Characteristics of Change in Solar Radiation and Solar Energy Resources Use over the Eastern Hexi Corridor
1960年至2009年河西走廊东部太阳辐射变化规律及太阳能资源利用分析

Using linear regression and the Mann-Kendal method, characteristics of variation in solar radiation over the eastern Hexi corridor during the period 1960-2009 were analyzed. Results showed that the annual average solar radiation was about 5988.7MJ/m2; it is therefore rich in solar energy resources. Years with solar radiation larger than 5800 MJ/m2 account for 76% of all years. The solar radiation showed obvious seasonal variation, largest in summer, followed by spring, and smallest in winter, with the solar radiation in summer being more than one time that in winter. Change in month solar radiation showed unimodal. The maximum and minimum monthly solar radiation appeared in June and in December, respectively. The time in a day with the strongest solar radiation was from 12:00 to 13:00. The mean annual solar radiation generally increased at a rate of 12.7 MJ/(m2·a), with increasing in the 1960s, decreasing in the 1970s, and increasing slightly since the 1980s. After that, it remained an increasing trend during the period of the 1990s and the first decade of the 21st century. The seasonal solar radiation increased to varying degrees, showing increasing rates of 4.72, 5.69, 2.0, 0.17 MJ/(m2·a) for spring, summer, autumn, and winter, respectively. The year of a sudden change in annual solar radiation and annual sunshine hour and the year of climate starting warming in the region were generally synchronous. The warming climate seemed to have caused increase in precipitation over the mid-north of the area. The increased precipitation appeared to mitigate air pollutant, making air visibility improved. As for spatial distribution, the annual sunshine hour gradually deceased from the northern desert areas, the central plain areas, to the southern mountains. It was concluded that solar energy is generally rich and has the potential to be exploited and utilized. This study would be conducive to a better understanding of solar radiation and sunshine hour over the eastern Hexi corridor, providing reference for solar energy development in the region.