Abstract The factors directly associated with land quality can be considered by the method of multi-factor comprehensive evaluation. This method combines qualitative and quantitative analysis, transforms experience into scientific indexes, and converts the direct judgment on the complicated things into the single judgment on some respects of the thing, which can decrease the subjectivity, and ensure the scientific classifications on land gradation. This paper chose multi-factor comprehensive evaluation to estimate land gradation. The main idea was that location factors influencing land grade were chosen in order to determine the gradation factors with land location conditions. The weights of all factors were given by their importance of influencing degree. Then, the scores of all factors and indexes were calculated with the uniform standard in the appointed sample unit. In view of the above, the land gradation was obtained. Firstly, this paper introduced the method of multi-factor comprehensive evaluation and the related equations. Then, based on analyzing the available literature, the paper constructed the index system of urban land gradation. Eight factors were selected, which are commercial-service prosperity, road access, external transport convenience, public transport convenience, public service maturity, cultural-sport facility maturity, population density, and urban planning, to construct the index system including 22 indexes on urban land gradation. Thirdly, the weights of factor layers were obtained by Delphi method with the amendment of mean and variance. In practical terms, this study designed the table of expert surveys so as to collect the ideas of expert panel. In all, thirty two experts accepted survey in the first round. The samples adopted had 30. According to the results of mean and variance to all samples, the initial views of the weights were determined. For reasons given above, the final weights were given by collecting the ideas of 10 experts in the second round. Finally, a case study was processed based on 6 sample units of built-up areas in Yinchuan City by multi-factor comprehensive evaluation. The analysis of the appraisal results shows it is in accordance with the real situation of development in Yinchuan City. To be more specific, the distinction of 6 sample units is accordant with the practical situation. According to measuring market price of land, the total scores of 6 sample units and market price of land are positively associated, and the price will increase along with the increasing land gradation stage by stage. It fully shows that land gradation is scientific and reasonable with the method of multi-factor comprehensive evaluation, and the index system of urban land gradation which the paper has constructed is practicable.
2008, Vol. 23 
