Estimation of Vulnerability and Risk to Meteorological Drought in Mexico

Prolonged droughts severely affect the economic, social, and environmental sectors in Mexico. The interest in reducing the costs of drought is now focused on prevention by means of vulnerability reduction. The present study proposes a methodology to estimate vulnerability and risk to drought, considering the physical, economical, and social factors that make regions of Mexico prone to experiencing hydrological and agricultural droughts. Recognizing that there is no universally accepted way to describe vulnerability, the proposed method defines the object under study, the natural hazard, and vulnerability factors by means of indicators. The vulnerability factors are related to water infrastructure, the condition of aquifers or water reservoirs, the levels of wastewater treatment, water productivity in agriculture, hydraulic infrastructure, and water tariffs. A drought vulnerability model for each Hydrological Administrative Region ( RHA) in Mexico is obtained by combining the vulnerability indicators. The product of vulnerability and hazard results in risk estimates that are compared with impact data to validate the approach. Information on agricultural or hydrological drought is used as impact data. The validation process is an important step in the methodology, since it allows examination of the causes of disasters by the vulnerability factors and leads to risk management strategies. It is found that although vulnerability to meteorological drought in the agricultural and hydrological sectors in Mexico has decreased in recent years, the drought risk is still high and results in severe economic losses, such as those registered in central and northern Mexico during the 2011-12 prolonged drought.