中国农业广义水资源利用系数及时空格局分析

Generalized water efficiency and strategic implications for food security and water management: a case study of grain production in China

为统一核算区域蓝水、绿水资源有效利用程度,构建了农业广义水资源利用系数(E_g)指标,核算中国31个省区粮食生产中的E_g,并基于空间自相关和通径分析方法对其时空格局及成因进行分析。中国1998—2010年E_g为0.588,大部分省区呈随时间增大趋势;E_g相似的省区在空间上显著地聚集,高值省区聚集于西部,低值省区集中于东南地区,且空间聚集现象呈减弱趋势;农业生产管理水平对E_g的影响大于气候要素,社会经济条件影响最小。结合广义水资源利用状况,西南省区可扩大粮食生产规模以发挥E_g较大优势,东北与华北粮食主产区应通过提高E_g以保障粮食安全和水资源可持续利用。研究可发展农业用水效率评价理论同时为国家粮食生产与水资源管理策略的制定提供参考。

An index, generalized water efficiency （Es ）, for the effective utilization rate of blue-green water evaluation was established in this paper. Es in grain production for 31 provinces of China during 1998-2010 were calculated. Then temporal-spatial patterns and attribution analysis of Eg in China were explored and conducted by using spatial autocorrelation and path analysis methods, respectively. The results show that, national value of Eg was estimated to be 0.588 in 1998-2010 and the index increased slightly in most of the provinces. Spatial autocorrelation analysis results shows, provinces with resemble Eg value shown significant aggregation. Regions with high Eg values are gathered in Western China while ones with lower Eg distributed in Southeast China; and the global and local spatial aggregation showed decreasing trends over time. Eg was affected strongly by regional agricultural production management level, while the climate and economic conditions had less influence on the effective rate of blue-green water resources. Making a general survey of provincial Es, water productivity （Pw） , water stress index （WSI） and grain production ability, southwest provinces may expand grain production scale in order to play the advantage of high Eg, and major grain producing areas of Northeast China should take measures to raise Es to ensure food security and sustainable utilization of water resources. The results of this report can provide reference for the development of national water efficiency in agriculture and food production and water resources management strategy.