【作者】 李智才； 王毅荣； 3朱林洪；

【Author】 Li Zhi-cai1 ,2 Wang Yi-rong1,3 Zhu Lin-hong4 (1.Key Laboratory of Arid Climate Change and Reducing Disaster of Gansu Province, Lanzhou Institute of Arid Meteorology, China Meteorological Administration, Lanzhou 730020, China; 2. Meteorological Bureau of Yangquan,Yangquan 045000,China; 3. Meteorological Bureau of Dingxi,Dingxi 743000,China;4. Meteorological Bureau of ShanXi Province,Taiyuan,030002,China)

【机构】 中国气象局兰州干旱气象研究所甘肃省干旱气候变化与减灾重点实验室； 山西省气象局；

【摘要】 为揭示黄土高原区域性暴雨演变特征,利用黄土高原51站40年降水资料,采用REOF(旋转经验正交分解)、小波分析和分维分析等方法,研究了该区域暴雨的时空特征。结果表明:黄土高原区域性暴雨事件趋于减少,过程雨量趋于增加;暴雨频数存在4a和7～8a的振荡,以4a周期为主;在1977年暴雨事件发生突变骤然减少,相应的短周期减弱、长周期相对加强;相关分析发现与500hPa的高度、副热带高压和青藏高压位置关系密切;与区域性暴雨事件伴随的全区降水量存在6个空间型,各型具有客观分形特点,分维数在0.8378～0.9242,其中高原西北部和高原东南部分维数值较小,高原中部分维数值较大,反映出高原中部暴雨的非线性机制最为复杂,高原西北部和高原东南部地区比中部简单。更多还原

【Abstract】 To make clear the characters of rainstorm evolvement, by investigating distributing of regional rainstorm over China plateau during 1961-2000 with analysis of REOF, wavelet and Fractal Dimension, results show the events of regional rainstorm decreased, the rainfall of the rainstorm increased. The correspondence between that rainstorm events had remarkable 2 phases divided by jump-point, 1977yr and that 4 and 7～8years variation period occurred abrupt change by using wavelet analysis. The abrupt change comes into contact with the longitudinal positions of SH (the longitude of west end of SH based on the contour of 5860 gpm), the Qinghai-Xizang high (the longitude of east end of Qinghai-Xizang high based on the contour of 16760 gpm) and the high field of 500Hpa. Six divisions are identified, showing Fractal Dimension of the rainfall of rainstorm was 0.837 8～0.924 2. Minimum Fractal Dimension was in the southeast of the china loess plateau, maximum in the hinterland of the plateau. It indicated that the reason of rainstorm was more complicated in the hinterland than others the plateau.更多还原