VOLUMETH

Basic Information

Name of Program

VOLUMETH

Version-Date

5.x / September 2015

Description-Date

September 2015

Catchwords

volume method
horizontal area distribution
volume sum
isolines
finite elements topography

Short Description of Functionality

The program VOLUMETH calculates horizontal area distribution and volume sum curve for regions inside a finite elements topography. The size of a horizontal area is defined by the area where the depth is greater than a given isobath. The volume sum is the volume under this defined horizontal area. Besides morphological analysis the program can be used to check model grids on their hydraulic properties (volume of water which can flow into an area). Different subregions for which the curves are calculated separately can be defined by closed polygons.

Volume calculations may be optionally executed also for a bathymetry which is derived from a finite difference grid for the mathematical model UNTRIM. Please notice that volumes computed by VOLUMETH are not identical with volumes used in UNTRIM applications. This is due to the fact, that VOLUMETH uses interpolated depth at nodes for volume computation while in UNTRIM depth values at polygon centers are used instead.

VOLUMETH supports input data of different coordinate reference systems (CRS). The user has to specify a coordinate reference system into which all coordinates will be transformed on the fly by the Environment variable BAWCRS. The use of BAWCRS is recommended! The user CRS has to be a projected system (UTM, Gauß-Krüger)!

The program VOLUMETH has been developed on the basics of GISO2D and therefore includes the complete functionality of this program. Because of that GISO2D has been moved to the program cemetery.

Input-Files

1. input file for program flow control (type volumeth.dat).
2. file with finite element mesh (type gitter05.dat/bin or untrim_grid.dat).
3. (optional) file with edge information (type fkvz.bin).
4. (optional) file with neighbour element information (type fkez.bin).
5. (optional) file with definitions of subregions (type poly.dat).

Output-Files

1. file with structure information of the isobaths which were found (type insel.dat).
2. ASCII file with results of the area distribution and volume sum function (type volsum.dat/excel.dat)
3. or EXCEL readable file with results of the area distribution and volume sum function (type volsum.dat/excel.dat) for each subregion.
4. GKS logfile (type gkslog.dat)

Methodology

For each isobath the intersection points with the mesh are determined first. During this process the element areas are summed up, when the lie inside the area which is deeper than the isobath. If an element is intersected by the isobath or the given boundary polygon of the current region, the element shape is modified such that the non relevant area of the element is cut. As the areas, the volumes above the element surfaces are summed up. The points are ordered by the separate isoline parts and stored in correct sequence. The output of all isoline parts is done into a file of type insel.dat.

The values of the volume sum are exact with respect to approximation of the topography and the computer accuracy!

Program(s) to run before this Program

FDGITTER05, GISMO, JANET, POLYUMFORM

Program(s) to run after this Program

EXCEL

Additional Information

Language

Fortran90

Additional software

-

Original Version

G. Seiß

Maintenance

working group PRE

Documentation/Literature

$PROGHOME/examples/volumeth/*

BAW, 1996: Anpassung der Fahrrinne der Unter- und Außenelbe an die Containerschiffahrt - Gutachten zur morphologischen Entwicklung der Nebenelben und Nebenrinnen seit 1945/1950. Bundesanstalt für Wasserbau, Außenstelle Küste, Hamburg.

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