DHSVM 3.1 for urban hydrologic processes is developed based on DHSVM 3.0. The adaptations to DHSVM 3.0 expand the model capabilities to applications in urbanized or partially urbanized areas.

The main changes in the configuration file

For each defined land cover category (or VEGETATION type):

• a fraction of impervious area (which can be extracted from land cover maps)

• impervious areas that is controlled by storm water detention

• a linear reservoir coefficient to described drainage from detention storage.

How to run DHSVM 3.1

• Set up the input configuration files (see example INPUT.3.1.SpringBrook)

• Set up the input files (dem, veg, soil, stream, shadow, skyview). Download tutorials for detailed instructions.

• Run the program find_nearest_channel.c (download) to generate the surface routing file. Click here for brief instructions.

• If the sediment module or mass wasting option is going to be implemented, follow the instructions in the Tutorial for DHSVM 3.0 section.

Issues regarding DEM SINK REMOVAL

ArcGIS tools calculate flow direction and distribute flow using an eight direction< approach (often referred to as D8) while DHSVM uses four flow directions (D4). Accordingly, in small-scale model applications, you may find surface water in some cells do not drain properly to the downstream cells.

In the 3.1 version, the elevation of identified sink cells is internally increased to the elevation of the lowest neighboring cell in order to form a downslope path.