Validation of Satellite Observations of Storm Damage to Cropland with Digital Photographs

Abstract

ABSTRACT Severe storm events that include hail and wind often cause widespread contiguous swaths of damage; however, their occurrence is typically documented at individual and disjointed locations. Satellite-derived products, such as the normalized difference vegetation index (NDVI), can provide a more spatially uniform look at the extent of these events, particularly in rural or remote areas. The utility of incorporating satellite-based products into the damage identification and documentation process was assessed through high-resolution ground surveys, which included digital photographs, to classify three levels of cropland damage for three severe hail/wind events occurring in the Great Plains during the summer of 2014. Pre- and postevent NDVI values at the photograph locations were calculated using surface reflectance values from the Moderate Resolution Imaging Spectroradiometer (MODIS) and grouped by damage severity level. In general, more severe crop damage displayed a lower NDVI in the postevent imagery compared to undamaged crops. Additionally, the difference in the median NDVI between the pre- and postevent images was statistically significant between the damage categories with similar trends observed across the three summertime events. Thus, satellite-derived products should be promoted as a valuable tool for the initial assessment of damage severity and extent to agricultural crops and should be integrated when possible into the current hazard documentation process as a supplement to the currently available point-based observations of storm damage.