太阳能资源的开发利用对人类减少化石燃料的消费及温室气体的排放具有极其重要的意义。因此,研究某一区域太阳能资源的时空分布及稳定性对于开发利用太阳能资源至关重要。论文从区域的角度,利用西北5省西安、西宁、兰州等27个辐射站逐日太阳总辐射(1961—2008年)和延安、乌鲁木齐、安康等163个气象站逐日日照时数资料(1958—2008年),用统计分析和规则样条函数插值相结合的方法,采用太阳总辐射和日照时数作为评价指标,分析了西北地区近50 a来太阳能资源的时空变化特征。结果表明:①研究区太阳能资源年际变化和季节变化特征基本一致,中部青海地区日照时数最长和太阳能总辐射最为丰富,属于资源丰富区,陕西南部及西南部地区太阳能资源相对最为贫乏,属于资源缺乏区;②近50 a来,西北地区年总辐射呈明显下降趋势,年均日照时数下降趋势较缓;③163个气象站近10 a各月日照时数大于6 h的天数有45~327 d,大部分站点在200 d以上,其中每年有15个站点大于300 d;④陕西中及南部、乌鲁木齐周边地区太阳能资源最不稳定,太阳能稳定程度指数K值最高,为12.21,而青海北部及青、甘、新三省交界地带资源最为稳定,K值最低,为1.27;⑤太阳能资源的稳定程度与资源潜力大小分布较为一致,即太阳能资源较为稳定的地区,总辐射最高、日照时间最长。

Development and utilization of solar energy play a vital role in reducing the fossil energy consumption and greenhouse gas emissions for human being. Solar energy, which is considered as one of the most significant renewable energy resources in the future, plays a vital role in mitigating global warming. Therefore, it is extremely necessary to figure out the spatial and temporal distribution of solar energy resources in certain regions, as well as its stability so as to better develop and utilize such renewable resources. Based on daily data of solar sunshine and solar total radiation from 27 metrological stations from 1958 to 2008 and 163 radiation stations from 1961 to 2008 such as Xi’ning, Lanzhou, Xi’an, etc., our study analyzes the characteristics of the spatial and temporal variations of solar energy resources of Northwest China for the past about 50 years through completely regularized spline methods. The results indicate that the characteristics of the inter-annual and seasonal changes of solar energy resources are almost the same. According to the sunshine hours and solar total radiation, central Qinghai Province is regarded as the most abundant solar energy region, while the regions, such as southern and southwestern Shaanxi Province, belong to the unavailable region of this kind of resources. Over the past 50 years, the annual total radiation of Northwest China has decreased clearly, and the annual sunshine hours have dropped off slowly. Among 163 metrological stations, the days which the daily sunshine hours were greater than 6 hours of a month during the past 10 years added up to 45-327, of which 15 sites are more than 300 days. Solar energy resources of the southern Shaanxi Province and Urumqi are most unstable, where the K value (the index of stability of solar energy resources) is 12.21, while the border area, including the northern Qinghai Province, and the interactive zone of Qinghai, Gansu and Xinjiang, belongs to the most stable area, where the K value is 1.27. Our study suggests that the stability of the solar energy resources is consistent well with the distribution size of resource potential, that the most stable area always has the largest amount of total radiation and the longest sunshine duration.