Documentation

# Creating a Project in QGIS

DANGER

This tutorial may differ from what you encounter when working with Mergin Maps. It will be updated soon to include recent changes in Mergin Maps, Mergin Maps Input and Mergin Maps plugin for QGIS.

In earlier tutorials you created a new survey project from within Mergin Maps Input. That was a very fast (albeit limited) way of creating a Mergin Maps project.

In this tutorial you will create a new project for surveying trees and hedges using QGIS.

# Before we start

Please ensure you have already:

# Create a minimal project

  1. Open QGIS

  2. Open the Create Mergin Maps Project tool:

  3. Select New basic QGIS project:

  4. Give the project a Project Name and ensure it's created under Documents\Mergin Projects:

    TIP

    Although you can create your Mergin Maps project under any folder, we recommend you store local projects under Documents\Mergin Projects. That convention is also used throughout this documentation.

  5. Press Finish. Your new project should now be created and opened:

# Add layers

You may have noticed that the Mergin Maps plugin for QGIS has created a project almost identical to the one created by Mergin Maps Input in a previous tutorial: A single point layer called Survey and OpenStreetMap base mapping.

TIP

Mergin Maps Input can make use of any type of background maps (offline and online) that are supported by QGIS.

You can learn how to add raster and vector background maps here.

We'll now add two more layers - a point layer for surveying trees and a line layer for hedges.

  1. Select Layer > Create Layer > New GeoPackage Layer...

  2. Using the Browse button, ensure the GeoPackage is saved under Documents\Mergin Projects\trees-and-hedges\trees.gpkg and its geometry type is Point:

  3. Add a New Field called date with the data type Date:

  4. Add two more fields species and conditions with the data type Text Data.

    The Fields List will look like this:

  5. Click OK. A new layer called trees has now been added to your project:

  6. Repeat steps 1 to 5 above to add another new layer called hedges with these details:

    • Database: Documents\Mergin Projects\trees-and-hedges\hedges.gpkg
    • Geometry type: LineString
    • Fields:
      • both_sides_surveyed, data type Boolean
      • num_access_gates, data type Whole Number (integer)
      • photo, data type Text Data

In the Layers panel, you should now have two new layers, trees and hedges:

# Configure attributes forms

Before we try out this new project in Mergin Maps Input we'll make a couple of small changes to the layers' attribute form settings which influence how users will interact with feature attributes in the field.

Notice how the tree species, Black alder, has been accidentally mistyped during the field survey. This can be avoided by setting up a drop-down list (right image). Attributes can also be aliased (renamed) for easier reading.

Now we will set up the drop-down list for the trees:

  1. Double-click the trees layer to open its Layer properties:

  2. Select Attributes Form on the left and click on the species attribute:

  3. Make the following changes to the species attribute:

    • Change the Widget Type to Value Map
    • Enter Values and Descriptions similar to these (both are set the same in this example):

    TIP

    Value is how the data will be stored in the underlying dataset and Description is how it will appear to the user.

  4. Ensure fid is not editable.
    fid

    TIP

    fid is a special attribute used to uniquely identify features. We recommend not allowing users to edit this attribute.

  5. Click OK to close the layer properties dialog.

# Configuring photo attribute

Our hedges layer has an attribute called photo. The attribute itself is stored as text but we'll use it to attach photos to surveyed features. To achieve this we'll need to set its Widget Type to Attachment:

  1. Double-click the hedges layer to open its Layer properties.

  2. Update the form for the photo attribute as follows:

    • Set its Widget Type to Attachment
    • Path defines where the photos will be stored. Set Store path as Relative to Project Path:
      photo widget

  3. Ensure fid is not editable.

  4. Click OK to close the layer properties dialog.

# Saving changes to Mergin Maps

In the next tutorial we will see how this project looks on Mergin Maps Input. We'll now save the changes we've made here and sync the project back to the cloud.

  1. Rename the layer called Survey to Survey notes (the name is a little ambiguous).

  2. Save the QGIS project
    save qgis project

  3. Use the Synchronise Mergin Maps Project button:
    sync project

    The Project status window will open with the overview of local changes. Click Sync to synchronise the project:
    project status

    In a few moments your changes are safely stored in the cloud:
    synced

Synchronising changes between users and devices is a core principle of Mergin Maps. When you sync a project, changes that have been made by other users and devices since you last synced are fetched and any changes you've made are pushed.

Changes are merged safely and easily from different users, even when they edit the same feature.

Mergin Maps tracks project version history so you can download a previous version of a project if you need to.

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