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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #360501
Research Project: Integrating Remote Sensing, Measurements and Modeling for Multi-Scale Assessment of Water Availability, Use, and Quality in Agroecosystems

Location: Hydrology and Remote Sensing Laboratory

Title: Consistency between NASS surveyed soil moisture conditions and SMAP soil moisture observations

Author
item COLLIANDER, A. - Jet Propulsion Laboratory
item YANG, Z. - US Department Of Agriculture (USDA)
item MUELLER, R. - US Department Of Agriculture (USDA)
item SANDBORN, A. - US Department Of Agriculture (USDA)
item REICHLE, R. - Goddard Space Flight Center
item Crow, Wade
item ENTEKHABI, D. - Broad Institute Of Mit/harvard
item YEUH, S. - Jet Propulsion Laboratory

Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2019
Publication Date: 8/21/2019
Citation: Colliander, A., Yang, Z., Mueller, R., Sandborn, A., Reichle, R., Crow, W.T., Entekhabi, D., Yeuh, S. 2019. Consistency between NASS surveyed soil moisture conditions and SMAP soil moisture observations. Water Resources Research. https://doi.org/10.1029/2018WR024475.
DOI: https://doi.org/10.1029/2018WR024475

Interpretive Summary: By allowing us to better monitor the extent and duration of agricultural drought, soil moisture products derived from satellite remote sensing have great potential for improving the in-season forecasting of post-harvest crop yields. The first step in this process is developing a link between these new satellite-based products and traditional measures of soil water availability currently used in operational drought monitoring. This paper provides such a link by examining the relationship between a satellite-based soil moisture product and soil water assessments made by county extension agents. It reveals that, despite their very different conceptual basis, these two types of measurements are broadly consistent. This supports the possibility of merging them to create a (more reliable) unified soil moisture product. The USDA National Agricultural Statistics Survey is currently looking into this possibility as a way of improving their ability to forecast domestic commodity crop production.

Technical Abstract: The USDA National Agricultural Statistics Survey (NASS) collects and publishes crop growth status and soil moisture conditions in major US agricultural regions. The operationally-produced weekly reports are based on survey information. The surveys are based on visual assessments and – in the case of soil moisture – report soil moisture levels in one of four categories (Very Short, Short, Adequate and Surplus). In this study, we show that these reports have remarkable correspondence with the NASA Soil Moisture Active Passive (SMAP) Level-4 Soil Moisture (L4SM) product. This consistency allows the combining the two distinct types of data to produce a value-added combination, which is mapped fields rather than State-by-State tables and it is refreshed daily rather than weekly. In this study classification thresholds are derived for L4SM by mapping cumulative distribution functions of L4SM surface and root-zone SM to the categorical NASS SM conditions. The results show that, year-over-year, the SMAP cumulative SM distributions are consistent with the NASS SM conditions and, furthermore, that the temporal evolution of the SMAP-derived thresholds is consistent with the seasonal crop growth cycles from year to year. The results signify that the SMAP SM retrievals are relatable to SM estimation conducted in agriculture by land managers and farmers, which underlines the general applicability of the SMAP data.