干旱区地理2011，Vol.34Issue(3)：436-441,6.
河西走廊春季透雨日期的变化特征
Climatic characteristics of spring soaking rain date in Hexi Corridor
摘要
Abstract
The Hexi Corridor is most main commodity grain base and the cash crop centralized production area in the northwest area. Although the area of majority belongs to the irrigated agricultural region, but it still has the very direct relations among the agricultural harvest and famine and the atmospheric precipitation. The occurrence frequency of spring drought in the Hexi Corridor achieves above 70% , which is very big influential in the agricultural production. Although there are many research achievements in the regularities of northwest arid area's changing and its influence on the agricultural production, but the study on spring soaking rain as well as drought's inhibitory actions have not been seen widely up to now in view of the Hexi Corridor. This article is presented to analyze the following issues of the Hexi Corridor : the spatial distribution characteristics on the spring first soaking rain dates, their temporal variation regularities and periodicities, on the basis of precipitation materials during 1971～2007 from 25 metrological stations, EOF, REOF and spectrum analysis methods. The results indicate that; the spring soaking rain dates have a good uniformity dealing with their spatial distribution,its first host component variance contribution occupies 36% of the overall variance, the first three items account for above 66% , three characteristic vectors may reflect main characteristics of the Hexi Corridor involving with the spring soaking rain dates. Under the overall consistent background, the Hexi Corridor has the partial differences in spatial distribution of the spring soaking rain, and may divide approximately into 3 areas: the first area is the extreme arid climatic region in the central and western Hexi Corridor, including 8 counties (city) of Dunhuang,Cuazhou, Yumen,Jinta,Subei,Jiuquan,Gaotai, Linze,Jiuquan station being a representative one. The second area is the partial arid climatic region in the eastern Hexi Corridor, including 7 counties (city) of Zhangye, Shandai, Yongchang, Wuwei, Minqin, Jintai, Baiyin, Wuwei station being a representative one. The third area is the arid and half arid transition region in the eastern Hexi Corridor, including 8 counties (city) of Sunan, Minle, Gulang, Tianzhu, Yongdeng, Gaolan, Jinyuan, Lanzhou, Yongdeng station being a representative one. The research also indicates that, the big terrain has certain influence on changing in distribution characteristics of the spring soaking rain in the Hexi Corridor, spring soaking rain dates are early in southeast area, late in northwest area, the reason is that the northwestern Hexi Corridor occupies the deeper interior near desert 's edge, with the Qilian Mountains' impeding the water vapor northward intrusion. The precipitation here is scarce, therefore the spring soaking rain dates are late. However, under the different geography conditions, there are differences in the spring soaking rain dates. The Hexi Corridor may approximately divide into 3 areas, the southeast's is early, northwest's is late. In the recent 30-40 years, the spring soaking rain dates assumed the undulation change, the overall tendency is that the 1970s soaking rain dates were postponed; the 1980s soaking rain dates moved up, the 1990s soaking rain dates postponed. After 2001 the soaking rain dates were moved up. There is a transposition change between soaking rain occurrence dates and the amount of spring rainfall. The spring soaking rain dates of the extreme arid climatic region and the arid climatic region assume 9-year periodical change, the spring soaking rain dates of the arid and half arid transition region have the 4-year periodical change.关键词
河西走廊/春季透雨/时空分布Key words
Hexi Corridor/ spring soaking rain/ temporal and spatial distribution分类
天文与地球科学引用本文复制引用
曹玲,刘明春,郭小芹,许蔚生,蒋菊芳..河西走廊春季透雨日期的变化特征[J].干旱区地理,2011,34(3):436-441,6.基金项目
甘肃省气象局第五批十人计划和公益性行业(气象)科研专项"西北地区旱作农业对气候变暖的响应特征及其预警和应对技术研究"(GYHY200806021)共同赞助 （气象）
