基于重心模型的粮食生产与水资源时空耦合分析

The spatio-temporal coupling analysis of grain production and water resources based on the barycenter model

随着水资源面临越来越大的压力,水资源约束下的粮食安全问题也愈发受到关注。为更加清晰地认识粮食生产与水资源之间的矛盾,文章首先对全国粮食产量与水资源总量进行了时空分布分析,其次运用重心模型从全国和区域层面对1999—2018年粮食生产重心与水资源重心的演变趋势、时空耦合程度进行分析。结果表明:1)我国粮食生产重心在1999—2018年间整体上向东北方向移动了238.78 km,在全国和区域层面均出现了北移的趋势;我国水资源重心始终位于粮食生产重心西南方向,移动范围不大。2)从全国层面看,研究期间粮食生产与水资源双要素重心的空间距离增加,整体上空间重叠性下降,但近几年空间距离增加趋势趋于平缓;双要素重心的变动一致性指数均值为-0.06,呈较不匹配状态,但2014—2018年间指数均值为0.14,耦合性略有增强。3)从区域层面看,结合双要素重心的空间距离与变动一致性指数,东北地区和西南地区时空耦合程度较强,西北地区较弱。通过合理规划粮食生产与水资源利用格局、提高农业水资源利用效率等途径,有利于缓解粮食生产与水资源之间的紧张形势。

With the increasing pressure on water resources,grain security under the constraint of water resources is getting more and more attention.To have a better understanding of the contradiction between grain production and water resources,this article analyzes the spatio-temporal distribution of national grain output and total water resources and utilizes the barycenter model to explore the evolution trend and the spatio-temporal coupling degree of grain production barycenter and water resources barycenter from 1998 to 2018 at the national and regional levels.Results show that:1) China’s grain production barycenter has moved 238.78 km to the northeast from 1999 to 2018 and has displayed a trend of northward movement in both national and regional levels.The barycenter of water resources is always located in the southwest of grain production barycenter,without a large range of movement;2) at the national level,the spatial distance between the barycenter of grain production and water resources has increased,meaning the spatial overlap degree of the two elements has decreased,but the increasing trend of the spatial distance has been subtle in recent years.The average value of the changing consistency index of the two barycenters is-0.06,indicating a relatively low matching level,however the mean value is 0.14 from 2014 to 2018,indicating the coupling degree is slightly enhanced;and 3) at the regional level,combined with the spatial distance and the changing consistency index of the two barycenters,the spatiotemporal coupling degree is the strongest in the northeast and the southwest regions,while it is weaker in the northwest region.This paper implies that optimizing planning of water resources utilization pattern and improving the utilization efficiency of water resources in grain production would help alleviate the tense relationship between grain production and water resources.