中国典型等降水量线年代际空间演变

基于1960-2013年中国573个气象站的月降水量数据,选用普通克里金插值法生成典型等降水量线(200、400,800 mm),从等降水量线移动距离和移动趋势的角度分析了中国近54年典型等降水量线的时空演变特征。结果表明:(1) 200、400,800 mm等降水量线近54年的空间分布大致呈东北-西南走向,且从西北到东南有序排列。(2) 200 mm等降水量线在宁夏平原和西藏中西部波动强烈,且均有向东和向南偏移趋势。200 mm等降水量线在宁夏平原20世纪70、80年代、21世纪初东移,20世纪90年代、21世纪10年代初西移。西藏中西部自20世纪80年代起200 mm等降水量线有西移和北移态势,新疆北部200 mm等降水量线范围不断扩大。(3) 400 mm等降水量线在华北中东部波动强烈,20世纪70年代、21世纪00年代东移,20世纪80、90年代和21世纪10年代初西移,且整体有向东和向南的偏移趋势,但年代际波动大。(4) 800 mm等降水量线在秦岭-淮河一线波动强烈,20世纪80年代、21世纪00年代北移,20世纪70、90年代、21世纪10年代初南移,且纬度降低趋势较明显。

The Interdecadal Spatial Changes of Typical Rainfall Contours in China

Based on the month precipitation data from 1964 to 2013 of 573 meteorological stations provided by China Meteorological Data Sharing Service System, the interdecadal fluctuation of the typical rainfall contours (200 mm, 400 mm and 800 mm) in China are analyzed from the points of the spatial shift and trends. The following conclusions are drawn: (1)On the whole, the 200 mm, 400 mm and 800 mm rainfall contours had spatial shift trend to northeast-southwest in the recent 54 years. (2)In recent 54 years, the 200 mm rainfall contour fluctuated greatly in the Ningxia Plain and the midwest of Tibet with the spatial shift trend to eastern and southern. The 200 mm rainfall contour shifted eastward in 1970s, 1980s, 2000s, whereas it moved westward in 1990s, the early 2010s in the Ningxia Plain. The 200 mm rainfall contour shifted westward and northward in central Tibet since 1980s and the area with rainfall more than 200 mm increased in the north of Xinjiang. (3)The 400 mm rainfall contour shifted eastward in 1970s, 2000s and westward in 1980s,1990s and the early 2010s, and the whole trend was to the east and south in middle of North China despite the great interdecadal variation. (4)The 800 mm rainfall contour shifted northward in 1980s, 2000s and shifted southward in 1970s, 1990s and the early 2010s in the Qinling-Huaihe area. The 800 mm rainfall contour had southern migration integrally.