Rain Gauge Data Quality May Hinder Confident Detection of Secular Changes in Rainfall Rates – A Key Aspect of the Evolving Global Water Cycle
Year: 2025
Type: preprint
Abstract: There is a wide diversity of methods by which rainfall arrival at the surface of the Earth can be measured and recorded. Among these are methods that provide extensive spatial geographical coverage, including radar-based, satellite-based, and other remotely-sensed approaches. However, these rely on assessments of their accuracy that rely on more direct observation at the surface. Rain gauges remain the dominant tool for point observations. Secular changes in rainfall arrival are of great potential significance in the study of the terrestrial water cycle, notably possible intensification at various timescales - daily, hourly, and particularly sub-hourly. Intensification may result in changes to the magnitude of surface runoff relative to initial losses or to infiltration, with consequent effects on urban flash flooding and related hazards. It is argued here that there are both well-known and little-known limitations to gauge data, that bear in particular on the confident detection of secular changes in short-term rainfall intensities, and in the correct identification of trends toward increasing intensity or declining intensity, both of which have been identified in published studies of regional secular rainfall change. This paper seeks to highlight some of these important data quality issues arising from the collection of 'ground-truth' point rainfall observations.
Source: Preprints.org
Author: David Dunkerley
Institution: Monash University
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4412148034