The satellite assessment of impact of the 2012 great drought on corn growth in the U.S. Corn Belt

In this paper, the relationship between drought effects on corn crop and satellite remote sensing assessment will be tested and verified. Current assessment of drought impact on corn growth in the Corn Belt relies on field surveys, which suffer from time inefficiency, expensiveness, subjectivity, and lack of spacial resolution. Therefore, a timely and objective assessment of drought impact on corn growth in the Belt is extremely important to agricultural decision makers and commodity traders. This project experiments the use of satellite remote sensing to effectively assess drought impact on corn growth. Current vegetation greenness indices, derived from NASA MODIS instrument that senses the Belt daily at 250-meters resolution, are compared with the past 13-year records of the same indices to obtain the current vegetation condition map. The map is overlaid with the USDA Crop Land Data Layer to form the corn condition map. Statistics is performed on the corn map for each state and the entire Belt. Results show that at 2012 growing season peak, 53.6% of corn was in stressed or worse conditions and 29.8% of corn was in exceptionally stressed conditions, the worst in the past 13 years of MODIS data records. The result is comparable with USDA reports on the corn condition.