Original scientific paper

Proposal of a new drought analysis method

Ognjen Bonacci orcid.org/0000-0002-7123-3421 ; Sveučilište u Splitu, Fakultet građevinarstva, arhitekture i geodezije, Split, Hrvatska
Duje Bonacci orcid.org/0000-0002-8168-1367 ; Sveučilište u Zagrebu, Fakultet hrvatskih studija

Abstract

The key factor in drought occurrence and intensity in any environment are quantities of precipitationthat are lower than the average. Additionally, drought phenomenon is stronglyaffected by air temperature - the higher it is than the average temperature value in a certain period of the year, the more severe are the adverse consequences of drought.In this period of climate change,whose most pronounced manifestation is increased air temperature, this key climatological parameter should be, indeed, included in the calculation of drought index. If included, it can, combined
with precipitation, determine the integrated drought index that is applicable to analyses of any kind of drought. The paper presents a newdrought analysis method using standardised values of precipitation and mean air temperature in a certain period. The standardised value is calculated by subtracting the average valuein the observed periodfrom each individual measured value of precipitation and temperature in a time interval (month, season, year, etc.), and then dividing this value with the standard deviation in that interval. The new drought index (NDI) is calculated by subtracting the value ofstandardised temperature from the value of standardised precipitation. The NDI values were analysed for series of monthly and annual precipitation quantities and mean monthly and annual air temperatures measured at the stations Split-Marjan and Zagreb-Grič in the 1948-2020 period. The calculated NDI values indicate that drought hazard has been significantly intensifying in the past decades, which can be linked to the effects of global warming. The months most affected by droughts are those in the warm part of the year, i.e. from April to August in Zagreb and from June to August in Split.

Keywords

drought, air temperature, New Drought Index (NDI), Mann-Kendall test, Split-Marjan, Zagreb-Grič

Hrčak ID:

275758

URI

https://hrcak.srce.hr/275758

Publication date:

30.3.2022.

Article data in other languages: croatian german

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