Abstract:  The water supply for municipal fire protection in China is selected according to the population. In ancient towns with a small population and high fire risk, there will be insufficient fire water supply. This paper proposes the district-net composite simulation technology to analyze the fire spreading process of the building complex and the scale of the fire at different moments. According to the experience statistics, the fire brigade's arrival and intervention time is analyzed to obtain the fire water demand at the corresponding time; the field fire hydrant discharge experiment is used to obtain the fire water supply to verify whether it meets the fire water demand. Taking an ancient town as an example, the results show that most of the fire fighting water supply in this ancient town is generally lower than the fire fighting water demand during the fire. According to the fire risk calculation result of the fire intervention time of 16~18 min, it is recommended that the water supply should be timely increased to 30~35 L/s. 

Key words:  , fire, ancient town, fire spread, fire water supply