South Dakota's current debate about whether the long drought in the state has ended underscores the difficulty climatologists face in making that call, a South Dakota State University scientist said.
"With drought it's very difficult to define beginning and ending, unlike a flood, hurricane, tornado or similar weather event," SDSU Extension state climatologist Dennis Todey said in a news release. "Drought differs in definition across the range of people affected."
The main national determination of drought currently is the U.S. Drought Monitor, online at http://www.drought.unl.edu/dm. This weekly map uses short-term and long-term measurements of precipitation, combined with soil moisture assessments, and subjective input to determine a single drought level for all locations in the country.
"Combining all effects into one number is easy for most people to understand, but also loses some of the complexity of drought, too, by minimizing some pieces of information," Todey said.
Most people in South Dakota's East River counties wouldn't consider themselves in drought currently because the short-term issues they have been dealing with include wet fields and some flooding, he said.
"West River is a little more difficult to handle. This is where the drought definition comes in again," Todey said.
Most West River locations have been quite wet this spring and early summer, allowing rangeland to begin to recover. The precipitation has filled ponds and dugouts in some places. However, all West River reservoirs except for the Belle Fourche Reservoir are still well below longer-term average levels, Todey said.
Todey said because of recent rains, the most recent U.S. Drought Monitor map from June 17 includes only the far southwest corner of the state in any category of drought.
"But even with our wet conditions, we have not been able to overcome all the drought issues accumulated over the past seven or eight years," Todey said. "And this is the Plains. Without more precipitation during the rest of the summer, we could start seeing those impacts return. While most people don't think of us being in drought conditions, the lingering effects are there."
Posted in Local on Friday, June 20, 2008 11:00 pm
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