Risk assessment is the systematic process of identifying hazards, analysing the likelihood and potential consequences of harmful events, and determining the level of risk they pose to people, property, infrastructure, the environment and essential services. In emergency response planning and disaster management, risk assessment helps authorities understand what disasters may occur, who or what may be affected, and what measures are required to reduce their impacts. It forms the basis for preparedness, mitigation, response and recovery planning. Risk is generally understood as a combination of the probability of a hazardous event occurring and the severity of its consequences. A proper risk assessment therefore considers hazards as well as exposure and vulnerability. For example, an earthquake may represent a serious hazard, but the level of disaster risk will be higher in a densely populated city with weak buildings and inadequate emergency services than in a sparsely populated area with earthquake-resistant infrastructure. The first major step in risk assessment is hazard identification. Hazard identification involves recognizing natural, technological, biological and human-induced conditions that have the potential to cause injury, death, property damage, environmental degradation or disruption of essential services. Several methods are used for this purpose.