This paper introduces a systematic but simple approach to classifying and ordering sources of risk faced by subject populations. By distinguishing between the incidence and severity of subjective risk perceptions, this method enhances understanding of the nature and variation of risks faced within a population. We demonstrate the usefulness of the method as applied to pastoralist communities in the arid and semi-arid lands of southern Ethiopia and northern Kenya. This method reveals the considerable heterogeneity of risk exposure and severity that exists within this seemingly homogeneous sector, particularly across strata defined by gender, wealth, and primary economic activity.