FAMS - Frequency Explorer

Frequency Analysis, Distribution Fitting & Return Period Estimation

Reporting Selection Portfolio

Expert Suggestion

Generalized Log-Logistic (Product-Moments)

Adopted

Generalized Log-Logistic (Product-Moments)

#1

Hydrologic Benchmark Check

Selected 100-Yr Event
328.992mm
Conservative Benchmark
310.142mm (TCEV)
Benchmark Delta:+18.851 mm (+6.1%)
⚠ Sensitivity Gap

Input Profile & Distribution Analysis

36 Sample YearsCV: 0.34
Station Peak:309.6 mm

Expert Advice

Excellent selection. The statistically superior Log-Logistic (PM) distribution provides a highly reliable basis for hydrologic frequency reporting.

Report Branding

Time Series Data

36 valid points

Statistics

n (sample size)36
Mean (x̄)148.497
Std Deviation (σ)50.379
Coefficient of Variation0.339
Skewness (γ₁)0.935
Excess Kurtosis (γ₂)1.187
Minimum72.930
Median141.200
Maximum309.610

Input Data Profiler

Samples
Mean (x̄)
Median (m)
Std Dev (±σ)

Frequency Curve

Goodness of Fit(Click row to select)

Ranked by Combined Score
RankPos
ModelDistribution
K-S(D)
Chi-Sq(χ²)
ScoreAvg. Rank
#1Log-Logistic (PM)0.06842.50001.28
#2Gamma (PM)0.09363.27781.69
#3TCEV (MLE)0.07074.05562.06
#4Gumbel (PM)0.07354.05562.06
#5Log-Normal (PM)0.07454.05562.07
#6GEV (LM)0.07784.05562.07
#7GEV (PM)0.07794.05562.07
#8Log-Pearson III (PM)0.07914.05562.07
#9Normal (PM)0.13874.05562.10
#10Pearson III (PM)0.07654.83332.45
#11Exponential (PM)0.12255.22222.67

Frequency Table

Return PeriodProb (%)Rainfall (mm)Lower 95%Upper 95%
500.000.2%443.68399.27488.10
200.000.5%374.33336.46412.20
100.001.0%328.99296.08361.91
50.002.0%288.87260.91316.83
20.005.0%242.46221.04263.87
10.0010.0%211.17194.71227.63
5.0020.0%181.76170.26193.27
2.0050.0%140.66135.71145.62
1.2580.0%108.86107.26110.45
1.1190.0%93.7092.9594.45
1.0595.0%81.6181.2481.98
1.0199.0%60.1460.0760.21

Model Comparison

Detailed Comparison Matrix
Return PeriodLog-Logistic (PM) (Active)Gamma (PM) TCEV (MLE) Gumbel (PM) Log-Normal (PM) GEV (LM) GEV (PM) Log-Pearson III (PM) Normal (PM) Pearson III (PM) Exponential (PM)
500.00 yr443.68335.08374.85369.90369.32356.80354.59358.84293.50350.56411.20
200.00 yr374.33309.88338.05333.85333.70325.90324.05326.34278.27321.39365.04
100.00 yr328.99290.01310.14306.52306.92301.78300.21301.59265.70298.64330.12
50.00 yr288.87269.24282.13279.09280.10276.95275.66276.54251.96275.13295.20
20.00 yr242.46239.89244.76242.49244.21242.82241.90242.54231.36242.46249.04
10.00 yr211.17215.61215.89214.22216.20215.65215.01215.63213.06215.98214.12
5.00 yr181.76188.40185.80184.74186.54186.56186.21186.74190.90187.04179.20
2.00 yr140.66142.84140.34140.22140.66141.10141.18141.22148.50140.76133.04
1.25 yr108.86105.32106.56107.13106.07106.07106.47106.20106.10105.50109.36
1.11 yr93.7088.6992.2093.0691.5290.8691.3991.3083.9391.04103.43
1.05 yr81.6176.4181.6582.7381.0279.5580.1780.4865.6380.97100.70
1.01 yr60.1456.7064.4165.8464.4760.8461.6263.3531.3066.1398.62