The history of rainfall data time-resolution in a wide variety of geographical areas

What is it about?

We present an historical analysis of the temporal evolution of the rainfall recording systems time-resolution based on a large database of rain gauge networks operative in many study areas. Globally, data were collected for 25,423 rain gauge stations across 32 geographic areas, with larger contributions from Australia, USA, Italy and Spain. For very old networks early recordings were manual with coarse time-resolution, typically daily or sometimes monthly. With a few exceptions, mechanical recordings on paper rolls began in the first half of the 20th century, typically with ta of 1 h or 30 min. Digital registrations started only during the last three decades of the 20th century.

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Photo by Darya Kraplak on Unsplash

Photo by Darya Kraplak on Unsplash

Why is it important?

An objective of this paper was to discover and analyze, at global scale, the evolution over the years of the time resolution of rainfall data. Even though the collected outcomes herein do not uniformly cover all geographical areas of the world, they may be considered as representative because the collections involve 25,423 rain gauge stations located in 32 different study areas. This study provides the first database set up for the time-evolution of the temporal aggregation of observed rainfall data. It is extended to a wide variety of geographic areas and, in addition to the historical information on the rainfall data logging: provides the basic elements to perform an improved analysis of extreme rainfalls of different durations using historical series of appropriate length, and allows a more appropriate comparation of the effect of climate change on short-duration heavy rainfall available on a very large scale in a variety of geographic locations. The presented database enables the scientific community to identify stations for which long duration series could become available for appropriate design of some hydraulic structures also with regard to possible effects of climate change. Finally, it could stimulate international cooperation in the light to identify appropriate stations for comparative investigations of the effect of climate change on short-duration heavy rainfalls at different spatial scales.

Perspectives