BioBase Data Use in QGIS 3X

Tutorial: Creating transects in QGIS and converting to .gpx for import

onto Lowrance

© Navico, Inc. 2019

First, obtain or digitize waterbody boundary polygon shapefile.

Reproject shapefile to the appropriate UTM zone. In this case we are using NAD83 / UTM zone 15N. (Vector ->

Data Management Tools -> ReprojectLayer…)

Generate a grid shapefile.(Vector -> Research tools -> Create Grid…)

Select desiredspacing. Useboundary shapefile forGrid extent.

Toggle Editing, select, and delete all undesired rows or columns. On the right, we now have deleted the East-West

polylines and are left with the North-South polylines.

Use Toggle Editing, Select, Rotate, Move, and Copy Paste Tools to optimize transect orientation (if needed).

Rotate editing tool

Clip the grid to the waterbody boundary. (Vector -> Geoprocessing Tools -> Clip)

Toggle Editing, Edit -> Merge Selected Features. Select the first row and then click OK. This will combine all the lines into one

feature for the sake of simplicity.

Reproject back to WGS84 (required for import to Lowrance).

Right click on final transect layer and select Export -> Save Feature As… (Format GPX. For GPX_USE_EXTENSIONS select YES.)

Your GPX file is now ready for importing onto your Lowrance.

Use measure tool to get visual for appropriate spacing

Load the GPX file onto your Lowrance