| Abstract: | The stability of individual soil aggregates to impacting water drops is now regarded as a fundamental parameter required in any soil erodibility assessment. This stability has been measured by the use of single drop rainfall simulators, the characteristics and operation of which have, in the past, shown considerable variation. The drop sizes, impact frequency, drop fall height, chemistry of drop-forming liquid, aggregate pretreatment, and definition of breakdown affect the way in which the apparatus can be used to define stability. Within this paper each one of these characteristics is considered and a piece of apparatus proposed which is believed to give results with increased consistency and replicability. The described apparatus can be readily reproduced in any laboratory situation, and has the added advantage of being not only appropriate for the measurement of indices of stability, but also of providing an environment in which the mechanisms of aggregate breakdown can be investigated. |
