Methods For Evaluating Grid-based Urban Benchmark Land Price

Land price is a barometer of the real estate market, land price and house prices closely related have become one of the important issues related to people’s livelihood, society’s harmony and stability and the national economy’s healthily development. As a government guide-price, the benchmark land price has become an important indicator of a national or regional macroeconomic regulation and control, by which the government and investors can dive insight into the trends of land market and then make decisions of how to control land or investment in land. Benchmark land price is a valid measure to make sustainable use of the land reasonably and effectively. To carry out the research and practice of benchmark land price evaluation have important theoretical and realistic significance.The application of benchmark land prices objectively demand the transformation from the current simple grade-based land price to the grid-based one, which put forward the new challenges of the methods for benchmark land price evaluation. The methods in current regulations and relevant literature, which simply establish a regression model between the land price and the score of series of affecting factors, or merely change the sample land price into the grid land price by spatial interpolation have many problems when using in grid land price evaluation. By necessity, we need new thinking and new method which mixed together both advantages.This paper, orienting the reality application demands, taking data-field theory as a guide, and using accessibility as an important indicator for the characterization of land price gradient, based on taking full account of the inner relationship between the urban structure and land price and the inherent characteristics of the land itself, such as spatial autocorrelation, spatial heterogeneity,etc, explores the new methods for grid-based urban land price evaluation which take into account the merits both of the "factor " method and "interpolation" method. In the new method, the spatial economic statistical methods (such as GWR) and the spatial statistical methods (such as CoKriging) are introduced into benchmark land price evaluation and the evidence-study has been conducted, these two methods achieve the integration of the two ideas from two ways. The specific studies are as follows:(1) The formation mechanism of land price The analysis should be penetrated into city interior transportation and land use system by two ration indicator, accessibility and land price, to interact as a link, to format specific city space structure, and than produce the interaction mechanism of the price changes.(2) The analytical framework of the urban grid benchmark price model based on the theory of data fieldIn the full analysis of the internal mechanism of the formation of urban land and the traditional idea of these two kinds of benchmark price evaluation ("factor" and "interpolation"), take the concepts and methods of physical fields in physics as an example; to describe the model of urban gird benchmark land price evaluation and define the land assessment data field, field source and its type, the field intensity and potential function and a potential functions added model.(3) The study of accessibility models which are oriented at land evaluationAiming at the issues of routine land price evaluation factor quantification, we discuss the applicability of the accessibility model in land price evaluation and come up with accessibility score computing method based on Huff probability model. Empirical studies show that Huff model can be properly used into accessibility score computing in urban land price evaluation. At the same time, we also conduct comparative study of parameter A and we believe that the model is better when A=1.(4)The discussion of distance metricDistance measure is the basis for all spatial analysis, In the same accessibility quantitative model, Different distance measures(Euclidean distance, the Euclidean distance taking into account barriers, Manhattan distance, the simple network distance) have different effect,For the limitations of existing studies, this paper proposed three points improvement methods from the network, the weighted network distance based on Resistance coefficient, empirical studies have shown that the weighted network distance based on Resistance coefficient has the superiority.(5)Grid land assessment based on GWR modelAnalyzing GWR to introduce the applicability and the necessity, proposing the GWR model, Building a space location parameter model to describe the spatial distribution of premium models, then proposing the evaluation method for the grid standard land price, putting forward the ideas that using GWR model for land use factor correction, take the Beihai, GuangXi for example, Using OLS and GWR models to do empirical study. Studies have shown that in practice, GWR model using the factor method mainly, both interpolation method, the integration of this two methods make GWR model have more precision index than traditional OLS model.(6)Grid land assessment based on CoKrigingRecalling the general idea of the grid standard land price, Particularly based on the existing problems, common land grid interpolation method proposed the accessibility of major public facilities Cokriging interpolation method, building grid standard land price, and do empirical research, The results show that the accuracy of Cokriging were better than other direct interpolation method, Achieved mainly by interpolation, taking into account the integration of the two factor method in practice.The main innovation of this paper can be summarized as follows:(1)About assessment analysis, based on the data field idea, put forward compatibility factor method and the interpolation of the urban grid benchmark land price evaluation model analysis framework.(2)As to land location scores quantization, come up with take accessibility scores as characteristic of the level of integrated land location indicators; empirical study the accessibility score of the land price evaluation factor based on Huff model; proposed and study the network weighted distance based on impedance coefficient in land price evaluation.(3) In the methods of building land in the urban grid reference, the GWR model and the Cokriging methods were introduced respectively, from two different ways to achieve "factor method" and "interpolation" of integration, we realize the complementary advantages of these two methods, providing the guidance for the conduct of city land to provide theoretical methods of assessment.