土地集约利用空间分异研究中指标标准化方法研究

土地集约利用空间分异研究中指标标准化通常采用极差标准化等方法,这类方法默认各区域集约临界值相同,从而使得评价中区位好的区域土地集约水平高于区位差的区域。基于级差地租Ⅰ和级差地租Ⅱ理论提出新的指标标准化方法,指出传统指标标准化方法的问题,并以重庆市耕地集约利用空间分异为例进行实证比较。研究充分考虑了不同区域因禀赋差异造成的单项指标理想值(临界值)的差异,弥补了传统指标标准化方法的不足,有助于完善土地集约利用空间分异的研究。研究表明:土地利用集约度是一个相对概念,其参照物为区域土地集约临界点,理论基础是级差地租Ⅱ;区位不同导致区域间土地利用强度存在差异,它是级差地租Ⅰ的一类现象,这类差异可称为"禀赋差异";每个区位点适度指标标准化值Y与该区位指标现状值x₁₁和集约临界点x₁有关,与其他区位指标现状值无关;传统标准化方法将指标现状值或现状平均值设为集约临界值,没有考虑不同区位集约临界点差异,因而空间分异结果更符合土地收益空间分异规律;重庆市耕地集约利用度空间分异研究表明该方法在空间分异、集约度绝对值和区县集约度比较等方面优于传统方法,更符合不同区县耕地利用实际。

METHODS OF INDICATOR NORMALIZATION IN THE EVALUATION OF SPATIAL VARIATION OF INTENSIVE LAND USE

The traditional methods of indicator normalization such as maximum difference normalization were used in the research of spatial variation of intensive land use. These methods seldom considered the effect of location differences and assumed the same critical point of intensive level at different locations, leading to higher land use intensive levels at better locations. This paper pointed out the shortcomings of the traditional normalization methods and built a theoretical model of spatial variation of land use intensive level based on the theory of differential rent I and differential rent II, and tested the model by assessing the spatial variation of the intensive level of the cultivated land Chongqing. This study considered the difference of the ideal value (critical value) of a single indicator caused by endowment variation of different regions. Therefore, it may overcome the shortcomings of the traditional indicator normalization methods and improve the research on the spatial variation of intensive land use. The results showed that: the land use intensive level is a relative concept, the reference frame of which is the critical point of regional land use intensive level and the theory basis is differential rent II. The location differences cause the differences of regional land use intensity, which is a type of differential rent I and can be called "endowment variation". The normalized value Y of a moderate indicator of one location has relationship with the actual value and the critical point of intensive level of this location, which has no relationship with the actual values of other locations. The traditional normalization methods set actual value or actual average value as the critical point of intensive level, leading to the consistence of the result with the spatial variation of land reward. The spatial variation assessment of the cultivated land intensive level of Chongqing showed that the theoretical model is better than traditional methods in the investigation of spatial variation, intensive level of land use and the comparison between counties. The theoretical model more conforms to the real cultivated land use of different counties than traditional methods.