Abstract: In order to study the risk of aircraft taxiing conflicts in large airports, a method was worked out for evaluating the operational risk of airport maneuvering area based on the spatial and temporal distribution characteristics of airport hotspots. Firstly, an airport in the south-central region of China was taken as an example, whose aerodrome surveillance radar data was divided into several 3 hours long segments, and airport hotspots were identified for the segments, and their spatial and temporal distribution characteristics were analyzed. Then a risk assessment model was built, in which the possibility of hotspots formation, severity of the consequence of the recognized hotspots, conflict sortie ratio of aircrafts, level of conflict possibility, duration of conflict and conflict level were considered. Based on the existing risk level assessment standards, the risk levels of the airport hotspots were evaluated. According to the results, risk levels of airport hotspots are affected by airport traffic flow and operational modes of runway. The operational risk of runway 02 is higher than that of runway 20. If the runway 02 is used for landing or taking-off, the highest risk level will be reached in the segment of 12:00-15:00. And if the runway 20 is used, the risk level of hotspots is relatively high in the segment of 9:00-12:00. The results conform with the reality of the airport.

Key words: risk evaluation, airport hotspots, spatial and temporal distribution characteristics, surface traffic flow, conflict sortie ratio of aircrafts;duration of conflict