求翻译：然而，关于自然灾害衍生事件的预警也只是停留在初步阶段，因为自然灾害的不可预测性，并没有真正意义上的能够完全防灾的政策和方法，大多数基于公共危机管理的相关理论提出的防灾模型也都缺乏实践和可操作性[1]。是什么意思？

However, derivatives of natural disaster early warning of events remain in the initial stage only, because the unpredictability of natural disasters, and there is no real sense fully the policies and methods of prevention, crisis management, the majority of the public based on the theory proposed al

However, with regard to natural disasters of derivative events warning is also just at the initial stage, and the unpredictability of natural disasters, and there is no real sense to be able to complete disaster prevention policies and methods based on a public crisis management, the majority of rel

However, also only is pauses about the natural disaster derivation event early warning in the preliminary stage, because of the natural disaster unpredictability, in the true sense has not been able to against disasters completely the policy and the method, majority the disaster prevention model whi

However, on natural disasters-derived early warning other than to stay at the initial stage of the event, because the unpredictable nature of natural disasters, and there is no real sense of complete disaster prevention policies and methods, most based on the theory of public crisis management and d

However, on natural disasters-derived early warning other than to stay at the initial stage of the event, because the unpredictable nature of natural disasters, and there is no real sense of complete disaster prevention policies and methods, most based on the theory of public crisis management and d