Assessment of change in drought risk influenced by water management

Disaster risks are the results of complex spatiotemporal interactions between risk components, impacts and societal response. In the context of the water supply chain, human processes have altered hydrological processes through the construction of reservoirs to dispose of the water resources with higher predictability and productivity. While reservoirs may attenuate flood events and help to bridge through period of water scarcity, they may also aggravate drought events in terms of duration and severity. The long-term effect associated to the presence of reservoirs is an over-reliance on the water supply hypothesized as constant and abundant as provided by the hydraulic structure, which in turn increases the vulnerability and the economic damage in case of a drought event occurrence. In addition, socio-economic and political changes should not be underestimated, as the social, economic, and political context can influence the impact and response to extreme events. Indeed, it has been observed that during long periods of drought, variations in exposure and in vulnerability have occurred, due to social dynamics taking place as a result of the extreme event, e.g. the natural migration of the population to water sources.
Here we aim at understanding the changes in risk components and the resulting impacts of structural measures, such as reservoirs, and also of nature based solutions in relation to consecutive extreme events. Different case studies around the world are considered to untangle the complexity of the dynamic relationship between human and hydrological processes.