Flood Flow Frequency Analysis 1-6-2009

Operating systemsOS : Windows / Linux / Mac OS / Solaris
Program licensingScript Licensing : Other Free / Open Source License
CreatedCreated : Jan 23, 2009
Size downloadDownloads : 25
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It uses a Log Pearson Type-3 distribution for ...

It uses a Log Pearson Type-3 distribution for estimating quantiles.
NaN need to be removed in the dataset. If any years have missing data, it will still assume to include that year as part of the sample size-- as stipulated in 17B guidelines. An exmaple MAT file is provided for the user to test.
A nice enhancement to this function is a plot of the analyses. It is plotted in probability space-- SKEWED probability space! Because data may not be normally distributed, plotting in skewed space maintains a straight line for the final frequency curve.
Usage
Syntax:
[dataout skews pp XS SS hp] = b17(datain, gg, imgfile)
Input:
datain = Nx2 double
datain(:, 1) = year or datenum
datain(:, 2) = peak annual flow rate
gg = a generalized weighted skew
imgfile = full path and file name to export the figure
Output:
(is in the form of a N x 6 double, and all flows are in Log10)
dataout(:, 1) = Return Period (in years)
dataout(:, 2) = Probability
dataout(:, 3) = Final Frequency curve
dataout(:, 4) = upper CI frequency curve
dataout(:, 5) = lower CI frequency curve
dataout(:, 6) = Expected Probability (N-1)
skews(1) = Station Skew
skews(2) = Station Skew outliers, zero removed
skews(3) = Synthetic Skew
skews(4) = Weight adjusted skew
pp(:, 1) = gringorten plotting position
pp(:, 2) = weibull plotting position
pp(:, 3) = observations
XS = mean of Log10(Flow rates)
SS = standard deviation Log10(flow rates)
hp = historically adjusted weibull plotting position where historical peaks our high outliers are ranked in integer values (e. g. 1, 2, 3, etc. ) and systematic observations are adjusted.
Most important functions of Flood Flow Frequency Analysis by Jeff Burkey:
• estimates of a final frequency (based on a weighted skew)
• confidence intervals (95%) for the final frequency
• expected frequency curve based on an adjusted conditional probability
• observed data with computed plotting positions using Gringorten and Weibull techniques
• various Skews
• mean of log10(Q)
• standard deviation of log10(Q)
• a probability plot that does not require a toolbox to create, but also plots the probability space using the computed weighted skew and not just the normal probability
Demands:
• MATLAB 7. 7 (R2008b)

Flood Flow Frequency Analysis 1-6-2009 scripting tags: annual extremes, flood frequency, curve, flow estimation, probability, flood flow frequency analysis, skews, dataout, space, plotting. What is new in Flood Flow Frequency Analysis 1-6-2009 software script? - Unable to find Flood Flow Frequency Analysis 1-6-2009 news. What is improvements are expecting? Newly-made Flood Flow Frequency Analysis 1-6-2009.1 will be downloaded from here. You may download directly. Please write the reviews of the Flood Flow Frequency Analysis. License limitations are unspecified.