Estimation, trend detection and temporal changes in maximum annual flow volume series of the Hron River in Slovakia

Abstract

The floods characterized by the volume exceedance probabilities and return periods with specific T-year flows may assist in enhancing the accuracy of local flood frequency estimates, and support the detection and interpretation of any changes in flood occurrence and their magnitudes. Therefore, the present paper deals with the trend detection and with temporal changes in the maximum flows volume series of the Hron River at Banská Bystrica and at Brehy gauging stations in Slovakia during the 90 years. The period 1931–2020 mean daily flows of the waves belong to the maximum annual flows and the series of maximum annual flows of the Hron River at Banská Bystrica and at Brehy gauging stations were used as input data. Subsequently the annual maximum runoff volumes with t-day duration were calculated. The Log-Pearson distribution type III were used to determine the T-year values of the maximum runoff volumes with t-day duration. The results indicated that there are decreasing linear trends in maximum annual runoff volumes with some duration of the flow.