黄河流域作物生产水足迹时空演变与尺度效应研究

Water footprint of crop production is a comprehensive indicator of water consumption volume, type, as well as the effect on water quality over the cropping period. As constrained by both natural and artificial factors, the level of water footprint for crop production within a region varies spatially and temporally. Therefore, there is high spatial and temporal scale dependence in water footprint assessment for crop production, so as to significant scale effects. Currently, the advanced estimation of spatial and temporal variability in water footprint of crop production is still limited in solely considering the effecting mechanism of natural factors, which leads to one-sidedness in regional agricultural water use assessment, and reduces the practicability in guiding the agricultural water management by the available achievements. The current project, taking Yellow River Basin as the study area, aims to improve the quantification method by building a module of irrigation methods within the water footprint estimation framework at a grid level; then to account and analyze the correlation and differences among the spatial and temporal variabilities at various spatial and temporal scales, by considering the water footprint during irrigation water delivery and distribution, in order to reveal quantitively the temporal, spatial and synthetic scale effects in water footprint of crop production. The goal of the project is to answer two scientific questions: ①How to simultaneously evaluate both of the natural and anthropogenic impacts on spatial-temporal variations in water footprint of crop production at different spatial and temporal scales? And ②What is the internal linkages in the spatial-temporal variability of water footprint of crop production among different spatial and temporal scales? The project will be able to provide important data, references of methods and theoretical foundation for agricultural water demand managements across different spatial and temporal patterns.

作物生产水足迹是表述作物生产过程耗水量、耗水效率与耗水类型，以及对水环境影响程度的综合定量评价指标。受自然与人为双重因素制约，区域作物生产水足迹时空差异性强，对时空尺度依赖性高，具有明显的尺度效应。当前作物生产水足迹的量化过程着重考虑自然因素影响，尚未考虑关键人为因素影响机制，且缺乏对时空尺度效应的定量研究，导致区域农业用水评价存在片面性，指导农业用水管理实用性较差。本项目拟以黄河流域为研究区域，在作物生产水足迹计算框架内构建灌溉方式模块，改进量化方法；考虑灌溉输水过程耗水，核算分析不同时空尺度间作物生产水足迹演变特征的相关性与差异性，揭示作物生产水足迹的时间、空间及综合尺度效应。回答：①如何在作物生产水足迹时空演变过程解析中统筹考虑自然-人工影响机制？②不同时空尺度间作物生产水足迹演变有何内在联系？等科学问题。可为在不同时间、空间格局全面开展农业需水管理提供重要数据、方法参考与理论依据。

作物生产水足迹是表述作物生产过程耗水量、耗水效率与耗水类型，以及对水环境影响程度的综合定量评价指标。受自然与人为双重因素制约，作物生产水足迹时空差异性强，对时空尺度依赖性高，具有明显的尺度效应。当前作物生产水足迹的量化过程着重考虑自然因素影响，尚未考虑关键人为因素影响机制，且缺乏对时空尺度效应的定量研究，导致区域农业用水评价存在片面性，指导农业用水管理实用性较差。本项目在作物生产水足迹计算框架内构建了灌溉方式模块，改进量化方法，实现了区分不同灌溉方式对作物耗水的影响机制的区域作物水足迹量化。基于此，对黄河流域主要作物生产水足迹时空演变及社会经济驱动力进行了定量评价；考虑灌溉输水过程耗水，核算分析了典型区域不同时间和空间尺度间作物生产水足迹演变特征的相关性与差异性，定量揭示了作物生产水足迹的时空尺度效应。研究成果可为提升区域农业水资源刚性约束机制，优化农业生产结构，发展适水农业提供方法和数据参考。基于项目研究，发表学术论文19篇，申请发明专利1项，培养青年人才1名，研究生4人。