南方避雨栽培下番茄茎流时间序列的小波分析

Wavelet Analysis on Stem Flow Time Series of Tomato under Southern Shelter Cultivation

对2013—2015年避雨栽培番茄的试验数据进行收集和整理,探讨番茄茎流时间变化规律,采用Morlet小波对南方地区避雨栽培番茄日茎流量变化时间序列进行了小波分析,揭示了避雨番茄茎流日变化时间尺度的复杂结构,分析了不同时间尺度下茎流序列变化的周期和突变点,由此得出存在的不同序列中的主要周期。结果表明:南方避雨栽培番茄日茎流量变化受天气的因素制约较大,尤其受气温的影响较大;平均茎流在一天内均存在09:00、13:30、17:00左右的时间尺度的交替,有明显的周期特征。小波分析的时频局部化特性可展示茎流时间序列的精细结构,为分析其他作物茎流时间尺度变化特征提供了参考。

Based on the data of tomato under shelter cultivation from 2013 to 2015,the change law of tomato stem flow time was explored,and the wavelet analysis on stem flow time series of tomato under southern shelter cultivation was carried out through Merlot wavelet to reveal the complex structure of daily variation time scale of tomato stem flow. Period and mutation point of stem flow time series of tomato under different time scale were analyzed to get main period existing in different series. The results showed as followed： the stem flow variation of tomato under southern shelter cultivation was limited by weather largely,especially the temperature. The average stem flow had time scales alternate at 09： 00,13： 30 and 17： 00 in a day,which showed an obvious cycle characteristics. The time-frequency localization of wavelet analysis can show the fine structure of stem flow time series,which can provide reference for analysis on variation characteristics of stem flow time series of the other crops.