近56年玉门四季降水量对气候变化的响应

Responses of Precipitation in Four Seasons to Climatic Change in Yumen during 1953-2008

利用1953～2008年玉门镇四季降水量，分析了近56年玉门的四季降水量变化趋势，气候突变、异常年份等。结果表明，春季降水量长期变化趋势不明显；夏季降水量呈上抛物线变化趋势，秋季表现为增多趋势，冬季降水量呈明显的下抛物线变化趋势。20世纪50年代除冬季降水量较多外，其他各季降水量都较少；60年代春季降水量较多；70年代夏季降水量较多；60年代和80年代秋季降水量都较少；90年代后冬季降水量较多。冬季降水量增多与气候变暖的响应更强；夏季降水量在1979年发生了突变，之前呈增多变化趋势．之后呈减少变化趋势，冬季降水量在1984年发生了突变，之前呈减少变化趋势，之后呈增多变化趋势。

Make use of precipitation all the year round in Yumen City during 1953 - 2008, analyze change trend of annual precipitation, the weather mutation, abnormal year, etc.. The results showed that： the long-term changing trend of precipitation in spring was not obvious; precipitation in summer showed a convex parabola changing trend, precipitation in autumn showed an increasing tendency, and in winter a concave parabola tendency. In 1950s, precipitation was less in all seasons except winter; in 1960s, relatively more precipitation in winter; in 1970s, relatively more precipitation in summer; in the autumns of 1960s and 1980s, the precipitation was relatively more; after 1990s the precipitation in winter was more. The precipitation in winter has a stronger response to the climatic change ; summer precipitation changed dramatically in 1979, before was an increasing tendency, but after was a decreasing tendency; winter precipitation changed dramatically in 1984, before was decreasing and after was increasing.