The Study On Revising Coefficient Of Plot Ratio In Urban Business Land Appraisal

As main guideline of controlling intensity of land use, floor area ratio plays great role in city planning. It is also one of most important factors which affect land-value, the change of which can bring land-value ascend or descend in great range, especially to commerce use of land. Delphi mensuration and sampling site land-value method are often used in amending the floor area ratio in valuing score of town's commerce use of land. These methods are both reasonable, though there are some bugs when they are applied in different places, which results in the problem that it's hard to reflect the correlativity between floor area ratio and land-value for the coefficient of correction table, and so it brings some trouble to the application of the table. So, analyzing the correlativity between floor area ratio and land-value scientifically, the operation mechanism of floor area ratio to land-value and establishing one reasonable and applied floor area ratio amend system, have become one important content of constituting a large amount land amend system.Based on the experience of town floor area ratio research both here and abroad, using methods of combining academic analysis and demonstration research, this article studies coefficient of correction of floor area ratio of commerce use of land in town of LiaoCheng city. Using commerce sampling site material which is update investigated according to benchmark land-value of town of LiaoCheng city, measuring and calculating, amending, and checking up are done. Some abnormal data are eliminated. After three mathematical models between total score and land-price are constituted, regression analysis and checking up are done on the models using microcomputer, and model of coefficient of correction of floor area ratio in commerce use of land is constituted after other models are eliminated, model of coefficient of correction of floor area ratio in commerce use of land of LiaoCheng city is constituted and commerce coefficient table of correction of floor area ratio is obtained, and amended coefficient in different floor area ratio of commerce use of land can be calculated if it is necessary. The main results include such four aspects:1. Effect of floor area ratio to land-price follows rule of increasing returns and decreasing returns, and land price is different because of the difference of city size, district condition, and types of land use according to the extent of effect of floor area ratio; There are positive correlation between coefficient of correction of floor area ratio and floor area ratio. The higher the floor area ratio is, the higher the coefficient of correction of floor area ratio, and the less the extent of the increasing; The higher the floor area ratio is, the larger of the gap between different land level.2. To different city size, district condition, and types of land use, coefficient table of correction of floor area ratio for commerce use of land should be worked out separately.3. When coefficient table of correction of floor area ratio is worked out, income mechanism and the effect of market supply and demand on land-price should be considered thoroughly, and exactness degree of the coefficient of correction of floor area ratio will be affected greatly if such factors are not considered or considered little.4. When measuring and calculating coefficient of correction of floor area ratio using land-price of sampling site, the sampling site should meet certain qualification, such as individual factor(shape, area, ratio between width and depth, and frontage status of the a large amount land)of which in same level (isotropic zone) should be representative; At the same time, in order to minish effect of such factor on land-price, amending the quality, year and time is necessary before measuring and calculating coefficient of correction of floor area.