山东省农业水足迹周期及趋势变化分析

Analysis of agricultural water footprint cycle and trend change in Shandong Province

农业用水状况及其周期趋势分析对合理制定农业用水分配、提高水资源利用效率有着重要的现实意义。依据水足迹理论,分别计算了山东省1978-2014年农业总水足迹及其分项,利用经验模态分解(EMD)分别分析了各水足迹值的波动周期,从多时间尺度分析了农业总水足迹值波动影响因素,并结合对数平均迪氏分解(LMDI)方法,分析了引起总水足迹增长的主要贡献因素。结果表明:林牧渔业水足迹以3.5a为周期波动,种植业水足迹以5a为周期波动,总水足迹以8a为周期波动;农业总水足迹值3a短波动周期主要受种植业影响,8a长波动周期在2002年前主要受畜牧业影响,2002年后则主要受种植业影响;农业总水足迹及各分项多年来均呈增长趋势;蓝水、绿水、灰水足迹值的变化均对总水足迹值的增长起正向促进作用,多年来农业总水足迹值的增长由绿水足迹主导逐渐转变为蓝水足迹主导。

The agricultural water utilization situation and the analysis of its cycle and trend is of great practical significance for the rational allocation of agricultural water and the improvement of water resource utilization efficiency.Based on the water footprint theory,in this paper we calculated the total agricultural water footprint and its components in Shandong Province from 1978 to 2014.Empirical mode decomposition （EMD） was used to analyze the fluctuation cycle of each water footprint value.We analyzed the influencing factors of total agricultural water footprint fluctuation on multiple time scales.Furthermore,adopting the logarithmic average Dewar decomposition method （LMDI）,we analyzed the main contributors to the growth of total water footprint.The results showed that the water footprint of forestry,animal husbandry,and fishery fluctuated over a period of 3.5 years,the water footprint of planting industry fluctuated over a period of 5 years,and the total water footprint fluctuated over a period of 8 years.The three-year fluctuation period of total agricultural water footprint value was mainly affected by planting industry.The eight-year fluctuation period was mainly affected by animal husbandry before 2002,and by planting industry after 2002.The total agricultural water footprint and its components showed an increasing trend over the years.The changes of blue,green,and gray water footprints all played a positive role in the growth of total water footprint.Over the years,the main factor influencing the growth of total agricultural water footprint switched from the green water footprint to the blue water footprint.