Hydrological drought assessment of the Tisza river

Abstract

: Drought is a natural phenomenon that occurs when the availability of water is significantly below the normal levels during a shorter or longer period of time and cannot meet the necessary demand. This study focused on hydrological drought assessment of the Tisza River on four gauging stations: Vásárosnamény, Szolnok, Szeged, and Senta for the period 1964–2018. An effective Streamflow Drought Index ( SDI ) has been recently proposed and widely used for determining hydrological droughts. Both long- and short-term droughts have very severe impacts on the investigated locations. Two drought periods can be singled out: the first period was from 1983 to 1993, with the exceptions in 1985 and 1987. This period is characterized by higher absolute SDI values on Vásárosnamény (–0.84) and Szolnok (–0.87) than on Szeged (–0.29) and Senta (–0.40) stations. The second period was more severe and lasted from 2011 to 2015, with an average SDI value of –1.32 on Vásárosnamény, –1.08 on Szolnok, –0.53 on Szeged, and –0.57 on Senta station. The Mann-Kendall test results indicate that there is no trend indicating transition from humid towards more arid condition over the investigated period.