The two DRMC theoretical models are very helpful for understanding the development curve in relation to a disaster, and what needs to happen at each stage.
My experience working in the Food Security & Agriculture sector here in Vanuatu during the EL Nino and associated drought is that a slow-onset hazard is much more complicated to respond to. The impact is not as sudden therefore not as clear, and although there is more time – this perception means that action can be slower. There is also difficulty in gathering detailed needs assessments as the time span of the disaster impact is over a long time – therefore requiring more investment (in terms of funding & personal) to get accurate ideas of the impacts.