METHOD OF SPATIAL PREDICTION THE DATES OF STARTING AND PASSING THE MAXIMUM WATER DISCHARGE OF SPRING FLOODS

Abstract

Introduction. The problem of long-term and prognostic assessment of the terms of spring floods on rivers is relevant in hydrological investigations. Due to climate warming, the flood tides shifted to early dates or the beginning of the calendar year. The purpose is to analyze the long-term passage of spring floods and to carry out their spatial mapping forecasting on the Dnieper (within Ukraine). Methods. Investigation of the dynamics of long-term changes in the timing of spring floods and the use of the forecast method based on the meteorological forecast of ten-day air temperature in the winter-spring season in the Dnieper basin. Results. The method of forecasting the dates of starting and passing the maximum water discharge (levels) is based on the regional equations of the forecast scheme and allows to make a preliminary estimation of flood terms each year, regardless of the availability of meteorological observations. Assessment of the forecasting methodology allows to recommend it as a consultation, and the earliness of forecast varies depending on the geographical location of the catchments and the current weather conditions of a particular spring. Conclusion. The methodology was implemented on the example of spring floods 2017-2018. The overall forecasts were satisfactory, but the quality of the forecasts was affected by the non-simultaneous terms of the spring flood formation in the Dnieper basin. The prognostic probabilities of the dates of spring flood allow characterizing the frequency of their occurrence over many years. On the example of the 2017-2018 spring flood, the rivers of the Dnieper basin found that, in a changing climate, floods can be shifted to earlier and later ones.