Summary
The TauDEM Toolbox uses 3 general types of input and output data files for its various tools:
- Grid Files
- OGR files
- Text Files
Also TauDEM, by default, uses a file naming convention that has been developed to assist in organizing the numerous files that are often involved in terrain analysis.
Grid Files
TauDEM 5.4 reads any grid data that supported by Geospatial Data Abstraction Library (GDAL). Raster formats supported by GDAL can be found here http://www.gdal.org/formats_list.html. However, TauDEM 5.4 only writes files with extensions ".tif",".tiff", ".img", ".sdat", ".bil", ".bin", using their corresponding GDAL definitions.
For a table listing the TauDEM grid definitions and naming conventions table click here.
OGR files
(TODO: check if we need to udate the version to 5.4) TauDEM5.3.2 supports OGR format files which are used for the following purposes:
- Outlets file - A point feature giving the location of outlets or internal monitoring points. The attribute "id" may be used to specify an identifier (e.g. stream flow recorder number) associated with these monitoring points. The value -1 is reserved to indicate "no identifier". There is no default filename for outlet files.
- Stream Reach file - A polyline file giving the links in a stream network. This is created by the "Stream Shapefile and Watershed Grid" function and has attributes tabulated below. The default filename for this shapefile is "*net.shp", where * is the base DEM name.
- Watershed Shapefile - A polygon shapefile demarcating each reach watershed. This is created by the function "Watershed grid to shapefile". The only attribute of this shapefile is polygon_id, identifier. This corresponds with the WSNO watershed number in the *net.shp file. The default filename for this shapefile is "*w.shp", where * is the base DEM name.
Stream Reach Shapefile Attributes
| Attributes | Description |
|---|---|
| LINKNO | Link Number. A unique number associated with each link (segment of channel between junctions). This is an arbitrary number that varies depending on the number of processes used. |
| DSLINKNO | Link Number of the downstream link. -1 indicates that this does not exist. |
| USLINKNO1 | Link Number of first upstream link. -1 indicates no links upstream. |
| USLINKNO2 | Link Number of second upstream link. -1 indicates no links upstream. |
| DSNODEID | Node identifier for node at downstream end of stream reach. This identifier corresponds to the "id" attribute from the Outlets shapefile used to designate nodes. |
| Order | Strahler Stream Order |
| Length | Length of the link |
| Magnitude | Shreve Magnitude of the link. This is the total number of sources upstream |
| DS_Cont_Ar | Drainage area at the downstream end of the link. Generally this is one grid cell upstream of the downstream end because the drainage area at the downstream end grid cell includes the area of the stream being joined. |
| Drop | Drop in elevation from the start to the end of the link |
| Slope | Average slope of the link (computed as drop/length) |
| Straight_L | Straight line distance from the start to the end of the link |
| US_Cont_Ar | Drainage area at the upstream end of the link |
| WSNO | Watershed number. Cross reference to the *w.shp and *w grid files giving the identification number of the watershed draining directly to the link. |
| DOUT_END | Distance to the outlet from the downstream end of the link |
| DOUT_START | Distance to the outlet from the upstream end of the link |
| DOUT_MID | Distance to the outlet from the midpoint of the link |
Text Files
Text files are used to store the Stream Network Tree and Stream Network Coordinate files, giving network topological connectivity and coordinates and attributes associated with points on the stream network.
Stream Network Tree File
This file defines the topological linkage of the stream network. The default filename is "*tree.dat", where * is the base DEM name. The Stream Network Tree File is created by the function "Stream order grid and network files". Columns are as follows:
| # | Description |
|---|---|
| 1 | Link Number. A unique number associated with each link (segment of channel between junctions). This is an arbitrary number that varies depending on the number of processes used. |
| 2 | Start Point Number in Network Coordinates (*coord.dat) file (Indexed from 0) |
| 3 | End Point Number in Network Coordinates (*coord.dat) file (Indexed from 0) |
| 4 | Next (Downstream) Link Number. Points to Link Number. -1 indicates no links downstream, i.e. a terminal link. |
| 5 | First Previous (Upstream) Link Number. Points to Link Number. -1 indicates no upstream links. |
| 6 | Second Previous (Upstream) Link Numbers. Points to Link Number. -1 indicates no upstream links. Where only one previous link is -1, it indicates an internal monitoring point where the reach is logically split, but the network does not bifurcate. |
| 7 | Strahler Order of Link |
| 8 | Monitoring point identifier at downstream end of link. -1 indicates downstream end is not a monitoring point. |
| 9 | Network magnitude of the link, calculated as the number of upstream sources (following Shreve). |
Stream Network Coordinate File
This file defines the coordinates and attributes of points along the stream network. The default filename is "*coord.dat", where * is the base DEM name. The Stream Network Coordinate File is created by the function "Stream Reach and Watershed". Columns are as follows:
| # | Description |
|---|---|
| 1 | X coordinate |
| 2 | Y coordinate |
| 3 | Distance along channels to the downstream end of a terminal link |
| 4 | Elevation |
| 5 | Contributing area |