Observation and Research of Daylight Climate in the Chongqing Region
LIANG Shuying
CHEN Guiqi
YANG Yi
Abstract：Observation of daylight climate is an important method to obtain region-specific data,which supports the development and utilization of local natural daylight resources.In this study,long-term field measurements were conducted in the Chongqing region to collect extensive light climate data over multiple years.The dataset includes global illuminance,vertical illuminance in various directions,sunshine duration,daylight spectrum,sky luminance distribution,and sky illuminance distribution.Focusing on the year 2020,this research provides a detailed analysis of the natural daylight illuminance characteristics specific to the Chongqing area.The results showed that the annual average global natural illuminance in the Chongqing area is 28 297 lx,with the average global illuminance between 9:00 and 15:00 reaching 35 379 lx.Natural illuminance shows a positive correlation with the solar altitude angle.The distribution of natural light resources throughout the year is highly uneven,exhibiting strong seasonality:summer＞spring＞autumn＞winter.During summer and spring,natural illuminance displays high variability,with the difference in maximum illuminance between two consecutive days or between adjacent hours exceeding 130 000 lx.Chongqing experiences a shortage of natural light resources,with the annual average duration of natural light exceeding the critical illuminance threshold being only 9.71 h.This duration is particularly low in autumn(8.17 h)and winter(7.61 h),significantly below the national average.The distribution of sky illuminance is closely related to sky types:under clear and intermediate skies,sky element illuminance decreases radially from the sun's position,whereas under overcast skies,the illuminance decreases radially from the zenith.This study has,to a certain extent,enriched the light climate database for the Chongqing region,providing data support for design and research related to natural light utilization in the area.
Keywords：daylight climate observationdaylight illuminancedaylight utilization durationhigh dynamicssky illuminance distribution
Publication Date：2025-08-30
Online Publishing Date：2025-09-17(First online date of this platform, not the publication date of the document)
Pages：12( 96-107 )