Table 1.
Determinants used to describe the crop-drought sensitivity analyzed in the study.
The dataset sources and format are listed in S1 Table.
Fig 1.
Crop yield sensitivity to drought based on 9-month SPI across global croplands based on GDHY for maize, rice, soybean, and wheat.
Sensitivity is calculated by the linear slope coefficient (β) as crop yield anomaly (%) per drought magnitude based on SPI, while white cells show no cropland or crop yield data. We show a map over entire global croplands for a spatially broader interpretation. The map showing only areas with significant crop yield sensitivity to drought is provided in S2 Fig (P < 0.05). The map is made with the “cartopy” library in Python (version 0.17) and the Natural Earth free vector and raster map data (naturalearthdata.com), which are freely available through the public domain [70].
Fig 2.
The relative importance of the determinant factors in explaining crop-drought sensitivity based on random forest model.
The importance values are normalized to the 0–1 range computed separately across different crops. The colored points represent the relative importance of each variable. Label order of the y-axis indicates the order from the most important variables to the least based on the overall average across crops.
Table 2.
Top six important parameters for each crop based on the average relative importance.
The overall average represents the average from combinations across crops corresponding to the order of the y-axis labels in Fig 2.
Fig 3.
Relationship between the response variable of crop-drought sensitivity (β) as the response variable and the six selected determinant factors as independent variables based on each partial dependence using random forest models.
The order shows higher to lower overall relative importance across crops (see Table 2). The lower negative y-axis indicates higher yield loss due to drought. The partial dependence plot for all variables (22 variables) is provided in S4 Fig.
Fig 4.
Crop-drought sensitivity in each rainfed and irrigated defined by >80% of irrigated harvested area for maize, rice, soybean, and wheat.
The x-axis represents the bins of crop yield sensitivity, and the y-axis represents the percentage of the harvested area where data is available. The dashed line indicates the center value (zero), separating yield loss (negative) and yield gain (positive).