Abstract:Using the data of sunshine duration over Chinese 34 main cities from 1988 to 2012, the authors studied the changes in annual and seasonal trends of the sunshine duration by liner trend analysis and accumulative anomalies, from the angle of light climate division. It is found that the annual sunshine duration distributes obviously at different levels and reduces from the 2nd to the 5th light climate zone, except the 1st light climate zone. The characteristics of seasonal sunshine duration are similar with that in the whole year, but the increasing or decreasing amplitude is different between 5 light climate zones. This research provides a new theoretical method to understand the changes of light climate in our country and there will be of great significance to guide the architectural lighting design and energy conservation in corresponding areas.
