摘要
对榆林、西安、汉中夏季降水量的历年变化进行分析，并用灰色拓扑方法作了趋势预测。分析表明，关中的初夏旱和伏旱突出，半湿润地区的西安夏季多年平均降水量比半干旱地区的榆林还少。自１９５１年以来，陕西省夏季降水量的总趋势是：关中、陕南有下降趋势，而陕北下降趋势不明显。另外，关中、陕南的夏季降水还存在连续几年多雨或连续几年少雨的时段，而陕北则呈现出少雨年和多雨年交替出现的高频振荡。
Based on summer precipitation data at stations of Yulin,Xi′an and Hanzhong,the trend of summer precipitation is predicted with the method of grey topology in this paper. Aanlyses show that there are obvious droughts at beginning and middle of the summer in Guanzhong area. It is found that the mean summer precipitation in Xi′an(semi-moisture area) is less than in Yulin(semi-drought area). Trends of summer precipitation decrease in Guanzhong and south part since 1951,while decreasing trend didn′t change obviously in north part. Beside,the features are apparent that more rain or less rain happened successively in Guanzhong and south part,and high oscillation happened frequently in north part.
出处
《高原气象》
CSCD
北大核心
1997年第3期326-330,共5页
Plateau Meteorology
