Effects of droughts on health: Diagnosis, repercussion, and adaptation in vulnerable regions under climate change. Challenges for future research.

There is little doubt about the effects of drought events on human health in the present climate. Projections of climate change indicate an increase in the occurrence and severity of droughts in the 21st century in a number of regions, thus it is likely that these types of hydrological extremes could have more of an impact if appropriate adaptation measures are not taken. The majority of studies on the effects of drought are focused on meteorological, agricultural, or hydrological contexts, but there are rather fewer assessments of the impacts of droughts on health. In particular, there have been hardly any attempts to compare different drought indices in order to identify and quantify the impacts of drought on health systems. In addition, rather better knowledge is needed on the mechanisms of vulnerability involved. In this paper, we attempt to describe the complexity of drought phenomena and the difficulty involved in quantifying the health risks linked to their occurrence. From an international perspective, we provide a brief review of the harmful effects of droughts on health in the context of climate change, as well as the vulnerability factors related to droughts. We make an assessment of aspects that have not yet been investigated, or which require further attention to be devoted to this topic. The principal aim of this paper is therefore to draw attention to the need to consider closely the relationship between drought indices and human health, in order to achieve a more fundamental understanding, and to propose specific courses or lines of action for future years, which could eventually be of use to healthcare providers and services.