灌区粮食生产水足迹的影响因素研究

发布时间：2018-08-13 18:27

【摘要】：气候变化正成为全球公认的环境问题,农业是国家的基础性产业,气候因素对粮食生产的影响研究一直是学术界关注的热点。除气候因素外,其他因素对粮食生产的影响也不容忽视。在农业生产领域,水足迹提供了一种新的方法来评估农作物对水资源的利用效率。本研究以半湿润地区的典型灌区人民胜利渠灌区以及纯井灌区和井渠灌区代表地成安县和获嘉县为例,综合灌区和农户两个层次研究灌区粮食生产单位产量水足迹的影响因素。研究内容与结论如下:(1)首先以人民胜利渠灌区为研究区,基于1961—2013年的长系列数据,采用彭曼公式和CROPWAT软件,计算出历年灌区冬小麦的单位产量蓝水、绿水足迹,并根据计算结果进行蓝水、绿水足迹及其影响因子的时间序列分析。采用结构方程模型方法,对蓝水、绿水足迹与气候和农业投入因子的作用关系进行路径分析。结果表明:1961—2013年灌区冬小麦的蓝水、绿水足迹均呈显著下降趋势,作物蒸散发(ETc)无显著变化,冬小麦产量显著增加是冬小麦蓝水、绿水足迹下降的主要原因;影响冬小麦ETc的主要气候因素是平均风速、平均气温、相对湿度和日照时数;在不考虑农业投入的影响时,灌区冬小麦生长季平均风速是对蓝水、绿水足迹影响最大的气候因素,日照时数和有效降水的影响次之;在农业投入和气候因素的共同作用下,冬小麦蓝水、绿水足迹的主要影响因素为农用化肥使用折纯量、农业机械总动力和有效降水。(2)以成安县与获嘉县为研究区,采用彭曼公式和作物需水量法从微观上定量核算在不同的灌溉程度下农户的粮食生产作物需水量,并进一步核算在不同的投入水平和自然条件下具有不同的社会经济特征的农户的粮食生产单位产量水足迹。在此基础上,采用多元回归分析方法对影响农户粮食生产水足迹的气候因素和非气候因素进行定量分离,明确影响农户粮食生产水足迹的关键因素。得出以下结论:从农户层次来看,农户的灌溉保障程度及家庭特征为影响农户粮食作物绿水足迹的关键因素。农户需水紧缺程度(作物生育期间的有效降水量/作物需水量)通过灌溉保障程度对粮食产量、作物水足迹间产生影响。其它条件不变的情况下,需水越紧缺,农户的粮食作物灌溉保障程度会减小,产量会随之减少,蓝水足迹随之增加,绿水足迹随之增加。夏玉米变化程度小于冬小麦。(3)本研究最后根据影响灌区和农户两个层次粮食生产单位产量水足迹的关键因素,探明主要影响因素对粮食作物单位产量水足迹的影响程度。分析灌区光温生产潜力的变化,明确气候变化对灌区粮食作物产量的影响。结合气候变化对作物需水量的影响分析,预测气候变化引起的灌区粮食生产水足迹的变化。得出结论:在保持现有农业投入水平和灌溉条件下,气候因素的综合影响使得未来灌区粮食作物蓝绿水足迹均呈小幅下降趋势,蓝水足迹下降趋势小于绿水足迹。
[Abstract]:Climate change is becoming a globally recognized environmental problem. Agriculture is the basic industry of a country. The impact of climate factors on grain production has always been a hot topic in academia. In this study, the influencing factors of water footprint per unit yield of grain production in the semi-humid areas were studied at two levels, i.e., the typical irrigation areas in Shengli Canal, Chengan County and Huojia County, as well as pure well as Jingqu and Jingqu irrigation areas. Based on the long series of data from 1961 to 2013 in the People's Shengli Canal Irrigation Area, the blue water and green water footprints of winter wheat per unit yield in the past years were calculated by Penman formula and CROPAT software, and the time series analysis of blue water, green water footprints and their influencing factors were carried out according to the calculated results. The results showed that: from 1961 to 2013, the green water footprint of Winter Wheat in the irrigation area showed a significant downward trend, crop evapotranspiration (ETc) had no significant change, winter wheat yield significantly increased was the main reason for the decline of winter wheat blue water, green water footprint; The main climatic factors of wheat ETc were average wind speed, average temperature, relative humidity and sunshine hours; the average wind speed in the growing season of Winter Wheat in irrigation area was the most important climatic factor for blue water, green water footprint, sunshine hours and effective precipitation, followed by the combined effects of agricultural input and climate factors. The main factors affecting the green water footprint and the blue water footprint of winter wheat were converted fertilizer use, total power of agricultural machinery and effective precipitation. (2) Taking Chengan and Huojia counties as study areas, the water requirements of grain production crops of farmers under different irrigation degrees were calculated quantitatively by Pengman formula and crop water requirement method. One-step calculation of water footprints per unit yield of grain production of farmers with different input levels and natural conditions is carried out. On this basis, the climatic and non-climatic factors affecting water footprints of grain production of farmers are quantitatively separated by means of multiple regression analysis, and the grain production of farmers is clearly affected. The following conclusions are drawn: From the level of farmers, the degree of irrigation security and family characteristics of farmers are the key factors affecting the green water footprint of grain crops. Other conditions remain unchanged, the more water demand, the less irrigation security of grain crops will be reduced, the yield will be reduced, the blue water footprint will be increased, and the green water footprint will be increased. The key factor of water footprint is to find out the influence degree of the main influencing factors on the water footprint per unit yield of grain crops. It is concluded that under the condition of maintaining the current level of agricultural input and irrigation, the combined effects of climate factors will make the blue and green water footprints of grain crops decrease slightly in the future, and the decreasing trend of the blue water footprints is smaller than that of the green water footprints.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S27

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