AP Human Geography — 2학기 중간 예상문제 + 해설

(a) The Concentric Zone model was proposed by Burgess in 1925, and it depicts the US city of 1900-1950, which was expanding rapidly as people moved away from inner-city locations toward places with a higher standard of living.
(b) The CBD contains the peak land value intersection, the most expensive land in the city, because of high demand and central accessibility. As a result, land is used intensively, with a high concentration of skyscrapers and multi-story commercial buildings.
(c) As the CBD continuously expands, it pushes into the Zone in Transition, causing the surrounding zones to continually push outwards and rebuild their infrastructures. In invasion, a new or incoming group, often newer, poorer immigrants, enters an established area; in succession, the incoming group completely replaces the previous group and changes the cultural, ethnic, or socioeconomic character of the neighborhood.
(d) One criticism is that the model is America-centric. While North American cities feature poorer populations in the CBD and wealth in the outer suburbs, cities in Europe and Asia were historically built around central fortresses or palaces, so the wealthiest residents stayed in the city center rather than on the periphery. Therefore the model lacks applicability outside North America.

(a) Zone 2, the Zone in Transition, has mixed land use in which residences are intermixed with industrial zones and factories, and most residences are tenements, rundown apartment buildings minimally maintained by landlords. Housing values are very low because of the noise and pollution from the nearby industrial zones.
(b) Zone 2 is primarily inhabited by lower-class citizens and new immigrants and forms high-density slums with substandard housing, whereas Zone 5 is typically the richest part of the urban agglomeration, where housing is spacious and spread out.
(c) The residents of Zone 5 could afford to commute to the CBD in their own private vehicles, which was a luxury in the early twentieth century, so they were able to live far from the CBD.
(d) The model does not account for geographical limits to expansion. It assumes an isotropic plane with no physical barriers, but in reality mountains, seas, or deserts limit outward growth, as in Tokyo, where mountains like Mount Fuji restrict expansion to the west, preventing the city from expanding in a uniform concentric pattern.
(e) The Chicago Loop is the oldest part of Chicago, home to its central business district and the heart of downtown, and 40% of all Chicago residents work there.
(f) Zone 3 is the Zone of independent workers' homes, the working-class residential zone in the inner suburbs. This is the zone where most of the working class employed in the central business district live; it lies close to the CBD because, historically, they did not possess the means to commute to the CBD for work.

(a) Urban sprawl is the unrestricted, low-density expansion of housing, commercial strip malls, and roads over vast expanses of rural land with minimal centralized urban planning.
(b) Two causes of suburbanization are automobile ownership and the Interstate Highway Act of 1956 in the U.S. Larger homes, lower land costs, and government mortgage policies and zoning also contributed.
(c) One negative impact is high infrastructure costs. Extending water, power, roads, and emergency services over large, spread-out distances drains municipal budgets.
(d) One consequence for the city center is the erosion of its tax base, which leads to urban decay. Suburbanization also increased socio-economic and racial segregation (white flight).

(a) One cause of suburbanization is lower land costs. Because land farther from the urban core is cheaper, housing, commercial strip malls, and roads spread outward over rural land at low density.
(b) One negative impact of urban sprawl is auto-dependency, because infrastructure favors cars exclusively, making public transit inefficient or non-existent.
(c) Two mitigation strategies are mixed-use development and transit-oriented development (TOD). Walkable communities and urban growth boundaries (greenbelts) are also used by Smart Growth and New Urbanism planners.
(d) Transit-oriented development reduces auto-dependency because it plans communities around public transit, so residents do not need a car for every trip, which addresses the problem that infrastructure favors cars exclusively.

Part A Two technological innovations associated with the Green Revolution are high-yield hybrid seeds (HYVs) engineered for higher grain density and synthetic nitrogen-based chemical fertilizers.
Part B The Green Revolution dramatically boosted global food security by exponentially increasing crop yields per acre in densely populated LDCs, which averted widespread famines and allowed countries like India to transition from food dependence to self-sufficiency in wheat production.
Part C First, Green Revolution research focused predominantly on rice, wheat, and maize, largely ignoring traditional African staple crops such as cassava, sorghum, and yams. Second, Sub-Saharan Africa lacked the necessary physical and financial infrastructure—such as transport networks, electricity, and mechanized irrigation—needed to support water- and input-intensive HYV crops.
Part D One negative environmental consequence is soil salinization caused by over-irrigation in arid regions. As heavy irrigation water rapidly evaporates under intense heat, dissolved mineral salts build up on the soil surface, rendering farmland toxic to future crops.
Part E Small-scale farmers in LDCs face high capital barriers because Green Revolution technologies require annual purchases of expensive patented seeds, synthetic chemicals, and fuel. Without access to affordable credit or government subsidies, these high input costs often force smallholders into severe debt.

A Two characteristics of the Green Revolution are the introduction of high-yield varieties (HYVs), such as dwarf varieties of wheat, rice (IR8 "Miracle Rice"), and corn, and agrochemical expansion, a massive reliance on nitrogen-based fertilizers, chemical pesticides, and herbicides.
B First, there was a surge in food production: cereals production more than doubled in targeted LDCs between 1960 and 1990 without a proportional expansion in cultivated land area. Second, the Green Revolution lowered global staple food prices, making basic food energy more accessible to urban poor populations. It also averted catastrophic famines in densely populated regions, particularly across South Asia.
C One limitation is that farmers fell into debt cycles. Annual reliance on commercial hybrid seeds, synthetic fertilizers, and fuel drove high debt burdens among rural farmers, and smallholders unable to afford costly inputs faced landlessness.
D A food desert is an urban or rural area with limited access to affordable, fresh, and nutritious whole foods. It primarily affects low-income populations who rely on processed foods from convenience stores.