ANALYSIS OF THE CHANGE OF PRECIPITATION WITH SHORT DURATION IN MACEDONIA

Abstract

The change in precipitation has a direct impact on people’s lives at different levels. For example, an increase rainfall can cause floods and / or landslides that affect individual homes, cities, and even entire countries. Floods cannot be prevented or accurately predicted, but effective mitigation measures based on their occurrence estimates can significantly reduce their impact. All models for estimating floods are based on precipitation analysis, with special emphasis on short-term precipitation, which is often the cause of catastrophically large floods. Knowing the changes in rainfall over a long period of time guarantees a better prognosis of floods and timely taking appropriate measures to mitigate or to some extent prevent them. Hence, access to up-to-date / new and accurate short-term precipitation data is essential. However, such key data are often unavailable in different parts of the world due to the lack of sufficient measuring stations, but also in the case of raw data. In R.N. Macedonia in practice is still used data on heavy rainfall for the period from 1956 to 1988. The need to update this information with more recent data is more than necessary, given that rainfall is an extremely stochastic phenomenon. The subject of this paper is updating the precipitation data in Macedonia for the period from 1956 to 2020. The changes of precipitation in the last 30 years in eight measuring stations have been analysed. Existing series for annual maximum precipitation with short duration for the period from 1956-1988, are supplemented with data for precipitation from 1989 to 2020. The procedure of processing pluviographic tapes in order to define the annual maximum precipitation of a certain duration have been done by the method of characteristic (transitional) points or the method of five-minute period of discretization (Dt = 5min). The obtained series are statistically analysed, a homogeneity test is performed and the i-D-p (intensity-duration-probability of occurrence) curves are defined. The results are presented in tabular and graphical form.