Many studies on the settlement population modalities and on the urbanisation dynamics show how, in the cities, some types of non-resident populations live together with the resident one using the same spaces with their own modalities. These are the individuals who, even if not residents, go there with different motivations (study, work, tourism, travel, etc.), with different frequency (daily, periodical, occasional) and for different periods.
The day-time population in a given area is composed of subpopulations of workers, students and city users, etc. The more attractive or repellent the area is, the more the daytime population differs from the population registered in the population registry. People moving towards cities with services or productive activities change the physiognomy of both the place of origin and the place of destination, and generate competition between the residents and non-residents in the use/consumption of resources and services.
Being able to answer questions such as “How many of these people are there?”, “Where do they come from?”, “What are their characteristics?”, “How far away are their places of origin?”, “How often do they travel?”, can be useful in the planning of transport, housing, energy, and health services, etc. It can be useful for prevention and intervention plans in case of natural disasters (earthquakes, floods, landslides, etc.).
Here we present the preliminary results of a study aimed at designing and implementing an information system to quantify and characterise the daytime population. To date, the available sources have made it possible to quantify by a unique information system an important proportion of the daytime population in a territory: the daytime population net of tourists, individuals who travel for business, or move for reasons of medical care or religious tourism, to which the traditional data sources are applicable.
Within this framework, new units of analysis have been formalised: the individuals whose movement is categorised as “dynamic for study/work”, for whom both the place of origin and destination of the movement are determined in the system, and the individuals who are classified as “static with respect to work/study”.
- as regards the question of “how many?” the numbers entering or leaving the various territorial domains can be quantified;
- as regards “how far away?” it is possible to calculate the distance in km between the place of origin and the place of destination of the movement, or the origin with respect to the perimeter of an area;
- as regards “what characteristics?” the information makes it possible to distinguish between primary/secondary school students, university students and workers; these types also include foreigners who are in Italy for work or study.
Finally, flexible processing methods are possible in terms of territorial output (both traditional administrative subdivisions and functional territorial partitions including Labour Market Areas or Functional Urban Areas). All this makes it possible to examine the distribution of the population in the territory from a new point of view.