应用气象学报 (Jan 2020)
Spatial and Temporal Distributions of Apple Drought in Northern China
Abstract
Clarifying the spatial-temporal distribution and the periodic law of drought during different growth stages of apple in northern China can provide a scientific basis for disaster prevention and mitigation and high yield and quality. Based on daily meteorological data of 144 meteorological stations in north of China from 1981 to 2016, precipitation, water requirement, continuous no-precipitation days and the drought index during different growth stages of apple are calculated. Spatial distribution characteristics and temporal trends of apple drought in the study area are clarified. Finally, the periodic law of drought during different growth stages of apple in northern China is revealed with wavelet analysis. Results show that the spatial distribution of precipitation during different growth stages of apple is consistent with the spatial distribution of drought index. The precipitation exhibits an increasing trend from northwest to southeast during different growth stages. The precipitation during fruit tree sprouts to flower buds and flowering to maturity show a decreasing trend and the precipitation in stages from flower buds sprout to flower full bloom and from mature to fallen leaves exhibit an increasing trend from 1981 to 2016. The apple water requirement during stages from fruit tree sprouts to flower buds and from flower bud sprout to flower full bloom exhibit an increasing trend, while the other growing stages exhibit a decreasing trend from 1981 to 2016. High values for drought index are mainly distributed in Gansu, Ningxia, Hebei and Beijing. The drought index during the stage from fruit tree sprouts to flower buds shows an increasing trend, while during the other growth stages the drought index shows a decreasing trend from 1981 to 2016. There are three different scales of periodic variation for apple drought during different growth stages.Above all, areas with the most serious drought are mainly concentrated in Gansu, Ningxia, Hebei and Beijing. The drought is the most serious during the stage from flower bud sprout to flower full bloom, and the drought index during the growth stage from fruit tree sprouts to flower buds shows an increasing trend.
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