APHUG 1.4

Spatial Patterns

• Clustered Pattern

  • Definition: Features are grouped closely together on Earth’s surface.
  • Significance: Indicates a shared attraction (e.g.
    resources, labor, markets) or a central organizing force.
  • Example: Silicon Valley’s tech firms clustering around venture‐capital hubs and research universities.

• Agglomeration

  • Deliberate form of clustering around a central point or economic growth pole.
  • Encourages economies of scale, knowledge spillovers, and shared infrastructure.
  • Real‐world relevance: Automobile manufacturing in Detroit historically; multimedia studios in Hollywood.

• Random Pattern

  • Distribution shows no discernible logic or systematic ordering.
  • Often implies minimal human planning or the dominance of natural factors.
  • Hypothetical scenario: Lightning strikes mapped over a year may show random spatial distribution.

• Scattered Pattern

  • Objects that are normally ordered instead appear dispersed.
  • May signal declining cohesion, e.g.
    suburban sprawl where homes are built far apart instead of in compact blocks.

• Linear Pattern

  • Features align in a straight line.
  • Common along rivers, railroads, or roads ("strip development").

• Sinuous Pattern

  • Features follow a wavy/curving line.
  • Often mirrors natural landforms such as meandering rivers.

• Influence of Land‐Survey Systems on Patterns

  • Property lines and political boundaries frequently trace survey systems.
  • Until the 1830s: Metes and Bounds relied on natural features (trees, streams, boulders) to demarcate land—causing irregular parcel shapes.
  • Post‐1830s (U.S.): Township and Range
  • Rectilinear grid based on \text{latitude} and \text{longitude}.
  • Produces uniform square/rectangular parcels.
  • Long‐Lot System
  • Narrow frontage along a road/river with elongated back lot.
  • Example: French colonial areas in Québec and Louisiana.

Density Measures

• Arithmetic Density

  • Standard calculation: \text{Arithmetic Density}=\frac{\text{Number of objects or people}}{\text{Total land area (km^2 or mi^2)}}
  • Used for broad comparisons (e.g.
    national population density).

• Physiological Density

  • Focus: Number of people per unit of arable land.
  • Formula: \text{Physiological Density}=\frac{\text{Population}}{\text{Arable Land Area}}
  • Indicates potential pressure on productive land (food security).

• Agricultural Density

  • Measures farmers per unit of arable land.
  • Formula: \text{Agricultural Density}=\frac{\text{Number of Farmers}}{\text{Arable Land Area}}
  • Lower values in highly mechanized regions (e.g.
    U.S., Canada) vs.
    higher in subsistence‐farming regions (e.g.
    parts of Sub‐Saharan Africa).

Diffusion Patterns

• Hearth (Point of Origin)

  • Starting location of an innovation or cultural trait.
  • Examples: Mesopotamia for agriculture; Silicon Valley for modern computing innovations.

• General Spatial Diffusion Modes (mentioned indirectly for future lectures)

  • Expect discussion of contagious, hierarchical, stimulus, and relocation diffusion.
  • Key idea: Phenomena move outward from hearths in identifiable patterns.

Practical / Ethical Considerations

• Understanding pattern, density, and diffusion helps planners address urban sprawl, resource allocation, and environmental impact.
• Ethical implication: High physiological density may require equitable food distribution policies.