As the main part of fire fighting force battle fire engines can reduce the property loss caused by fire. In the above section,
the influence of fire engines on the risk of heavy fire is analyzed qualitatively. And then, for the serious fire risk causing
great property loss, we would focus on how many fire engines needed to be dispatched to meet the requirement. As the
burned area represents the property loss in certain extent, so in this section, through the serious fire cases, the relationship
between the burned are of different types of building fire and fire engines needed to be dispatched is analyzed, to
quantitatively describe the relationship model of the property loss caused by fire and the total number of fire engines needed
to be dispatched.