Swan River

MapInfo and QGIS

GOt river data from geoscience australia, was unimpressed with quality.

Used DEM to create new river outline. Due to poor resolution of DEM, the edge is quite jagged, but more closely resembles what can be seen in aerial photography on Google than the GA layer.

CReated new layer by using Vertical Mapper to create contours from DEM. I could only find this option within the Grid manager, go figure.

Made intervals quite small, seemed to pick well. Created new TAB file from interval that matched shape of river.

USed distance calculator tool in Mapinfo to calculate distance between GNAF points and new rriver TAB. For some reson, they all seem to aggregate to certain nodes. I think it might be due to the jagged shape of the river file, but I'm not sure. One way to check, would be to smooth out the river boundary and see how distance tool works once destination geometry has more nodes.

Note that the distance calculator is under tools, but not by default. It needs to be turned on by going into tool manager.

Distance calculator created lines between the GNAF points and the closest node in the river polygon. I then used QGIS to create nodes from the lines, which created 2 points for each line, as the lines were all dead straight - obviously as this is the shortest distance between 2 points.

QGIS>Vector>Geometry Tools>Extract nodes.

Then in Vertical Mapper, used the point inspection tool to add heights to the points.

From here, its a simple process of matching the two points - obviously the one with the larger height value is the property.

Splitting lines into points

used Qgis - worked really well, fast, and kept all the attributes.

IDRISI - where the heck is that command?

I created a shortcut to the IDRISI Taiga manual, and put it on my desktop.

It has links to all the macro commands, beyond what is in the help documentation

"C:\Program Files (x86)\IDRISI Taiga\Documentation\Taiga Manual.pdf"

The list of modules and the menu they can be found at page 76, the 77th page of the pdf.

IDRISI

Idrisi gets used here to rasterize vector layers. Convert from Mapinfo to shape using Global Mapper, or Mapinfo. Then use IDRISI to convert from shape to IDRISI vector format. Then use IDRISI to convert from IDRISI vector to IDRISI raster.

To import/convert in IDRISI:
File>Import>Software-Specific Formats>ESRI formats>SHAPEIDR

To convert between vector and raster:
Reformat>RASTERVECTOR

Note - you might be converting from Mapinfo to shape, which will create multiple geometry types. Make sure you convert all the geometrys. First create an image using Data Entry> INITIAL, create the empty image and then add rasters to it.

MapInfo - view tables

In mapinfo, to view tables, either

F2

or Window>New Browser

Stoopid, huh?