Lisa Schweitzer

Archive for the ‘evacuations’ Category

Heartbreaking news from Taiwan and China

In evacuations on 08/10/2009 at 23:24

The folks from the compact development research argue that high human population settlements make for more resilient cities. However, it is disasters such as these which make me wonder: is it likely that there is a one-size-fits-all urban form for resiliency against disasters. 400 people victim to one mudslide is terrifying, and while I guess we could go into long arguments about how climate change is causing all this, we’ve had typhoons for some time. What we haven’t had in the scope of human history are the population levels and densities in particular locations which heighten the casualties from major events.

As irritating as Los Angeles is to many urbanists, developers’ response adaptation to earthquakes made perfect sense before the technology was available to build upwards. The spread also creates a feedback problem for the wildfire resiliency folks. Yes, it would be better if people weren’t living in the fire ecosystem on the fringes. But given that there are people living in the fire ecosystem, the fewer the better, the easier it is to evacuate them, etc. I’m not suggesting that LA fringe is an optimal urban form, but it does carry some advantages. The spatial spread in LA’s population and economic activities meant that while Northridge and surrounding areas suffered immensely from the earthquake, the rest of the region went on largely as before.


New manuscript on evacuation

In evacuations on 07/22/2009 at 12:12

Murray-Tuite, P., L. Schweitzer, S. Liu. 2009. “Impacts of Family Responsibilities and Car Availability on Household No-Notice Evacuation Time.” 14 p.

Available for download here.

The family gathering phenomenon is a critical evacuation consideration. Recently, researchers have placed greater emphasis on capturing household member interactions for emergencies, but most of these efforts have not specifically addressed associated gender issues. This paper examines the impact of gender-based family gathering responsibilities on family evacuation delay from the optimal conditions for a hypothetical no notice event during school hours. This study uses initial results of an original interview data collection effort addressing home and work locations, pre-evacuation actions, and family gathering responsibilities, among other considerations. Many of the women with appropriately aged children indicated responsibility for collecting them. The impact of assigning gathering responsibilities to a single parent on household evacuation time is determined using a nonlinear integer program that assigns activity chains, meeting locations, and final destinations so as to minimize household evacuation time in a multimodal transportation network. The effects of car availability are also examined for a sample household in Chicago Heights. The number of and locations of dependents were also varied as well as whether one parent stayed at home or both parents worked. If only one vehicle was available and with the parent further from the dependents, household evacuation time could substantially increase (e.g. double), especially if the family did not unite prior to arriving at the final destination. Consideration of gathering behavior, household responsibilities, and persons dependent on transit will lead to more accurate evacuation models that help emergency agencies make better decisions and potentially save lives.


Evacuation and Resilience Manuscript

In evacuations on 07/16/2009 at 00:19

Relocation of Household Dependents For a Daytime No-Notice Evacuation in a Multimodal Transportation System

Sirui Liu, Pamela Murray-Tuite and Lisa Schweitzer

Under no-notice conditions with family members collecting dependents, the locations of these pickup points becomes a crucial factor to efficient evacuation. This paper presents a mathematical program for facilities to relocate, optimally, dependents that need to be picked up. The program, solved using Lingo, is iterated with a traffic simulation model to obtain an optimal set of locations based on anticipated travel times with dependents relocated to those sites. The entire methodology is applied to a case study based on Chicago Heights with three safety thresholds. In two of the three cases, relocation improved evacuation conditions.

You can download the draft here.


Ethanol explosion

In evacuations, hazardous materials, resilience on 06/22/2009 at 09:44

One of the topics I study is hazardous materials transport, so this accident on Sunday caught my eye. Deaths to nonemployees are extremely rare in the hazmat world–engineering has done an amazing job with hazmat containers. Nonetheless, these types of evacuations are more common than we think. I have a new study coming out (I hope soon) describing the spatial distribution of severe hazmat events, like evacuations. Stay tuned.