Expanding D0 in Central NC Utilizing 0-200cm RSoM in Conjunction with 30-90 Day Precip Deficits
The North Carolina Drought Management and Advisory Council (NCDMAC) has a teleconference each Tuesday afternoon to discuss drought conditions and submit recommended changes to the U.S. Drought Monitor (http://drought.gov/drought). A variety of data are considered, such as streamflows, reservoir and monitored well levels, and agricultural reports. Relative soil moisture fields from NASA’s Short-term Prediction Research and Transition Center (NASA/SPoRT- http://weather.msfc.nasa.gov/sport), are newer datasets which have been introduced and evaluated over the past few months.
A Case from 10/28/2014
Below are 30, 60, and 90 day rainfall deficits, as well as the 0-200 cm relative soil moisture (RSoM) product from NASA/SPoRT. The circled area in each image corresponds to the area designated as ‘abnormally dry’ (D0) for the previous week. The RSoM (using a rather subjective 25% threshold) shows very strong correlation to rainfall deficits in the longer time frames (60 and 90 days), which are the fields typically used to help delineate low base flow in areas where reliable streamflow data is more sparse. The high resolution of the RSoM (which is more evident than can be seen in the downsized image), allows for sub-basin and sub-county scale delineation of areas of concern.
Southerly expansion of D0 conditions were recommended (below), with the RSoM’s weighing heavily on the decision to do so. The U.S. Drought Monitor author for the week, Brian Fuchs, was on the call and requested information concerning the NASA/SPoRT product suite. He was provided LIS links and information.