FGSK: webgis for water systems (rivers, streams) in Mecklenburg-Vorpommern. It deals with hydromorphology: morphology (shape, character) and hydrology (how, how fast, does it flow). What they’re doing is a standardisation of the data for the various segments of the water structures and grading the streams accordingly. The goal is to have a good, natural water stream that’s good for the environment.
What they’re doing is measuring how straight or bendy a stream is and what the flow velocity is. A stream that’s straight is a line is bad, something that meanders through the landscape is perfect.
When they started, the map material was in need of improvement. Mostly it was only entered based on airial images. Also they needed more metadata (“parameters”), like shape of the stream bottom. They mapped it three steps.
Entering metadata in a web application means that the web application should be simple to use. And it should include automatic checks for plausability of the entered data. And it should include rule-based grading of the streams.
A necessity: it should be free software.
As a framework, they used MapFish with a GeoExt client. And the UMN Mapserver. Postgis/postgres as the database. Geojson is used for exchanging data.
Some big parts of the software:
LINESTRINGM. And they partially calculate this dynamically from x,y locations to linear locations and back.
Some problems they encountered:
My name is Reinout van Rees and I work a lot with Python (programming language) and Django (website framework). I live in The Netherlands and I'm happily married to Annie van Rees-Kooiman.
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