中文摘要：

以河北省147个县域为研究单元，借助数理统计和GIS空间分析等方法，揭示1990—2010年粮食单产及其驱动因子的时空演化特征。结果表明：①县域粮食单产“中部高、东西两侧低”与“中南部高、北部低”的层次分异格局非常明显；（爹县域粮食单产以普遍上升为主，单产水平较高的区域沿京广铁路和京哈高速公路向左右两侧扩张，单产水平较低的区域集中分布在河北北部和河北西部，海河冲积平原区粮食单产上升幅度较快；③县域粮食单产的驱动因素呈现为非均衡联动的局域性特征，耕地有效灌溉面积比重对粮食单产的影响最显著。与1990年相比，2010年4种投入要素对粮食单产的影响系数均在下降，系数为负值的县域明显增加，表明部分县域农业生产投入对粮食单产的边际效应已经达到递减阶段。因此，应结合县域粮食单产的现状和驱动因子的效应机理，积极采取相应措施以保障京津冀地区的粮食安全。

英文摘要：

Taking 147 counties as sampling units in Hebei, this paper carries out a preliminary study on the temporal and spatial variability of grain yield per hectare and driving factors by mathematical statistics method, spatial analysis model and GWR model, etc. The following results are obtained. Firstly, the patterns - ＂High in the central while low in both eastern and western sides＂ and ＂High in the southern and central while low in the northern＂ -of grain yield per hectare are very evident. The counties with higher grain yield per hectare are gathering in Taihang and Yanshan piedmont p~lains, while the counties with lower are clustering in the basins of Northwest Hebei mountains, including Bashang plateau area and alluvial plain area of Haihe River. Secondly, grain yield per hectare in 139 counties show an upward trend, increasing by 1402 kg/hm2 from 1990 to 2010. The counties with higher grain yield per hectare are expanding along ＂Beijing-Guangzhou＂ railway and ＂Beijing-Harbin＂ highway, while the counties with. lower are gathering in the northern and the western of Hebei. The grain yield per hectare in the alluvial plain area of Haihe River rises faster. Thirdly, there is a significant autocorrelation for grain yield per hectare in different counties. Compared with 1990, the influence coefficients of the four kinds of inputs to grain yield per hectare show downward trend, and the number of counties with negative coefficient increases significantly, which indicates that some counties are in the phase of diminishing marginal returns for inputs. Therefore, effective measures should be adopted to ensure Jing-Jin-Ji grain security according to present situation of grain yield per hectare and effect mechanism of driving factors.