基于EMD的河北省耕地数量变化与社会经济因子多尺度关系分析

Analysis on the multi-scale relations between cropland and socio-economic factors in Hebei Province based on Empirical Mode Decomposition method

使用1949年至2006年河北省经济统计数据，对耕地数量、GDP、人口和粮食产量增长率作EMD分解，分别得出四级本征模函数IMF1、IFM2、IFM3、IMF4，生成系列EMD分解图。在此基础上分析其波动周期，并把耕地数量波动IMF分量与其它要素IMF分量进行比较找出相关关系。研究结果表明：在20世纪未21世纪初7～8年尺度上GDP增长为耕地数量变化的主要驱动因子；在13—15年尺度上人口变化是耕地数量变化的驱动力；在多尺度上粮食产量波动受耕地数量变化控制。未来2～4年内依惯性耕地增长率还有持续下降的可能，未来7～10年内耕地数量有望稳定在一定水平。

Cropland resources play an important role in agricultural production and regional socio - economic development. A large amount of cropland has been converted into construction land duo to rapid industrialization and urbanization. Empirical Mode Decomposition （EMD） is a powerful method for analyzing the nonlinear and non - stationary time series. EMD method was introduced to study the fluctuation of cropland in Hebei Province, and the data were decomposed into four IMFS. Research results indicated that： （ 1 ） There were multi - time scale fluctuations cycles in Cropland, GDP, population, and grain output. （2） By comparing the IMF component of cropland fluctuations with the IMF component of GDP, population and grain output in the same fluctuations cycle, we found that economic growth was the main driving factor for cropland change in 7 -8 yr scale in the end of the 20th century and beginning of the 21st century; population change was the driving force of cropland in 13 -15 yr, and cropland change controlled the fluctuations in grain output in 15 -20 yr. （3） The growth rate of cropland may be declining according to the inertia in the next 2 to 4 years, and it may be trending in the next 7 to 10 years.