Clay (finest) 37-52% Clay <30% Clay (coarsest) N/A Sources: Map - Campanella, Particle size - Christopherson

  10. Water Table Depth ~ The depth of the water table is important in determining the ability of soil to absorb surface waters ~ The water table affects the footing type of built structures (i.e. high water table = no basement) 0-2 feet below the surface 1-3 feet below the surface 1.5-4 feet below the surface N/A Source: Campanella

  11. Organic Content of Soil ~ Soil rich in organic matter is prevalent in frequently water saturated, low lying areas ~ In the presence of oxygen bacteria decompose this organic material, which can lead to considerable subsidence >55% Organic Matter 2-13% Organic Matter N/A Source: Campanella

  12. Subsidence Causes of shrinking (sinking) soil: ~ draining water leads to decomposition of organic matter ~ consolidation of particles, a non-reversible process ~ surface load -10 to -29mm -8 to -9.9mm -6.3-7.9mm -5.5 to -6.29mm -5.1 to – 5.49mm -4.7 to -5 -4 to -4.69 -3.1 to -3.9 -1.8 to -3 -1.79 to 10.3 mm Source: Adapted from Dixon

  13. Source ListCampanella, Richard. 2006. Geographies of New Orleans: Urban Fabrics Before the Storm.Christopherson, Robert. 2006. Geosystems: an Introduction to Physical Geography. Dixon, Timothy H. Nature, vol 441, pps 587-588, 1 June 2006. U.S. Department of Agriculture Natural Resource Conservation Service Web Soil Surveyhttp://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx

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