Several issues about urbanization and urban safety

The worldwide urbanization has a profound impact on the life style of human beings; however, some problems prone to occur during urbanization are also shown in the process, which are mainly disasters and urban safety problems. It is shown from the major events concerning the safety of mega-cities in developed countries and major developing countries in recent years that urban safety is essential for the healthy development. Based on the general situation of urbanization development worldwide and analysis of city size, the paper lists and analyzes hazards and risks which that may be encountered in the process of rapid development of cities, especially mega-cities, and analyzes and compares the safety of major cities world-wide in combination with the more authoritative data. Finally, several measures and suggestions are proposed in connection with the urban safety problems