NDVI-Based Winter Wheat Responses to Heatwave in the North China Plain

The changes of climate variables due to climate change have a great impact on agricultural practices and finally will affect global food security. Thus, it is of great significance to study the responses of crops to climate change, especially for the winter wheat in the North China Plain (NCP), which accounts for about 75% of wheat production in China and is vulnerable to climate change. Knowledge of current changes and responses of crops to climate changes are critical for developing strategies to address climate change challenges. In this paper, the long-term Global Inventory Modelling and Mapping Studies (GIMMS) normalized difference vegetation indices (NDVI) was used to study wheat coverage changes and its responses to heatwave events in the NCP. The results indicate that the NDVI show significant increasing trends for most of the wheat planting areas during 1983-2014. In addition, as indicated by the SHI heatwave index, the heatwave days of almost all the study region show significant increasing trends. The increase of the heatwave days during wheat growing season would strikingly decrease the annual NDVI at a rate of -0.33% when heatwave days increase one day per year.