Can satellite information estimate rice yield variability in Korea?

The objective of this study was to estimate rice yield in Korea using satellite images and meteorological data such as sunshine hours or solar radiation, and rainfall. Terra and Aqua MODIS (The MOderate Resolution Imaging Spectroradiometer) products; MOD13 and MYD13 for NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index), MOD15 and MYD15 for LAI (Leaf Area index), respectively from a NASA web site were used. Relations of NDVI, EVI, and LAI obtained in July and August from 2002 to 2011 with rice yield were investigated to find informative days for rice yield estimation. Meteorological data of rainfall and sunshine hours (meteorological data 1) or solar radiation (meteorological data 2) were selected to correlate rice yield. Aqua NDVI at DOY 233 was chosen to represent maximum vegetative growth of rice canopy. Sunshine hours and solar radiation during rice ripening stage were selected to represent climate condition. Multiple regression analysis based on MODIS NDVI and sunshine hours or solar radiation were conducted to estimate rice yields in Korea. The results showed rice yield of 509.7 kg 10a^-1 in 2011 and the difference from statistics was 14.1 kg 10a^-1. Rice yield distribution in 2011 was presented to show spatial variability in the country.