基于县域尺度的耕地“非粮化”时空分异及驱动机制研究 ——以湖南省为例

湖南省耕地“非粮化”现象日趋凸显，揭示其时空分异特征及驱动机制、提出“非粮化”缓释策略，对当地农业经济发展及国家粮食安全具有重要意义。基于2003—2020年湖南省地理空间属性数据，运用综合评价法、空间自相关分析模型以及地理探测器模型等方法，从县域尺度探析耕地“非粮化”时空演变格局及驱动机理，并提出缓释策略。结果表明：1）湖南省耕地“非粮化”水平整体波动上升，粮食安全情势不容乐观。2007—2017年耕地“非粮化”水平较前一阶段小幅度下降，2018—2020年耕地“非粮化”水平增幅明显；2）县域耕地“非粮化”水平空间差异特征明显，呈现“西北高-东南低”的分布格局，并在年际间表现出由四周向中部聚集的态势，具有显著的正向空间集聚效应，高-高集聚区主要分布于凤凰县、泸溪县、麻阳苗族自治县、芷江侗族自治县等地；3）粮食单产为耕地“非粮化”的主要驱动因素，地势起伏度的驱动程度最低，二者交互驱动力对“非粮化”的解释度达93.2%。基于此，未来湖南省应开展差异化的区域“非粮化”管控对策、提高粮食产出水平、增加农民经济收益，以针对性地缓解耕地“非粮化”趋势。

The spatiotemporal differentiation and driving mechanism of farmland “non-grain use” at county scale: A case study of Hunan Province

The phenomenon of farmland “non-grain use” in Hunan Province is becoming more and more prominent. To explore its spatiotemporal differentiation and driving mechanism, and to propose mitigation strategies is of great significance for local agricultural economic development and national food security. Based on the geospatial attribute data of Hunan Province from 2003 to 2020, this study adopts the comprehensive evaluation method, the spatial autocorrelation analysis model and the geographical probe model to investigate the spatiotemporal evolution patterns and driving mechanisms of farmland “non-grain use” at the county level, and put forward the alleviation strategies. Results indicate that: 1) The level of farmland “non-grain use” in Hunan Province fluctuated, posing a concerning situation for grain security. The “non-grain use” level of farmland decreased slightly from 2007 to 2017 compared with the previous period, but increased significantly from 2018 to 2020; 2) The spatial differentiation characteristics of “non-grain use” at the county level are significant, displaying a “northwest high-southeast low” distribution pattern, with an annual trend of aggregation from the periphery towards the center. The level of farmland “non-grain use” in Hunan Province has a significant positive spatial agglomeration effect. The high-high agglomeration areas are mainly distributed in Fenghuang County, Luxi County, Mayang Miao Autonomous County, Zhijiang Dong Autonomous County; and 3) Grain unit yield is the primary driving factor for farmland “non-grain use”, while the lowest driving degree attributed to terrain undulation. The interactive driving force of these factors accounts for 93.2% of the explanatory power for “non-grain use”. Based on these findings, Hunan Province should carry out differentiated regional “non-grain use” control countermeasures, improve grain output level, and increase farmers’ economic income to effectively alleviate the trend of “non-grain use” of farmland.