基于地质环境适宜性的基本农田布局优化研究

基本农田划定及布局受自然、经济社会、生态环境等多元因素的影响,但是当前基本农田布局研究中仍然缺少对地质环境因素的系统考察。该文试图从耕地利用的地质环境约束出发,以徐州市城市规划区为例,开展面向耕地的地质环境适宜性评价,通过GIS空间叠加分析对现行基本农田布局方案进行优化。研究结果表明:1)依据耕地利用与地质环境的关系,整合地形、土壤、水文、地质灾害、地质环境问题等要素开展区域地质环境适宜性评价,是进行基本农田布局优化的前提。2)研究区地质环境适宜性评价等级为较不适宜、不适宜的基本农田面积共2 431.69 hm~2,研究区基本农田存在明显的地质环境约束。3)通过将较不适宜、不适宜的基本农田调出,再从一般农地中调入适宜、较适宜的耕地形成新的布局方案,从地质环境角度看研究区基本农田布局实现了优化。该研究探索了基于地质环境约束的区域基本农田布局优化路径,还可以在城乡建设用地、工矿用地等类型的土地布局优化中进行应用,从而为空间规划编制和管理中实现"矿地融合"服务。

Optimization of prime farmland layout on basis of geological environment suitability

As the essence of cultivated land, prime farmland under the special protection is significant for the cultivated land output and the national food security. Thus the delineation and layout of the prime farmland is not only the starting point for the prime farmland protection, but also the foundation of the efficient use and effective supervision for the prime farmland. It has found that the layout of prime farmland is affected by various factors, such as natural factors, economic and social factors, ecological environmental factors, etc. Although some studies have considered to put individual geological environmental indicators into cultivated land and prime farmland layout, there is still a lack of systematic investigation about the geological environmental factors in prime farmland layout study. From the constraints of the geological environment on cultivated land use, in this paper, we took Xuzhou urban planning area as an example, to build the evaluation index system of regional geological environment suitability for cultivated land, which was constructed from five aspects: topographic conditions, soil conditions, hydrological conditions, geological disasters and geological environment problems, and used the matter-element model to evaluate the geological environmental suitability of cultivated land. Furthermore, after superimposing the evaluation results with the prime farmland layout scheme of the General Land Use Planning in Xuzhou City (2006-2020), there were arable land with less suitable grade or unsuitable grade which should be transferred out of the Prime Farmland Protected Area. At the same time, because of the constraint of the prime farmland retention index, the same amount of cultivated land with suitable grade or general suitable grade should be transferred from the general agricultural land area into the Prime Farmland Protected Area. Finally, the optimization scheme of the prime farmland layout based on the geological environment constraint was obtained. The result showed that according to the relationship between cultivated land use and geological environment, it was the premise for optimizing the layout of prime farmland to integrate the factors including topography, soil, hydrology, geological disaster and geological environmental problems to establish indicator system of the region geological environmental suitability assessment. There were 2 431.69 hm2 of the prime farmland whose suitability level was less suitable grade and unsuitable. Through transferring the less suitable and unsuitable prime farmland, then adding the suitable and less suitable cultivated land from the general farmland area, the new layout of prime farmland in study area was optimized from the point of geological environment. In this paper, we explored the optimization path of prime farmland layout in region based on the constraints of geological environment, which can also be used in the layout optimization of urban and rural construction land, industrial and mining land and other types of land, in order to promote the "mine and land integration" in process of spatial planning decision and management.