Novel approach to quantifying long-term rainfall distribution variation

Abstract

The impacts of climate change on rainfall and flood regimes worldwide are increasingly evident, necessitating a deeper understanding and the development of more robust methodologies to understand and address these challenges. This paper introduces a new, novel framework for understanding how rainfall distributions are changing through time, enabling more accurate flood risk analysis. The framework offers two complementary approaches to comparing rainfall distributions, the first of these utilises a benchmark distribution to compare against whereas the second highlights a moving benchmark approach. The case study region of Europe is used to highlight the capability of both frameworks to capture different forms of rainfall distribution shift. The first approach reveals rainfall distributions have intensified since 1940 with the strongest intensification in Northern and Western Europe. The second unveils large shifts in rainfall variability across both Western and Eastern Europe during the 1960–1980 period. The suggested frameworks do not rely on fitting statistical distributions, enabling both long and short term change identification. This flexible nature provides opportunity to use this approach across a variety of domains, not least extreme weather evaluation. In this paper we have shown the approach offers flood risk managers a new solution to understanding local, regional, and global rainfall variability and quantification.