Over 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.

在许多地区，轻降雨，日降水量少（通常<10 mm d ^-1）和低强度降雨（通常<1 mm h ^-1）），造成很大一部分下雨时间和很大一部分年降水量。但是，相对于强降雨和强降雨而言，小雨的研究不足，后者的发生和影响更容易看到，并且可能对基础设施造成重大破坏。但是，对于许多地面过程而言，轻而低强度的降雨（以下简称LLIR）很重要。这篇综述着重介绍了基于每日降雨量或短期强度的关于LLIR的非标准化术语和分类系统。尽管从生态水文学，植物新陈代谢，土壤侵蚀和其他领域获得了一系列实例，但突出了LLIR的作用。因此建议需要对LLIR进行更大的研究。进一步监测LLIR的另一个理由，就适用于地面观测站的仪器而言，技术上的一项挑战仍然是，这种降雨似乎表现出长期变化。变化的方向和变化率在地理上是可变的，并且可能对适应于LLIR体制的生态系统构成挑战，而LLIR体制是气候变化影响之前的标准。更加一致的术语以及对LLIR的改进观察和记录，包括对更多气候的轻度和低强度降雨的组合，将有助于跟踪此类长期变化。并可能对适应于LLIR体制的生态系统构成挑战，而LLIR体制是气候变化影响之前的标准。更加一致的术语以及对LLIR的改进观察和记录，包括对更多气候的轻度和低强度降雨的组合，将有助于跟踪此类长期变化。并可能对适应于LLIR体制的生态系统构成挑战，而LLIR体制是气候变化影响之前的标准。更加一致的术语以及对LLIR的改进观察和记录，包括对更多气候的轻度和低强度降雨的组合，将有助于跟踪此类长期变化。