1 Reply Latest reply on Sep 12, 2018 8:41 AM by patrick.byrne.0

    Iron viz Water - feeder 3 - 2018

    Annabelle Rincon

      I cannot help myself, I promised to step down and don't compete for a time... but I did it again I participated to the Ironviz

      Here the details about this competitition : Make a splash in Iron Viz Water | Tableau Public

       

      First I wondered what I subject I could possibly pick, and how to represent it. Because the subject was Water, I decided to do a viz on the Seine, or more precisely about the Seine's floods.

       

      To do so I need maps, a lot of maps. This blog post will explain how to create those maps in Tableau, nothing fancy though.

       

      1- Paris altitude map : This is probably the easier

       

      This map shows some of the Paris monuments in an elevated map. I collected the information Google earth pro and I then copied them in Excel,

      Once you connect Excel to tableau, this view is a dual axis : one drawing the profile and the other one representing the monuments. I tried to find the most similar icons possible and work out the colour. Even if it not always easy without a designer ( who draw them for you), the results is satisfactory. I had to modulate the position of the icons so they appear on top of the line.

       

      Capture d’écran 2018-08-26 à 19.29.45.png

       

       

       

      2-The Seine profile

       

       

      This map is done by connecting a shapefile ( from https://www.data.gouv.fr/fr/datasets/dcpsl-hydrographie-1820-fleuves-rivieres/) for the Seine's mapping and an Excel file for marking the exact beginning  and end of the Seine ( in order that the comments point out exactly to them). A dual axis does the trick

      For the first one, the geometry field in details, and for the second the departure and arrival.

      The Map is a traditional Tableau map with a light style and without base to be able to colour the background.

       

       

       

       

      3-Custom geography

       

       

      To illustrate the fact that Paris is divided by the Seine in two parts, I create in Tableau this custom map. Having the postal code, I simply create a group of the different postal code matching the "right part" of the river and the ones matching the "left part". This group can then be used.

      Capture d’écran 2018-08-26 à 21.42.51.png

       

       

      4-Joining two shapefiles

       

       

      In the journey of my viz, I wanted to compare the 1910's floods (dark blue) with the actual prevision for the same level of flood ( light blue). But I had two shapefiles and I don't have any software able to do the work. But with the new feature of Tableau, I can join the two shapefiles with the intersects option. Et voila ...

      Capture d’écran 2018-08-26 à 22.05.40.png

       

       

      5-Go further

       

       

      To finish, the last map, I used in my viz is a join of differents geo datesources one for the floods and one for the monuments represented as the points. But here the difficulty comes from the fact that I had to create the latitude and longitude for the monuments. I had the streets localisation, but as you may know, I couldn't use it in Tableau. Tableau cannot (yet) to go below the postcode level.

      So I connect my datasource to Alteryx, and in two simple steps ( I am an Alteryx beginner) I could use their geocoder to convert my streets in gps location, and used it in my viz.

       

       

       

      Concerning the design of the full dashboard, I just choose to have a clear and epurate design only grey and of course blue ( for the water theme).

       

      Hope you like it.

       

       

      link to the viz : Tableau Public

       

      Sources :

      This viz has been done with free copyright icons and open data coming from the following websites :

       

      - icons : www.colourbox.com

      - 1910 floodshttps://www.geoportail.gouv.fr/donnees/crues-du-bassin-de-la-seine-phec

      - Floods previsions : http://www.driee.ile-de-france.developpement-durable.gouv.fr/IMG/pdf/2012-02-08_notice_scenarios_v3_cle781374-1.pdf

      - Zouave info : https://fr.wikipedia.org/wiki/Zouave_du_pont_de_l%27Alma

      - Seine mapping : https://www.data.gouv.fr/fr/datasets/dcpsl-hydrographie-1820-fleuves-rivieres/

      - Monuments : https://www.data.gouv.fr/fr/datasets/immeubles-proteges-au-titre-des-monuments-historiques/

      - protections in case of floods :

      1- http//www.prefectures-regions.gouv.fr/ile-de-france/Region-et-institutions/L-action-de-l-Etat/Prevention-et-gestion-des-risques/Risques-naturels/Inondation/Crue-et-inondation-comment-s-en-proteger/#titre

      2- https//www.lci.fr/societe/crues-vigicrues-mais-pourquoi-ne-peut-on-pas-empecher-la-seine-de-deborder-2076746.html

      3-https//www.la-croix.com/Culture/Expositions/musees-parisiens-face-crue-Seine-2018-01-25-1200908760

      - Other : wikipedia of course

       

      Annabelle

      August 25th 2018