Meteorological drought characteristics of tea in Zhejiang based on relative humidity index
[Objective]The objective is to study the evolution law of tea meteorological drought in Zhejiang,which is important for safe production of tea.[Method]Based on the daily data(temperature,precipitation and sunshine duration)of 68 meteorological observation stations in Zhejiang Province for 50 years(1971-2020),the spatial and temporal distribution characteristics of tea meteorological drought in Zhejiang were studied by relative humidity index,orthogonal empirical function(EOF),and wavelet analysis.[Result]The intensity and frequency of tea drought in summer were higher than those in autumn in Zhejiang,higher in the west and lower in the east.The drought intensity and frequency of drought were the strongest in the central and western parts of the province,especially in Jinqu Basin,followed by northern Zhejiang,and the least in coastal areas.The proportion of tea drought stations in summer decreased year by year,while in autumn it increased first and then decreased.After 2000,there was an increase in years of extreme large-scale tea drought in the summer and autumn seasons.The first modal of EOF of tea drought intensity in summer and autumn showed the consistency of changes in the whole province.In the second modal,local coastal areas and inland areas showed an inverse phase change.The main mode time series of drought intensity in summer and autumn had oscillation periods of 2-6,2-4,and 6-10 years respectively.[Conclusion]The frequency of tea drought during summer and autumn in Zhejiang is decreasing,but the probability of extreme droughts has increased in recent years.Special attention should be paid to the improvement of drought monitoring and warning capability in the main tea producing regions.[Ch,8 fig.1 tab.26 ref.]
万方数据
维普
