Scientists with the United States Drought Monitor define drought as a moisture deficit bad enough to have social, environmental, or economic effects. Because water is a critical resource for life, drought has multiple effects. For example, social effects of drought can include decreases in human health and increases in conflicts between groups about water use. Environmental effects include damage to fish and wildlife habitat and decreased water quality due to erosion. Economic impacts include crop losses, which lead to increased food prices.
Because of the hazards caused by drought, a team of scientists produces weekly maps giving snapshots of current drought conditions across the United States (http://droughtmonitor.unl.edu). Data from these weekly maps are available from January 2000 to the present. In this study, data from the US Drought Monitor help determine if there are patterns of spring drought from 2010-2020 in six states, each in a different climate region of the United States.
Scientists from the National Drought Mitigation Center at the University of Nebraska Lincoln, the US Department of Agriculture, and the National Oceanic and Atmospheric Administration (NOAA) produce weekly U.S. Drought Monitor maps like the one shown here. Maps are based on local reports from more than 350 expert observers and data from five key indicators:
Based on these data, scientists classify land into six categories, ranging from no drought to exceptional drought. Darker colors on the map represent more extreme drought.
The dataset below uses data from the US Drought Monitor maps and shows the percent of each state that was in moderate to exceptional drought at the start of spring (March 31) in each year from 2010 until 2020. The United States is a very large country, so the climate in different regions varies widely. To look for large-scale patterns in drought, this dataset includes data for one state in six of the nine US Climate Regions, as defined by the NOAA National Center for Environmental Information: Northern Rockies (Montana), Southwest (New Mexico), Upper Midwest (Wisconsin), South (Mississippi), Northeast (New York), and Southeast (Florida).
CODAP is a free educational software for data analysis, a product of The Concord Consortium (https://concord.org) and funded by NSF grants.