中国农业科学

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最新录用:西北主要粮食作物种植的水碳足迹评估及布局优化

王楚凡1,2,牛俊1,2,3*
  

  1. 1中国农业大学中国农业水问题研究中心,北京 1000912农业水资源高效利用全国重点实验室,北京 1000913甘肃武威绿洲农业高效用水国家野外科学观测研究站,甘肃武威 733000
  • 发布日期:2023-05-23

Water and Carbon Footprint Assessment and Layout Optimization of Major Grain Crops in Northwest China

WANG ChuFan1,2, NIU Jun1,2,3* #br#   

  1. 1 College of Water Resources and Civil Engineering,China Agricultural University, Beijing 100091; 2National Key Laboratory for Efficient Utilization of Agricultural Water Resources, Beijing 100091; 3National Field Scientific Observation and Research Station for Efficient Agricultural Water Use in Wuwei Oasis, Wuwei 733000, Gansu 
  • Online:2023-05-23

摘要: 【目的】对西北地区主要粮食作物碳足迹和水足迹进行评估,并基于碳足迹和水足迹建立多目标种植结构优化模型,对各省份粮食作物进行空间布局调整,为减少碳排放量和增强水资源管理提供理论依据。【方法】以西北地区小麦、玉米和水稻种植面积、产量和农资投入量为基础数据,利用生命周期法(LCA)对碳足迹进行评估;以蒸散量和有效降水量为基础数据,利用Penman-Monteith公式对水足迹进行评估;基于熵权法对西北五省三大粮食作物布局进行多目标优化。【结果】1999—2020年西北地区小麦、玉米、水稻的碳足迹和水足迹在不同省份表现出明显的差异性。西北地区3种粮食作物小麦、玉米、水稻碳排放呈现出东西部较高,中部较低的分布特点,其单位产量碳足迹(PCF)的范围分别为:0.36—0.630.330.560.570.97 t CO2-eq·t-1单位面积碳足迹(FCF)分别为:(2.46±0.77)、(3.21±0.49)、(5.57±0.91t CO2-eq·hm-22010—2018年西北地区小麦、玉米、水稻绿水总量呈平稳上升趋势,平均绿水总量较高的地区分布在陕西、甘肃和宁夏。蓝水总量在2010—2015年呈上升趋势,2016—2018年呈现下降趋势,平均蓝水总量较高的地区分布在甘肃、宁夏和新疆玉米是西北地区三大粮食作物中蓝水足迹消耗最小的作物,平均生产蓝水足迹为0.45 m3·kg-1;水稻蓝水足迹消耗最大,平均生产蓝水足迹为0.77 m3·kg-1。基于碳足迹和水足迹进行粮食作物种植结构优化,以各省份不同作物种植面积为决策变量,并根据不同权重设置重点减少碳排放和重点增加绿水利用的优化情景。情景1中碳排放总量减少1.9%,绿水总量增加5.0%;情景2中碳排放总量减少11.8%;情景3中绿水总量增加6.7%。【结论】西北地区三大粮食作物碳排放和水总量时空差异显著,在粮食作物安全保障的前提下,增加小麦(7.1%种植面积、减少玉米(5.5%水稻(8.7%)的种植面积,经济、资源和生态效益均有一定的改进。在保证一定社会公平性条件下,优化后可以提高绿水资源利用,减少碳排放量,缓解环境污染。

关键词: 碳足迹, 水足迹, 种植结构优化, 粮食作物, 西北地区

Abstract: 【ObjectiveThis paper assesses the carbon footprint and water footprint of major food crops in the northwest region, and establishes a multi-objective planting structure optimization model based on the carbon footprint and water footprint to adjust the spatial distribution of food crops in each province, providing a theoretical basis for reducing carbon emissions and enhancing water resource management. MethodBased on the planting area, yield, and agricultural inputs of wheat, maize, and rice in the northwest region, the carbon footprint was evaluated using Life Cycle Analysis (LCA); Based on evapotranspiration and effective precipitation, the water footprint is evaluated by Penman-Monteith formula; Multi objective optimization of the layout of three major grain crops in the five northwest provinces based on entropy weight method. ResultThe data showed that the carbon footprint and water footprint of wheat, maize and rice in northwest China from 1999 to 2020 showed significant differences in different provinces. The carbon emissions from the production of three grain crops, wheat, maize and rice, in the northwest region show a distribution pattern of higher levels in the eastern and western regions and lower levels in the central region; The range of carbon footprint per unit production (PCF) is 0.36-0.63, 0.33-0.56, 0.57-0.97 t CO2-eq·t-1; The carbon footprint per unit area (FCF) is (2.46±0.77), (3.21±0.49) and (5.57±0.91) t CO2-eq·hm-2, respectively. From 2010 to 2018, the total green water content of wheat, maize and rice in the northwest region showed a steady upward trend, with regions with higher average green water content distributed in Shaanxi, Gansu, and Ningxia. The total amount of blue water showed an upward trend from 2010 to 2015, and a downward trend from 2015 to 2018. The regions with higher average total blue water were distributed in Gansu, Ningxia, and Xinjiang. Among the three major grain crops in northwest China, maize consumes the least blue water footprint, with an average blue water footprint of 0.45 m3·kg-1; The blue water footprint consumption of rice is the largest, and the average production blue water footprint is 0.77 m3·kg-1. Based on the carbon footprint and water footprint, optimize the planting structure of food crops, using different crop planting areas in different provinces as decision variables and set optimization scenarios focusing on reducing carbon emissions and increasing green water use efficiency according to different weights. In Scenario 1, the total carbon emissions decreased by 1.9% and the total green water increased by 5.0%; In scenario 2, the total carbon emissions decreased by 11.8%, while in scenario 3, the total green water emissions increased by 6.7%.ConclusionThere are significant spatiotemporal differences in carbon emissions and total water content among the three major grain crops in the northwest region. Under the premise of ensuring food crop safety, increasing the planting area of wheat (7.1%), reducing the planting area of maize (5.5%), and rice (8.7%) has resulted in certain improvements in economic, resource, and ecological benefits. Under certain social equity conditions, optimization can improve the utilization of green water resources, reduce carbon emissions, and alleviate environmental pollution.


Key words: carbon footprint, water footprint, optimization of planting structure, food crops, Northwest region