Light and low-intensity rainfalls: A review of their classification, occurrence, and importance in landsurface, ecological and environmental processes

D. L. Dunkerley

Research output: Contribution to journalReview ArticleResearchpeer-review

Abstract

ver many areas, light rainfalls, those delivering small daily amounts (typically, < 10 mm d−1), and low-intensity rainfalls (typically, < 1 mm h−1), contribute a large proportion of raining time and an important proportion of the annual precipitation. However, light rain is understudied relative to heavy and intense rainfalls whose occurrence and effects are more readily seen and that can result in major damage to infrastructure. For a number of landsurface processes, however, light and low-intensity rainfalls (hereafter LLIRs) are important. This review highlights the non-standardised terminology and classification systems used in the literature on LLIRs, based on daily rainfall amounts or on short-term intensities. Though a series of examples drawn from ecohydrology, plant metabolism, soil erosion, and other fields, the roles of LLIRs are highlighted. From this is it proposed that greater investigation of LLIRs is needed. An additional rationale for more monitoring of LLIRs, still in part a technical challenge in terms of instrumentation suitable for ground observing stations, is that such rainfall appears to exhibit secular change. The direction and rate of change are geographically variable, and may pose challenges for ecosystems adapted to regimes of LLIRs that were the norm prior to the effects of climate change. Tracking such secular change will be aided by more consistent terminology and by improved observation and recording of LLIRs, including the assembly of more climatologies of light and low-intensity rainfall.

Original languageEnglish
Article number103529
Number of pages16
JournalEarth-Science Reviews
Volume214
DOIs
Publication statusPublished - Mar 2021

Keywords

  • Landsurface processes
  • Light rainfall
  • Low-intensity rainfall
  • Secular change

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