Dealing with Disasters by Gisli Olafsson is a superb narrative on how technology has boosted the ways in which humanitarian response is taking place.
"The hierarchical level of disaster response works very well in most disasters, since the majority of disasters are small enough to handle locally or with mutual-aid support from nearby cities. Even for medium level disasters, most disasters can be handled at the state level, with minimal support from the federal level. It is however when mega-disasters, such as Hurricanes Katrina and Sandy occur that the entire response model gets stretched beyond its limits. The system was simply not built for so many cities, counties and states to all be experiencing disaster of this magnitude, all at the same time."
"At the same time we have seen how through an explosion in mobile phone ownership and through social media and networks, people affected by these major disasters are not only communicating their needs but also leveraging those same technologies to coordinate their own community response often independent of the official response channels. Although this community lead response at the moment may result in some duplication of efforts, it in most cases ends up meeting the gaps the official response leaves. This community based response also starts immediately after the disaster, way before the first responders arrive."