Determination of Western Mediterranean Basin Flood Discharges by L-moments Method and Flood Frequency Analysis

In this study, annual maximum flow data of 5 stations on the West Mediterranean Basin which are measured by E.I.E.I. were used. Using the data from the selected stations, the flood discharges were calculated regionally by using the L-moment method, and the most appropriate probability density functions (PDF) were determined according to the goodness-of-fit test of Kolmogorov-Smirnov by using Flood Frequency Analysis (FFA). The flood discharges were calculated by using determined PDF. When the calculations are examined, it can be seen that the flood values 50, 100, 1000 and 10000 years return period calculated with the determined PDF are very close to the flood values calculated by the L-moments method except the 809 numbered station. It has been seen that the flood discharges calculated by the L-moments method can be calculated with the same accuracy by using the FFA methods. It is considered that the reason why the calculated values are too big at number 809 gauging station by using FFA is the outliers’ effect and it would be useful to remove the effects of outliers in the calculations for this station