The chapter by Steinemann, Hayes, and Cavalcanti in the first edition of Drought and Water Crises: Science, Technology, and Management Issues covered the topic of drought triggers well, and that particular chapter remains one of the best descriptions of triggers available. As defined in Chapter 8, triggers are "specific values of an indicator or index that initiate and/or terminate" responses or management actions by decision makers based upon existing guidelines or plans. Triggers remain a challenge within drought early warning information because, as already described, the link between drought severity and impact levels remains difficult to quantify. As more information about drought severity and impacts becomes available, as well as the linkage between the two, the development of triggers will become less challenging. Triggers must be tailored to the local context, and as local characteristics change, triggers must also be adaptable to adjust to these changing vulnerabilities, for better or worse, as mitigation actions can ultimately help reduce risk to future droughts. Decision makers are slowly adopting more triggers into management actions. The USDA, for example, uses the USDM product as a trigger for multiple drought disaster relief programs for agricultural producers.