城市化背景下山区耕地撂荒的地域分异研究：以粤北山区为例

Farmland marginalization has become the main trend of land-use change in the mountainous areas of China since 2000, during the process of rapid urbanization. However, this trend runs counter to the strictest farmland protection system currently implemented in China, resulting into unreasonable consequences of the coexistence of farmland abandonment and new farmland reclamation in mountainous areas. Moreover, China's rural poverty regions are mostly distributed in mountainous areas, and farmland abandonment objectively increases the probability of poverty and the difficulty of rural poverty alleviation. How to reduce farmland abandonment and its negative effects have become one of the key issue about land-use in Chinese mountainous areas in the new period. Taking the mountainous area of Guangdong Province as an example, this project uses large-scale and high resolution land data, combining with the remote sensing images and rural households' survey to identify the abandoned farmland plots since 2000, and then quantitatively depicts the spatial distribution characteristics and laws of abandoned farmland. Next, coupling natural and human factors, this project will systematically study the key factors to explain the spatial difference of farmland abandonment among the study regions and their mechanisms in mountainous areas. Third, using spatial boosting model and GeoDetector, we will identify the leading factors driving abandonment in different regions, and scientifically classify the types of farmland abandonment and their ranges. Finally, we will propose targeted land-use policies and measures of farmland abandonment and poverty alleviation for different types, and also the suitable mode for agricultural scaled production in mountainous areas. This project will contributes to a deep understanding of the occurrence and development of farmland abandonment in mountainous regions, and provide scientific suggestions for rational protection and utilization of land resources, the adjustment of farmland protection policy and mountainous rural vitalization.

在城镇化过程中山区耕地撂荒的现象十分普遍，但这一趋势与我国当前实施最严格耕地保护制度相悖，造成山区耕地开垦与撂荒共存的不合理后果。同时，我国贫困地区多分布在山区，耕地撂荒客观上增大贫困发生概率和脱贫难度。如何减少耕地撂荒及其所带来的负面效应成为新时期山区土地利用研究的难点。本项目以粤北山区为例，利用大比例尺土地调查数据和遥感影像，结合农村、农户抽样调查数据，提取粤北山区撂荒耕地信息，定量刻画山区撂荒耕地空间分布特征和规律；耦合自然和人文因素，系统分析山区耕地撂荒程度差异的关键因素及其作用机理；借助空间增强回归树模型和地理探测器，识别不同地域耕地撂荒的主导因素，科学划分耕地撂荒地域类型，提出差异化的精准调控措施和经营模式。这一研究有助于深入剖析山区耕地撂荒发生和发展机理，为合理保护和利用山区耕地资源、促进乡村振兴提供政策建议。

山区耕地撂荒是城镇化过程中的普遍现象，但这一趋势与我国当前实施最严格耕地保护制度相悖，对国家的粮食安全构成威胁。因此，如何减少耕地撂荒及其所带来的负面效应成为新时期山区土地利用研究的难点。本项目以粤北山区为例，利用大比例尺土地数据和遥感影像，结合农村、农户抽样调查数据，构建山地丘陵区耕地撂荒空间信息提取技术方法，提取粤北山区50个山区县的撂荒耕地信息，建立粤北山区耕地撂荒空间信息数据库，定量刻画了山区撂荒耕地空间分布特征和规律。在此基础上，借助多元回归模型和地理探测器，基于多尺度视角，系统研究山区耕地撂荒程度差异的关键因素及其作用机理，识别不同地域的耕地撂荒的主导因素，科学划分耕地撂荒地域类型，提出差异化的精准调控措施和经营模式。. 研究结果表明：（1）基于高精度土地利用数据能有效提取了山区耕地撂荒地块信息，准确率达94%；（2）粤北山区2015年撂荒耕地面积达4399平方公里，撂荒率为27.57%，撂荒率热点区主要分布在河源市北部、梅州市东部、汕尾市北部和阳江市北部；（3）撂荒地大部分为1亩以下的地块，主要分布在坡度6度以下和居民点500米范围内；（4）乡镇撂荒率与所在乡镇的平均高程、平均起伏度、平均林地比重、到县中心平均距离、平均通勤距离、耕地平均坡度为正相关关系，与耕地平均质量、耕地平均地块面积呈负相关；（5）不同地区的撂荒主导影响因素不同，北部地区中地块坡度因子决定力q值最大，东部和西部地区中林地比重的决定力q值最大；（6）根据撂荒主导因子将粤北山区耕地划分为“地形主导型撂荒”“区位主导型撂荒”和“比较劣势主导型撂荒”，并相应划定为森林转型促进区、适度规模化利用区和特色发展区，实施差异化的调控措施。本研究中的撂荒地块提取技术以及撂荒空间信息数据库能为自然资源和农业部门开展山区耕地撂荒监测、监管提供技术支撑和数据支撑，耕地撂荒地域分异规律和机理分析能为合理保护和利用山区耕地资源提供政策建议。