Help to use the Mobiliscope

1) Preliminary notes

Initial data come from Origin-Destination surveys (from 2009 to 2019). Once transformed, these data have been used to estimate the present population in every district at exact hours (04.00, 05.00 etc.) during a typical weekday (Monday-Friday).

Number and proportion of present population aggregated by district and hour are estimation : they are subject to statistical margins of error.

58 city regions(spread over 5 countries) are included in the actual version of the Mobiliscope (v4.1).
To choose the city region you want to observe, please selection the city region in the drop-down menu or use the magnify tool from a search by name.

2) Select a map

In the left-hand menu, you can choose indicator (classified into broad families such as demographic or social profile) and its map representation - eitheir as aof the total population, or number or flows.
To get informations about indicators, click button on the right side.

accordeonmenu

With flows maps you get number of non-resident people at district level. With links (displayed on mouseover), you can see their district of residence (not available on touch screens).

oursins

3) Change hours

At the top of the screen, click play button in the timeline to animate map and graphics according to the 24 hours of the day.

timeline

4) Explore a specific district

Select one district by clicking on the map.

select-secteur

Have a look at the chart entitled "In the selected district" where you can follow hourly variations of present population (for each group of the selected indicator) in the district under consideration. Colours have the same colour code than in the indicator menu. Here, last transportation mode used by present population in the selected district was coloured in blue for public transportation, in pink for private motor vehicle and in green for soft mobility.

graph-empile

By clicking on 'Unique' mode, you can limit representation of the hourly variations for only one subgroup :

graph-simple

5) Explore spatial segregation

The block of graphs entitled "In the whole region" displays two segregation indices computed from every district of the region for each hour of the day.

Duncan Index (also called Dissimilarity Index) measures the evenness with which a specific population subgroup is distributed across districts in a whole region. This index score can be interpreted as the percentage of people belonging to the subgroup under consideration that would have to move to achieve an even distribution in the whole region.

duncan

The example above displays, hour by hour, the Duncan Index (Paris region - 2010) for to present people residing in or outside 'Poverty Areas'. Duncan index range from 0 to 1. A Duncan Segregation Index value of 0 occurs when the share of present people residing in 'Poverty Areas' in every district is the same as the share of people residing in 'Poverty Areas' in the whole region. Conversely, a Duncan Segregation Index value of 1 occurs when each district gathers only one of the two population subgroups. In our example, Duncan value is found to be higher between 8pm and 7am, indicating a stronger segregation at night (further away from an even distribution): this corresponds to the hours when most of the individuals are at home or in their district of residence. The value of the index decreases during the day: because of their mobility, people residing in and outside of 'Poverty Areas' are more mixed (situation closer to even distribution).

By clicking on the "Moran" button, a second graph is displayed with the Moran index which measures the similarity of the profiles of the population present for the neighbouring districts.

moran

The Moran index values vary from -1 to +1: the closer its value is to 1, the more similar the spatially close districts are (with same distribution of the present subgroup under consideration); the closer its value is to -1, the more dissimilar the spatially close districts are (with different distribution of the present subgroup under consideration). When the Moran index value is 0, no similarity/dissimilarity pattern between neighbouring districts appears in the whole region. In our example, the Moran index values are positive and increase during the day: it means that spatial blocks of similar districts (according to the proportion of inhabitants of 'Poverty Areas') are formed during the day. This result does not contradict Duncan's index but complements it: people residing in 'Poverty Areas' visit during the day other districts than their residential district but tend to visit districts close to each other. And the same is true for people residing outside 'Poverty Areas'

It should be noted that in the case of an indicator subdivided into two groups (eg. male/female or people residing in/outside 'Poverty Areas'), Duncan and Moran values are the same for the two groups and therefore the curves are overlapping.

For more information on the two indices used (Duncan et Moran), click help button next to the index name.

6) Change map backgrounds

By clicking on the button in the central map, several layers can be displayed to make it easier to find your way around the interactive map: a simple base map (default layer), a more detailed one and aerial photos.

osm-simple osm-setail satellite

According to the city region under consideration, some other layers can also be displayed such as 'Poverty Areas' in French cities or urban/peripheral rings in Latin American cities.

osm-simple couronne

7) Download data

Data displayed in the Mobiliscope are under open license (ODbL). Mobiliscope data are reusable as they remain under open license and that the sources are mentioned.

By clicking on the button above the central map, you can download data aggregated data by district and by hour. By clicking on the button in the bottom graph, you can also download data about hourly segregation values (Duncan's or Moran's index) computed for the whole region over the 24 hours period.

To go further

To get more information about indicators and data which are currently used and displayed in the Mobiliscope, you can read Data, Indicators or Geovizualisation pages.

Enjoy!

Geovizualisation

To explore city around the clock

With timeline (on the top), users can animate maps hour by hour. In the indicator block (on the left-side), users can choose to display the whole present population ('Global overview') or to look at the population present according to demographic profile (sex and age), social profile (socioprofessional status, educational level and occupational status), or residential areas. It is also possible to explore the types of activities carried out by the population present in each area in a given hour, as well as the last mode of transport used to get to destination.

In the center of the screen, maps are displayed according to the indicator chosen in the indicator block. Maps are dynamics: users can zoom, move around it, display the names of the sectors on mouseover. Three cartography modes are available: numbers (choropleth maps), % (proportional symbol maps) or flows (from residential districts).

In the right side of the screen, a first chart (top) shows hourly information for a specific district (selected on the map).
A second chart (bottom) provides information on the hourly spatial distribution of population in the whole city region.

Central map

Three map representations can be displayed: choropleth maps, maps in proportional symbols and 'flow' maps.Flow maps allow to visualize on the one hand the stock of "non-resident" population present in the areas and on the other hand to display (on the mouseover) their original districts of residence.
In the case of the 'Whole Population' indicator, present population densities (people per km²) can also be displayed. Population densities are discretised into 8 classes according to the nested mean method. The resulting classes are therefore region-specific, but remain the same throughout the day in a given region.

In other choropleth maps (displaying estimated proportions of people in a specified group at district level), five class have constantly been defined. For each group, same class intervals apply over the 24h period for all maps of the same city region. Different discretisation methods are used to delineate the thresholds of these five classes.

  • For the majority of the avalaible indicators (age; education level; socioprofessional status; occupational status; professional informality; socio-economic stratum; household composition; housing tenure and travel mode), we used a quintile method based on the values distribution over the 24h period in every city. Class intervals can then diverge according to the city.
  • The equal amplitude method has been used for three indicators: Resident/Non-resident population; French 'Poverty Areas'; and household income. For the latter two indicators, the class thresholds differ from city to city due to highly variable statistical distributions. For the indicator Residents/Non-residents, the legend is identical for all Mobiliscope regions and for both modalities since the distributions always range between 0% and 100% (of residents or non-residents per sector).
  • For the indicator relating to sex, the classes are defined manually: the central class always includes the average of the percentage of men or women (which varies respectively between 40% and 50% and between 50% and 60% depending on the surveys) whatever the region observed. The class boundaries are therefore identical for all cities. In this way, the inter-city comparison of the proportion of women (or men) is facilitated.
  • For the indicator related to the French residential rings, class intervals have been defined manually ensuring they remain unchanged for every city region.
  • Natural threshold discretization (Fisher) is used for the activity indicator based on the distribution of data across all city regions. Class intervals are therefore the same regardless of the city region. The same method is used for the residence rings indicator for Latin American cities.
  • For the departement of residence indicator (only displayed in the Paris region), class intervals have been determined according to natural thresholds (Jenks).

In proportional symbol maps (representing estimated number of people in a specified group at district level), circles are proportionally sized according to the number of people and are similar over the 24h period for all maps of the same city region (but can diverge according to the city region). Flow maps cannot be displayed for the group 'at home' from 'activity' indicator to prevent unnecessary duplications.

In flow maps, link thickness (displayed on mouseover) represents estimated flow of people from their main original districts of residence. For confidentiality and statistical power reasons, we have indeed introduced a filter for not displaying the estimated flow of people from their original districts of residence when the crude number of concerned respondents is below 6. Link thickness are similar over the 24h period for all maps of the same city region (but can diverge according to the city region).

Top chart

The top chart shows the estimated number/proportion of people in the district selected in the central map over the 24h period. Two modes are available: unique or stacked.

Bottom chart

In the buttom chart, two segregation indices measure spatial distribution over the 24h period in the whole city region

  • Duncan dissimilarity index gives information about the dispersal of every group across spatial units. It is commonly used as a measure of pairwise segregation (e.g. Black versus White) but can also be used when measuring segregation through an indicator divided in more than two groups. In this case, Duncan dissimilarity index expresses the proportion of individuals of a given group who would have to change spatial unit (without being replaced) to get an even distribution of the group relative to the total population.
  • Moran index is a measure of spatial autocorrelation. It ranges from -1 (nearby locations tend to be more different than distant locations - negative autocorrelation) to 1 (nearby locations tend to be more similar than distant locations - positive autocorrelation), a value close to zero indicating no spatial structure.

In charts representing Duncan or Moran indices, minimum and maximum values are similar for all groups of a same indicator which makes them comparable. Moreover, intervals between minimum and maximum values cannot be less than 0.4 not to give too much importance to minor variations in spatial structure (eg. sex).

Hourly Duncan and Moran values displayed in the Mobiliscope are freely reusable, as they remain under open license (ODbL) and the sources are mentioned. Values can be downloaded by clicking the button next to the bottom chart.