Kojiro Watanabe

Cellular automata modeling of fire spread in built-up areas- : A tool to aid community-based planning for disaster mitigation

Abstract Japan has many built-up areas with a high proportion of old wooden structures. These areas will be badly damaged by collapsed buildings and the spread of fire in the event of a seismic disaster. The government is therefore focusing on the improvement of these areas. For the promotion of such improvement, there is a need to build consensus for disaster prevention countermeasures through community-based planning by both the residents concerned and the administration. In the present study, we developed a model as a planning support tool that can visually simulate the spread of fire. This model incorporates firefighting activities and can realistically show the detailed fire spreading process that traditional models cannot represent in built-up areas, using cellular automata. The model was applied to a historical built-up area in Japan. Based on the simulation results obtained by application of the model and the actual fire records of Japanese built-up areas, the calibration and reproducibility of the model were examined and reviewed. From the outcome of this process, we are confident that the use of simulation results is of value when examining the effects of improvements in the local environment during the collaborative planning process.

Cellular Automata Modeling For Fire Spreading As a Tool to Aid Community-Based Planning for Disaster Mitigation

As a tool to support collaboration in community-based planning for disaster mitigation in Japanese old wooden built-up areas, we attempt to develop a fire spreading simulation model incorporated a fire fighting activity using Cellular Automata (CA). The proposed model can deal with the process of fire spreading in a building that traditional models can not represent. Whether or not fire can spread is based on a stochastic calculation process to reproduce uncertain fire spreading. The errors caused by the stochastic factor are analyzed by carrying out simulation two or more times under the same condition. Moreover, the reproductivity of the model is examined by comparing simulation results with actual fire records.

Modeling Land Conversion in the Colombo Metropolitan Area Using Cellular Automata

Abstract This paper proposes a Cellular Automata (CA) model to evaluate the urbanization patterns arising from the regulation of urban growth on paddy lands in the Colombo Metropolitan Region (CMR). Most of the historic map data available for the CMR before 1990 are temporally sporadic and spatially incomplete. As an alternative to maps, classified remote sensing data are used to analyze the urbanization process. Logistic regression is applied to derive factors of urbanization and the various relationships among them. The relation between ′urban′ and ′non–urban′ serves as an explanatory variable. The factors explaining that relationship are calculated by exploratory logistic regression analyses. The probability calculated from the statistical model is used for CA transition with a random number. Several growth patterns are simulated based on a range of transition thresholds to test the CA model. Status quo growth and several growth control scenarios are simulated for the period from 1987 to 2002 based on an optimum threshold. The simulation result of the status quo growth is evaluated with several evaluation methods. The level of agreement between the estimated result from the status quo model and the actual data is 62%, while the multi–scale goodness–of–fit method produces highly accurate values for the given range of resolutions.

Estimating the Changing Distributions of Population and Employees by Cellular Automata

This paper aims to develop an operational cellular automata model to simulate the changing distributions of population and employees in a local city of Japan. The model is composed of two parts of process of these changes. In order to provide a realistic simulation of the distributions, we introduce a critical parameter representing the relation of zoning system in Japan and urban activity. The reproductivity of the model is examined by illustrating simulation results.