Feature Analysis of Precipitation with Flow and Landslide Based on Hour-rainfall

Using the rainfall data in encrypted automatic weather stations from June to September, 2007-2010 in Sichuan province, the hour-rainfall characteristics is analysed, and by combining with the occurrence of flows or landslides which happened at the same time, the characteristics of precipitation is analysed.The results show that:The hour-average heavy rainfall mainly occurred during 1 a.m.to 7 a.m.when its geopotential height is below 1500 meters, else other happened during 10 p.m.to 8 a.m.the next day when its geopotential height is above 1500 meters, short-duration heavy rainfall is a key factor induced flows, and the occurrence of landslides is impacted by the cumulative and lagged effects of precipitation.The occurrence of flows or landslides generally require 50mm of rainfall when its geopotential height is below 1500 meters, and 6-hour precipitation has 15-20mm may lead to debris flows or landslides happen when its geopotential height is between 1500-3500 meters, and 6-hour precipitation has 10-15mm can when its geopotential height is above 3500 meters.