The scientists created a rain-runoff model using Geographic Information Systems (GIS) to better understand how rainfall leads to water flow in watersheds. Traditional models assume all rainfall is the same across an area, but this new model considers how rainfall and land characteristics vary across a region. By automatically analyzing soil and land use data with GIS, the researchers found ways to estimate the amount and timing of water runoff more accurately. This approach could improve the design of structures like dams and sewer systems that rely on understanding how water moves, by providing more precise data on peak water flows and the time it takes for that flow to reach its highest point.