不同比例尺下耕地质量分等结果的差异及影响因素研究

近年来,耕地质量保护问题已逐渐成为我国最突出的问题之一,而耕地质量管理工作需在不同层次上进行,同时也要求有不同比例尺的耕地质量分等成果,但不同比例尺下的耕地质量分等结果在等别面积、空间分布、等别组合以及精度上均存在差异。因此,分析不同比例尺耕地质量分等结果的尺度差异,研究其影响因素,对于提高土地质量管理水平具有重要意义。论文采用计量经济学模型和二元Logistic回归模型,以江苏省东海县为例,对1∶5 000(大比例尺)、1∶100 000(中比例尺)和1∶500 000(小比例尺)3种比例尺下耕地分等结果的差异及其影响因素进行了研究。结果表明:1)不同比例尺下耕地质量分等结果在面积数量、空间分布以及表达精度上均存在一定差异,且比例尺越大,结果越精确;2)导致不同比例尺间耕地质量分等结果差异的影响因素,主要有高程、植被覆盖度、耕地连通度、耕地面积占比、耕地图斑数、坡度、路网密度以及耕地集聚度等,不同比例尺之间的耕地等别差异影响因素是不一致的,且各因素对结果差异的影响力大小也有一定的差别。综合以上结论,可以得出:由于耕地质量分等结果比例尺差异明显,并受多因素影响,所以不同比例尺下耕地分等数据转换与组织十分重要。

Analysis on the Differences and Influential Factors of Cultivated Land Quality Gradation at Different Scales

With the rapid development of economy and the progress of the society, land resource management has been transformed from quantity management to quantity-quality ma-nagement, in which the accuracy of the cultivated land quality grade plays a vital role. Currently, due to the various needs of management such as meticulous management and macro-control, cultivated land quality grading at different scales are needed. However, the results of cultivated land quantity grade differ greatly in accuracy, quantity and spatial distribution because of the effect caused by different scales. Thus, analyzing the scale difference towards cultivated land quantity grade, exploring influencing factors and realizing data integration between different scales on this basis has significant implications to improve the management of land resource quality. This paper conducted a case study of the Donghai County in Jiangsu Province. Firstly, the scale effect on regional cultivated land quality gradation at three different scales (1∶5 000, large scale; 1∶100 000, medium scale; 1∶500 000, small scale) were investigated. The studied scale effect included the differences in terms of the landscape characteristic, grades structure and spatial distribution. Various methods including spatial autocorrelation model, gradient analysis and the Binary Logistic Model were adopted. Then, the natural and socio-economic factors of these scale effects were studied by employing the Binary Logistic Model. The main results were as follows: 1) For the studied three different scales, the corresponding grading results, though in line with each other in general, differed in the spatial distribution of each quality grade. In terms of spatial distribution characteristics such as spatial clustering and variation, the spatial autocorrelation and gradient analysis showed that the consistency between medium scale and large scale was relatively better than that between small scale and large scale. Compared with the cultivated land grading in large scale, the precision of the cultivated land grading in small scale was better than that in medium scale. 2) The influencing factors of cultivated land grading varied from scale to scale. The Binary Logistic Model analysis implied that the grading differentiation between large scale and medium scale was mainly affected by elevation, vegetation cover, patch cohesion, the proportion of cultivated land area, and the ratio of the cultivated land units between two scales. For the cultivated land grading differentiation between large scale and small scale, it was mainly influenced by slope, road density and patch aggregation. 3) The differences of cultivated land quality gradation among different scales are obvious, and it was subject to a number of objective factors, so exploring the conversion and organization of cultivated land grading at different scales was particularly necessary.