Non-Peer ReviewedAgricultural drought is a major climate concern which occurs frequently on Canadian prairies. It
acts negatively on crop production, which directly affects the Canadian economy. The
Normalized Difference Vegetation Index (NDVI) has been widely used to assess crop yield
losses related to drought events. However, this index suffers from some shortcomings such as the
apparent time lag between drought impact due to rainfall deficit and NDVI response. This study
was undertaken to investigate the effectiveness of the integrated Vegetation Health Index (iVHI)
for the assessment of spring wheat yield across Canadian prairies. A time series of five years
from the Advanced Very High Resolution Radiometer (AVHRR) sensor were used to develop a
spring wheat yield model for three agroclimatic regions: subarid, semiarid and subhumid. The
results demonstrated that spring wheat yield assessment is feasible through the use of iVHI,
especially in subarid and semiarid regions where it reached a correlation coefficient of 0.75 and
0.61, respectively. This finding shows that iVHI can be used to estimate spring wheat yield losses
due to agricultural drought across the Canadian prairies. However, in subhumid regions where
spring wheat growing conditions are favourable because of adequate water supply, the integrated
NDVI (iNDVI) outperforms iVHI with a correlation coefficient of 0.44 compared to 0.34.
Consequently, to develop an efficient tool, it suggested coupling the iVHI with iNDVI to better
estimate spring wheat yield in the Canadian prairies