Drought in Montana and Risk Assessments
Though a familiar term, drought can be a confusing concept because it is often defined by on-the-ground impacts such as reduced streamflow or agricultural crop losses. The broad range of drought impacts across water uses and geographies makes it difficult to pinpoint when a drought begins and ends.
To help with drought classification and monitoring, scientists have defined several types of droughts. Meteorological drought is a result of below normal precipitation for an extended time – ranging from a season to several years. This impacts groundwater and streamflow. Hydrological drought is a lack of water in the hydraulic system due to precipitation shortfalls. Often, hydrological drought and its impacts lag meteorological drought by months or even years. Terrestrial drought results in soil water deficits. This can be exacerbated by high air temperature, low humidity, and wind.
While drought is a natural and recurring feature of Montana’s semiarid climate, according to the Montana Climate Assessment, future droughts in Montana are likely to be more frequent and intense due to warming air temperatures and decreasing snowpack.
To understand how drought conditions are evolving, the Montana Climate Office is leading the development of a cooperative statewide soil moisture and meteorological information system (Mesonet). It is designed to support decision-making in agriculture, range and forest watershed contents. The Mesonet stations measure temperature, relative humidity, wind speed and direction, incoming solar radiation as well as rain, snow, and soil moisture measurements. This data will be used, not just to study drought, but to make flood predictions and monitor fire conditions.
When this project is complete it will be one of densest meteorological networks in the world. With this data, it’s becoming much easier to characterize these conditions and also have lead time so that policy makers and water resource managers are not just responding to what has happened but getting insight as to how conditions are going to develop as the year progresses.
Check out the Mesonet Data Dashboard at https://mesonet.climate.umt.edu/dash/.
Information provided from the Montana Climate Office, MT DNRC, Drought.gov, and the Montana Climate Assessment.
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