LONG-TERM DYNAMICS OF THE MAIN HYDROMETEOROLOGICAL CHARACTERISTICS OF SPRING FLOOD IN THE DESNA RIVER’S BASIN

Liudmyla Gorbachova, Olga Kolianchuk, Ukrainian Hydrometeorological Institute, Ukraina

Abstract

In the conditions of global and regional climate changes it is very important know their impact on the rivers water regime. Because its formation depends on such climatic factors like temperature, precipitation, evaporation, etc. Redistribution of these factors in space and time causes the changes of the rivers water regime. Therefore, an actual task is to analyze the dynamics of long-term hydrometeorological factors of water runoff. It is especially important have the knowledge about the changes of maximum runoff, because the high floods are the cause of the negative consequences. Such as the flooding of human settlements, the destruction of hydraulic structures, bridges, etc. It bring significant material losses, and often to human victims.
The goal of the research is the analyses of the long-term variations of the hydrometeorological spring flood characteristics in the Desna River basin that will allow to find possible changes in these factors and analyzing the causes of their changes.
Long-term changes the maximum discharges, the maximum water equivalent of snow cover and the dates of their occurring, the precipitation during the spring floods period, the sums of the negative and positive temperatures during the winter period were analyzed for the Desna river basin. For research was used the period from 1947 to 2009. The base of this research is materials of stationary hydrological observations of 6 gauges (Desna-Chernihiv, Desna-Rozlety, Ivotka-Ivot, Snov-Nosivka, Seim-Mutin, Kleven-Sharpivka) and 10 meteorological stations (Bilopillya, Hluhiv, Druzhba, Konotop, Nizhyn, Oster, Pokoshychi, Semenivka, Chernihiv, Schors) on the territory of Ukraine and 2 gauges (Desna - Bryansk, Seim - Rylsk) and 9 meteorological stations (Bogoroditskaya-Fenin, Bryansk, Zhukovka, Kursk, Obojan, Ponyri, Rylsk, Spas-Demensk, Trubchevsk) on the territory of Russian Federation.
Analysis of the long-term variations of hydrometeorological characteristics of the spring floods were carried by the total and difference integral curves, by the statistical criteria of Fisher and Stjudent, and by the statistical significance of linear trends.