A large part of the Mexican Republic suffers periods of drought that threaten productive activities such as agriculture and livestock and put food security at risk. Academics from the Center for Research in Food and Development (CIAD) explain what we can expect in this regard.

Climate change or a cyclical issue?

Arturo Ruiz Luna, research professor at CIAD's Mazatlán Coordination, explained that, without a doubt, drought or water shortage, as well as torrential storms, represent two extremes that pose risks to productive activities that are the livelihood of a large part of the Mexican population. These phenomena are recurrent, that is, they occur with a certain periodicity, although not always in a cyclical manner. In most of the planet, he pointed out, the dry season or summer and the rainy season have had more or less defined periods that have been repeated seasonally for thousands of years, and due to this climatic stability, many populations and civilizations could flourish.

However, he added, some of these patterns are changing due to human influence on the climate and other processes occurring in both the atmosphere and the oceans. Thus, phenomena such as extreme droughts, which used to occur occasionally, have become more frequent.

The head of CIAD's Environmental Management Laboratory commented that, in the case of Mexico, some historical sources refer to the existence of important droughts since the 16th century, but the records are more reliable from the second half of the 19th century, reporting, in most cases, loss of crops and livestock. In the 20th century, the droughts recorded were numerous and this, in part, led to the construction of dams as a strategy to combat them.

Currently, droughts cause significant damage to the agricultural industry, tourism, and the population in general, by reducing the availability of drinking water, said Ruiz Luna. "Unfortunately, global warming, rising sea levels, and changes in land use are causing this type of phenomena to become more frequent and extensive, favoring other environmental risks, such as forest fires, which to date cannot be accurately predicted due to their multivariable nature".

What are the effects of the drought?

The CIAD academic, who is an expert in landscape ecology, aquatic resources, and ecosystem diversity, considers that it is not easy or reliable to make forecasts on the duration of the drought, nor is it easy to delimit the scope of its impact. "Based on recent events, for example, in California, USA, the 2011-2012 drought generated losses of billions of dollars, while the loss of more than 17,000 jobs is assumed, he said.

In the most recently documented case in Mexico, 2011 and 2012, some of the data reported mention more than 1,200 municipalities in 19 states affected to varying degrees by the phenomenon. There were also more than 1,500 communities without drinking water, with close to two and a half million inhabitants. It was also estimated that between 600,000 and 2,700,000 hectares of crops were lost, mainly corn and beans, putting food sovereignty at risk.

"It should be considered that, even when the drought is followed by a regular rainy season, the water deficit may prevail, so rainfall alone will not guarantee immediate recovery from the effects of the drought," warned the researcher.

What can science do to mitigate these effects?

Although so far it is not possible to forecast the occurrence of droughts with a good level of reliability, it seems that great advances are being made in the modeling of this type of phenomenon, which could contribute to the generation of local strategies to mitigate the effects, said Ruiz Luna. Likewise, the rehabilitation and restoration of disturbed terrestrial environments and all the efforts made to contain the rise in ambient temperature will undoubtedly reduce the impacts of droughts.

From academia, the participation of researchers in the identification of the causes and patterns that define droughts, their trends, and their possible impact, will help to refine the mechanisms that, from the government and the communities themselves, exist or can be structured to fight against this phenomenon proactively, with a preventive character and not only in reaction to it.

For her part, Jaqueline García Hernández, a researcher at CIAD's Guaymas Coordination, shared that, to mitigate the effects of drought on agriculture and livestock, rainwater capture technologies can be used to help make the best possible use of the little rainwater.

"One option is the use of borders that retain water from streams for a longer time, another is the use of special plows, such as the "Yeomans" type, which store a greater amount of water for a longer time, generating moisture for crops or pasture for livestock," explained the head of the Environmental Sciences Laboratory at CIAD.