TITLE:
Monitoring Heat Waves and Their Impacts on Summer Crop Development in Southern Brazil
AUTHORS:
Anibal Gusso, Jorge Ricardo Ducati, Mauricio Roberto Veronez, Victor Sommer, Luiz Gonzaga da Silveira Junior
KEYWORDS:
Land Surface Temperature; Soybean; Remote Sensing; Canopy; Vegetation Index; MODIS Data
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.4,
March
21,
2014
ABSTRACT: Periods in the soybean summer cycle that are sensitive
to the occurrence of high temperatures were studied. An analysis was performed
on the variability of soybean yields associated with crop canopy temperatures
during key development periods. A land surface temperature (LST) data series
from MODIS (Moderate Resolution Imaging Spectroradiometer) on the Aqua
satellite was processed between 2003 and 2012 that covered the entire state of
Rio Grande do Sul, in Brazil. Enhanced
vegetation index (EVI) data from MODIS on the Terra satellite were used to
monitor the LST during different phenological stages. Spatially interpolated
maps of soybean yield distributions were generated using data obtained from
Instituto Brasileiro de Geografia e
Estatística (IBGE) at state and municipality levels. The results indicate that
canopy-LST occurrence in mid-February, during the grain filling, is most
correlated to yield reduction (R2 = 0.82 and RMSD = 14.4%). At the state level, the average yield is 2003 kg·ha-1 with a standard
deviation of 308 kg·ha-1. The overall average of the canopy-LST is
305.0 K (31.8°C) with a standard
deviation of 1.9 K. The slope of the downward linear relationship between
canopy-LST and yield was -28.7%. These results indicate that monitoring heat wave events can provide important information for characterising agriculture vulnerability.