Evaluation Index Construction and Hazard Risk Assessment on Apple Drought in Northern China

Abstract

It is of great merit to construct apple drought index and analyze its hazard risk so as to support apple drought monitoring, prevention and mitigation, as well as agricultural disaster insurance management. Based on meteorological data, associated with historical disaster and phenophase data, apple drought index (DI) in northern China is firstly constructed, which fully considered previous and current water demand and precipitation supply. Afterwards, historical disaster remodeling, disaster sample reconstruction and process-based historical disaster analysis are comprehensively used as key technologies in evaluating the level of apple drought, integrating the independent sample T-test, Kolmogorov-Smirnov(K-S) test, cumulative probability inverse method, etc. Meanwhile, the apple drought risk is consequently estimated to seek the characteristics of apple drought hazard in detail. The results show that there are significant differences by independent T-test of drought index (DI) between historical recorded disaster samples and the non-disaster samples in three apple tree phenophases, i.e., the tree germinating to flower budding period, flower budding to full bloom and full bloom to mature periods (passing the test of 0.05 level). Therefore, the apple drought index constructed can effectively represent the drought disaster in different stages of apple development. The threshold of DI in the same level is higher in tree germinating to flower budding period, followed by flower budding to full bloom and full bloom to mature periods. The drought risk during flower budding to full bloom is high with regional average apple drought hazard index (M) of 0.44, followed by tree germinating to flower budding period and full bloom to mature period, with reginal average M of 0.40 and 0.25, respectively. Furthermore, the Bohai Bay region and northern Loess Plateau are detected as high-risk areas of apple drought. The evaluation method of apple drought based on historical disaster processing and re-analysis can provide new ideas for economic forest and fruit meteorological disaster research. The results of apple drought hazard risk assessment could provide evidence for the prevention and mitigation of apple drought in northern China.