Output:Time Series Data at Internal Locations

GSSHA has the capability to save time series data of a number of parameters at internal locations in the channel network and within cells in the 2-D grid.

14.4.1 Time Series Data at Internal Stream Network Locations

GSSHA can save time series of discharge, depth, concentration and sediment flux at any link-node pair in the channel network by specifying the cards listed in Table 23. If internal time series data are desired then the IN_HYD_LOCATION and OUT_HYD_LOCATION files must be specified in the project file.

CARD NAME	ARGUMENT	DESCRIPTION
IN_HYD_LOCATION	table name	Name of input ASCII file containing the link/node pairs to write out hydrograph ordinates to the file specified by OUT_HYD_LOCATION.
OUT_HYD_LOCATION	file name	Filename to output discharge (m³/s or ft³/s) every HYD_FREQ time steps, at internal channel locations specified in IN_HYD_LOCATION. REQUIRED if IN_HYD_LOCATION was specified.
OUT_DEP_LOCATION	filename	Filename to output time channel depths (m) every HYD_FREQ time steps at internal channel locations specified in the IN_HYD_LOCATION file.
IN_SED_LOC	filename	Name of input ASCII file containing the link/node pairs to write out sediment discharge ordinates to the file specified by OUT_SED_LOC.
OUT_SED_LOC	filename	Filename to output sediment flux every HYD_FREQ time steps at internal channel locations specified in the IN_SED_LOC file. REQUIRED if SOIL_EROSION and IN_SED_LOC card are specified.

Table 23 – Internal stream network output cards

The file specified by the IN_HYD_LOCATION card has a fixed format, which consists of an integer number equal to the number of points where hydrographs are to be saved (N), followed by N pairs of link and node numbers. For instance, if one wished to write out the hydrographs at 2 locations ( link 8, node 18) and (link 6 node 113), the contents of IN_HYD_LOCATION file would be:

	2
	8  18
	6  113

During the simulation, hydrograph ordinates would be written to the file specified with the OUT_HYD_LOCATION project file. The OUT_HYD_LOCATION file has (N+1) columns of data, where the first column contains the time in minutes since the beginning of the simulation for single events, the time in decimal years for continuous simulations, or the strict Julian date if the STRICT_JULIAN_DATE project card is used, and N columns of hydrograph ordinates. The hydrograph ordinates are written in the order they appear in the IN_HYD_LOCATION file. So, for example, an OUT_HYD_LOCATION file for the above example might appear as:

	0.000   0.000  0.000
	15.0    2.678  1.184
	30.0    5.988  3.714
	  •        •      •
	  •        •      •
 	  •        •      •

If depths are desired at the same locations specified in the IN_HYD_LOCATION file, then the OUT_DEP_LOCATION project card is used to specify the filename where depths (m default, ft if OUT_CFS is used) will be output.

If sediment flux at internal link-node locations is desired, the OUT_SED_LOC card is used to specify the filename where the sediment flux (m³/s) will be output. For sediment flux the link-node locations must be specified in a file identified with the IN_SED_LOC project card. To get time series data of in-stream sediment flux, the SOIL_EROSION project card must be specified along with the appropriate sediment erosion inputs.

Strictly, there are no limits on the number of link-node pairs at which time series ordinates can be saved. Practically, however, there may be limits due to the number of columns of data that may be imported into your data analysis/plotting software. Hydrograph ordinates are written every HYD_FREQ time steps.

14.4.2 Time Series Output at Internal 2-D Grid Cell Locations

Time series data of soil moisture and groundwater level may be output at any cell in the 2-D grid network. This capability is provided to be able to compare to measured soil moisture and groundwater level data.

When saturated groundwater is being simulated observation, wells at any row (i) and column (j) in the 2-D grid can be specified in the OUT_WELL_LOCATION file. The OUT_WELL_LOCATION file contains the number of locations where groundwater levels are desired, followed by the ij location of each desired observation well. The file has the following format.

# observation wells (N)
i location of well 1 (i1)     j location of well 1 (j1)
i2        j2
i3        j3
etc.
iN-1      jN-1
iN        jN

Time series values of groundwater elevation (m) at every well location will be output every HYD_FREQ time steps to the file specified in the GW_WELL_LEVEL project card. This file will have one column for time and one column of groundwater surface elevation (m) for each well (N wells) listed in the OUT_WELL_LOCATION. The order of the output is the same as the order of the input.

Anytime infiltration is being calculated, soil moistures may be output at any cell in the soil column of any cell in the 2-D grid. To get time series data of soil moistures the IN_THETA_LOCATION card is used to provide the name of a file that contains the locations of cells where soil moisture output is desired. When any Green and Ampt approximation is used the location 2-D grid location, i row, j column, is specified in the IN_THETA_LOCATION file. For the various Green and Ampt approximations, soil moistures at the soil surface will be output. For Green and Ampt approximations the IN_THETA_LOCATION file has the following format.

The first line contains the number of 2-D grid locations where output is desired. Then for each 2-D grid cell where soil moisture output is desired the i location and j location are specified. This sequence is repeated for each 2-D grid location. This file has the following format:

# 2-D Grid Locations (N)
i1     j1    
i2     j2   
...
...
....
iN-1  jN-1   
iN     jN

To get output from a given cell in the Richards’ equation solution, the location in the 2-D grid, i row, j column, and the location within that ij location, k^th cell, must be specified. The IN_THETA_LOCATION file has the following format. The first line contains the number of 2-D grid locations where output is desired and the maximum number of cells desired at any 2-D grid point. Then for each 2-D grid location desired, the i location, j location, and the number of vertical cells at that ij location are specified. This is followed by the vertical cell numbers (k) of each of the cells at the ij location. This sequence is repeated for each 2-D grid location. This file has the following format:

# 2-D Grid Locations (N)      Maximum number of cells at any location (M)
i1     j1     M1
vertical cell # 1 (k1)
k2
k3
etc.
kM1-1
kM1
i2     j2     M2
k1
etc.
kM2-1
kM2
etc.
iN     jN     MN
k1
etc.
kMN-1
kMN

For example, soil moistures are desired at 2 locations in the 2-D grid, at cell i = 40, j = 13 and at cell i = 24, j = 32. Soil moistures are desired at 5 depths at each of these ij locations, corresponding to vertical cell # (k) 25, 50, 71, 111, 170 at both sites. The required file would look like

2     5
40     13     5
25
50
71
111
170
24     32     5
25
50
71
111
170

The soil moistures are then output to the file specified in the OUT_THETA_LOCATION file whose format is identical to that of the OUT_HYD_LOCATION file. For the Richards’ equation example above, the OUT_THETA_LOCATION file would contain 11 columns of data, one for the time and 10 for soil moistures at the specified locations, which will appear in the order requested in the IN_THETA_LOCATION file. For all Green and Ampt approximations each line will contain the time followed by one value of soil moisture, soil moisture at the surface, for each 2-D grid cell selected in the IN_THETA_LOCATION file, in the order requested in the IN_THETA_LOCATION file.