San Dimas Experimental Watershed Modeling Project

The San Dimas Experimental Forest (SDEF), as shown in Figure 1, was selected by the United States Forest Service as a research area for hydrological properties. This hydrologic study will be focusing on Bell Canyon, the highest of three canyons in the Big Dalton watershed, which is within SDEF. To better understand hydrological properties such as flow rate and infiltration, digitial and physical models were created of Bell Canyon in the SDEF that can demonstrate hydrologic properties and can be used for research, education, and outreach. The digital model is created using Hydrologic Engineering Center Hydrologic Modeling Software (HEC-HMS) and will represent the actual flow rates and volumes leaving the watershed. The peak 24-hour 50-year storm flow was found to be 360cfs. This value was scaled down to the 12 square foot physical model to obtain a rough estimate of the amount of flow the model can hold, which was determined to be 2 gpm. The physical model contains a water system, which depicts infiltration and flow rate; flow rate is calculated using a rectangular weir at the outlet of the modeled watershed. The digital model and the physical model are subsequently compared and the digital model is used to calibrate the physical model.