The first rains that mark the start of the growing season trigger a wave of activity in rural and farming communities. Farmers decide when to plant, how much labor to allocate, how much resources to devote to this season’s harvest, and so on.
For members of the famine response community, the start of the season (SOS) is also the first indicator of what will happen in the following months. As a result, scientists at UC Santa Barbara worked to use SOS as an early indicator of food insecurity.
Researchers at the university’s Climate Hazards Center (CHC) published a study in Environmental Research Letters linking conditions at the start of the growing season to grain prices in five African countries. This is the second study published by the group analyzing the impacts of SOS, and the results should allow even earlier predictions of a potential famine.
“The onset of the rainy season – its conditions and whether it is early or late – has real predictive power for food security,” said first author Frank Davenport, associate researcher at CHC. The timing of the SOS sends a tangible signal to markets in the region, which researchers can take into consideration when forecasting food security and planning the famine response.
Indeed, the CHC works closely with the Famine Early Warning System Network Team (FEWS NET), which was established by the United States Agency for International Development (USAID), to coordinate humanitarian assistance.
FEWS NET uses several metrics to judge a population’s vulnerability to food insecurity. Food availability and accessibility are two major factors, said co-author Shraddhanand Shukla, also a CHC associate researcher. Food availability is generally correlated with agricultural production (i.e. the quality of the previous harvest). Food accessibility is linked to production as well as to prices and distribution.
“An area can have good production, but if the prices are very high, people will always have less access to food,” said Shukla. In addition, many rural households in sub-Saharan Africa spend much of their time and money feeding their households, so even small fluctuations in grain prices can have large impacts in terms of vulnerability to food. food insecurity.
The team combined standard economic forecasting models with two aspects of the start of the season – how quickly it onset and the amount of precipitation in the first month of the season – to see how they affect the predictive power of the models.
The precipitation data comes from CHIRPS, a precipitation data set developed by the CHC that uses satellite imagery and in situ stations. During this time, the team compiled grain prices from various ministries of agriculture and consumer price indices when available. This was supplemented by data from FEWS NET field scientists who examine grain prices in the markets at regular intervals.
The authors found that SOS data increased the predictive power of models over a six-month window by up to 25% in some cases. The results were better in the East African countries of Ethiopia, Kenya and Somalia than in the South East African countries of Malawi and Mozambique.
Scientists at CHC believe this may be due to a combination of factors. The main reason is that the rainy season is relatively shorter in East Africa than in the west or south. As such, a deviation from the norm sends a stronger signal. “In East Africa when the season starts late you know it’s going to be short,” Davenport said. As a result, each day lost has a stronger effect on production and prices.
Worse yet, the warming of the Indian and Western Pacific Oceans could further shorten this season, due to later onset and earlier cessation of rains. While the causes of the increase in sea surface temperature are unclear, the implications are concerning.
“If the start of the season continues to be delayed and the end of the season remains fixed, there comes a time when the season is so short that crops cannot grow in that time,” said the co -author Will Turner, graduate. research student at CHC. In this case, farmers must choose to invest in a growing season that may not be productive or to find other sources of income.
“In any case, reduced production can lead to reduced food availability, increased market prices and associated reductions in food accessibility,” he added.
In January, the CHC released a paper correlating the start of the season with a measure of greenery or plant growth. The results showed that conditions during the first month of the growing season can provide a reasonable estimate of production levels at harvest time. This study shows that it can also provide a reliable signal on grain prices during the growing season.
A surge in grain prices is in itself a harbinger of food insecurity. As Shukla explained, even if an area has a good harvest, high prices can still restrict access to food. This document allows researchers to use the SOS to provide even earlier indicators of grain prices; because when it comes to famine alleviation and humanitarian aid, the extra time translates into extra lives saved.
“We are always looking for better indicators, and we are always looking for earlier indicators,” Davenport said.
In fact, the team are working on the early season prediction itself, pushing back its advance warning even earlier. This effort, led by Shukla and Turner, aims to use the precipitation forecast to project the start of the season 20 to 40 days in advance.
The center also aims to start integrating SOS into their current forecasting methods within the next year. They are already developing a grain yield forecasting system, which they plan to send out as a regular report. The team also plans to study regions where SOS data has not significantly improved forecasts.
“What excites me about SOS is that it’s very simple and very intuitive,” Davenport said. For example, the start of the season is not influenced by external factors, such as government policy. This simplicity facilitates communication with stakeholders.
And, the start of the season has always been a very tangible event for farming communities. It’s something they always pay attention to. Confirming that its appearance has real effects probably validates what many of these people already knew qualitatively. Now, these results will allow experts to quantify these impacts in a way that makes them more actionable.
Funding for this research came from several sources, including USAID, the NASA SERVIR program, and the US Army Research Office. All opinions, findings and conclusions or recommendations expressed in this document are those of the authors and do not necessarily reflect the position or policy of the government or the developer, and no official endorsement by either party should be inferred.