During his nearly 40-year career at Pennsylvania State University’s College of Agricultural Sciences, DeWalle has made important scientific contributions in various areas of hydrology. While his fundamental contributions advanced the understanding and theory of a wide range of hydrological sciences, DeWalle demonstrated a career commitment to pursuing science that people care about.
Consistent with the mission of the University Council on Water Resources and the spirit of the Warren A. Hall Medal, DeWalle pursues research that benefits people and ecosystems. With his longtime collaborator Arlango, he published his textbook in 2011 entitled Principles of Snow Hydrology.
DeWalle is perhaps best known for studying the basis of acid rain and its effects on wild brook trout. To understand why some watersheds respond so quickly to low-pH precipitation, he used isotopic hydrology to understand where and how rivers get water.