Functional Method for Analyzing Open-Space Ratios around Individual Buildings and Its Implementation with GIS

Abstract

An open-space ratio is often used as a first basic metric to examine the distribution of open space in urbanized areas. Originally, the open-space ratio was defined as the ratio of the area of open space (unbuilt area) to the area of its building site. In recent years, residents have become more concerned with the open-space ratios in the broader neighborhoods of their individual buildings than with their own building sites. To address this concern, this paper proposes a method for dealing with the open-space ratio in the variable x-meter buffer zone around each building, called the open-space ratio function, and implements it using standard GIS operators. The function and its implemented analytical tool can answer the following questions. First, this function shows how the ratio varies with respect to the bandwidth to discuss the modifiable area unit problem. Second, as the ratio changes, the function shows in which bandwidth zone the ratio is the highest, indicating the best open-space environment zone. Third, in the pairwise comparison for housing selection, the function shows in which bandwidth zone a specific house is better than another. Fourth, the function shows in which bandwidth zone the variance among all buildings in a region is the greatest. Fifth, in this zone, buildings are clustered in terms of open-space ratio. The resulting clusters are the most distinct. Sixth, to examine the open-space ratio around a clump of buildings (such as a housing complex), the function shows how to obtain clumps. Seventh, it is shown how the open-space function provides a wide range of applicability without changing the mathematical formulation. Finally, this paper shows how to implement the function in a simple computational method using operators and a processing modeler provided by the standard GIS without additional software.