A STUDY OF THE TIME-SPATIAL VARIATION OFSOLAR RADIATION RESOURCES IN NINGXIA
宁夏太阳辐射资源时空变化规律研究

y using the methods of power spectrum and mathematical statistics, the time-spatial variation of solar radiation resource of Ningxia has been studied inthis paper. The results indicate that apparent areal differentiation laws of solarradiation tesource of Ningxia in time-spatial variation have been observed, e. g.,much more and higher sunshine hours, percentage of sunshine and total solar radiation are found in northern part than in southern part in spatial distribution.Apparent temporal variation laws of solar radiation resource occur, e. g., in terms of intra-annual variation, it is sufficient in tab half year of summer but deficient in the half year of winter; in inter-annual case, quasi-periodic variationexists generally whereas for secular variation, a ten-to-twelve-year period occursfollowing a quasi-three-year variation.