drought climate change 30 Research & information: general 28 precipitation 13 temperature 9 NDVI 8 remote sensing 8 abiotic stress 7 machine learning 7 photosynthesis 7 random forest 7 MODIS 6 resilience 6 rice 6 sustainability 6 SPI 5 Technology: general issues 5 agriculture 5 climate 5 flood 5 maize 5 rainfall 5 trend analysis 5 validation 5 China 4 Environmental economics 4 Landsat 4 Sentinel-1 4 Sentinel-2 4 antioxidants 4