松嫩高平原黑土区耕地利用系统安全格局及其空间演变

Security pattern and spatial evolution of cultivated land use system in black soil region, Songnen high plain

为切实保护耕地和实现区域耕地的可持续利用,该文以巴彦县为研究区,将研究区的耕地利用分为西北部平原耕地区、中部漫岗平原缓坡耕地区、东部低山丘陵坡耕地区、南部平原耕地区和南部冲积平原耕地区5个区,从系统角度,以影响研究区耕地利用系统安全的自然、经济社会、生态等驱动因子分析为切入点,运用"3S"技术手段,利用因子分析法和加权综合评价法计算耕地利用系统安全值,采用Kriging插值法将安全值分为Ⅰ级(非常安全)、Ⅱ级(较安全)、Ⅲ级(基本安全)、Ⅳ级(临界安全)和Ⅴ级(不安全)5个等级,运用栅格数据的空间分析功能,分析研究区1991-2009年耕地利用系统安全格局变化及空间演变。结果表明:1991年和2009年,研究区各安全等级所占比例以Ⅰ级、Ⅱ级、Ⅲ级为主,Ⅴ级最低。从1991-2009年的变化趋势上看Ⅰ级、Ⅱ级呈减少趋势,Ⅲ级、Ⅳ级、Ⅴ级呈增加趋势,耕地利用系统安全程度在降低;1991年和2009年2个时点,耕地利用系统安全水平空间分布均不平衡,西部、北部高,东部、南部低,且2009年较1991年有增强趋势,各安全等级在不同耕地利用分区上空间分布格局差异明显,安全级别较高的Ⅰ级、Ⅱ级集中在西北部平原耕地区、中部漫岗平原缓坡耕地区和东部低山丘陵坡耕地区,安全级别较低的Ⅳ级和Ⅴ级主要分布在南部平原耕地区和南部冲积平原耕地区,安全等级最高的Ⅰ级在中部漫岗平原缓坡耕地区分布最多;1991-2009年近20 a研究区耕地利用系统安全格局空间演变特征明显,Ⅰ级表现为集中向西北部平原耕地区转移,Ⅱ级变化较为分散,在西北部平原耕地区和南部平原耕地区分布比例降低,在其余3区升高,Ⅲ级由南部平原耕地区向南部冲积平原耕地区过渡,Ⅳ级以原区域为中心向四周扩散,Ⅴ级由南部冲积平原耕地区向南部平原耕地区转移;为保障研究区耕地利用系统安全,提出应优化土地利用结构、改变传统的农业生产方式、严格控制非农建设侵占耕地以及合理开发耕地后备资源等对策建议。

To protect cultivated land earnestly and realize its sustainable utilization, this paper took Bayan county as a study area, dividing it into five cultivated land zones： a plains cultivated land area in the northwest area （region I ）, a plains of diffuse hillock gentle slope cultivated land area in the central area （region II）, a low mountain slope cultivated land area in the east area （region III）, a plains cultivated land area in the south area （region IV）, and an alluvial plain cultivated land area in the south （region V）. From the system point of view, taking a driving factors analysis, which impacts on the cultivated land use system security from the natural, economic, social, and ecological perspectives as the breakthrough, by employing ＂3S＂ technology, the study used the factor analysis and weighted comprehensive evaluation methods to calculate security value, and the Kfiging interpolation method to divide it into five levels： level I （safest）, level II （safer）, level III （basic safety）, level IV （critical safety）, and level V （unsafe）, and used the spatial analysis function of raster data to analyze security pattern changes and the spatial evolution of the cultivated land use system during the years 1991--2009 in the study area. The results showed that： in 1991 and 2009, the proportion of each of the security levels in the study area gave priority to level I, II, III, and for level V it was low, but from the changing trend of 1991--2009, level I and II showed a decreasing trend, levels III, IV, V were an increasing trend, and the security degree of the cultivated land use system was reducing; For the spatial distribution, the security levels of the cultivated land use system were showed imbalance in 1991 and 2009, the northwest was high, the southeast was low, and this trend was higher in 2009 than in 1991. The spatial distribution pattern in each security level showed significantly differences in different cultivated land zones, security level I, II concentrated in region I, II and III, level IV and V were mainly distributed in region IV and region V, level I as the highest safety rating were mostly in region II. The security pattern spatial evolution characteristics were obvious during the past 20 years （1991--2009）, and level I was focused on the performance of transfers to region I, the changes of level II were more dispersed, the distribution ratio was decreased in region I and IV, and increased in the other three regions, level llI was transferred from region IV to region V, level IV was spread around the original region, and level V was transferred from the region V to region IV. In order to guarantee the cultivated land use system security of the study area, what was needed was to optimize the land utilization structure, change the traditional mode of agricultural production, strict control of non-agricultural occupation farmland, and exploitation of the reserve resources of the cultivated land reasonably should be used.