基于LESA的城市边缘区永久基本农田划定研究

城市边缘区耕地自然质量较好,但易受城市扩张和乡村集聚影响,因此,从耕地质量和立地条件两方面综合划定城市边缘区永久基本农田,能够保障耕地优质稳定。本研究以沈阳市边缘区沈北新区为研究区,引入美国LESA体系考虑耕地质量和立地条件,借鉴农用地分等成果构建城市边缘区永久基本农田划定指标体系,进行耕地质量和立地条件综合评价,划定城市边缘区永久基本农田。结果表明：一、二、三级耕地质量优越,立地条件稳定,可划定为永久基本农田,面积为35 510.50hm²,占平原耕地面积的77.94%;四、五级耕地不宜划为永久基本农田。本研究符合国家优先划定大城镇周边永久基本农田的要求,为今后类似工作的深入开展提供参考和借鉴。

Permanent prime farmland demarcation in urban fringes based on the LESA system

The purpose of this study is to demarcate permanent prime farmland in urban fringes and protect permanent stability. Farmland in urban fringes has a better natural quality but is vulnerable to urban expansion and rural agglomeration. When demarcating permanent prime farmland in urban fringes it is necessary to consider farmland from two aspects, the natural quality and site (social economic) condition, and comprehensively judge the stability of future development. Drawing on the LESA (land evaluation and site assessment) system we referenced agricultural land classification results to establish a system of land evaluation and site assessment. Shenbei district in the north of Shenyang, China is in a plain region with superior social economic conditions. We comprehensively evaluated land natural quality and site conditions and demarcated permanent prime farmland in the urban fringe. The results show that total farmland in Shenbei can be divided into five grades. Farmland of grades Ⅰ、Ⅱ、Ⅲ has better natural quality and site conditions and can be demarcated as permanent prime farmland. The area of permanent prime farmland is 35 510.50hm² and the protective rate is 77.94%. Farmland of grade Ⅳ、Ⅴ have relatively poor ones and is unfit to be demarcated as permanent prime farmland. We discuss the national policy need of prior demarcated permanent prime farmland in a big urban fringe and provide a reference for improving and deeply developing analogous work in the future.