ASC to ASC: Difference between revisions

 

=2023-03-AA (and later)=

 

The '''ASC_to_ASC-2023-03-AA''' release incorporates several new GIS formats - '''GeoTIFF''', '''GPKG''', '''NetCDF''' (note: NetCDF was previously supported but now has better integration with all operations). The commands are largely unchanged and now support input and output to a range of new formats.

*Converts the file "DEM_M01.asc" for .flt format.<br>

:<tt>asc_to_asc.exe -conv DEM_M01.asc</tt>

 

==Maximum==

*A classified grid with the name _src.asc which contains the source grid for the maximum value.<br>

Examples:<br>

 

==Difference==

*A second grid with a “_wd” suffix is output to indicate which .asc grid cells were once wet and are now dry (value -99) or once dry and are now wet (value +99 with first .asc to be the developed case and second .asc to be the existing case). Importing this grid into Vertical Mapper creates a .grc (grid classification) grid that has two categories: “Was Wet Now Dry” and “Was Dry Now Wet”. This grid is particularly useful for displaying areas that were previously inundated or previously flood-free.<br>

Example:

Secondary options (only one can be used):

*"-nowetdry" does not carry out a wet/dry test. If both cells are active a difference is calculated.

*If three grids are specified, the third grid is used for setting the filename for the output grid. This is ignored if the "-out" option is used.<br>

Examples:

 

==Resize==

This is the defualt processing method, which can also be specified with the '''-rm_avg''' (resize method - average) input flag. When processing for each tile in the new grid, the average of all non-null values in the input grid is taken. For example with a resize factor of 5, the 25 values in the input grid are averaged.<br>

Example:

 

===Minimum===

Alternative processing method for resize, specified with the '''-rm_min''' (resize method - minimum) flag. At each output grid the values is the minimum of the values in the input grid.<br>

Example:

 

===Maximum===

Alternative processing method for resize, specified with the '''-rm_max''' (resize method - maximum) flag. At each output grid the values is the maximum of the values in the input grid.<br>

Example:

 

==Transform==

Transforms the values using a simple y = mx + c approach the multiplier (m) is specified with flag '''-trans_m<value>'''. The add value (c)'''-trans_c<value>'''. Only one values is required to be specified.<br>

Examples:

 

==Decimal==

Converts .flt to .asc format with specified number of decimal spaces. ASC format created directly from TUFLOW comes only with three decimal spaces, FLT format has more decimal spaces.<br>

Example:

 

==Classify==

|2.0|| 1.0 to 2.0

|}

Examples:

 

 

! style="background-color:#005581; font-weight:bold; color:white;" width=20% | Cutoff Value

[[File:TUFLOW Utilities GRC01.jpeg|600px]]<br>

<br>

 

==Extract Breaklines from DEM==

'''"-brkline <gis file in 2d_zsh format>"'''<br>

This feature was added to the 2013-06-AA version of the utility.<br>

Depending on the line width and DEM cell size, the following methods are used:<br>

* If the width is set to 0, the closest DEM value to the vertex is used. If a "shape_option" is specified this is ignored.

'''NOTE:''' For the output GIS file, the '''dz''' attribute is set to 0.0 regardless of the value set in the input field. <br>

Example:

 

==Fuzzy Map==

For each input grid (or scenario) the grid is classed as either 1 if the results grid is wet or 0 if dry. The total score for each grid cell is is calculated and then divided by the total number of input grids. A value of 1 indicates that the cell was wet in each simulation a value of 0 is dry in all simulations. Grids with a value of 0.5 are most sensitive.<br>

This can be useful for quantifying the sensitivity of the model to parameters.<br>

 

==Histogram==

This feature was added to the 2014-03-AB version of the utility.<br>

Calculates the number of cells and percentage of cells that fall in each range. Requires and input .csv file containing the bin values.<br>

 

! style="background-color:#005581; font-weight:bold; color:white;"| Bin

|}

 

 

! style="background-color:#005581; font-weight:bold; color:white;"| Bin

|Above 5.0|| Above 5.0 || 973 || 0.06

|}

 

==Extract 1D Model Inputs==

|FLC per Unit Length == <form loss per unit length> || The form loss per unit length is written to the "exit_loss" attribute of all 1d_nwk channels.

|}

An example .egc file is:<br>

<pre>

The input GIS region file should have the same attributes as the 1d_tab file format produced by TUFLOW. The first attribute ("Source" ) should contain a valid .csv file name.<br>

The out nodal area table extends from the minimum to the maximum elevation in the DEM. A user defined minimum value can be specified using the "Skew" attribute of the GIS region.<br>

 

==Calibration Points==

'''"-cpmm<mm>"''' (optional)<br>

The second search radius used to search for maximum and minimum values in meters.<br>

 

==Statistics==

<big>'''"-stat<type>"'''</big>

As of the 2017-10-AA build, the ASC_to_ASC.exe utility allows the user to perform a number of statistical analyses on a group of input grids (*.flt or *.asc format). This is particularly useful when extracting information from assessments that produce multiple result files for a single event, for example, processing grids from an ensemble assessment with numerous temporal pattern arrangements.

 

 

The below gives a description on each option as well as an example. It is also useful to consider using wildcards in the batch file to supplement typing out each input grid file individually. Several of the examples below utilise this ability to demonstrate how it can be done.<br>

 

The -statMedian flag outputs the median value at each grid cell from all the input grids. All the input grids are considered, regardless of if the grid cell is dry in some of the input grids (dry areas are still ranked as low e.g. Rank1, Rank2 and so on).

 

* A value grid: the resulting median value

* An SRC grid: a grid listing which source input grid the median result value came from (a corresponding .csv file is also written as a legend)<br>

 

[[File: asc_to_asc_statsMedian_eg.PNG|1000px|]]<br>

 

==="-statMean"===

The -statMean flag outputs the mean value at each grid cell. Unlike the median, the mean is only calculated at grid cells that are wet (that show flooding) in all input grids. Please note that the source grid is the next grid above the mean value. The mean command outputs two grids:

* A value grid: the resulting value

* An SRC grid: a grid listing which source input grid the result value came from or was the next above (a corresponding .csv file is also written as a legend)<br>

 

==="-statFrac"===

The -statFrac flag outputs a value at each grid cell that represents the fraction of the events that the grid cell is wet in. For example, if the number of input grids is 10, and a value of 0.2 is returned, this means this grid cell experienced flooding in 2 out of the 10 events. A value of 1.0 means that the grid cell was wet in all events.

 

The utility outputs one grid:

* A Frac grid: the resulting Fraction value<br>

 

==="-statMin"===

The -statMin flag outputs the minimum value at each grid cell from all the input grids.

 

* A value grid: the resulting value

* An SRC grid: a grid listing which source input grid the minimum result value came from (a corresponding .csv file is also written as a legend)<br>

 

==="-statMax"===

The -statMax flag outputs the maximum value at each grid cell from all the input grids. This flag is analogous with the [[#Maximum|-Max]] operation flag.

 

* A value grid: the resulting value

* An SRC grid: a grid listing which source input grid the maximum result value came from (a corresponding .csv file is also written as a legend)<br>

 

==="-statAll"===

The -statAll flag undertakes and creates results for all the statistic operations mentioned above.

 

* An SRC grid: for the median, mean, min and max calculations (calculation of source grids as detailed above)

* A .csv file that contains the legend for all SRC grids<br>

 

==="-statRank<integer id>"===

The -statRank<integer> flag outputs the ''n<integer>'' ranked value at each grid cell from all the input grids. All the input grids are considered, regardless of if the grid cell is dry in some of the input grids (dry areas are still ranked as low e.g. Rank1, Rank2 and so on). For example, if the number of input grids is 10, at each grid cell the values are ranked lowest to highest (from 1 to 10). -statRank8 will output results taken from the 8th ranked grid. In this example, -statRank1 is equivalent to ''Min'', -statRank10 is equivalent to ''Max'', and -statRank6 is equivalent to ''Median''. The Rank flag allows additional functionality that lets users extract results in between those that are pre-programmed.

 

* A value grid: the resulting value

* An SRC grid: a grid listing which source input grid the ranked result value came from (a corresponding .csv file is also written as a legend)<br>

 

==Flood Extent==

Returns a simple grid with value of 1 where the input grid has an active, non-zero value.<br>

 

==Remap==

Sets the finer resolution DEM.<br>

The default interpolation method is TIN. But "-idw_npt<number of points>" flag can be used to change the interpolation method to IDW and set the number of points used for IDW interpolation (default is 12).<br>

 

Note that, for any output types other than depth, this utility does NOT interpolate the result from the coarser grid to the finer grid, but only extends/reduces the output extent to the dry/wet extent. More discussions on this function is documented here [[TUFLOW_Remapping | TUFLOW Remapping Tool]].<br>