基于限制程度排序的卢龙县耕地质量提升重点区域划定研究

耕地是保证国家粮食安全的先决条件,也是保障社会安全及社会可持续发展的物质基础。中国耕地总体数量基数大,但整体的质量水平却很低。为明确耕地整治方向,针对不同地区进行不同重点的耕地整治,本文基于秦皇岛卢龙县农用地分等定级,构建耕地质量评价指标体系,运用得分因子标识法,确定限制因子组合类型,引入障碍度模型对限制因子组合进行修正,对卢龙县进行限制因子重点区域划定。结果显示,卢龙县15 981个耕地地块都存在高限制因子,汇总95种限制因子组合类型,共计43 909.71 hm~2。引入障碍度模型修正后卢龙县耕地可划分为5个主导限制因子重点区域:道路通达度限制因子主导区、地形坡度限制因子主导区、灌溉保证率限制因子主导区、农田防护林比率限制因子主导区和有效土层厚度限制因子主导区;其中农田防护林比率限制因子主导区整治面积最大,为37 680.91 hm~2,占耕地总面积的85.81%,主要分布在卢龙镇、燕河营镇和双望镇;其次为有效土层厚度限制因子主导区,面积为3 861.32 hm~2,主要分布在印庄乡;道路通达度限制因子主导区整治面积为1 876.16 hm~2,主要分布在双望镇;灌溉保证率限制因子主导区整治面积为319.44 hm~2,主要分布在燕河营镇;地形坡度限制因子主导区整治面积最小,为171.87 hm~2,占耕地总面积的0.39%,主要分布在刘田各庄镇。结合重点区域内限制因子可知,卢龙县主要限制因子以农田防护林比率和有效土层厚度为主,灌溉保证率和道路通达度为辅;在进行耕地整治时,可重点加强防护林建设,增加有效土层厚度,改良土壤,提高土壤肥力,加强农田设施及田间道路建设,确保粮食稳中增产,保障区域内粮食安全。研究结果可为丘陵山区整治规划、划定耕地质量提升重点区域提供技术支持,为今后耕地整治提供科学依据。

Delineation of key areas of cultivated land quality improvement in Lulong County based on restriction degree

Cultivated land is not only an essential precondition for national food security,but also a material foundation for social security and sustainable development. The overall quantity of cultivated lands in China is large,but quality level has remained low. In order to design a definite direction for cultivated land consolidation and planning for different areas in Lulong County of Qinhuangdao,Hebei Province,this study established a quality evaluation indicator system for cultivated lands and determined the composite types of the limiting factors based on a score factor identification method. The study also introduced the obstacle degree model to modify the limiting factor combination used to delimit the key areas of cultivated land quality improvement. The results showed 15 981 plots of cultivated lands with high level limiting factors and 95 limiting factor combination types in Lulong County,which totally accounted for 43 909.71 hm² of cultivated croplands. After the introduction of an modified obstacle degree model,cultivated land of Lulong County was divided into 5 dominant limiting factor areas consisting of road accessibility dominated region,terrain slope dominated region,irrigation guaranteed dominated region,farmland shelter belt ratio dominated region and effective soil thickness dominated region. The biggest area (37 680.91 hm²) was mainly limited by farmland shelter belt ratio,accounting for 85.81% of the total cultivated area and mainly distributed across Lulong,Yanheying and Shuangwang Towns. The second-biggest area (3 861.32 hm²) was mainly limited by effective soil thickness,which was mainly distributed across Yinzhuang Town. The area limited mainly by road accessibility was 1 876.16 hm² and was mainly distributed across Shuangwang Town. The area limited mainly by probability irrigation was 319.44 hm²,which was mainly distributed across Yanheying Town. The smallest area limited mainly by terrain slope was 171.87 hm²,making up only 0.39% of the total cultivated area and mainly distributed across Liutiangezhuang Town. Based on the limiting factors in the main areas,the dominant limiting factors of cultivated land quality in Lulong County were farmland shelter belt ratio and effective soil thickness. Then probability irrigation and road accessibility played subsidiary roles in limiting cultivated land quality in the study area. The remediation processes of cultivated land included the strengthening of construction of shelter forest and the increase of effective soil thickness and improvement of soil fertility through enhancing farmland establishment and construction of feeder roads. The study provided technical support for planning consolidation strategies in hilly and mountainous areas and defining each section in the improvement of cultivated land quality. It also provided scientific basis for future farmland regulation in the region.