Review article

Analysis of daily, monthly and annual precipitation at the Zagreb-Grič observatory (1862 -2017) for purposes of engineering hydrology

Ognjen Bonacci orcid.org/0000-0002-7123-3421 ; Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Split, Croatia
Tanja Roje-Bonacci orcid.org/0000-0002-1751-0045 ; Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Split, Croatia

Abstract

The paper conducts the analysis of daily, monthly and annual precipitation quantities measured at the Zagreb-Grič observatory in the period from 1862 to 2017, which comprises of: (1) 156 years; (2) 1,872 moths and (3) 56,979 days. The analysis uses the following methods: (1) the linear and non-linear regression; (2) linear and nonlinear correlation; (3) log-normal distribution curves; (4) Kolmogorov–Smirnov test; (5) Mann-Kendall test; (6) RAPS method; (7) t-test; (8) F-test. The annual precipitation ranges from 520.8 mm (2011) to 1387.4 mm (1937), with an average value of 886.7 mm. The maximum monthly precipitation occurring in each individual year ranges from 85.3 mm (June 2011) to 267.5 mm (October 1895), with the average value of 158.1 mm. The maximum daily precipitation occurring in each individual year ranges from 21.7 mm (14 November 1949) to 118.8 mm (9 August 1926), with the average value of 47.6 mm. The maximum daily precipitation of 118.8 mm equates to a return period of over five thousand years. The presence of a statistically significant upward or downward trend in the annual or monthly (expect in October) precipitation series as well as maximum daily precipitation in a year or a month cannot be confirmed. The presence of a statistically significant difference in the precipitation quantities has been determined only for October, and comprises of two sub-periods: (1) 1862-1941 and (2) 1942-2017. In the first sub-period, the average monthly precipitation quantity equalled 105.1 mm whereas in the second sub-period it decreased by 29 mm and equalled 76.1 mm. According to the analyses conducted in this paper, it can be concluded that the precipitation of different time durations measured in the period from 1862 – 2017 at the Zagreb-Grič observatory showed no significant impact of either the climate change or urbanisation.

Keywords

precipitation; Zagreb-Grič; log-normal distribution; Mann-Kendall test; Kolmogorov–Smirnov test; RAPS method

Hrčak ID:

219890

URI

https://hrcak.srce.hr/219890

Publication date:

8.4.2019.

Article data in other languages: croatian

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