♻️AP Environmental Science Unit 5 – Land & Water Use

Key Concepts

• Land use refers to how humans utilize and manage land resources for various purposes (agriculture, urban development, conservation)
• Water resources are essential for sustaining life and supporting human activities but are unevenly distributed across the globe
  • Freshwater accounts for only 2.5% of the Earth's total water supply
  • Groundwater, surface water, and atmospheric water are the main sources of freshwater
• Agriculture is the primary land use worldwide and is crucial for food production
  • Irrigation, crop rotation, and pest management are key agricultural practices
• Urban areas are expanding rapidly due to population growth and urbanization, leading to significant land-use changes
• Land and water use practices can have both positive and negative environmental impacts
  • Deforestation, soil erosion, and water pollution are common negative consequences
• Sustainable land and water management strategies are essential for balancing human needs with environmental conservation
• Case studies provide valuable insights into real-world challenges and solutions related to land and water use

Types of Land Use

• Agricultural land use involves cultivating crops and raising livestock for food production
  • Arable land is used for growing crops (wheat, corn, rice)
  • Pastureland is used for grazing animals (cattle, sheep, goats)
• Forestry land use focuses on the management and extraction of forest resources (timber, paper, fuel)
• Urban and built-up land use encompasses areas developed for human settlements and infrastructure
  • Residential areas include housing and neighborhoods
  • Commercial areas include businesses, offices, and retail spaces
  • Industrial areas are used for manufacturing, processing, and storage
• Recreational land use involves areas designated for leisure activities and tourism (parks, nature reserves, golf courses)
• Conservation land use aims to protect and preserve natural ecosystems and biodiversity
  • Protected areas, such as national parks and wildlife refuges, fall under this category
• Barren land refers to areas with minimal vegetation cover (deserts, rock outcrops, beaches)

Water Resources and Distribution

• Surface water resources include rivers, lakes, and reservoirs
  • Rivers are vital for water supply, irrigation, and hydroelectric power generation
  • Lakes and reservoirs store water for various uses and support aquatic ecosystems
• Groundwater is water stored in underground aquifers and is accessed through wells
  • Aquifers are recharged by precipitation and surface water infiltration
  • Groundwater is a critical source of drinking water and irrigation in many regions
• Desalination is the process of removing salt from seawater to produce freshwater
  • Reverse osmosis and distillation are common desalination techniques
• Water scarcity occurs when the demand for water exceeds the available supply
  • Arid and semi-arid regions are particularly vulnerable to water scarcity
• Water stress is a measure of the pressure on water resources due to human and ecological demands
• Virtual water refers to the water embedded in the production of goods and services
  • International trade of water-intensive products (crops, textiles) can impact regional water resources

Agricultural Practices

• Irrigation is the artificial application of water to crops to supplement rainfall
  • Surface irrigation, sprinkler irrigation, and drip irrigation are common methods
  • Irrigation can improve crop yields but can also lead to water depletion and salinization
• Crop rotation involves alternating different crops on the same land to maintain soil fertility and reduce pests
• Pest management strategies aim to control crop damage caused by insects, weeds, and diseases
  • Integrated pest management (IPM) combines biological, cultural, and chemical control methods
• Soil conservation practices help prevent soil erosion and maintain soil health
  • Contour farming, terracing, and cover cropping are examples of soil conservation techniques
• Livestock farming involves raising animals for meat, dairy, and other products
  • Intensive livestock farming (factory farms) can have negative environmental impacts
• Aquaculture is the farming of aquatic organisms (fish, shellfish, algae) in controlled environments
  • Aquaculture can help meet the growing demand for seafood but can also cause pollution and disease outbreaks

Urban Development and Planning

• Urbanization is the process of population shift from rural to urban areas
  • Rapid urbanization can lead to challenges such as overcrowding, housing shortages, and infrastructure strain
• Urban sprawl refers to the uncontrolled expansion of urban areas into surrounding rural land
  • Urban sprawl can result in loss of agricultural land, increased traffic congestion, and environmental degradation
• Smart growth strategies aim to create compact, walkable, and mixed-use communities
  • Transit-oriented development (TOD) focuses on building around public transportation hubs
• Green infrastructure incorporates natural elements into urban design to provide ecosystem services
  • Urban parks, green roofs, and rain gardens are examples of green infrastructure
• Sustainable urban planning considers the long-term environmental, social, and economic impacts of development
  • Energy-efficient buildings, waste reduction, and community engagement are key aspects of sustainable planning
• Urban resilience refers to a city's ability to adapt and recover from shocks and stresses
  • Climate change adaptation and disaster risk reduction are important for building urban resilience

Environmental Impacts

• Deforestation is the removal of forests for agriculture, logging, or urban development
  • Deforestation contributes to biodiversity loss, soil erosion, and climate change
• Habitat fragmentation occurs when contiguous habitats are divided into smaller, isolated patches
  • Fragmentation can disrupt wildlife migration and reduce genetic diversity
• Water pollution can result from agricultural runoff, industrial discharges, and urban wastewater
  • Eutrophication is the excessive growth of algae due to nutrient pollution, leading to oxygen depletion in water bodies
• Soil degradation involves the decline in soil quality due to erosion, compaction, or contamination
  • Overgrazing, intensive tillage, and improper irrigation can contribute to soil degradation
• Desertification is the process of fertile land turning into desert due to climate change or human activities
  • Overexploitation of land resources and prolonged droughts can lead to desertification
• Invasive species are non-native organisms that can cause ecological and economic harm when introduced to new environments
  • Invasive species can outcompete native species and disrupt ecosystem balance

Conservation Strategies

• Protected areas are designated regions managed for conservation purposes
  • National parks, wildlife refuges, and marine protected areas (MPAs) are examples of protected areas
• Ecosystem-based management (EBM) is a holistic approach that considers the interactions between humans and the environment
  • EBM aims to balance conservation with sustainable resource use
• Sustainable land management (SLM) practices aim to maintain and enhance land productivity while minimizing environmental impacts
  • Agroforestry, which integrates trees into agricultural systems, is an example of SLM
• Integrated water resources management (IWRM) is a coordinated approach to managing water, land, and related resources
  • IWRM considers the social, economic, and environmental aspects of water management
• Payments for ecosystem services (PES) involve incentivizing landowners to protect and restore ecosystems that provide valuable services
  • Carbon sequestration, water regulation, and biodiversity conservation are examples of ecosystem services
• Community-based conservation engages local communities in the management and protection of natural resources
  • Indigenous knowledge and traditional practices can inform conservation efforts

Case Studies and Real-World Applications

• The Aral Sea in Central Asia has shrunk significantly due to excessive water diversion for irrigation
  • The Aral Sea's decline has led to environmental and health problems in the region
• The Green Belt Movement in Kenya, founded by Wangari Maathai, focuses on planting trees to combat deforestation and empower communities
• The Loess Plateau in China has undergone extensive restoration efforts to address soil erosion and improve agricultural productivity
  • Terracing, afforestation, and grazing management have been key strategies in the Loess Plateau
• The Everglades in Florida, USA, is a unique wetland ecosystem threatened by urban development and water management practices
  • Restoration projects aim to restore the natural water flow and protect the Everglades' biodiversity
• The Netherlands has implemented innovative flood management strategies, such as the Room for the River program
  • The program involves creating space for rivers to overflow safely and naturally
• The Mekong River Basin in Southeast Asia is a transboundary water resource shared by six countries
  • Sustainable management of the Mekong River requires international cooperation and integrated planning