Drought app seeks to measure, help predict trends for agri sector

When the peanut industry returned to Northeast Arkansas in 2010, the rationale for the companies investing in buying points was simple. Disease and a lack of water ravaged many parts of Georgia, Oklahoma and other peanut-producing states.

A decade and a half later peanuts are still among the thriving row crops that dominate Arkansas’ agricultural fields, but a new and persistent problem is brewing — consistent droughts.

The region was mired in drought two of the last three years, and long-term projections along the Mississippi River indicate that drought is likely to be a problem for the next several decades due to climate change, according to the National Weather Service.

A new tool is being developed to help producers and other stakeholders understand how the problem is developing in the Natural State. Arkansas Agricultural Experiment Station researchers analyzed drought dynamics during a five-year period to assess the short- and long-term climate trends in the state using satellite imagery.

Hamdi Zurqani, an assistant professor of geospatial science for the College of Forestry, Agriculture and Natural Resources and the Arkansas Forest Resources Center at the University of Arkansas at Monticello (UAM), developed the Arkansas Vegetation Drought Explorer v.2.0 as part of a drought mapping study. The app gives users access to maps showing drought levels in Arkansas by county, year and month.

“One of the reasons we did this study was that there is no state climatologist and no state climate office in the state of Arkansas,” Zurqani said. “This kind of data set can show the trend. For example, if you select from 2000 to 2024 within sub ranking, you can see what’s going on within that specific region to determine what you may expect next year because we predict the future on the past.”

The data and combined interactive map provide an essential foundation for policymakers, environmental scientists, and agricultural stakeholders looking to mitigate drought impacts and safeguard against future climate uncertainties, Zurqani said.

“Overall, the study and the associated app have the potential to significantly improve drought management, water resource planning and climate change adaptation in Arkansas and other regions facing similar challenges,” Zurqani said. 

The Arkansas Water Resources Center, a part of the University of Arkansas System Division of Agriculture, funded the study through the U.S. Geological Survey program with matching funds provided by the Division of Agriculture and the UAM. The experiment station is the research arm of the Division of Agriculture.

The Arkansas Vegetation Drought Explorer leverages MODIS satellite imagery to display drought severity across Arkansas. Users can select county and timeframes for which they want to observe, and the app generates drought severity maps based on Vegetation Health Index. The index is a metric that combines satellite-based observations of vegetation conditions and temperature. Healthier vegetation reflects more sunlight, while stressed or drought-affected plants reflect less, indicating potential drought conditions.

By analyzing the patterns over time, the index can distinguish between normal and drought-affected areas, with the color-coded map displaying levels of severity — ranging from green for healthy vegetation to red for extreme drought. This allows users to track how drought conditions evolve and impact vegetation health across Arkansas.

Zurqani said it was essential to keep in mind that using spatial distribution maps to evaluate droughts may only reveal general trends. Short-term meteorological data shows more frequent droughts, while long-term trends suggest possible improvement in some areas, researchers found.

Arkansas experiences a higher frequency of droughts during March and August. Droughts are most frequent in eastern and southern Arkansas, especially in the Mississippi River Alluvial Plain. Flash droughts strongly affect vegetation, with agricultural lands and grasslands being the most vulnerable. A flash drought includes a sharp decline in soil moisture below its normal conditions in the first 16 days, decreasing to its minimum within 24 days.

Zurqani and his team noted increasing drought conditions in agricultural land across time scales of 14 to 180 days. Other land cover types exhibited similar trends, with drier short-term conditions and wetter long-term spans. However, they saw progressively wetter conditions over two to five years.

“As we look at drought trends across different time scales, we see an interesting contrast,” Zurqani said. “In the short term — over periods of 14 to 180 days — we observe increasing drought stress in agricultural areas, as well as other land cover types. This is largely due to immediate factors such as crop needs and seasonal weather patterns.

“When we extend the time frame to two to five years, many regions, especially in areas like the southwest part of the state, show a trend toward wetter conditions, which suggests that these ecosystems have the capacity to recover and balance out over time,” he said. 

While droughts may be more frequent in the short run, there is evidence that longer-term climate cycles can bring about improvements, offering some relief to the land and the communities that rely on it, he noted. In simple terms, Zurqani said, the state’s short-term drought signals can often be severe and widespread. Still, there’s evidence that longer-term patterns could bring some areas back into balance.

The research suggests that even areas with seemingly abundant rainfall can experience drought events, particularly during periods of below-average precipitation or when evaporation rates exceed precipitation. Zurqani said this threat has increased in recent years.

Arkansas experienced varying levels of drought throughout the years 2000 to 2022. March typically saw the most widespread drought conditions, with around 32% of the state’s land mass impacted, including 1% and 12% experiencing severe and moderate drought, respectively. November and October showed relief with the least drought activity.

The most intense drought period was in the southeastern and northeastern regions in December, with 15% of the area experiencing mild drought, 8% having moderate drought, and 2% facing severe drought. Severe drought conditions were seen in 14 counties. The U.S. Drought Monitor also observed a trend of increasing drought in the northern and eastern regions of the state.

During mid-December the Monitor indicated that all of the counties in eastern Arkansas were in some form of drought. While Chicot County in the southeast suffered the most, with 10% of its area experiencing extreme drought, Garland County in the southwest quadrant saw the highest concentration of extreme drought within a single county, reaching 18%.