Definitions that we use are specified below:
• Data sources: mobile phone data or mobile network data or telecom data or telco data or cell phone data (synonyms) and relevant abbreviations; GIS data produced by online maps, such as Google or Open Street Map (includes road network mapping, venues, and addresses, main settlements); census and other official statistical sources.
• Local unit: administrative unit (district, region).
• Commuting zone: local units (districts) or grid-level areas, passing the commuting flow thresholds to the urban center of the FUA.
• Urban center: a set of contiguous, high-density (1,500 residents per square kilometer) grid cells with a population of 50,000 in the contiguous grid cells.
• Functional urban area (FUA): funcational urban area is a combination of a densely inhabited urban center and a commuting zone, itdentified above. The boundary of the FUA forms a single contiguous area.
• Area class: class of the area (cluster), based on two distinct classifications:
• Degree of urbanization:
• Urban center: see above;
• Urban cluster: contiguous (using eight-point contiguity) 1km grid cells with a density of at least 300 inhabitants per km2, with a collective population of at least 5 000 in the cluster;
• Rural cluster: contiguous (using eight-point contiguity) 1km grid cells with a density of at least 300 inhabitants per km2, with a collective population of at least 500 in the cluster;
• Population dynamics (based on the difference between nighttime and daytime population):
• Stable cluster/area: area, where % difference between nighttime and daytime population is less than a set threshold;
• Acceptor cluster/area: area, where the nighttime population is larger;
• Donor cluster/area: area, where the daytime population is larger.
Spatially, the general pattern for all FUA is the prevalence of
donor clusters surrounding the urban center. Acceptors and stable
areas can both be adjacent to urban center (as in the case of
Samarkand and some others, see further descriptions below) or be
located further away (smaller-sized clusters, forming local labor
market nodes).
It is important to note that each cluster class presence and
development plays its role in balanced FUA development:
• Donor of daytime population: concentrates labor force, may need better
connection to jobs (acceptors, centers), local job alternatives
(supply of services and associated jobs), and comfortable amenities
supply that would allow people consume services not only in the
places of work (centers and acceptors) but also in their living
areas. Developing fast and easy transportation services between
these areas is also essential;
• Areas where the delta between daytime
and nighttime population is not significant (stable clusters) may be
considered as targets for commercial services development, both for
the local residents and workers, which would not only increase the
comfort of life, but also generate more jobs, so that a stable
cluster can gradually turn into an acceptor/secondary center;
• Acceptor clusters, in their turn, already are attracting workforce,
and with further development of commercial density and diversity,
may complement urban centers as secondary nodes of socio-economic
activity, and be the drivers of polycentric FUA development.