Unit 5: Urbanization and environment

Development, Displacement, and Industry

Development-induced displacement

This is the forced movement of people from their homes and lands to make way for large-scale development projects.

• Causes: Construction of dams, mines, industrial plants, highways, and special economic zones (SEZs).
• Impacts: Leads to loss of livelihood (especially for farmers), homelessness, social and cultural disruption, and increased poverty.

Resettlement and Rehabilitation

This is the process by which authorities are supposed to compensate and resettle the displaced populations. It is often poorly planned and executed, leading to social-economic problems for the affected people.

Impact of industry and technology on environment

• Pollution: Industries release pollutants into the air (e.g., SO₂, PM), water (e.g., heavy metals, chemical effluents), and soil (e.g., hazardous waste).
• Resource Depletion: Industries consume large amounts of raw materials (minerals, timber) and energy (fossil fuels).
• Waste Generation: Manufacturing processes create large volumes of solid and hazardous waste.

Urban Sprawl and its Consequences

Urban Sprawl

This is the uncontrolled, low-density expansion of urban areas into the surrounding countryside (rural land). It is characterized by spread-out housing, reliance on cars, and the loss of agricultural land and open space.

Consequences of Urban Sprawl

• Traffic Congestion: As people live farther from work, they must commute long distances by car, leading to clogged roads, wasted time, and increased air pollution.
• Social-economic Problems:
  • Social: Can lead to social isolation and a loss of community feel.
  • Economic: Increases the cost of public services (e.g., building new roads, water pipes, schools) and increases reliance on expensive fossil fuels.
• Environmental: Loss of farmland, forests, and wetlands; increased water runoff and pollution; fragmentation of habitats.

Urban Heat Island Effect

The Urban Heat Island (UHI) effect is a phenomenon where urban areas (cities) are significantly warmer than their surrounding rural areas, especially at night.

Causes:

1. Dark Surfaces: Concrete, asphalt roads, and dark roofs have a low albedo (reflectivity) and absorb more solar radiation.
2. Lack of Vegetation: Less trees and plants means less cooling from shade and evapotranspiration.
3. Waste Heat: Heat is released from buildings (air conditioning), vehicles (engines), and industries.
4. Urban Geometry: Tall buildings create "canyons" that trap heat and block wind.

Impacts:

• Increased energy consumption (for air conditioning).
• Aggravated air pollution (smog forms faster at higher temperatures).
• Heat-related health problems (e.g., heat stroke).

Modern Agriculture and Environmental Degradation

Modern, intensive agriculture (like the "Green Revolution") has dramatically increased food production but has also caused significant environmental problems.

Key Impacts:

• Chemical Pollution: Runoff of chemical fertilizers (N, P) causes eutrophication of water bodies. Pesticides kill non-target species (like pollinators) and can bio-magnify.
• Water Depletion: Intensive irrigation (especially for water-hungry crops) is rapidly depleting groundwater aquifers.
• Soil Degradation: Monocropping (planting the same crop year after year) and heavy machinery use can lead to soil erosion, compaction, and loss of fertility.
• Loss of Biodiversity: Replacing diverse landscapes with vast monocultures destroys habitats and reduces genetic diversity of crops.