Computing Basin Data

After defining basin boundaries, attributes such as basin areas, slopes, and stream lengths can be computed using the Compute Basin Data command. These attributes are all geometric parameters used in defining basins and routing networks in HEC-1, TR-20, and other hydrologic models. If the basins are changed in any way, the drainage data must be recomputed using this command. When computing basin data the model units and the parameter units must be specified. The only choices available for model units are feet and meters whereas the parameter for area include square miles, square kilometers, and acres, and for distance include mile, kilometer, feet, and meters. A complete definition of the different geometric attributes computed and how they may be used to compute travel times (lag time, time of concentration) is given in the Hydrologic/Hydraulic Calculations page.