三峡库区山地灾害基本特征及滑坡与降水关系

The Basic Characters of Mountain Disasters and Relationship between Landslide and Rainfall in the Area of Three-Gorge Reservoir

分析三峡库区山地灾害的基本特征,着重讨论库区滑坡灾害与前期降水量的相关关系,运用Fisher判别法则建立该区滑坡发生的降水预报方程。结果表明,三峡库区山地灾害主要出现在雨季,7月发生最为频繁,灾害种类多样,主要以滑坡为主,降水是诱发山地灾害的主要因素;当日和前5d的暴雨日数、当日和前10d降水量与滑坡发生的关系最为密切,诱发库区滑坡灾害的主要降水类型为暴雨诱发型和多日中大雨诱发型;通过Fisher判别方法,以两个降水因子建立起的滑坡发生的预报方程,对于三峡库区滑坡发生具有一定的判别能力,为库区山地灾害的预防提供科学依据。

In this paper firstly we have briefly introduced the basic characters of mountain disasters in Three- Gorge Reservoir, and then our attention is laid stress on the relationship between landslides and their antecedent rainfall in the area, at last fisher discriminate technique has been used in order to establish a forecast equation about rainfall for the occurrence of landslides.The results showed that in Three-Gorge Reservoir mountain disas- ters mainly happen in rainy season, which occur the most frequency in July.There are many kinds of mountain disasters and landslides is most serious and precipitation is the primary factor that triggers the mountain disas- ters.Based on the previous analysis we have found that in this areas the occurrence of landslides is closely rela- tive to two factors of rainfall and two different rainfall patterns triggered landslides are deduced, one type is days of heavy rain and the other is precipitation of the current day of landslides and previous days, and there are two types of precipitation triggered the mountain disasters.The forecast equation based on above two factors of rain- fall has the ability to forecast the occurrences of landslides of Three-Gorge Reservoir, and the results will be a scientific basis for preventing mountain disasters in Three-Gorge Reservoir.