基于栅格的嫩江县耕地资源安全等级划分及地域分异特征

Security Classification and Regional Differentiation of Cultivated Land Resources in Nenjiang County Based on Raster

耕地资源安全是保护耕地和保障国家粮食安全的基础,其空间安全格局是土地利用规划的重要依据。以松嫩平原北部典型区域黑龙江省嫩江县为研究区,综合运用RS和GIS技术,基于1km空间尺度栅格数据,运用因子分析法和加权综合评价法计算每个栅格的耕地资源安全值,运用自然断点法划分安全格局,将研究区耕地资源安全分为Ⅰ级(非常安全)、Ⅱ级(比较安全)、Ⅲ级(基本安全)、Ⅳ级(临界安全)、Ⅴ级(不安全)五个等级,并研究其空间分异。结果表明:栅格数据可以为耕地资源安全研究提供准确的数据;研究区耕地资源安全等级所占比例最高的是Ⅳ级,最低的为Ⅴ级,所占比例分别为25.74%和8.36%,大部分的地区都处于安全状态,临界安全等级耕地所占比例略高;耕地资源安全等级随着高程、坡度的增加而降低,由平原向低海拔丘陵过渡,呈现出由西向东安全等级逐渐降低的空间地域分布格局,并且在不同行政单元分布不同。研究结果可为县域耕地资源可持续利用提供参考。

The security of cultivated land resources is the foundation of protecting farmland and ensuring national food security, and its spatial security pattern is an important basis for land use planning. Taking Nenjiang County, a typical region of northern Songnen Plain in Heilongjiang Province, as the study area, based on raster data of 1 km scale, RS and GIS technology, we calculated the security value of cultivated land resources for each grid by using the method of factor analysis and weighted evaluation; by using the natural break point safety law pattern, we divided the cultivated land resources security grades in study area into 5 levels： level Ⅰ （very safe）, level Ⅱ （safe）, Ⅲ （basic safe）, Ⅳ （critical safe）, Ⅴ （not safe） five levels, and examined its spatial differentiation. The results show that the raster data can provide accurate data for the research on the security of cultivated land resources; the proportion of cultivated land resources security level in study area is the highest in level IV, the lowest in level V, the proportions are 25. 74% and 8. 36%, respectively, most of the areas are in the safe condition, and the proportion of the critical safe level is slightly higher; cultivated land resources security level decreases with the increase of elevations and slope gradients, from the plains to the low altitude hills transition, showing a spatial distribution of security level pattern gradually decreases from west to east, and the distribution is different in each administrative units. The results can provide references for the sustainable utilization of cultivated land resources in this county.