CGN5930 Spring 2008, Environmental Hydrologyr

Frequency Analysis of Unsteady Flow

Chapter / Section Title: Flood Frequency Analysis Meth= ods Chapter / Section Number: D.4.3 Resource File: View / Download / Print<= /a> (pdf 209K)

Home work:

Using fo= llowing data to do frequency analysis,

Note: T=3D (n+1)/m, n=3D total number of sample, m is = the mth largest value, T is the return year.

1)Find 100-year flow value = using linear regression

Example of Flow data

2)Analysis using Gum= bel method to predict 100 year flow

2-a) traditional method (textbook method) for parameter estimation

Readin= g : other method in determining Gu= mbel parameters

L-moment= method in parameter estimation (see

Recent Journal paper [1], [2] on = using L-moment method in estimating parameters in Gumbel distribution

Unsteady flow data for HEC-RAS unsteady simulations

Course Review for= Test #1:

1) Cont= inuity equation, 2) Momentum equation.
- · Applicati= ons of HEC-RAS for unsteady flow problems
  - = 1)      Specify unsteady boundary conditions, such as
    
    Upstream time series of fl= ow,
    
    Down stream time series wa= ter elevation, etc
    
            =       2). View model out put to show flood area.
    
            =       3). Design/modify hydraulic design to reduce flood area.
    
            =        4) ability to create culvert section with= deck, and design culvert.
    
            =
    
    
    
    2. Hydrodynamics reference book
    
    hydrodynamics.pdf
    
    3. HEC-RAS homepage
    
    free model package, documents of user manual and appli= cation examples
    
    http://www.hec.usace.army.mil/software/hec-ras/
    
    New features of HEC-RAS
    
    hec-rasnewfeature.pdf<= /p>
    
    HEC-RAS theory :
    
    hecraschap02.pdf
    
    Examples:
    1.        use data from above example 2, recreate river geometry=
      
      hec_create.xls
      
      -Unsteady flow boundary conditions:
      
              = upstream: flood hydrograph,
      
               downstream: water level variations ivan.xls
      
      -hydraulic designs in HEC-RAS
      
      GIS maps, lay= ers:
      
      FDOT
      
      Welcome to the FDOT Planning Offices Web pages -- a si= te for statewide transportation planning in Florida.
      
      htt= p://www.dot.state.fl.us/planning/statistics/gis/default.htm
      
      FDOT PROJECTS AT THE GEOPLAN CENTER
      
      http://www= .geoplan.ufl.edu/projects/fdot/fdotindex.html
      
      Collins Software Houston Texas, 713-682-1556
      
      Providing GIS Web Publishing solutions and GIS Database Migration software utilities
      
      Web Mapping Software
      
      http:/= /www.collinssoftware.com/freegis_by_region.htm#United
      
      Coun= ty Resources
      
      Land surveying and related links for Florida Counties<= /p>
      http://www.floridageomatics.com/common/county.html
      
      Tallahassee-Leon County GIS i= s the Geographic Information Systems (GIS)
      
      http://www.tlcgis.o= rg/
      
      NOAA data website
      
      http://www.n= gdc.noaa.gov/mgg/gdas/gd_designagrid.html
      
      example: