Itter Catchment Data
====================

About
-----

A long standing drawback of GREAT-ER was the lack of a really free 
distributable geographic data set. To overcome this with GREAT-ER II 
CEFIC LRI contracted Intevation GmbH for the digitization of a catchment. 
The Itter catchment has been choosen since it is small but validated.
Its applicability for environmental modelling has been proven by various 
publications. 

Contents
--------
itter.thuban    : Thuban-file to load and display the whole map in one step
catchbound.*	: Geographic data, catchment boundary
discharges.*    : Geographic data, discharge sites
disch_river.*   : Geographic data, connection of discharge site to river
rivernet.*      : Geographic data, river network
disch.dbf       : Discharge site data
disch_tab.dbf   : Discharge site data processed for GREAT-ER II
river.dbf       : River stretch data
stretch_tab.dbf : River stretch data processed for GREAT-ER II
COPYING         : Licence information
README          : This file

(Geographic data is provided in ESRI Shapefile format, Geographic Coordinates)

The Itter Catchment
-------------------

The Itter is a small tributary to the Rhine in a region of high 
population density. The source is located in Solingen, 20 kilometers downstream
the Itter meets the Rhine (in Duesseldorf-Benrath). A mayor tributary to the
Itter is the Lochbach.

The Itter drains waste water of approximately 150,000 persons plus industrial 
waste water discharged from three municipal treatment plants. At low flow 
approximately 80 percent of the water flow are coming from the STPs. The
contribution of the Itter to the Rhine is about 0.7 m^3/s (at low flow).


The Geographic Data
-------------------
 
The Catchment Boundary was generated by Dr. Carsten Schulze during his
Diplomarbeit at the Institute of Environmental Systems Research (USF) at the
University of Osnabrueck joined with Henkel KGaA, Duesseldorf. Thankworthy the
data was made freely available. Also the attribute data has been provided by
this work.

The discharge sites and the river network have been digitised by Intevation
GmbH on behalf of CEFIC LRI. Based on aerial photos provided by the 
Bergisch-Rheinischer Wasserverband (BRW) the river network has been created 
using GRASS.

The discharge - stretch link layer finally has been generated automatically by
the GREAT-ER II pre-processing.

While the data is provided in geographic coordinates, an appropriate 
map projection for presentation is "Gauss-Krüger Zone 2". See the files
catchment.thuban or itter.prj for details.


The Data Tables
---------------

The raw attribute data (geographic data dbf-files) provide only the shape IDs.
For discharge sites and river stretches more detailed data is available which
is provided in the disch.dbf and river.dbf files. These can be joined to the
geographic data (e.g. in Thuban) or copied over the raw attribute data.

The disch_tab.dbf and stretch_tab.dbf tables provide the same data processed 
for GREAT-ER II. Especially the river data contains some virtual stretches to
fullfil the GREAT-ER II topology requirements for a river network.


Sources
-------

The source files (ie. text-formats) are part of the GREAT-ER pre-processing
package which can be found on the GREAT-ER development homepage (see links).


Copyright
---------

    Itter Catchment Data
    Copyright (C) 2003, Intevation GmbH

    This data is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This data is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this data (file COPYING); if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Links
-----

Thuban 
	http://thuban.intevation.org

GRASS
	http://grass.itc.it/index.html

Diplomarbeit C.Schulze
	http://www.usf.uni-osnabrueck.de/archive/~cschulze/itter/index.de.html	

Shapefile Format
	http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf

GREAT-ER
	http://www.great-er.org

GREAT-ER Development
	http://great-er.intevation.org
