中国粮食生产蓝绿水资源利用效率分析

Assessing blue and green water use efficiency in grain production in China

为分析蓝绿水资源利用效率的空间差异,计算了省区尺度总农田与灌溉农田广义水资源利用量水分生产率(P_(tu),P_(iu))与蒸散量水分生产率(P_(tET),P_(iET))以及雨养农田水分生产率(P_r).分析了2010年不同水分生产率指标的空间差异和灌溉对水分生产率的影响.结果显示:P_(tu),P_(tET),P_(iu),P_(iET)和P_r分别为0.765,0.979,0.767,1.002及0.758 kg/m^3;P_(tu),P_(tET),P_(iu)及P_(iET)的空间分布格局相似,均与Pr无显著相关性,灌溉农田在粮食生产、水资源利用及水分生产率空间分布上起主导作用;全国灌溉农田粮食单产是雨养农田的2.6倍,黄淮海平原及其周边省区的Piu高于Pr,而灌溉在海南等15个省区的增产效益以降低水分生产率为代价.东北和西北地区蓝绿水资源利用效率的提升空间较大.研究可为农业水资源利用及管理实践提供参考.

In order to assess the spatial variation of blue and green water use efficiency in grain pro- duction in China, the provincial total and irrigated farmland water resources utilization of generalized water productivity （ Ptu, Pu ）, evapotranspiration and water productivity （ Per, PiEr ） and rain-fed grain crops water productivity （Pr） in the year 2010 were calculated. Then the spatial distribution pat- tern of all water productivity indicators, as well as the effects of irrigation on regional water and produc- tivity were analyzed. The results show that national Ptu, Per, Piu, PiEr and Pr were estimated to be 0. 765, 0. 979, 0. 767, 1. 002 and 0. 758 kg/m3, respectively. The spatial distribution pattern of four indicators Ptu, PET, Pu and PET was similar with each other, while none of them was significantly cor- related with Pr in grain production. Irrigated farmland played a leading role in both water use and the spatial distribution of water productivity in China. The unit production of grain yield in irrigated farm- land was 2.6 times than that in the rain-fed farmland at the national level. Piu in the North China Plainand its surrounding provinces were higher than Pr, while irrigation reduced water productivity in 15 provinces, for example Hainan Province, although the yield of grain crops increased. The results can provide a reference for agricultural water management.