Daniel Johnson, PhD, is an Associate Professor of Geography in the IUPUI School of Liberarl Arts. His research focuses on social and environmental vulnerability and how they inter-relate in space and time. Both can be highly dynamic and when they coincide, there is an increased risk for a disaster. Professor Johnson focuses on modeling these interactions and working toward predictive models that can help increase resilience, prevent disaster or mitigate the effects. The forces of both social and environmental vulnerability are very pronounced in urban areas where disparities between populations are highly evident.