Abstract:

Based on the daily observed sunshine duration data of 28 meteorological stations in Liaoning province from 1962 to 2017 and Fortran language automatic recognition technology and statistical diagnostic analysis method, the temporal and spatial variations of sparse sunlight disaster in the facility agriculture growing season were analyzed taking cucumbers and eggplants as examples.The results show that the frequencies of mild sparse sunlight disaster account for 96.1% of the total, whereas the frequencies of moderate sparse sunlight disaster only account for 3.9%, and there is no severe sparse sunlight disaster during the 56 years.Spatially, the frequencies of mild sparse sunlight disaster appear a zonal pattern with the lowest frequency in the west and the highest frequency in the north and east of Liaoning province, with the most significant increasing trends in east Fuxin and east Chaoyang.Temporally, the frequencies of mild sparse sunlight disaster appear the most in November whereas the least in February and March, with a climatic trend rate of 0.68 per 10 years and a significant inter-decadal mutation around 1999.The frequencies of mild sparse sunlight disaster are negatively correlated with the wind speed, whereas positively correlated with the relative humidity and rainfall days.Wind speed and rainfall days have a significant influence on the linear increasing trend of the frequency of mild sparse sunlight disasters over most parts of Liaoning province, while relative humidity has a significant influence on it over individual parts.Since 1962, cucumbers and eggplants are the most vulnerable to mild sparse sunlight disaster in Liaoning province, showing significant linear increasing trends spatially and temporally.

Key words: Facility agriculture, Sparse sunlight disaster, Impact factors