The trough valley zone of the Gele mountains is largely covered by limestone,with a hill landform and complex geological environment.Influenced by the subtropical monsoon climate,the rainfall of the rainy season (from May to October)in this area reaches 881.40 mm,accounting for 80 percent of the total annual precipitation,resulting in nonuniform distribution of rainfall between the rainy and dry seasons.With the in-creasing human engineering activity in recent years,karst collapse occurs frequently,which have become the main geological disaster in this region.This work collected and analyzed relevant data of previous surveys and related data of existing hydrological boreholes with long-term observations,and made a special investiga-tion of environmental geology and geological disasters on scales of 1∶2 000~1∶10 000.The purpose was to determine the number and distribution of karst collapse and human engineering activity status in this region. The survey area is 60 km2 .The results show that the number of karst collapse has an increasing trend year by year,which are mainly distributed in those places where the karst developed well,the groundwater level changed significantly,more calcium carbonate are present,and the thickness of the loose cover ranges from 3 to 8 meters.It divided the process of collapse development into early stage,middle stage and late stage and analyzed the characteristics of these developmental stages.By analysis of the types and function of collapse forces in the process above,it suggests that the latent erosion is the primary mechanism for the collapse.To sum up,the number of karst collapses increases year by year,which mostly occur in rainy seasons.There is an obvious characteristic pattern of spatial distribution as well as stage-wise development of karst collapse, and the latent erosion is the dominant mechanism.%歌乐山为高位岩溶地带，加之近年来人类工程活动加剧，岩溶地面塌陷发生频繁。中梁山山脉沙坪坝行政区段基本覆盖传统意义上歌乐山地区，文章以此为研究范围，搜集以往调查、勘察资料并加以系统分析，旨在研究、总结歌乐山地区岩溶地面塌陷发育特征。研究结果表明，区内岩溶地面塌陷数量呈现逐年递增的趋势，但季节分布不均匀，其空间上主要分布在岩溶较发育、地下水位变动较大、地层岩性碳酸钙含量较高、土层厚度3~8 m 的地带；塌陷发育过程分为早期、中期、晚期三个阶段，以潜蚀作用为主导因素。
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