唐山市暴雨特征及风险评估研究

Storm Characteristics and Risk Assessment Research of Tangshan City

运用小波变换揭示了暴雨日数和暴雨量的主要周期以及暴雨强度和风险的空间分布特征。结果表明:唐山地区夏季暴雨日数和暴雨量的年际变化幅度较大,1960、1970年代,呈缓慢波动;1980年代转呈上升趋势;进入1990年代后期到21世纪初下降明显,2007年后呈明显的上升趋势;唐山地区夏季暴雨日数和雨量呈10年主周期;暴雨日数中心和暴雨量中心多集中在迁安、乐亭,其次是遵化、丰南一带。唐山地区暴雨致灾风险等级最高的地区主要在迁安中南部,其次是乐亭中东部以及丰南区、曹妃甸区等零散暴雨中心;从孕灾环境看,危险等级最高的地区主要分布在北部山区迁西、南部沿滦河部分地带;唐山地区暴雨灾害存在两大风险带:迁安风险带、乐亭滦南风险带以及遵化市、丰南区两地以城区为中心的两个小风险带。

Main cycle of rainstorm day number and storm rainfall and spatial distribution characteristics of storm intensity and hazard are revealed by using wavelet transform. The results show that： the interannual variation amplitude of rainstorm day number and storm rainfall in Tangshan region is great, fluctuating slowly during 1960s and 1970s, going upwards in 1980s, falling obviously in the late 1990s to the beginning of the twenty-first century and rising up obviously since 2007. Torrential rain days and rainfall in the area in summer are of a 10 years main cycle. Torrential rain days and rainfall concentrated more in Qian＇an, Leting, followed by Zunhua and Fengnan area. The highest risk areas in Tangshan area is in central and southern Qian＇an, followed by some scattered rainfall centers as the eastern part of Leting and Fengnan area, Caofeidian area. From the aspect of disaster-breeding envi- ronment, the highest risk rank region mainly distributed in Qianxi and the northern mountainous area of southern part along the Luan River region. Two risk zones of rainstorm disaster are existed in Tangshan area as Qian＇an risk zone and Leting Luannan risk zone. And two small risk zones centered in Zunhua city and Fengnan District.