Regional Frequency Analysis of Extreme Precipitation in the Huaihe River Basin, China

Extreme precipitation often results in the flooding events, which is a kind of serious natural disasters with huge losses of life and economy. Based on the extreme precipitation series (annual maximum precipitation series) of 30 stations for the period 1960-2011 in the Huaihe River Basin, regional frequency analysis using L-moments method of extreme precipitation are undertaken. The stationarity and independence test are carried out prior to the frequency analysis. Specially, the independent and identically distributed (i.i.d.) test is applied to check whether the data in the same homogeneous region is i.i.d.. Finally, the spatial structure of the extreme precipitation in the Huaihe River Basin is analyzed through the Shannon entropy method. The extreme rainfall series at 30 stations can be considered as stationary and independent series via Mann-Kendall test and autocorrelation coefficient test. The Huaihe River Basin is categorized into three homogenous regions. The extreme precipitation series in all homogeneous regions pass the i.i.d. test. Generalized Extreme Value (GEV) distribution is the optimal distribution for homogeneous region I and III, and for homogeneous region II Generalized Logistic (GLO) distribution is the best-fit distribution. The quantile estimates become less accurate when the return period is large. The extreme precipitation in the Huaihe River Basin doesn't possess the obvious longitude and latitude zonality and the relationship between entropy and longitude, latitude is complex according to the Shannon entropy analysis.