Rumbach is a mixed-methods researcher who studies household and community risk to natural hazards and climate change. He is especially interested in how federal, state, and local government plans and policies shape hazard mitigation, climate adaptation, and community disaster recovery. He has studied numerous federal and state-declared disaster events and has written about affordable housing and disaster vulnerability, land-use policy and environmental risk, the vulnerability of cultural and historic resources to disasters and climate extremes, and rural governance of disasters. His writing has appeared in numerous urban planning, urban studies, and disaster studies journals, and he sits on the editorial boards of the Journal of the American Planning Association and the Journal of Planning Literature.. His research has been supported by the National Science Foundation; the National Academies of Sciences, Engineering, and Medicine; the Natural Hazards Center; and the Rockefeller Foundation, among others.

Rumbach earned a BA in political science from Reed College and a PhD and MRP in City and Regional Planning from Cornell University.