Recovering the Italian daily hydrological measurements with a citizen science approach

The availability of long and reliable records of hydrological data is essential for hydrological analyses, especially under climate change. In Italy the collection of hydrological data has been managed at the national level by the National Hydrological and Mareographic Service (SIMN) since early 1900. The dismantlement of the SIMN, that occurred about 30 years ago, resulted in data collection being transferred to the regional level. This change has determined problems in the availability of complete series for the whole country. Historical hydrological measurements are usually available only in the printed version of the Hydrological Yearbooks and limited efforts have been spent to digitize this collection. This lack of information is critical in a nation like Italy, with both a complex geomorphology and a changing climate. Despite the remarkable improvements achieved in recent years by Optical Character Recognition software and machine learning / artificial intelligence techniques, in several cases the most accurate digitization approach is still based on manual transcription. Within the SIREN (Saving Italian hydRological mEasuremeNts) project we aim to digitize these data by crowd-sourcing the recovery of hydrological measurements from historical Hydrological Yearbooks to produce a consistent dataset. Phase 1 of the SIREN project will be devoted to recover more than 17000 annual tables of daily discharge measurements. This considerable amount of data not only will allow us to better understand the climate of the past century but will also serve to inform models whose objective is to estimate how the climate and the hydrological cycle will change in the future.