02089naa a2200277 a 450000100080000000500110000800800410001910000210006024500930008126000090017450001390018352011470032265000190146965000170148865000260150565300250153165300290155665300220158565300230160765300090163065300190163965300200165870000170167870000190169577300970171420834092017-12-22       2017    bl uuuu     u00u1 u    #d1 aPICOLI, M. C. A.  aIdentifying drought events in sugarcane using drought indices derived from Modis sensor.  c2017  aTítulo em português:  Identificação de eventos de seca em cana-de-açúcar com base em índices de seca derivados do sensor Modis.  aThe objective of this work was to evaluate the potential of several spectral indices, calculated using moderate resolution imaging spectroradiometer (Modis) images, in identifying drought events in sugarcane (Saccharum officinarum) crops. Images of Terra and Aqua satellites were used to calculate the spectral indices, using visible (red), near infrared, and shortwave infrared bands, and eight indices were selected: NDVI, EVI2, GVMI, NDI6, NDI7, NDWI, SRWI, and MSI. The indices were calculated using images between October and April of the crop years 2007/08, 2008/09, 2009/10, and 2013/14. These indices were then correlated with the standardized precipitation-evapotranspiration index (SPEI), calculated for 1, 3, and 6 months. Four of them had significant correlations with SPEI: GVMI, MSI, NDI7, and NDWI. Spectral indices from Modis sensor on board the Aqua satellite (MYD) were more suited for drought detection, and March provided the most relevant indices for that purpose. Drought indices calculated from Modis sensor data are effective for detecting sugarcane drought events, besides being able to indicate seasonal fluctuations  aImage analysis  aWater stress  aSaccharum Officinarum  aImagem por satélite  aProcessamento de imagens  aSatellite imagery  aSistemas de alerta  aSPEI  aTress hídrico  aWarning systems1 aDRUFT, D. G.1 aMACHADO, P. G.  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 52, n, 11, p. 1063-1071, novembro 2017.