基于时间序列模型的黑龙江省粮食水足迹分析与预测

Analysis and prediction of grain water footprint in Heilongjiang province based on time series model

利用CROPWAT 8.0模型计算了2000—2017年黑龙江省主要粮食作物水足迹,并利用自回归移动平均模型ARIMA对2018—2022年黑龙江省粮食作物水足迹进行了预测.黑龙江省粮食作物生产水足迹增长迅速,2000—2017年黑龙江省粮食作物生产水足迹总量增长了2.84倍;玉米的水足迹为0.47~1.07 m^3/kg,而大豆、小麦和水稻的水足迹分别为1.35~2.39,1.12~2.99和0.76~1.41 m^3/kg;小麦的绿水足迹占比最高,约为72.74%,其次是玉米(66.26%)和大豆(64.59%),而水稻的绿水足迹占比最低,约为46.99%;4种作物的灰水占水足迹的比例均低于1.12%.ARIMA模型预测结果表明,黑龙江省粮食作物的水足迹总量将逐年升高,玉米的水足迹呈逐年下降趋势,水稻和大豆的水足迹呈逐年上升趋势,小麦的水足迹基本不变.考虑到黑龙江水资源相对缺乏,而粮食作物水足迹总量逐年上升,建议加强农业管理,提高作物的水分利用效率.

The water footprint of main grain crops in Heilongjiang province from 2000 to 2017 was calculated by using CROPWAT 8.0 model,and the water footprint of grain crops in the province from 2018 to 2022 was predicted by using autoregression moving average(ARIMA)model.From 2000 to 2017,the total water footprint of grain crops increased by 2.84 times.Specially,the water footprint of maize fluctuated between 0.47 and 1.07 m^3/kg,while the water footprints of soybean,wheat and rice were in 1.35-2.39 m^3/kg,1.12-2.99 m^3/kg,and 0.76-1.41 m^3/kg,respectively.The proportion of green water footprint of wheat was the highest(72.74%),followed by corn(66.26%)and soybean(64.59%).The proportion of green water footprint of rice was the lowest(46.99%).The proportion of grey water of the four crops was all lower than 1.12%.As a simple prediction method,ARIMA model can predict the change of water footprint of grain crops in a fair accuracy.The predicted results show that the total water footprint of grain crops in Heilongjiang province will increase year by year,but the water footprint of corn per unit mass will decrease yearly,the water footprint of rice and soybean per unit mass will rise year by year,and the water footprint of wheat per unit mass will remain unchanged basically.Considering the relative shortage of water resources in the province and the total water footprint of grain crops to increase year by year,it is suggested that agricultural management of the province should be strengthened to improve water use efficiency of crops.