A precipitation-based regionalization for Western Iran and regional drought variability
A precipitation-based regionalization for Western Iran and regional drought variability
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DOI：
10.5194/hess-12-1309-2008
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发表时间：
2008-12
影响因子：
6.3
通讯作者：
T. Raziei;I. Bordi;L. S. Pereira
中科院分区：
文献类型：
--
作者：
T. Raziei;I. Bordi;L. S. Pereira
利用1965-2000年期间140个测站的数据分析了伊朗西部季节和年降水量的空间分布。应用降水集中指数（PCI）研究了降水的年内变化.利用主成分分析和聚类分析技术，对伊朗西部的9个降水参数进行了气候分区。结果表明，五个空间均匀的子区域可以识别出不同的降水制度的特点。季节降水的空间分布似乎受该地区的纬度范围和明显的地形起伏的高度控制，最大降水发生的时间从北部的春季到南部的冬季不等。使用降水指数（PI）分析了识别的子区域中的干湿期的时间变异性，并检验了任何长期趋势的存在。结果表明，伊朗西部北方和南部地区具有不同的气候变率特征。研究区北部长期呈负线性趋势，南部呈弱正趋势，但不具有统计学意义。
The spatial distribution of the seasonal and an- nual precipitation was analyzed in western Iran using data from 140 stations covering the period 1965-2000. Apply- ing the Precipitation Concentration Index (PCI), the intra- annual precipitation variability was also studied. Further- more, nine precipitation-derived parameters were used to re- gionalize climate in western Iran using principal component analysis and clustering techniques. Results suggest that five spatially homogenous sub-regions can be identified charac- terized by different precipitation regimes. The spatial pattern of seasonal precipitation seems to be highly controlled by the wide latitudinal extent of the region and by the pronounced orographic relieves, and the time of occurrence of the max- imum precipitation varies from spring in the north to winter in the south. The time variability of dry and wet periods in the identi- fied sub-regions was analyzed using the Precipitation Index (PI) and the existence of any long-term trend was tested. Re- sults show that the northern and southern regions of western Iran are characterized by different climatic variability. Fur- thermore, a negative long-term linear trend in the north and a weak positive trend in the south of the study area have been detected though they are not statistically significant.