Color Me Dry: Drought Maps Blend Art and Science — But No Politics

100+ Indicators Simeral says authors look at more than 100 indicators, ranging from precipitation data and snowpack levels, to soil moisture, stream flows and “vegetative health” (including satellite data that looks at “greenness”).
Apart from the rotating authors, there are about 450 contributors from various government agencies, who collaborate on the weekly maps.
“In the end it’s my judgment call as an author whether to make the changes or not, on the map.” The next week, it’ll be up to the next author in the rotation.
Critics Abound The Drought Monitor has its critics, including Jay Lund, co-founder of the Center for Watershed Sciences at UC Davis, who has called it “misleading.” In his California Water Blog, he writes: The US Drought Monitor is a common drought indicator, based mostly on soil moisture – designed mostly to indicate drought for rain-fed agriculture.
“We hear them all the time,” he says, and counters that Lund’s assertion that the Monitor is “based mostly on soil moisture,” is simply incorrect.
Simeral says the authors take all types of drought into account.
The California Challenge “California poses a challenge for a single map such as the drought monitor,” admits state climatologist Micheal Anderson, who is part of the regional focus group that advises the national authors.
Consequently, Anderson says the California map could lag behind conditions going into a drought.
Simeral says the authors hear from many with perceived stakes in the map, such as local water agencies that don’t want to alarm customers.
Simeral says that none of these political concerns influence the authors.

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