【作者】 王伟；

【导师】 卓拉；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2021， 硕士

【摘要】 灌溉是提高粮食产量的重要途径和保障,由于水资源短缺而导致的产量不稳定被认为是粮食危机的根源之一,故没有水安全就没有粮食安全。同世界大多数地区一样,中国由于工业、生活和生态用水激增,农业灌溉用水空间受到严重挤压。作物生产水足迹指示一定时间、一定地理范围内作物生产过程中产生的水资源消耗量,实现了对作物生长发育各阶段耗水量和耗水类型的综合评价,突破了以往旱作农业与灌溉农业用水效率指标不统一的局限,为综合性农业水资源管理提供了新视角。为准确评价不同时空尺度作物生产耗水量及耗水效率的动态变化及其分布规律,本研究以2000～2014年中国小麦为研究对象,基于Aqua Crop模型的5弧分栅格尺度作物生产水足迹计算框架,明晰了不同供水方式（灌溉和雨养）和灌溉方式（地面灌、喷灌和微灌）对作物生产水足迹核算的影响,解析相应干旱区和湿润区的作物生产水足迹基准,并在流域尺度以黄河流域降雨典型年作为研究对象进行了地区应用研究。初步取得以下研究进展:（1）研究时段内,中国小麦生产总水足迹下降了4.4%,但是不同灌溉方式对总水足迹的贡献量在年际间变化明显。特别的,经过15年的发展,小麦微灌水足迹实现了7倍的增长,尽管其在研究初期占比较小。（2）中国小麦单产水足迹研究时段呈下降趋势。在全国平均水平下,当从地面灌转换到微灌时,单产仅降低2.8%,而蓝水消耗减少了4.7%。此外,不同灌溉方式下小麦生育期生产性耗水和非生产性耗水都保持在一个固定的比例,但喷灌总蒸发蒸腾量和无效蓝水蒸发量最大,其次是地面灌和微灌。（3）小麦基准受气候和单产水平发展空间差异影响较显著。整体而言,小麦单产水足迹基准在干旱区要比湿润区低17%（10th产量百分位水平）到9%（20th产量百分位水平）。一方面干旱区不同灌溉方式下水足迹基准差异明显,另一方面同一灌溉方式下不同气候区水足迹基准也有较大差异。故在不同的气候区,应设置基于不同灌溉方式的小麦单产水足迹基准。（4）黄河流域小麦单产水足迹多年均值为1216 m3t^-1,其中蓝水足迹占比为65%,且空间分布上表现出由上游向中下游递减的趋势。不同降雨典型年,枯水年小麦单产水足迹最高,其次是丰水年和平水年。不同灌溉方式下,传统地面灌在流域小麦生产总蓝水足迹及总绿水足迹中都占主导地位,分别为92%和50%。在节水灌溉面积占比最大的上游地区,微灌小麦单产水足迹最小,其次是地面灌和喷灌。本研究力求克服区域高空间分辨率作物生产水足迹核算中仅考虑自然因子、脱离实际生产情况的不足,为提高区域农业用水效率和田间水分生产力、缓解用水矛盾、实现可持续水管理提供科学依据。更多还原

【Abstract】 There is no food security without water security around the fact that irrigation is an important guarantee for increasing grain production.Water resource scarcity have led to the variable grain production,which was adjudged to be the cause of the existing food crisis.China,as in most parts of the world,inter-sector competition for water intensifies has severely restricted the water usage for irrigation.The water footprint（WF）is an indicator to consider the impact of human activities on the quantity and quality of water resources comprehensively.The WF can reflect the water consumption and water type,respectively,in each stage of crop growth compared with the current crop production water consumption evaluation indicator（ET）.Moreover,the WF per ton of cereal has broken through the limitations of water efficiency indicators for dry farming and irrigation farming and provides a new perspective for integrated water resources management.The objective of this study is to explicitly address the effect of the popularization of water-saving irrigation techniques on large-scale WF accounting,through the case for wheat in China over 2000～2014.The green and blue WFs of both rain-fed and irrigated wheat are estimated using the Aqua Crop model at a 5?×?5 arc-minute resolution for each year.For irrigated wheat,we distinguish three irrigation technologies（furrow,sprinkler and micro-irrigation）.The WF benchmark levels for each irrigation technology are further estimated for arid and humid zones,respectively.In addition,three typical reference years in the Yellow River Basin are taken as the research object for regional application.Mainly conclusions are as following:（1）Overall,the WF（m3）related to China’s wheat production decreases by 4.4%during the study period,while the share of WF for different irrigation methods changed significantly to the total WF over the years.In particular,there is a 7-fold increase of WF of micro irrigation after a 15 years development,though it accounted for a small proportion at the beginning of the study.（2）The total green-blue WF(m3t^-1)of wheat in China continue to decline.Both productive water consumption T and non-productive water consumption E are kept at a fixed ratio under different irrigation methods,but the total evapotranspiration and the ineffective blue water evaporation are the highest in sprinkler,followed by furrow and micro irrigation.From the national average,the yield decreases by only 2.8%while the blue water consumption is reduced by 4.7%when switching from furrow to micro irrigation.（3）The benchmarks for WF of wheat in China are strongly affected by climate and the spatial differences in yield levels.We conclude that WF benchmarks differ greatly under both the scenarios of different irrigation methods in arid regions and different climate regions with the same irrigation method.Therefore,the benchmarks for WF of wheat must be set by distinguishing the irrigation methods and climate zones.（4）The average annual WF of wheat in the Yellow River Basin was 1216 m3t^-1,of which the blue water footprint accounted for 65%,and the spatial distribution showed a decreasing trend from the upper reaches to the middle and lower reaches.In typical years,the WF(m3t^-1)was the highest in dry years,followed by wet years and normal years.Under different irrigation techniques,the blue WF and green WF（m3）of wheat were dominated by traditional surface irrigation,which were 92%and 50%,respectively.In the upstream region with the largest proportion of water-saving irrigation area,the WF(m3t^-1)of wheat under micro irrigation was the smallest,followed by furrow irrigation and sprinkler irrigation.This study aims to overcome the shortcoming of considering only natural factors and separating from actual production conditions in the water footprint calculation of regional high-spatial resolution crop production,and to provide a scientific basis for improving regional agricultural water use efficiency and field water productivity,alleviating water contradiction and realizing sustainable water management.更多还原