Karst development law of Huashan Town and Huadong Town in Huadu District of Guangzhou City

In recent years, many karst process ground subsidences have occurred in Huadong Town and Huashan Town of Huadu District, Guangzhou City. However the research on karst development laws in this area is relatively weak. Therefore, utilized the project platform that detailed survey of geological disasters for 1∶50 000 scale in Guangzhou, Guangdong Province, to study the karst process development laws, scale and genesis of the alluvial plains in Huadong Town and Huashan Town by field investigations combined with drilling and geophysical methods. The study shows that the area is strong karst development area, which is mainly buried karst. The karst process in this area is controlled by landform, stratum lithology, geological structure, groundwater characteristics and other factors. Human engineering activities can promote the development of karst by changing the groundwater balance. The vertical and horizontal development of karst in the study area is controlled by topography and elevation. In the longitudinal direction, it is mainly distributed in the elevation section of-15 to-10 m, and decreases gradually from the upper and lower sides, and generally distributed in low-lying areas horizontally. Under similar geological conditions, the scale and quantity of karst development are negatively correlated with the terrain, and positively correlated with the content of Ca^{2 +}.