Ap Human Geography Models Review

AP Human Geography Models: A Comprehensive Review

This article provides a thorough review of key models frequently encountered in AP Human Geography. Understanding these models is crucial for success in the course and the AP exam. We will explore each model in detail, providing explanations, diagrams where applicable, and examples to solidify your understanding. This comprehensive guide covers everything from basic spatial concepts to complex urban and demographic models, equipping you with the knowledge to analyze geographical patterns and processes effectively.

I. Introduction to Geographical Models

Geographical models are simplified representations of complex real-world phenomena. They are not perfect replications of reality but rather tools to help us understand, explain, and predict spatial patterns and processes. These models utilize various theoretical frameworks, providing a structured way to analyze geographical data and issues. Mastering these models will significantly enhance your ability to interpret maps, graphs, and case studies, central components of the AP Human Geography exam.

II. Spatial Interaction Models

This section covers models explaining the movement of people, goods, and ideas across space.

A. Gravity Model

The gravity model suggests that the interaction between two places is directly proportional to the product of their populations and inversely proportional to the square of the distance between them. Think of it like gravity – larger places attract each other more strongly, and closer places interact more frequently.

Formula: Interaction = (Population A * Population B) / Distance²
Limitations: Doesn't account for intervening opportunities or barriers (e.g., mountains, political borders), or transportation infrastructure.
Example: The high interaction between New York City and Los Angeles, despite their distance, is due to their large populations. Conversely, interaction between two smaller, closer towns might be less despite the proximity.

B. Distance Decay

Distance decay describes the decline in interaction between two places as the distance between them increases. The rate of decay can vary depending on factors like transportation, communication technology, and the nature of the interaction.

Example: The influence of a major city diminishes as you move further away. Its cultural impact might be strong in nearby suburbs but significantly weaker in distant rural areas.

C. Spatial Diffusion

Spatial diffusion is the spread of a phenomenon (idea, innovation, disease) across space over time. Several models describe different patterns:

Expansion Diffusion: The spread originates from a central point and expands outward. This can be:
- Contagious diffusion: Rapid spread, like a virus.
- Hierarchical diffusion: Spread through a hierarchy (e.g., from major cities to smaller towns).
- Stimulus diffusion: The underlying idea spreads, but the specific form adapts to the new location.
Relocation Diffusion: The spread occurs through the physical movement of people or things, carrying the phenomenon with them to a new location.
Example: The spread of McDonald's restaurants globally is a great example of expansion diffusion, particularly hierarchical diffusion and stimulus diffusion (adapting menus to local tastes). The spread of a language through migration is an example of relocation diffusion.

III. Demographic Transition Model

The demographic transition model (DTM) explains changes in birth and death rates over time, leading to changes in population growth. It typically progresses through five stages:

Stage 1: High stationary – High birth and death rates, resulting in slow population growth or even stagnation.
Stage 2: Early expanding – Death rates fall due to improvements in healthcare and sanitation, while birth rates remain high, leading to rapid population growth.
Stage 3: Late expanding – Birth rates begin to decline due to factors like increased access to education and contraception, resulting in slowing population growth.
Stage 4: Low stationary – Low birth and death rates, resulting in stable population growth.
Stage 5: Declining – Death rates exceed birth rates, leading to a declining population.
Limitations: Doesn’t account for migration or government policies impacting fertility. Many countries have exhibited variations in their transitions.
Example: Many developed nations are in Stages 4 or 5, while many developing nations are in Stages 2 or 3.

IV. Urban Models

Several models attempt to explain the spatial structure of cities.

A. Concentric Zone Model (Burgess)

This model depicts a city as a series of concentric rings expanding outwards from the central business district (CBD). Each ring represents a different land use, with the CBD at the center, followed by a zone of transition, zone of independent workers’ homes, zone of better residences, and a commuter zone.

Limitations: Oversimplified; doesn't account for variations in topography or transportation infrastructure. Does not reflect contemporary suburban sprawl and decentralization.

B. Sector Model (Hoyt)

This model suggests that cities develop in sectors, radiating outwards from the CBD along transportation lines. Similar land uses cluster together in wedges.

Limitations: Still simplified; overlooks the role of social and economic factors beyond transportation.

C. Multiple Nuclei Model (Harris and Ullman)

This model recognizes that cities can have multiple centers of activity, not just one CBD. These centers attract specific land uses, creating clusters based on their interactions.

Example: A university campus might attract bookstores, restaurants, and student housing. An industrial park will cluster factories and warehouses.

D. Galactic City Model (Peripheral Model)

This model accounts for suburbanization and the rise of edge cities. It depicts a decentralized city structure with the CBD surrounded by suburban areas connected by highways and beltways. Edge cities develop at highway intersections, offering employment and residential options outside of the traditional city center.

Limitations: Doesn't fully capture the complexities of urban sprawl and transportation patterns in all cities.

V. Agricultural Models

Models help explain agricultural practices and their spatial distribution.

A. Von Thünen's Model

This model explains the location of agricultural activities around a central market based on transportation costs and land rent. Intensive, high-value crops are located closer to the market, while extensive, low-value crops are further away.

Limitations: Assumes a flat, uniform landscape with no transportation barriers or variations in soil fertility. Doesn't fully account for technological advancements and government subsidies.

B. World-Systems Theory (Wallerstein)

While not strictly an agricultural model, it significantly impacts agricultural production. This theory divides the world into a core, periphery, and semi-periphery. Core countries control capital and technology, often exploiting peripheral countries for raw materials, including agricultural products.

Example: Many developing countries in the periphery specialize in producing agricultural commodities for export to core countries, often at low prices.

VI. Political Geography Models

Models illuminate political power dynamics and spatial organization.

A. Heartland Theory (Mackinder)

This theory argues that control over the "heartland" of Eurasia is crucial for global domination. This area is rich in resources and serves as a base for expansion.

B. Rimland Theory (Spykman)

This theory counters the Heartland Theory, arguing that control over the coastal regions ("rimland") surrounding the heartland is more important for global power.

C. Organic Theory (Ratzel)

This theory views states as living organisms that require nourishment (territory and resources) to grow and survive. This can lead to expansionist policies.

VII. Conclusion

Mastering these AP Human Geography models is essential for success in the course and on the AP exam. While these models offer simplified representations, understanding their strengths, weaknesses, and applications allows you to critically analyze spatial patterns and processes. Remember to consider the limitations of each model and apply them judiciously within the specific geographical context. By combining your knowledge of these models with case studies and map analysis, you'll be well-prepared to tackle the complexities of human geography. Remember to practice applying these models to different geographical scenarios to solidify your understanding and build your analytical skills. Good luck!