衡阳地质灾害特点及与降水相关性研究

Study on Correlation between Geological Hazards Feature and Precipitation in Hengyang

衡阳地质环境复杂,人类工程活动频繁,是湖南省地质灾害高-中易发区。本文对影响地质灾害发生的地形地貌、地质构造、降水、人类活动强度等诸多因子量化处理,将衡阳划分出6个崩塌、滑坡及泥石流灾害高发带及4个塌陷地质灾害高发带;无论在年、月时间尺度上,地质灾害发生数与降水量的相关性均不好,但与80 mm以上降水次数的相关度高(r=0.845),80 mm以上降水可作为地质灾害发生的重要指标;1990年代以来,衡阳地质灾害数呈波动性增长,目前处于灾害高发后的趋缓期。一年中,7月发生地质灾害的几率较大(34.8%)。

Geological hazards often occur in Hengyang because of complex geological environment and frequent human engineering activity. This paper made quantitative disposal of impact factors for geological hazards, such as topography and geomorphology, geological structure, precipitation, human activity intensity, etc. The studied region may be divided into 6 high frequency regions of collapse, landslide and debris flow and 4 frequently-hit regions of subsidence. Correlation between geological hazards and precipitation was unmarked in year or month, but it was strong correlated （r = 0. 845 ） with precipitation times （ ≥ 80 mm）. So precipitation （ ≥80 mm） may be an important index of geological hazards. The times of geological present increase of fluctuation since the 1990＇ s, and it is in extension of time after high frequency disaster occurred at present. The maximum probability of geological hazards is 34. 8% in July.