【摘要】 利用1960-2006年陕北黄土高原区发生的地质灾害及对应的年、月、逐日降水资料,采用数理统计方法分析二者关系,确定该区域地质灾害气象预报思路。结果表明:陕北黄土高原区地质灾害年发生次数和年降水量不成正比;地质灾害主要发生在降水量集中的7～9月,特别是和前10 d的累积降水量有明显的相关性。暴雨、大雨诱发的地质灾害主要是在当日或次日发生,中雨诱发的地质灾害在降水后10 d内各日均可出现。陕北黄土高原区地质灾害属于多日降水诱发型,一般需要3 d以上的降水日。过程雨量大于50 mm时滑坡次数明显增多,过程雨量大于10mm,就可出现较多崩塌。陕北黄土高原区铜川、耀县的临界雨量较大,子长、子洲、米脂、绥德、延安、延川、延长、安塞、吴旗、志丹的临界雨量较小。更多还原

【Abstract】 This paper analyzes the relationship between geological disasters and rainfall based on the records of geological disasters and the data of annual precipitation and monthly and daily rainfall during the period of 1960- 2006.The results show that the occurring frequency of geological disasters is not the direct proportion with annual precipitation,and the geological disasters occur mainly in July,August and September.Especially,there is a significant correlation between the occurrence of geological disasters and the 10-day accumulated rainfall before the occurrence of geological disasters.The geological disasters caused by rainstorm or heavy rain occur mainly in the first two days,and the geological disasters caused by moderate rainfall may occur on any day after rainfall.The geological disasters in the Loess Plateau in north Shaanxi Province are caused by several-day rainfall,and their occurrence needs generally a three-day rainfall at least.Many landslide disasters may occur when the accumulated rainfall in a weather process exceeds 50 mm,and many loess-collapse disasters may occur when the accumulated rainfall in a weather process exceeds 10 mm.The critical rainfall for the occurrence of geological disasters is obviously different from different areas,and it is relatively high in Tongchuan City and Yaoxian County but relatively low in Zichang,Zizhou,Mizhi,Suide,Yanchuan,Yanchang,Ansai,Wuqi and Zhidan counties and Yan’an City.更多还原