基于蓝绿水视角的稻田水资源利用效率评价方法研究

The efficient utilization of blue and green water resources is the core of agricultural water management and also the foundation of national food security. Water use efficiency was frequently failed to be fully understood due to the estimating of green water, supposing of irrigation probability and the ignoring of irrigation and crop growth process. Taking paddy field as research object, this potential project aims to put forward the method for blue and green water utilization process and efficiency evaluation based on field experiment and numerical analysis. The main idea was: to: build the analytical equation for blue and green water utilization process description for various irrigation and drainage measures on the basis of the field experiment and principle of water balance and the concepts of blue and green water; then to build calculation method of grey water footprint referring to the concept of water footprint, and quantify and analysis the water footprint indices and traditional water use efficiency evaluation indices such as irrigation efficiency and water productivity; thirdly, to filter water footprint indices and traditional water use efficiency indices and construct the index system for water use efficiency evaluation by considering the volume , profit and quality of water utilization; and finally to summarize main work and gain the method for agricultural water use efficiency evaluation from the perspective of blue-green water after the empirical research for the experimental treatments. If the idea can be proved to be valid and reliable, it will help to provide scientific basis for water resources management practices and irrigation and drainage measures selection for the paddy field and a new methods for the research of agricultural water resources use efficiency evaluation in future.

基于蓝绿水视角的农业高效用水是保障国家粮食安全和水资源可持续利用的基础。当前研究多以假设为前提对蓝、绿水利用进行核算与区分，使得难以全面衡量农业生产与水资源和水环境的关系。为此，本研究以稻田为对象，以田间试验为载体来探索基于蓝绿水视角的农业用水效率评价方法。基本思路是：基于不同灌排模式试验处理与蓝绿水概念，利用实测的田间水分运移过程参数组建蓝绿水利用过程的描述方程；参照水足迹理论建立适于稻田灌排特征的灰水足迹计算方法，计算并分析作物生产水足迹及传统的灌溉效率、水分生产率指标；将用水量、用水效用及环境影响统一于用水效率，对水足迹指标及传统效率指标进行筛选，构建水资源利用效率评价指标体系；对不同灌排模式稻田处理进行实证研究，总结得到基于蓝绿水视角的稻田水资源利用效率评价方法。项目研究成果可为稻田灌排措施选择和水资源管理实践提供理论依据，并为农业水资源利用效率评价的研究提供方法参考。

蓝绿水与水足迹理论为农业水资源高效利用提供新的视角和工具。本研究以蓝绿水利用效率评价基础理论为主线，通过理论分析、试验观测和数值模拟相结合的方法，开展田间蓝绿水利用过程解析，稻田作物生产水足迹计算方法，基于蓝绿水的农业水资源利用效率评价指标以及稻田蓝绿水资源利用效率综合评价研究。得到了灌溉排水条件下的田间蓝绿水利用过程解析方程，描述了稻田作物生产蓝、绿水资源的利用机制；识别出排水中总氮浓度为作物灰水足迹的决定参数，量化了不同降水条件下作物生产灰水足迹的时间步长效应；确立核算时空尺度的基础上形成了稻田作物生产水足迹计算方法；基于蓝绿水和水足迹理论，构建了广义水系数、灌溉边际水分生产力、农业用水效果以及水短缺足迹等农业用水效率评价指标，补充和完善了农业水资源利用效率评价指标体系；量化和评价了不同灌溉排水模式下作为生产水足迹及其组成，进行了以作为生产水足迹为标准的水稻灌溉排水模式筛选。建立了基于蓝绿水的农业用水效率综合评价方法和指标体系，评价了不同灌溉排水模式水稻用水综合效率；补充与完善了农作物生产水足迹计算方法及农业水资源利用效率评价方法和指标体系，为农田水分管理策略选择、节水评价以及水足迹和虚拟水流动相关研究提供基础理论与方法。