Risk Assessment of Crop Production Amid Climate Change Based on the Principle of Maximum Entropy: A Case Study of Winter Wheat Production on the North China Plain

Conventional methods for assessing the impacts of climate change on crop production are often unable to account for the impacts of extreme weather events and therefore underestimate the impacts of climate change. Risk assessment allows for the inclusion of inconsistent impact assessment results in the risk assessment framework and thus provides a qualitative or quantitative assessment of possible risks suffered by crops amid climate change. Due to the subjective assumptions on prior distributions (e.g., emission scenarios and climate model performance) and the assumption that variables are independent of one another, conventional risk assessment methods for crop production amid climate change could produce relatively large errors. In this study, a probability function for future weather scenarios is established based on the principle of maximum entropy using future weather scenario data from the Intergovernmental Panel on Climate Change. In addition, by linking future weather scenarios and winter wheat yields, the risks of winter wheat yield reduction caused by high temperatures as well as the risks of a decrease in rainfall on the North China Plain (NCP) amid climate change are systematically investigated. The results show the following. The risks of winter wheat yield reduction caused by high temperatures will be higher in the north than in the south of the NCP in 2030, 2050 and 2080. In particular, the probabilities of winter wheat yield reduction will be relatively high in central Hebei and northwestern Shandong. In addition, the risks of a decrease in rainfall during the winter wheat season will be higher in the northern NCP than in the southern NCP in 2030, 2050 and 2080. The probabilities of a decrease in rainfall will be relatively high in northern Hebei, Beijing and Tianjin in 2030, and the risks of a decrease in rainfall are gradually increasing. In this study, the principle of maximum entropy is successfully introduced into the field of risk assessments for crop production amid climate change and used to assess the risks to winter wheat production. The method used in this study could enrich the theories and technical methods for assessing crop production risks amid climate change. The results could provide a theoretical basis for developing measures and techniques for adapting winter wheat production to climate change.