Abstract:Karst collapse is the primary geological disaster in the karst area of the Pearl River Delta. Taking the hilly area of Guangzhou as an example, this work analyzed the current development status and characteristics of karst collapses, studied the formation mechanism of karst collapse, and proposed suggestions for prevention measures based on the 1:50,000 environmental geological survey results from 2016 to 2018. The results indicate that a total of 35 geological disasters related to karst collapses have occurred. Their spatial distribution exhibits characteristics of concentration and repetition, while their time distribution shows characteristics of persistence and periodicity. The karst collapses primarily involve small soil layer collapses of carbonate rock, primarily induced by human factors and secondarily by natural factors. The main forms of damage are building damage and farmland damage. The geological model of karst collapse formation includes four types: collapse caused by latent erosion effects, collapse caused by the superposition of latent erosion, loss of load, and suction erosion effects, collapse caused by the superposition of latent erosion and vibration effects, and collapse caused by the superposition of latent erosion and vertical seepage pressure effects. Prevention measures for karst collapses are proposed from the perspectives of decision-making and engineering technology. These measures provide a geological scientific basis for the development of ecological agricultural areas and ecological parks in northern Guangzhou and the creation of a beautiful and livable Lingnan countryside.
