Updated GIS documentation

docs/src/gis.md

@@ -5,6 +5,22 @@ for field geometries, and one for soil types. Additionally, a weather input
 file is needed. This documents describe how to obtain and process the data 
 needed for each of these.
 
+There is a QGIS project file at `data/regions/auxiliary/persefone.qgz`, which
+can be used get an overview of the existing region input files and add new ones.
+All region data files are stored using the following convention:
+
+```
+data/regions/<regionname>/
+-> <regionname>.geojson
+-> landcover.tif
+-> fields.tif
+-> soil.tif
+-> weather.csv
+```
+
+Where `<regionname>` is currently one of `bodensee`, `eichsfeld`, `hohenlohe`, `jena`,
+`oberrhein`, or `thueringer_becken`.
+
 ## Land cover maps
 
 Land cover maps for Germany at 10m resolution can be obtained from 
@@ -22,12 +38,13 @@ land cover classes:
 ```
 
 To create a Persefone map input file, you need to crop the national Mundialis
-map to the extent that you want to simulate (suggestion: approx. 10x10km is a 
-reasonable size).
+map to the extent that you want to simulate (suggestion: edge lengths between 10-20 km
+are a reasonable size).
 
 To do so, download the Mundialis map and import it into QGIS. Then create a new
 vector layer and create a rectangle feature to delimit the extent of your
-region. Then go to `Raster -> Extraction -> Clip Raster by Extent`. Select
+region. You can save this as a GEOJSON file to the region folder for future reference. 
+Then go to `Raster -> Extraction -> Clip Raster by Extent`. Select
 the Mundialis map as the input layer, set the clipping extent by choosing your
 region vector layer under `Calculate from Layer` and specify the output
 file name before clicking `Run`. This will generate a TIF file that you can
@@ -41,8 +58,9 @@ farming agents. Unfortunately, getting this is rather more complicated.
 
 In the EU, every country runs a Land Parcel Information System (LPIS) to
 administer CAP payments. In Germany, this is called InVeKoS and is run by the
-Länder. For example, you can view and download the InVeKoS data for Thüringen
-[here](https://thueringenviewer.thueringen.de/thviewer/invekos.html).
+Länder. For example, you can view and download the InVeKoS data for 
+[Thüringen](https://thueringenviewer.thueringen.de/thviewer/invekos.html) or
+[Baden-Württemberg](https://metadaten.geoportal-bw.de/geonetwork/srv/eng/catalog.search#/metadata/03873032-80e7-41ec-bb3e-3d34231617e4).
 This gives you a vector layer which can be loaded into QGIS. However, it needs
 to be converted to a raster layer and cropped to your region extent before it
 can be used in Persefone.
@@ -79,9 +97,14 @@ Rohstoffe in form of the [Bodenatlas](https://bodenatlas.bgr.de/). This provides
 a (coarse, but for our purposes sufficient) map of the distribution of the basic
 soil types such as clay, silt, sand, and loam.
 
-To create the Persefone input file, you need crop this national map to the same 
-region as the other maps, then rasterise it (see instructions in the last paragraph
-of the previous section).
+To create the Persefone input file, you first need to rasterise the data. See the
+instructions above - choose `BODENART` as the field for the burn-in value. (Note:
+rastering the whole map produces a 20GB file! This can later be deleted again.)
+Then you need to align and crop it to the extent you require, using the dialog at 
+`Raster -> Align Rasters...`. Select your landcover map as the reference layer
+and the extent layer, then choose your national soil map as the input. (Don't forget
+to define the output file name using `Configure Raster...`, this is a bit hidden.)
+The created output file can then be used for the `soilmap` parameter.
 
 ## Weather data