Book of Abstracts and Contributed Papers ,
Pages: 37-38,
https://doi.org/10.69646/aob260907
2nd International Meeting on Building Bridges Between Climate Science and Society Through a Transdisciplinary Network
Published by: Scientific Society Isaac Newton Belgrade

Modern climatology produces a large amount of data, while society experiences climate through concrete impacts: when it rains, how long the dry season lasts, and whether the water comes all at once or evenly. Simple quantitative metrics can bridge this gap. This study proposes four complementary indices describing precipitation concentration, seasonality and climatic continentality - PCI (Oliver), SI (Walsh and Lawler), PCD/PCP (Zhang), and Shver K - for monthly precipitation from Babušnica (485 m) and Sofia (550 m) for 1961-2020. Both stations show a moderate-seasonal regime. Babušnica: mean 675.5 mm, PCI 11.38, SI 0.47, PCD vector 0.17, PCP 195° (July), K 52.9%. Sofia: 597.5 mm, PCI 11.72, SI 0.50, PCD 0.22, K 60.1% - more continental. Comparing 1961-1990 vs 1991-2020, annual totals remain stable (Babušnica 674.3→676.8 mm; Sofia 576.3→616.1 mm). Concentration trends diverge: Babušnica shows a slight increase (PCI 11.34→11.43, SI 0.46→0.47) with a 14° shift of PCP to late May (188°→202°); Sofia shows a slight decrease (PCI 11.86→11.62, SI 0.51→0.49, PCD 0.24→0.20). These indices translate directly into societal information: adjustments to the sowing calendar, irrigation needs, and seasonal water storage. They provide a visual, understandable tool for agriculture, water management, and transboundary early warning and more.