Abstract: As a kind of geological hazard, earth fissures brought serious side effects to the development of the Suzhou-Wuxi-Changzhou area. It is difficult to use linear methods to finish the work about the zoning of earth fissure hazards on account of the nonlinear process during the birth of earth fissures and the complexity of action between each influencing factor. With analyzing the primary influence factors of earth fissure-the discrepancies in the forms of bedrock, the aggradations’ structure of Quaternary period, the asymmetry of land subsidence and excessive development of ground water, six evaluating indicators-the depth of bedrock burial, the degree of bedrock relief, water level, the gradient of land subsidence, transmissivity and the thickness of clay soil are selected to be input to the GA-ANN model, which combines BP with GA and is established to evaluate the fatalness of earth fissure in Suzhou-Wuxi-Changzhou area. According to the danger classification, the research area is divided into four zones-danger zone, sub-danger zone, sub-safe zone and safe zone. The danger zone is centered in the east of Changzhou, the middle of Wuxi and the south of Jiangyin. The safe zone is mainly distributed in the northeast of Zhangjiagang, the east of Changshu City and the north and southwest of Changzhou City. The sub-danger zone and sub-safe zone is the transition zone.

Key words: fatalness zoning, GA-ANN, earth fissure, Suzhou-Wuxi-Changzhou area