Key Concepts in Urban Geography and City Planning Models

Essential Definitions in Urban Geography

• Isochronous Urban Lines

  Lines that connect points of the city or its surroundings, from which the time taken to reach the urban center is the same.

• Urban Isoprice Lines (Isoprecios)

  Lines that connect various parts of the city or its surroundings, from which the travel cost to the city center is the same, assuming a system without specific fees and multipurpose transport.

• Urban Hierarchy

  Classification of cities according to their order of importance. This hierarchy can be measured in terms of:

  • Demographics: Population size.
  • Economic factors: Production parameters quantified in Gross Value Added (GVA).
  • Commercial factors: Market share.
  • Directional factors: Advanced services.
  • Polyfunctional factors: Nelson rates or Davies indices.

• Peri-urban Area (Periurbana)

  The peripheral area of the city subject to the advance of the urbanization front, situated within the surrounding rural fringe. Morphologically defined by the existence of:

  • Single-family residential developments (free or attached types).
  • Large shopping centers and services located near highway exits.
  • New industrial parks.
  • Technological poles featuring avant-garde architecture, etc.

• General Urban Plan (General Plan)

  An integrated management tool for the municipal territory. It serves to:

  • Classify the soil to establish detailed land use.
  • Define the key elements of the overall structure of the territory.
  • Identify urban development programs.

City Morphology: Urban Planning Models

Linear Plan

This morphology structures the city along a main line of communication. Principal buildings and urban services are arranged on both sides, although a number of streets parallel to the central axis are often also distributed. The best-known model of this morphology is the Ciudad Lineal (Arturo Soria).

Irregular Plan (Disordered Plan)

Characterizes the part of town developed mainly in the Middle Ages, whose paths do not follow a regular geometric structure but are sinuous.

Orthogonal Plan (Grid Plan)

A rational model of city planning designed to optimize land use with a rectangular arrangement of streets.

Concentric Plan (Radial Plan)

A city structure that prioritizes a central square or crossroads, from which structural pathways radiate outwards and are connected by successive concentric rings.