巴丹吉林沙漠腹地降水特征的初步分析  

A preliminary study of precipitation characteristics in the hinterland of Badain Jaran desert

作　　者：王乃昂[1,2] 马宁[1,2] 陈红宝[1,3] 陈秀莲[4] 董春雨[1,2] 张振瑜[1,2] 

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000 [2]兰州大学干旱区气候变化与水循环研究中心,甘肃兰州730000 [3]甘肃省水利水电勘测设计研究院,甘肃兰州730000 [4]内蒙古自治区阿拉善盟气象局,内蒙古阿拉善左旗750306

出　　处：《水科学进展》2013年第2期153-160,共8页Advances in Water Science

基　　金：高等学校博士点专项基金项目(20090211110025;20100211120006)~~

摘　　要：利用巴丹吉林沙漠腹地定位观测的降水数据,结合其外围南缘、东南缘、北缘和西北缘4个气象站同期降水资料,分析了沙漠腹地的降水特征以及高大沙山对降水的影响,比较了沙漠腹地与外围降水量的差异。结果表明,沙漠腹地降水以小雨为主,且一般在1～2 h内结束。沙漠腹地与外围的降水在季节分布上有较好的一致性,观测期间腹地的年降水量少于南缘阿拉善右旗气象站,但明显多于东南缘、北缘和西北缘。沙漠腹地降水的季节变率很大,年降水量往往由某些集中降水日决定,具有高度集中性。腹地的高大沙山对降水有一定影响,沙山顶部年降水量和年降水日数皆略多于丘间地,较长的单次降水过程之持续时间及累积降水量亦有类似特征。强降水事件发生时,沙漠腹地在16.8 km的空间距离上有"斑块"现象。日降水量的相关距离分析显示,夏半年日降水量空间相关性随距离的增大而明显减小;冬半年因多冷锋降水而使其日降水量在约50 km空间尺度上仍有较好的相关性,50 km以外相关性则显著减小。Based on the positioning observation of precipitation in the hinterland of the Badain Jaran desert and data from four surrounding gauges in the vicinity of the desert, the characteristic of precipitation in the hinterland of the desert is examined. The effect of megadunes on precipitation is primitively analyzed. The difference in precipitation a- mounts between the margin area and the hinterland of the desert is discussed. Results show that light rain dominates the hinterland and the most common rainfall events are likely to be short in duration less than two hours. Precipitation exhibits a great deal of seasonal variability, and the annual precipitation depends very much on a few rainy days. A good consistency is found in the seasonal distribution of precipitation between the hinterland and the margin area. Dur- ing the observation, the precipitation amount of the hinterland is lower than that of the southern margin, but is evi- dently higher than that of the northern, northwestern and southeastern margins. It is possible for the hinterland region to encountering local heavy rainfall events with precipitation greater than 20 mm and the maximum intensity of precipi- tation exceeding 4 ram/h; however, the occurrence of such events is rather instantaneous and random. It is evident that a megadune can influence precipitation as the annual precipitation and rainy days on the top of the megadune are slightly more than those in the interdune areas, and so do the duration and accumulation of a single precipitation e- vent. During heavy rainfall events, spottiness is likely to occur on an average scale of 16.8 krn. The cross-correlation analysis demonstrates that the space correlation decreases significantly with the increase of distances in the summer time of a year. However, the space correlation to 50 km is still high in the winter time of a year due to cold frontal pre- cipitation.

关 键 词：定位观测 降水 地形效应 相关距离分析 巴丹吉林沙漠腹地 

分 类 号：P426.6[天文地球—大气科学及气象学]