Estimation of the magnitude and spatial distribution of combustible materials in urban areas. A case study of the San Jose area, California

Abstract

AbstractThis paper describes a methodology for estimating the magnitude and spatial distribution of urban fuel loadings using San Jose, California, as a case study. The study was undertaken to provide basic inputs into the modeling of large urban fires ignited by nuclear explosions, which has important implications for studies of the global climatic effects of nuclear war, or the so‐called ‘nuclear winter’ phenomenon. The methodology is based on the measurement of the numbers and sizes of different building occupancy types from aerial photographs for approximately 6000 1000‐ft (304.8‐m) grid cells covering the study area. These measurements were combined with literature‐derived average fuel loadings for each building type to yield the total fuel loading per cell. The total fuel loading thus calculated is approximately 4558.56 × 106 kg, yielding an average of 8.4 kg m−2 (1.7 lb ft−2) for the built‐up area of the city and 9.4 kg m−2 (1.9 lb ft−2) if unoccupied cells (i.e. cells containing no fuel) within the built‐up area are excluded. These figures are lower than previously published average values, due to the low‐density character of San Jose and the exclusion of certain components of total fuel loading by the methodology.