Author(s): V. V. Ilinich; T. D. Larina
Linked Author(s): Vitaly Ilinich
Keywords: No keywords
Abstract: Every dam of water reservoir must be projected in respect to catastrophic flood of normative probability exceeding relative to maximum of water discharge and volume of flood. Some water reservoirs are located on the small river basin. Usually we not have ranks observations for the runoff on small rivers. Consequently there are different models and formulas for determination of flood characteristics in dependence on storm rainfall. Different probabilistic quintiles of maximum daily precipitation are used in the models and formulas. Some researchers have written hypothesis about increase of maximum daily precipitation (Groisman2005, Dore 2005, Wilks 1999). However we must have very long time series of observation relative to daily precipitation for the checking of the hypothesis. The research was dedicated to the checking of such hypothesis. Several problems were solved in the work: selection of meteorological stations which have very long time series of observation the daily rainfall; the forming statistical ranks for different discrete values of precipitation and assessment their trends; determination of the main statistical characteristics relative to the formed ranks and evaluation of their changes in the time; evaluation of the changes in the time of frequencies of appearance dangerous storm rainfalls; evaluation of the changes in the time of probabilistic quantiles of maximum daily precipitation in the frames of concrete distributions of random values. The results have showed that maximums of daily precipitations are increasing during the time on majority of researched meteorological stations.