Evaluation of the 2012 Drought with a Newly Established National Soil Monitoring Network

Abstract

Core Ideas New US soil moisture network provides new opportunity to evaluate drought Soil moisture at deeper depths did not fully recover from the 2012 drought in 2013 Soil moisture varied by region in the response to drought The NOAA United States Climate Reference Network (USCRN) deployed soil moisture sensors during 2009 to 2011 to monitor the temporal and spatial variability of soil moisture at 114 locations in the contiguous United States. These new soil observations will enhance our understanding of changing soil conditions for better drought monitoring. One year after full deployment of the network, a large drought occurred across most of the United States and provided an opportunity to evaluate the utility of this network for drought monitoring. The soil moisture signal of the 2012 drought in the continental United States was detected nationally at all observational depths (5, 10, 20, 50, and 100 cm), with an overall 11.07% decrease from the average of the 2011 to 2013 summers. The top three depths (5, 10, and 20 cm) experienced the largest decrease in soil moisture. Although 2013 national precipitation totals returned to normal values and national soil moisture levels recovered from the 2012 drought, the national average soil moisture concentrations combined at the 50‐ and 100‐cm depths remained around 18% below pre‐drought levels. Regional analysis of the 2012 drought identified that the Upper Midwest, Northeast, Northern Rockies and Plains, and Ohio Valley climate regions were most impacted and demonstrated a temporal pattern similar to the national analysis. These results demonstrate the utility of using USCRN for monitoring national soil moisture conditions, assessing droughts, and tracking climate change with time.

Soil Water Monitoring and Numerical Flow Modeling to Quantify Drought Conditions in a Rangeland Ecosystem

“…The clear difference between the dry 2012 growing season as compared with the relatively normal 2013 to 2015 growing seasons in both the measured and calculated soil water contents is particularly encouraging. Precipitation during the 2012 growing season was only 83 mm (Table 4) and 2012 has been documented as a serious drought year for much of the United States (Bell et al, 2015).…”

“…Drought is a recurring natural hazard that causes billions of dollars in loss every year. The latest drought of 2012 alone, that covered more than 80% of the United States, caused approximately $30 billion in damage in the United States (Bell et al, 2015). Drought refers to water or moisture conditions that are below normal.…”

“…They developed a soil water drought index based on the weekly soil water deficit from the 70‐yr median value. Bell et al (2015) compared 8‐yr average soil water predictions for the summer months (June, July, and August) from a machine learning algorithm with measured 2011 to 2013 data to evaluate 2012 US drought conditions. Soil water content during the 2012 summer months was below the 8‐yr average predicted soil water, confirming that the 2012 summer months were relatively dry.…”

Relating coccidioidomycosis (valley fever) incidence to soil moisture conditions

“…With soil moisture playing an increasingly important role in precision agricultural decision support [ Coopersmith et al ., ], complex hydrologic models [e.g., Grayson et al ., ; Bell et al ., ], drought monitoring [e.g., Sheffield et al ., ; Bell et al ., ], and General Circulation Models [e.g., Koster and Milly , ; Belair et al ., ; Campoy et al ., ; De Rosnay et al ., ; Joetzjer et al ., ], the availability of in situ soil moisture resources has increased dramatically in the past decade. As discussed in the previous section, an in situ network, the U.S.…”

“…In equation (3), the detrended value for coccidioidomycosis cases reported (already normalized for population, see equation (1)) is denoted by detrended_VF c,m,y , obtained by dividing the population-normalized With soil moisture playing an increasingly important role in precision agricultural decision support [Coopersmith et al, 2014a], complex hydrologic models [e.g., Grayson et al, 1997;Bell et al, 2010], drought monitoring [e.g., Sheffield et al, 2004;Bell et al, 2015], and General Circulation Models [e.g., Koster and Milly, 1997;Belair et al, 2005;Campoy et al, 2013;De Rosnay et al, 2013;Joetzjer et al, 2013], the availability of in situ soil moisture resources has increased dramatically in the past decade. As discussed in the previous section, an in situ network, the U.S.…”