15.1. Abrir Dados

Como parte de um ecossistema de software de código aberto, o QGIS é baseado em diferentes bibliotecas que, combinadas com seus próprios provedores, oferecem capacidades para ler e muitas vezes escrevem vários formatos:

  • Os formatos de dados vetoriais incluem GeoPackage, GML, GeoJSON, GPX, KML, Valores separados por vírgula, formatos ESRI (Shapefile, Geodatabase…), formatos de arquivo MapInfo e MicroStation, AutoCAD DWG/DXF, GRASS e muito mais… Leia o artigo completo lista de formatos vetoriais suportados.

  • Raster data formats include GeoTIFF, JPEG, ASCII Gridded XYZ, MBTiles, R or Idrisi rasters, GDAL Virtual, SRTM, Sentinel Data, ERDAS IMAGINE, ArcInfo Binary Grid, ArcInfo ASCII Grid, and many more… Read the complete list of supported raster formats.

  • Database formats include PostgreSQL/PostGIS, SQLite/SpatiaLite, Oracle, MS SQL Server, SAP HANA, MySQL…

  • Web map and data services (WM(T)S, WFS, WCS, CSW, XYZ tiles, ArcGIS services, …) are also handled by QGIS providers. See Working with OGC / ISO protocols for more information about some of these.

  • You can read supported files from archived folders and use QGIS native formats such as QML files (QML - O Formato de Arquivo de Estilo QGIS) and virtual and memory layers.

Mais de 80 formatos de vetor e 140 raster são suportados pelos provedores nativos GDAL e QGIS.

Nota

Not all of the listed formats may work in QGIS for various reasons. For example, some require external proprietary libraries, or the GDAL/OGR installation of your OS may not have been built to support the format you want to use. To see the list of available formats, run the command line ogrinfo --formats (for vector) and gdalinfo --formats (for raster), or check the Settings ► Options ► GDAL menu in QGIS.

In QGIS, depending on the data format, there are different tools to open a dataset, mainly available in the Layer ► Add Layer ► menu or from the Manage Layers toolbar (enabled through View ► Toolbars menu). However, all these tools point to a unique dialog, the Data Source Manager dialog, that you can open with the dataSourceManager Open Data Source Manager button, available on the Data Source Manager Toolbar, or by pressing Ctrl+L. The Data Source Manager dialog (Fig. 15.1) offers a unified interface to open file-based data as well as databases or web services supported by QGIS.

../../../_images/datasource_manager.png

Fig. 15.1 QGIS Data Source Manager dialog

Beside this main entry point, you also have the dbManager DB Manager plugin that offers advanced capabilities to analyze and manipulate connected databases. More information on DB Manager capabilities can be found in Plugin do gerenciador de banco de dados.

Existem muitas outras ferramentas, complementos nativos ou de terceiros, que ajudam a abrir vários formatos de dados.

Este capítulo descreve apenas as ferramentas fornecidas por padrão no QGIS para carregar dados. Ele se concentra principalmente na caixa de diálogo Gerenciador de Fonte de Dados, mas, além de descrever cada guia, também explora as ferramentas baseadas no provedor de dados ou nas especificidades do formato.

15.1.1. The Browser Panel

The Browser is one of the main ways to quickly and easily add your data to projects. It’s available as:

  • a Data Source Manager tab, enabled pressing the dataSourceManager Open Data Source Manager button (Ctrl+L);

  • as a QGIS panel you can open from the menu View ► Panels (or kde Settings ► Panels) or by pressing Ctrl+2.

In both cases, the Browser helps you navigate in your file system and manage geodata, regardless the type of layer (raster, vector, table), or the datasource format (plain or compressed files, databases, web services).

15.1.1.1. Explorando a Interface

Na parte superior do painel Navegador, você encontra alguns botões que ajudam a:

  • addLayer Add Selected Layers: you can also add data to the map canvas by selecting Add selected layer(s) from the layer’s context menu;

  • refresh Refresh the browser tree;

  • filterMap Filter Browser to search for specific data. Enter a search word or wildcard and the browser will filter the tree to only show paths to matching DB tables, filenames or folders – other data or folders won’t be displayed. See the Browser Panel(2) example in Fig. 15.2. The comparison can be case-sensitive or not. It can also be set to:

    • Normal: mostra itens que contêm o texto de pesquisa

    • Wildcard(s): fine tune the search using the ? and/or * characters to specify the position of the search text

    • Expressão regular

  • collapseTree Collapse All the whole tree;

  • metadata Enable/disable properties widget: when toggled on, a new widget is added at the bottom of the panel showing, if applicable, metadata for the selected item.

The entries in the Browser panel are organised hierarchically, and there are several top level entries:

  1. Favorites where you can place shortcuts to often used locations

  2. Spatial Bookmarks where you can store often used map extents (see Bookmarking extents on the map)

  3. Project Home: for a quick access to the folder in which (most of) the data related to your project are stored. The default value is the directory where your project file resides.

  4. Home directory in the file system and the filesystem root directory.

  5. Connected local or network drives

  6. Em seguida, vêm vários tipos de contêiner/banco de dados e protocolos de serviço, dependendo da sua plataforma e bibliotecas subjacentes:

    • geoPackage GeoPackage

    • spatialite SpatiaLite

    • postgis PostgreSQL

    • hana SAP HANA

    • mssql MS SQL Server

    • oracle Oracle

    • wms WMS/WMTS

    • vectorTileLayer Vector Tiles

    • xyz XYZ Tiles

    • wcs WCS

    • wfs WFS/OGC API-Features

    • afs ArcGIS REST Server

    • geonode GeoNode

15.1.1.2. Interacting with the Browser items

The browser supports drag and drop within the browser, from the browser to the canvas and Layers panel, and from the Layers panel to layer containers (e.g. GeoPackage) in the browser.

Project file items inside the browser can be expanded, showing the full layer tree (including groups) contained within that project. Project items are treated the same way as any other item in the browser, so they can be dragged and dropped within the browser (for example to copy a layer item to a geopackage file) or added to the current project through drag and drop or double click.

The context menu for an element in the Browser panel is opened by right-clicking on it.

Para entradas de diretório do sistema de arquivos, o menu de contexto oferece o seguinte:

  • New ► to create in the selected entry a:

    • Diretório…

    • GeoPackage…

    • ShapeFile…

  • Add as a Favorite: favorite folders can be renamed (Rename favorite…) or removed (Remove favorite) any time.

  • Hide from Browser: hidden folders can be toggled to visible from the Settings ► Options ► Data Sources ► Hidden browser paths setting

  • Fast Scan this Directory

  • Abrir Diretório

  • Abrir no Terminal

  • Propriedades…

  • Propriedades do diretório…

For leaf entries that can act as layers in the project, the context menu will have supporting entries. For example, for non-database, non-service-based vector, raster and mesh data sources:

In the Layer properties entry, you will find (similar to what you will find in the vector and raster layer properties once the layers have been added to the project):

  • Metadados for the layer. para a camada. Grupos de Metadados: Informações do provedor (se possível,será um hiperlink para a fonte Path), Identificação, Extensão, Acesso, Campos (para camadas vetoriais), Bandas (para camadas raster), Contatos, Links (para camadas vetoriais), Referências (para camadas raster), Histórico.

  • A Preview panel

  • The attribute table for vector sources (in the Attributes panel).

Para adicionar uma camada ao projeto usando a Navegador:

  1. Enable the Browser as described above. A browser tree with your file system, databases and web services is displayed. You may need to connect databases and web services before they appear (see dedicated sections).

  2. Encontre a camada na lista.

  3. Use the context menu, double-click its name, or drag-and-drop it into the map canvas. Your layer is now added to the Layers panel and can be viewed on the map canvas.

    Dica

    Abra um projeto QGIS diretamente do navegador

    You can also open a QGIS project directly from the Browser panel by double-clicking its name or by drag-and-drop into the map canvas.

Depois que um arquivo é carregado, você pode ampliar usando as ferramentas de navegação do mapa. Para alterar o estilo de uma camada, abra a caixa de diálogo :guilabel: Propriedades da Camada clicando duas vezes no nome da camada ou clicando com o botão direito do mouse no nome da legenda e escolhendo :menuselection:` Propriedades` no menu de contexto. Veja a seção Propriedades da simbologia para mais informações sobre a configuração de simbologia para camadas vetoriais.

Right-clicking an item in the browser tree helps you to:

  • for a file or a table, display its metadata or open it in your project. Tables can even be renamed, deleted or truncated.

  • para uma pasta, adicione-a aos favoritos ou oculte-a na árvore do navegador. As pastas ocultas podem ser gerenciadas a partir da guia Configurações ► Opções ► Fontes de Dados.

  • manage your spatial bookmarks: bookmarks can be created, exported and imported as XML files.

  • crie uma conexão com um banco de dados ou um serviço da web.

  • atualizar, renomear ou excluir um esquema.

Você também pode importar arquivos para bancos de dados ou copiar tabelas de um esquema/banco de dados para outro com um simples arrastar e soltar. Há um segundo painel do navegador disponível para evitar rolagem longa enquanto arrasta. Basta selecionar o arquivo e arrastar e soltar de um painel para o outro.

../../../_images/browser_panels.png

Fig. 15.2 QGIS Browser panels side-by-side

Dica

Add layers to QGIS by simple drag-and-drop from your OS file browser

You can also add file(s) to the project by drag-and-dropping them from your operating system file browser to the Layers Panel or the map canvas.

15.1.2. The DB Manager

The DB Manager Plugin is another tool for integrating and managing spatial database formats supported by QGIS (PostGIS, SpatiaLite, GeoPackage, Oracle Spatial, MS SQL Server, Virtual layers). It can be activated from the Plugins ► Manage and Install Plugins… menu.

The dbManager DB Manager Plugin provides several features:

  • connect to databases and display their structure and contents

  • preview tables of databases

  • add layers to the map canvas, either by double-clicking or drag-and-drop.

  • add layers to a database from the QGIS Browser or from another database

  • create SQL queries and add their output to the map canvas

  • criar virtual layers

More information on DB Manager capabilities is found in Plugin do gerenciador de banco de dados.

../../../_images/db_manager.png

Fig. 15.3 Caixa de diálogo Gerenciador DB

15.1.3. Provider-based loading tools

Beside the Browser Panel and the DB Manager, the main tools provided by QGIS to add layers, you’ll also find tools that are specific to data providers.

Nota

Alguns: ‘plugins externos <plugins>’ também fornecem ferramentas para abrir arquivos de formato específico no QGIS.

15.1.3.1. Carregando uma camada de um arquivo

Para carregar uma camada de um arquivo:

  1. Abra a guia do tipo de camada na caixa de diálogo Gerenciador de Fonte de Dados, ou seja, clique no botão dataSourceManager Abrir Gerenciador de Fonte de Dados (ou pressione: kbd:Ctrl+L) e ative a guia de destino ou:

    • for vector data (like GML, ESRI Shapefile, Mapinfo and DXF layers): press Ctrl+Shift+V, select the Layer ► Add Layer ► addOgrLayer Add Vector Layer menu option or click on the addOgrLayer Add Vector Layer toolbar button.

      ../../../_images/addvectorlayerdialog.png

      Fig. 15.4 Add Vector Layer Dialog

    • para dados raster (como camadas GeoTiff, MBTiles, GRIdded Binary e DWG): pressione Ctrl+Shift+R, selecione a opção Camada ► Adicionar Camada ► addRasterLayer Adicionar Camada Raster do menu ou clique no botão addRasterLayer Adicionar Camada Raster da barra de ferramentas.

      ../../../_images/addrasterlayerdialog.png

      Fig. 15.5 Add Raster Layer Dialog

  2. Check radioButtonOn File source type

  3. Click on the … Browse button

  4. Navegue no sistema de arquivos e carregue uma fonte de dados suportada. É possível carregar mais de uma camada ao mesmo tempo mantendo pressionada a tecla Ctrl e clicando em vários itens da caixa de diálogo ou pressionando a tecla Shift para selecionar um intervalo de itens clicando em o primeiro e o último item do intervalo. Somente os formatos que foram bem testados aparecem no filtro de formatos. Outros formatos podem ser carregados selecionando Todos os arquivos (o item superior no menu pull-down).

  5. Press Open to load the selected file into Data Source Manager dialog

    ../../../_images/openoptionsvectorlayer.png

    Fig. 15.6 Carregando um Shapefile com opções em aberto

  6. Press Add to load the file in QGIS and display them in the map view. Fig. 15.7 shows QGIS after loading the alaska.shp file.

    ../../../_images/shapefileloaded.png

    Fig. 15.7 QGIS com Shapefile do Alasca carregado

Nota

For loading vector and raster files the GDAL driver offers to define open actions. These will be shown when a file is selected. Options are described in detail on https://gdal.org/drivers/vector/, https://gdal.org/drivers/raster and if a file is selected in QGIS, a text with hyperlink will directly lead to the documentation of the selected file type.

Nota

Como alguns formatos como MapInfo (por exemplo, .tab) ou Autocad (.dxf) permitem misturar diferentes tipos de geometria em um único arquivo, carregar tais conjuntos de dados abre um diálogo para selecionar as geometrias a serem utilizadas a fim de ter uma geometria por camada.

The addOgrLayer Add Vector Layer and addRasterLayer Add Raster Layer tabs allow loading of layers from source types other than File:

  • You can load specific vector formats like ArcInfo Binary Coverage, UK. National Transfer Format, as well as the raw TIGER format of the US Census Bureau or OpenfileGDB. To do that, you select radioButtonOn Directory as Source type. In this case, a directory can be selected in the dialog after pressing … Browse.

  • With the radioButtonOn Database source type you can select an existing database connection or create one to the selected database type. Some possible database types are ODBC, Esri Personal Geodatabase, MS SQL Server as well as PostgreSQL or MySQL .

    Pressing the New button opens the Create a New OGR Database Connection dialog whose parameters are among the ones you can find in Criando uma conexão armazenada. Pressing Open lets you select from the available tables, for example of PostGIS enabled databases.

  • O tipo de fonte radioButtonOn Protocolo: HTTP(S), nuvem, etc. abre dados armazenados localmente ou na rede sejam publicamente acessíveis, ou em armazenamentos em nuvem particulares fornecidos por serviços comerciais. Os tipos de protocolo suportados são:

    • HTTP/HTTPS/FTP, with a URI and, if required, an authentication.

    • Cloud storage such as AWS S3, Google Cloud Storage, Microsoft Azure Blob, Alibaba OSS Cloud, Open Stack Swift Storage. You need to fill in the Bucket or container and the Object key.

    • service supporting OGC WFS 3 (still experimental), using GeoJSON or GEOJSON - Newline Delimited format or based on CouchDB database. A URI is required, with optional authentication.

    • For all vector source types it is possible to define the Encoding or to use the Automatic ► setting.

15.1.3.2. Carregando uma camada de malha

A mesh is an unstructured grid usually with temporal and other components. The spatial component contains a collection of vertices, edges and faces in 2D or 3D space. More information on mesh layers at Working with Mesh Data.

Para adicionar uma camada de malha ao QGIS:

  1. Open the Data Source Manager dialog, either by selecting it from the Layer ► menu or clicking the dataSourceManager Open Data Source Manager button.

  2. Ative a guia addMeshLayer Malha no painel da esquerda

  3. Pressione o botão … Buscar para selecionar o arquivo. Vários formatos são suportados.

  4. Select the file and press Add. The layer will be added using the native mesh rendering.

  5. If the selected file contains many mesh layers, then you’ll be prompted with a dialog to choose the sublayers to load. Do your selection and press OK and the layers are loaded with the native mesh rendering. It’s also possible to load them within a group.

../../../_images/mesh_datasource_manager.png

Fig. 15.8 Mesh tab in Data Source Manager

15.1.3.3. Importando um arquivo de texto delimitado

Delimited text files (e.g. .txt, .csv, .dat, .wkt) can be loaded using the tools described above. This way, they will show up as simple tables. Sometimes, delimited text files can contain coordinates / geometries that you could want to visualize. This is what addDelimitedTextLayerAdd Delimited Text Layer is designed for.

  1. Click the dataSourceManager Open Data Source Manager icon to open the Data Source Manager dialog

  2. Ative a guia addDelimitedTextLayer Texto Delimitado

  3. Select the delimited text file to import (e.g., qgis_sample_data/csv/elevp.csv) by clicking on the … Browse button.

  4. No campo Nome da camada, fornecer o nome a ser utilizado para a camada no projeto (por exemplo Elevação).

  5. Configure as configurações para atender seu conjunto de dados e necessidades, conforme explicado abaixo.

../../../_images/delimited_text_dialog.png

Fig. 15.9 Delimited Text Dialog

Formato de arquivo

Depois que o arquivo é selecionado, o QGIS tenta analisar o arquivo com o delimitador usado mais recentemente, identificando campos e linhas. Para permitir que o QGIS analise corretamente o arquivo, é importante selecionar o delimitador correto. Você pode especificar um delimitador escolhendo entre:

  • radioButtonOnCSV (valores separados por vírgula) para utilizar o caractere de vírgula.

  • radioButtonOffRegular expression delimiter and enter text into the Expression field. For example, to change the delimiter to tab, use \t (this is used in regular expressions for the tab character).

  • radioButtonOffCustom delimiters, choosing among some predefined delimiters like comma, space, tab, semicolon, … .

Registros e campos

Algumas outras opções convenientes podem ser usadas para reconhecimento de dados:

  • Number of header lines to discard: convenient when you want to avoid the first lines in the file in the import, either because those are blank lines or with another formatting.

  • checkboxFirst record has field names: values in the first line are used as field names, otherwise QGIS uses the field names field_1, field_2…

  • checkboxDetect field types: automatically recognizes the field type. If unchecked then all attributes are treated as text fields.

  • checkboxSeparador decimal é vírgula: você pode forçar o separador decimal a ser uma vírgula.

  • checkboxTrim fields: allows you to trim leading and trailing spaces from fields.

  • checkboxDiscard empty fields.

  • Custom boolean literals: allows you to add a custom couple of string that will be detected as boolean values.

Field type detection

QGIS tries to detect the field types automatically (unless checkboxDetect field types is not checked) by examining the content of an optional sidecar CSVT file (see: GeoCSV specification) and by scanning the whole file to make sure that all values can actually be converted without errors, the fall-back field type is text.

The detected field type appears under the field name in sample data preview table and can be manually changed if necessary.

The following field types are supported:

  • Boolean case-insensitive literal couples that are interpreted as boolean values are 1/0, true/false, t/f, yes/no

  • Whole Number (integer)

  • Whole Number (integer - 64 bit)

  • Decimal Number: double precision floating point number

  • Date

  • Time

  • Date and Time

  • Text

Definição de geometria

Once the file is parsed, set Geometry definition to

  • radioButtonOnPoint coordinates and provide the X field, Y field, Z field (for 3-dimensional data) and M field (for the measurement dimension) if the layer is of point geometry type and contains such fields. If the coordinates are defined as degrees/minutes/seconds, activate the checkboxDMS coordinates checkbox. Provide the appropriate Geometry CRS using the setProjection Select CRS widget.

  • radioButtonOnWell known text (WKT) option if the spatial information is represented as WKT: select the Geometry field containing the WKT geometry and choose the approriate Geometry field or let QGIS auto-detect it. Provide the appropriate Geometry CRS using the setProjection Select CRS widget.

  • If the file contains non-spatial data, activate radioButtonOn No geometry (attribute only table) and it will be loaded as an ordinary table.

Configurações de camada

Além disso, você pode habilitar:

  • checkboxUse spatial index to improve the performance of displaying and spatially selecting features.

  • checkboxUse subset index to improve performance of subset filters (when defined in the layer properties).

  • checkboxWatch file to watch for changes to the file by other applications while QGIS is running.

At the end, click Add to add the layer to the map. In our example, a point layer named Elevation is added to the project and behaves like any other map layer in QGIS. This layer is the result of a query on the .csv source file (hence, linked to it) and would require to be saved in order to get a spatial layer on disk.

Sample Data

As you set the parser properties, the sample data preview updates regarding to the applied settings.

Also in the Sample Data Table it is possible to override the automatically determined column types.

15.1.3.4. Importando um arquivo DXF ou DWG

DXF and DWG files can be added to QGIS by simple drag-and-drop from the Browser Panel. You will be prompted to select the sublayers you would like to add to the project. Layers are added with random style properties.

Nota

For DXF files containing several geometry types (point, line and/or polygon), the name of the layers will be generated as <filename.dxf> entities <geometry type>.

To keep the dxf/dwg file structure and its symbology in QGIS, you may want to use the dedicated Project ► Import/Export ► Import Layers from DWG/DXF… tool which allows you to:

  1. import elements from the drawing file into a GeoPackage database.

  2. adicionar elementos importados ao projeto.

In the DWG/DXF Import dialog, to import the drawing file contents:

  1. Input the location of the Target package, i.e. the new GeoPackage file that will store the data. If an existing file is provided, then it will be overwritten.

  2. Especifique o sistema de referência de coordenadas dos dados no arquivo de desenho.

  3. Check checkbox Expand block references to import the blocks in the drawing file as normal elements.

  4. Check checkbox Use curves to promote the imported layers to a curved geometry type.

  5. Use the Import button to select the DWG/DXF file to use (one per geopackage). The GeoPackage database will be automatically populated with the drawing file content. Depending on the size of the file, this can take some time.

After the .dwg or .dxf data has been imported into the GeoPackage database, the frame in the lower half of the dialog is populated with the list of layers from the imported file. There you can select which layers to add to the QGIS project:

  1. At the top, set a Group name to group the drawing files in the project.

  2. Check layers to show: Each selected layer is added to an ad hoc group which contains vector layers for the point, line, label and area features of the drawing layer. The style of the layers will resemble the look they originally had in *CAD.

  3. Escolha se a camada deve estar visível na abertura.

  4. Marcar a opção checkbox Mesclar camadas coloca todas as camadas em um único grupo.

  5. Press OK to open the layers in QGIS.

../../../_images/dwg_dxf_import_dialog.png

Fig. 15.10 Import dialog for DWG/DXF files

15.1.3.5. Importando vetores OpenStreetMap

The OpenStreetMap project is popular because in many countries no free geodata such as digital road maps are available. The objective of the OSM project is to create a free editable map of the world from GPS data, aerial photography and local knowledge. To support this objective, QGIS provides support for OSM data.

Using the Browser Panel, you can load an .osm file to the map canvas, in which case you’ll get a dialog to select sublayers based on the geometry type. The loaded layers will contain all the data of that geometry type in the .osm file, and keep the osm file data structure.

15.1.3.6. Camadas SpatiaLite

addSpatiaLiteLayer The first time you load data from a SpatiaLite database, begin by:

  • clicking on the addSpatiaLiteLayer Add SpatiaLite Layer toolbar button

  • selecting the addSpatiaLiteLayer Add SpatiaLite Layer… option from the Layer ► Add Layer menu

  • ou digitando Ctrl+Shift+L

This will bring up a window that will allow you either to connect to a SpatiaLite database already known to QGIS (which you choose from the drop-down menu) or to define a new connection to a new database. To define a new connection, click on New and use the file browser to point to your SpatiaLite database, which is a file with a .sqlite extension.

O QGIS também suporta visualizações editáveis ​​no SpatiaLite.

15.1.3.7. GPS

Existem dezenas de formatos de arquivo diferentes para armazenar dados GPS. O formato que o QGIS usa é chamado GPX (formato GPS eXchange), que é um formato padrão de intercâmbio que pode conter qualquer número de pontos de passagem, rotas e trilhas no mesmo arquivo.

Use the … Browse button to select the GPX file, then use the check boxes to select the feature types you want to load from that GPX file. Each feature type will be loaded in a separate layer.

More on GPS data manipulation at Trabalhando com dados GPS.

../../../_images/gps_datasource.png

Fig. 15.11 Carregando a janela de dados do GPS

15.1.3.8. GRASS

Working with GRASS vector data is described in section Integração com SIG GRASS.

15.1.4. The Layer Metadata Search Panel

The layer metadata search panel allows to browse layers metadata from registered metadata providers and add them to the project.

The list can be filtered by text, by current project and by map canvas extent.

The sources of metadata are implemented through a layer metadata provider system that can be extended by plugins.

QGIS provides out of the box the layer metadata providers that retrieve the metadata from the connections that allow for metadata storage (for more details save metadata to the database).

../../../_images/layer_metadata_search_panel.png

Fig. 15.15 Layer Metadata Search Panel

15.1.5. Formatos personalizados QGIS

O QGIS propõe dois formatos personalizados:

15.1.6. QLR - QGIS Layer Definition File

Layer definitions can be saved as a Layer Definition File (QLR - .qlr) using Export ► Save As Layer Definition File… in the layer context menu.

The QLR format makes it possible to share “complete” QGIS layers with other QGIS users. QLR files contain links to the data sources and all the QGIS style information necessary to style the layer.

QLR files are shown in the Browser Panel and can be used to add layers (with their saved styles) to the Layers Panel. You can also drag and drop QLR files from the system file manager into the map canvas.

15.1.7. Conectando-se a serviços da web

With QGIS you can get access to different types of OGC web services (WM(T)S, WFS(-T), WCS, CSW, …). Thanks to QGIS Server, you can also publish such services. Guia/Manual do Servidor QGIS contains descriptions of these capabilities.

15.1.7.1. Using Vector Tiles services

Vector Tile services can be added via the addVectorTileLayer Vector Tiles tab of the Data Source Manager dialog or the contextual menu of the Vector Tiles entry in the Browser panel. Services can be either a New Generic Connection… or a New ArcGIS Vector Tile Service Connection….

Você cria um serviço, adicionando:

  • a Nome

  • the URL: of the type http://example.com/{z}/{x}/{y}.pbf for generic services and http://example.com/arcgis/rest/services/Layer/VectorTileServer for ArcGIS based services. The service must provide tiles in .pbf format.

  • the checkboxMin. Zoom Level and the checkboxMax. Zoom Level. Vector Tiles have a pyramid structure. By using these options you have the opportunity to individually generate layers from the tile pyramid. These layers will then be used to render the Vector Tile in QGIS.

    For Mercator projection (used by OpenStreetMap Vector Tiles) Zoom Level 0 represents the whole world at a scale of 1:500.000.000. Zoom Level 14 represents the scale 1:35.000.

  • a Style URL: a URL to a MapBox GL JSON style configuration. If provided, then that style will be applied whenever the layers from the connection are added to QGIS. In the case of Arcgis vector tile service connections, the URL overrides the default style configuration specified in the server configuration.

  • a autenticação configuração, se necessário

  • a Referer

Fig. 15.16 shows the dialog with the MapTiler planet Vector Tiles service configuration.

../../../_images/vector_tiles_maptilerplanet.png

Fig. 15.16 Vector Tiles - Maptiler Planet configuration

Configurations can be saved to .XML file (Save Connections) through the Vector Tiles entry in Data Source Manager dialog or its context menu in the Browser panel. Likewise, they can be added from a file (Load Connections).

Once a connection to a vector tile service is set, it’s possible to:

  • Edit the vector tile connection settings

  • Remover a conexão

  • From the Browser panel, right-click over the entry and you can also:

    • Add layer to project: a double-click also adds the layer

    • View the Layer Properties… and get access to metadata and a preview of the data provided by the service. More settings are available when the layer has been loaded into the project.

15.1.7.2. Using XYZ Tile services

XYZ Tile services can be added via the addXyzLayer XYZ tab of the Data Source Manager dialog or the contextual menu of the XYZ Tiles entry in the Browser panel. Press New (respectively New Connection) and provide:

  • a Nome

  • a URL

  • a autenticação configuração, se necessário

  • the Min. Zoom level and Max. Zoom level

  • a Referer

  • the Tile Resolution: possible values are Unknown (not scaled), Standard (256x256 / 96DPI) and High (512x512 / 192DPI)

  • Interpretation: converts WMTS/XYZ raster datasets to a raster layer of single band float type following a predefined encoding scheme. Supported schemes are Default (no conversion is done), MapTiler Terrain RGB and Terrarium Terrain RGB. The selected converter will translate the RGB source values to float values for each pixel. Once loaded, the layer will be presented as a single band floating point raster layer, ready for styling using QGIS usual raster renderers.

By default, QGIS provides some default and ready-to-use XYZ Tiles services:

  • xyz Mapzen Global Terrain, allowing an immediate access to global DEM source for the projects. More details and resources at https://registry.opendata.aws/terrain-tiles/

  • xyz OpenStreetMap to access the world 2D map. Fig. 15.17 shows the dialog with the OpenStreetMap XYZ Tile service configuration.

    ../../../_images/xyz_tiles_dialog_osm.png

    Fig. 15.17 XYZ Tiles - OpenStreetMap configuration

Configurations can be saved to .XML file (Save Connections) through the XYZ Tiles entry in Data Source Manager dialog or its context menu in the Browser panel. Likewise, they can be added from a file (Load Connections).

The XML file for OpenStreetMap looks like this:

<!DOCTYPE connections>
<qgsXYZTilesConnections version="1.0">
  <xyztiles url="https://tile.openstreetmap.org/{z}/{x}/{y}.png"
   zmin="0" zmax="19" tilePixelRatio="0" password="" name="OpenStreetMap"
   username="" authcfg="" referer=""/>
</qgsXYZTilesConnections>

Once a connection to a XYZ tile service is set, it’s possible to:

  • Edit the XYZ connection settings

  • Remover a conexão

  • From the Browser panel, right-click over the entry and you can also:

    • Exportar camada… ► Para Arquivo, saving it as a raster

    • Add layer to project: a double-click also adds the layer

    • View the Layer Properties… and get access to metadata and a preview of the data provided by the service. More settings are available when the layer has been loaded into the project.

Examples of XYZ Tile services:

  • OpenStreetMap Monochrome: URL: http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png, Min. Zoom Level: 0, Max. Zoom Level: 19.

  • Google Maps: URL: https://mt1.google.com/vt/lyrs=m&x={x}&y={y}&z={z}, Min. Zoom Level: 0, Max. Zoom Level: 19.

  • Temperatura do Mapa Meteorológico Aberto: URL: http://tile.openweathermap.org/map/temp_new/{z}/{x}/{y}.png?appid={api_key} Nível Mín. de Zoom: 0, :​​guilabel: Nível Máx. de Zoom`: 19.

15.1.7.3. Using ArcGIS REST Servers

ArcGIS REST Servers can be added via the addAfsLayer ArcGIS REST Server tab of the Data Source Manager dialog or the contextual menu of the ArcGIS REST Servers entry in the Browser panel. Press New (respectively New Connection) and provide:

  • a Nome

  • a URL

  • a Community endpoint URL

  • a Content endpoint URL

  • a autenticação configuração, se necessário

  • a Referer

Nota

ArcGIS Feature Service connections which have their corresponding Portal endpoint URLS set can be explored by content groups in the browser panel.

Se uma conexão tiver os terminais do Portal definidos, expandir a conexão no navegador mostrará uma pasta “Grupos” e “Serviços”, em vez da lista completa de serviços normalmente exibida. Expandir a pasta de grupos mostrará uma lista de todos os grupos de conteúdo dos quais o usuário é membro, cada um dos quais pode ser expandido para mostrar os itens de serviço pertencentes a esse grupo.

Configurations can be saved to .XML file (Save Connections) through the ArcGIS REST Server entry in Data Source Manager dialog. Likewise, they can be added from a file (Load Connections).

Once a connection to an ArcGIS REST Server is set, it’s possible to:

  • Edit the ArcGIS REST Server connection settings

  • Remover a conexão

  • Refresh the connection

  • usar um filtro para as camadas disponíveis

  • choose from a list of available layers with the option to checkboxOnly request features overlapping the current view extent

  • From the Browser panel, right-click over the connection entry and you can:

    • Refresh

    • Edit connection…

    • Remove connection…

    • View Service Info which will open the default web browser and display the Service Info.

  • Right-click over the layer entry and you can also:

    • View Service Info which will open the default web browser and display the Service Info.

    • Export layer… ► To File

    • Add layer to project: a double-click also adds the layer

    • View the Layer Properties… and get access to metadata and a preview of the data provided by the service. More settings are available when the layer has been loaded into the project.