PRECIPITATION TOTALS AT TWO CZECH METEOROLOGICAL STATIONS AFTER CORRECTION OF SYSTEMATIC ERRORS IN MEASUREMENT
Abstrakt
This contribution presents the results of correcting the systematic errors that accompanied precipitation measurements at the Svratouch and Hradec Králové meteorological stations from 1961 to 1990. The selected stations are located in eastern Bohemia: the Svratouch station is situated 735 metres above sea level, the Hradec station at 270 metres above sea level.
A slightly modified correction procedure constructed by R. Tihlárik was used in this study.
After correction, the yearly precipitation totals recorded at the Svratouch and Hradec stations were greater by 32% and 17% of the original values, respectively. Undervaluation in Central European conditions is more significant in winter - between November and March, the average monthly undervaluation at Svratouch and Hradec reached 58-69% and 31-33%, respectively.
From May to September, the average monthly undervaluation reached 7-17% at both stations. April and October were transitional months.
Corrections in winter are generally indicative; corrections in the summer months are more reliable. According to the results and to literature, we can conclude that there is an undervaluation of at least 5% from May to September and an undervaluation of at least 25% from November to March at most stations in the Czech Republic.
The year-to-year variability in annual and monthly corrected precipitation totals was also studied. The purpose of correcting such data is to provide more accurate precipitation totals, which subsequently provides a more accurate picture of trends in precipitation and of rainfall-runoff relationships.