Abstract:

Frozen damage during flowering is one of the main meteorological disasters that affect the yield of pear trees in Hebei province. This study analyzed the spatial distribution characteristics of frost damage risk during flowering of pear trees in Hebei province, in order to provide support for the rational layout of local pear trees and the prevention and control of frozen damage risks. This paper selected four indicators from the risk of disaster causing factors, the vulnerability of disaster pregnant environment, the exposure of bearing bodies, and the ability to prevent and reduced disasters to build a risk assessment model of pear tree frozen damage in flowering period in Hebei province. The robustness of the model was tested, and the rationality of the risk assessment results was confirmed by the average yield per unit area of pear trees in 11 cities in Hebei province from 1997 to 2017. As a result, there were three conclusions as follows, (1)the risk of pear trees frozen damage during flowering in the northern part of Hebei province was high, which was related to the high risk and vulnerability of the region, the risk of frozen damage during flowering in the central and southern parts was low, mainly due to the lower risk, vulnerability, and high disaster prevention and mitigation capabilities. (2)When adjusting the indicators and methods of the risk assessment model, the change in the risk ranking of pear trees frozen damage during flowering period at each station was relatively small, with an average ranking change of 6.2, reflecting the good robustness of the model. (3)The rationality of the frost damage risk assessment results was verified using the average annual yield of pear trees. The average difference in risk and yield ranking among 11 cities was 2.0, which verified the rationality of the risk assessment results obtained based on the aggregation method proposed in this study. Establishing a risk assessment model for pear trees frozen damage during flowering period in Hebei province, with stations as the unit, can grasp the strength of frozen damage risk in each station in the study area, formulate frozen damage response strategies according to local conditions, and provide theoretical support and policy recommendations for stable and high yield pear trees in the study area.

Key words: Pear, Frozen damage, Risk assessment, Robustness test, Production confirmation