ISM CARTO Workshop Análisis y visualización de datos ambientales con CARTO

This intermediate workshop was given by Ramiro Aznar on October 11, 2016 at Análisis y visualización de datos ambientales con CARTO. As taught, it was 2h hours long.

Introduction

Prerequisites

  • Laptop
  • A modern browser (Google Chrome would be perfect)

Map Academy, tutorials and other online resources

You can take a look on those resources if you want to warm up with CARTO

Further questions and troubleshooting

  • Email to support@carto.com.
  • Some questions could be already anwered at GIS Stack Exchange carto tag.

Contents

  1. Introduction to CARTO
  2. Builder
  3. Demo

Accounts set up

  • The instructor will provide you a user and passwor to access your account
  • Log into your ismcartoXX account going to https://ismcartoXX.carto.com

Introduction to CARTO



Slides available here.

Builder



The BUILDER is the new main web interface to interact with the CARTO platform. It’s a product aimed to everyone willing to manage, analyze and visualize geospatial information. It’s highly focused on usability, with a friendly graphical interface that unlocks all the power of the CARTO ENGINE without having to know all the details on underlying technologies such as PostGIS or CartoCSS.

Demo

With this demo we want to answer the following question: what is the river more polluted within the Comunidad de Madrid?

1. Import datasets and create a map

1. 1. Import datasets into CARTO

  • Download the following datasets* from the builder-demo account:
    • vertidos (as csv file), pollution point sources.
    • rios (as shapefile file), Spanish rivers.
    • subcuencas (as shapefile), small Spanish rivers watersheds.

  • Import the three datasets (one by one) into your CARTO account.

  • Select vertidos, rios and subcuencas from your datasets dashboard, click on NEW MAP.

*These datasets were previously download from the MARM website.


1. 2. Rename map title and layers

  • Rename map title to Vertidos, ríos y subcuencas.
  • Order the layers: first vertidos, then rios and at the bottom, subcuencas.
  • Rename layers:
    • vertidos as Vertidos,
    • rios as Ríos,
    • subcuencas as Subcuencas.


2. Style Vertidos layer and add your first widgets

2. 1. Add your first widgets

  • Click on Vertidos layer.
  • On the DATA taba, you will be able to see an overview of all the fields that this layer contains.
    1. Activate the checkbox of points count.
    2. Click on EDIT.
    3. Rename the widget as Número de vertidos.

This widget is a formula which counts the number of points (vertidos) within the visualization bounding box. Try to add a widget which filters rivers by name.


2. 1. Style Vertidos layer

  • Back to the main menu, in order to style Vertidos layer follow these steps:
    1. Click on Vertidos layer.
    2. Click on the STYLE tab.
    3. Click on the number 7 next to FILL and set the marker size to BY VALUE.
    4. Select volumen_m. Leave the min and max default values.
    5. Click on the color bar and set the opacity to 0.5.
    6. Set the STROKE to 0.

You have just created a bubble map! Larger points are “vertidos” with higher “volumen”, and smaller points are “vertidos” with lower “volumen”.


2. Filter rivers by watersheds

2. 1. Connect Rios and Subcuencas layers

  • In order to connect these two datasets, we need a common field. In our case, cod_demar. Then, we need to apply the Filter by layer analysis. Please, follow these steps:
    1. Back to the main menu, click on Rios layer.
    2. Click on ANALYSIS tab.
    3. Click on ADD NEW ANALYSIS.
    4. Select Filter by layer analysis. Click on ADD ANALYSIS.
    5. Set the parameters as follow:
      • FILTER BY LAYER: Subcuencas.
      • SOURCE COLUMN: cod_demar.
      • FILTER COLUMN: cod_demar.
    6. Click on APPLY.


2. 2. Add a widget in order to filter Rios by Subcuencas

  • You have both layers connected by the cod_demar. Now you would only need to add a category widget for filtering by this field:
    1. Back to the main menu, click on Subcuencas layer.
    2. Activate the checkbox of cod_demar.
    3. Click on EDIT.
    4. Rename the widget as Demarcación.
  • Because we are only interested on the rivers that crosses the Comunidad de Madrid where the “vertidos” are located, we will click on 31 value (Tajo river watershed).


3. Intersect Vertidos points with areas of influence from every Rio

3. 1. Create areas of influences

  • Back to the main menu, in order to improve the visualization, disable the view of the Subcuencas layer.
  • Then click on ADD ANALYSIS just below the Rio layer.
    1. Select Create areas of influence. Click on ADD ANALYSIS.
    2. Set the RADIUS parameter to 500 meters.
    3. Click on APPLY.

You can check how dynamically the analysis is run by BUILDER changing the RADIUS parameter.


3. 2. Intersect Vertidos points and get aggregate values

  • You do not need to go back to run a new analysis. Just click on the + sign to concatenate a third and last analysis to the Ríos layer:
    1. Select Intersect with second layer analysis. Click on ADD ANALYSIS.
    2. Set the parameters as follow:
      • TARGET LAYER: Subcuencas.
      • OPERATION: SUM(volume_m).
    3. Click on APPLY.
  • Go back, to the main menu. Click on Ríos layer and check the new column sum_volume_m in the table view.


3. 3. Add an histogram widget to explore volume of Vertidos per Ríos

  • Back to the main menu, click on Ríos layer.
    1. Activate the checkbox of sum_volume_m.
    2. Click on EDIT.
    3. Rename the widget as Volumen (m3) per river.

Could you answer the question?

3. 4. Color Ríos layer by Volumen of Vertido

  • Back to the main menu, in order to style Vertidos layer follow these steps:
    1. Click on Ríos layer.
    2. Click on the STYLE tab.
    3. Click on the color bar next to FILL and set the polygon fill to BY VALUE.
    4. Select sum_volumen_m.
    5. Choose a color palette and set the number of buckets to 5.
    6. Click on the color bar and set the opacity to 0.7.
    7. Set the STROKE to 0.2.



  • The same intersect analysis can be done to the Subcuencas layer:



3. 5. Share your analysis and visualization!

  • In order to publish your results, back to the main menu and click on SHARE.
  • Click on PUBLISH (change from Private to Public if need).
  • Copy the link and share it via email, Twitter, LinkedIn or your favorite social network.