Distribution and genesis of karst collapse in Shandong Province

As a major economic and cultural province in China, Shandong Province has developed rapidly in recent years. Human activities have made a great impact on the geological environment, especially in the karst areas. The main karst geological hazards include karst collapse, groundwater pollution and spring cut-off, among which karst collapse is the most significant. Frequent karst collapse not only restricts the sustainable development of economy and society, but also brings about great hidden danger to the safety of people's life and property. This paper analyzes the distribution and genesis of karst collapse in Shandong, so as to provide a basis for decision-making on targeted prevention and control of such geologic hazard.Karst collapse documented in Shandong Province began in the early 1970s in Shandong Province. Since then, with the development of economy and society and the growth of population, the exploitation amount of karst groundwater mushroomed and human activities increased. According to incomplete statistics, up to now, there have been more than 1，300 karst collapse events, which are mainly distributed in Tai'an, Zaozhuang, Linyi, Jinan, Jining and Jiaodong Peninsula.The karst collapse in Shandong Province is a representative geologic hazard in northern China. This study suggests that constrained by many natural factors, such as karst development, cap rock thickness, fault structure and surface water systems, karst collapse in Shandong Province exhibits certain regularity. Associated with human factors, karst collapse mostly occurs in the period of abrupt rise and fall of groundwater level and fluctuation of bedrock roof. From the perspective of mechanics, the genetic mechanism of karst collapse is dominated by vacuum suction erosion and potential erosion. From the perspective of influence factors and control factors, on the basis of basic control factors, the main inducing factors include atmospheric precipitation, excessive mining, irrigation and infiltration and major surface engineering.