Climate forecasts indicate that in the following months there could be conditions of the "La Niña" phenomenon, which would cause droughts like those registered in the country at the beginning of 2021, warned the researcher of the Institute of Atmospheric Sciences and Climate Change, Christian Domínguez Sarmiento.
For this reason, she qualified as beneficial the rains of the previous months, which allowed several dams in the country to recover their storage levels. As of October 18, 75 were at 100 percent, 64 had between 75 and 100 percent; another 41 had between 50 and 75 percent, and only three had less than 50 percent, according to reports from the National Water Commission (Conagua). Total storage was 0.9 percent more than the average figure for this date.
In addition, the three main ones of the Cutzamala System-El Bosque, Valle de Bravo, and Villa Victoria-, which supply an important part of the Metropolitan Zone of the Valley of Mexico, were at 69.4 percent. In mid-April 2021, several regions of the country near the border with the United States presented extreme and/or exceptional drought conditions and some dams had "red lights" because they had less than 50 percent of water.
La Niña" conditions produce a lot of evaporation, few clouds and radiation entering directly into Mexican territory.
"Since this October, the World Meteorological Organization declared that we are in 'La Niña' conditions and it is expected, for the following months, that it will develop from moderate to intense, so we could again have drought conditions from the north to the center of the country; the history that occurred in December 2020 and January-April 2021 could be repeated.
"This rainy season (June-October) has been beneficial for the country because we have full dams and we are ready for what awaits us in the following season (December 2021-May 2022); because if we are going to have less precipitation than what is normally expected, we are going to face drought conditions," remarked the researcher from the Department of Atmospheric Sciences.
Some tropical cyclones that made landfall, as well as remnants of the severe storms that occur during the North American Monsoon and other tropical phenomena, allowed this recovery, added the doctor in Earth Sciences. However, maintaining these water levels also depends on the regional management of water resources by decision-makers.
"It can happen that in a region that has 100 percent of the filling of the dam, they release water to lower it to 75 percent," exemplified the specialist who has among her lines of research Tropical Meteorology, Climate Modeling, and Hydrometeorological Risks. She also mentioned that, according to Conagua, it is estimated that 14.2 percent of the national liquid is used for human consumption and 76.7 percent for agriculture and livestock.
La Niña and El Niño
"La Niña" is a very cold sea surface temperature anomalies in the tropical Pacific and is part of a natural phenomenon called El Niño-Southern Oscillation (ENSO). "La Niña" is the negative (cold) phase. Meanwhile, the warm phase is "El Niño", which generates very high temperatures in the Tropical Pacific and also induces wind changes at a global level.
ENSO was discovered in the early 1900s and since then its influence on the world climate has been studied. The interesting thing is to take advantage of the information provided by current climate forecasts so that authorities can make scientifically based decisions on how they will manage water use, to avoid havoc in the lives of people and communities.
It is also up to citizens to make better use of the resource, avoid leaks, and implement technologies that allow them to capture rainwater, such as "water harvesting", which can be used for cleaning.