Wednesday, 15 May 2002: 8:45 AM
A Soil Moisture Analysis of the Drought Conditions using the Oklahoma Mesonet
Droughts in the Southern Plains have profound impacts on the state of Oklahoma and are evident using surface based instrumentation and observations. This study focuses on the subterranean analysis of these hydrologic events. The Oklahoma Mesonet has nearly 100 sites with soil moisture sensors at four depths, which provide observations every 30 minutes. Through the use of the Oklahoma Mesonet, the impact of droughts (1998 and 2000) on soil moisture conditions was quantified. In addition, the lag time between the onset of the droughts and their impact on varying soil depths was determined at individual sites as well as in each specific climate region. Finally, the recovery time between the conclusion of the meteorological drought and the replenishment of soil water at various depths was investigated. Preliminary results have revealed moderate to strong correlations between soil porosity and the lag and recovery time of the soil moisture in portions of Oklahoma. In addition, the data from some sites demonstrated that, following extreme drought conditions, the recharge of soil moisture at depths deeper than 25 cm may take months of continuous intermittent rainfall.