Design Rainfall: A New Slovak Publication on Extreme Precipitation

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A fascinating history of rainfall measurement

The opening chapter (by D. Výberči) is a historical gem. Readers learn that systematic rainfall measurements in present-day Slovakia date back to the mid-19th century, with the core rain gauge network built in the late 1800s as part of flood protection programmes under the Austro-Hungarian monarchy. The evolution of instruments is equally compelling — from old Austrian bayonet-type gauges through Hellmann instruments to today's automatic weather stations that form the backbone of the Slovak Hydrometeorological Institute's (SHMÚ) operational network.

Statistical foundations of extreme rainfall

Chapters 2 and 3 provide a rigorous yet accessible overview of statistical methods for extreme value analysis. The authors cover classical approaches (Gumbel, GEV, Pearson Type III), maximum likelihood estimation, L-moment methods, and Bayesian inference.

Particularly valuable is the section on the areal reduction factor (ARF), which addresses the conversion of point measurements to areal totals for catchments of various sizes. The authors derive ARFs from the COSMO-REA6 reanalysis — a methodologically innovative approach. Also noteworthy are the sections on synthetic rainfall models and the Scott-Neumann rainfall generator.

Gridded design rainfall maps from COSMO-REA6

Chapter 4 presents a rich set of gridded design rainfall maps for the entire territory of Slovakia, derived from the COSMO-REA6 reanalysis at ~6 km resolution. The maps cover various combinations of return periods (2, 5, 10, 20, 50, 100 years) and rainfall durations (from 1 hour to 72 hours). These are complemented by tabular annexes for individual municipalities.

Regional frequency analysis using L-moments

Chapters 5 and 7 are devoted to regional frequency analysis (RFA) — an approach that trades temporal information for spatial information. The authors employ L-moments and the Hosking & Wallis methodology to identify homogeneous regions and select appropriate distribution functions. Special attention is given to multi-day totals (Rx2D and Rx5D), where climatologically distinct regions of Slovakia are clearly delineated.

Climate change and extreme precipitation

Chapter 6 explores the impact of climate change on extreme precipitation using EURO-CORDEX regional climate model simulations. The authors examine projected changes in short-duration extremes under RCP4.5 and RCP8.5 scenarios, finding notable increases in extreme rainfall intensity across most of Slovakia by the end of the 21st century.

Who should read this book?

This publication is an essential reference for:

• Hydrologists and water engineers designing drainage, retention, and flood protection systems
• Urban planners implementing blue-green infrastructure solutions
• Climatologists working on extreme precipitation and regional climate projections
• Students and academics in hydrology, meteorology, and environmental engineering
• Municipal authorities developing climate adaptation strategies