# Study Notes: Urban Systems & Urban Planning --- ## Key Concepts ### Urban Systems and Ecosystems - **Urban System**: A built-up area functioning as a system with interconnected components such as population, infrastructure, and resources. - **Urban Ecosystem**: Urban areas viewed as ecosystems, where **biotic** (living) and **abiotic** (non-living) components interact to influence overall functioning. In an urban ecosystem: - **Biotic components**: Humans, plants, animals. - **Abiotic components**: Buildings, roads, water supply, air quality. Think of an urban system as a "living city" where every part—people, infrastructure, and nature—works together like organs in a body. --- ## Urbanization and Suburbanization ### Urbanization - **Definition**: The population shift from rural to urban areas. - **Significance**: Over 80% of people in High-Income Countries (HICs) now live in urban areas. - **Key Drivers**: - **Push Factors**: Lack of jobs, poor infrastructure, and limited services in rural areas. - **Pull Factors**: Better job opportunities, education, healthcare, and lifestyle in urban areas. A farmer moves to a city because of drought (push factor) and the promise of factory work (pull factor). ### Suburbanization - **Definition**: Movement of people from dense central urban areas to lower-density peripheral areas. - **Causes**: - Desire for larger homes and green spaces. - Improved transportation allowing commuting. - **Environmental Impacts**: - Loss of agricultural land. - Increased air pollution from commuting. - Habitat destruction and disruption of natural cycles. Suburbanization is often confused with urbanization. Remember, suburbanization refers to the *spread* of urban areas, not the initial population shift from rural to urban areas. --- ## Environmental Impacts of Urban Expansion ### Urban Sprawl - **Definition**: Uncontrolled expansion of urban areas into surrounding rural land. - **Key Environmental Impacts**: 1. **Loss of Agricultural Land**: Farmland is converted into housing and infrastructure. 2. **Habitat Loss**: Forests and wetlands are destroyed, leading to biodiversity loss. 3. **Heat Island Effect**: Urban areas become significantly warmer than surrounding rural areas due to concrete and asphalt absorbing heat. A city expanding into a forested area may lead to: - Loss of trees (affecting carbon sequestration). - Increased flooding due to impermeable surfaces. - Disruption of bird migration patterns due to light pollution. ### Water and Air Quality - **Water**: Urban expansion alters river flows, increases runoff, and reduces water quality due to pollutants. - **Air**: Increased vehicle emissions and industrial activity raise levels of air pollution. Urban sprawl can also lead to invasive species thriving in disturbed ecosystems, such as rats and pigeons in cities. --- ## Urban Planning ### Definition and Purpose - **Urban Planning**: The process of designing and organizing land use, infrastructure, and resources in urban areas. - **Primary Purpose**: To create functional, sustainable, and livable cities. ### Objectives of Urban Planning 1. **Environmental Sustainability**: Incorporating green spaces and renewable energy. 2. **Community Wellbeing**: Ensuring access to housing, healthcare, and education. 3. **Efficient Land Use**: Balancing residential, commercial, and industrial zones. Zoning laws are a key tool in urban planning, separating areas for specific uses to reduce conflicts (e.g., keeping factories away from homes). --- ## Sustainable Urban Planning ### Definition - **Sustainable Urban Planning**: Designing cities to meet current needs without compromising future generations' ability to thrive. ### Key Factors 1. **Green Infrastructure**: - Green roofs reduce air pollution and flooding. - Parks and urban forests improve air quality and provide recreation. 2. **Integrated Public Transport**: - Reduces reliance on cars, lowering emissions. - Improves accessibility for all residents. 3. **Renewable Resources**: - Solar panels and wind turbines reduce dependency on fossil fuels. Copenhagen uses extensive bike lanes and wind energy to create a sustainable urban environment. Green spaces also create microclimates, reducing urban temperatures and improving mental health. --- ## Ecological Urban Planning ### Definition - **Ecological Urban Planning**: Treating urban areas as ecosystems, focusing on the relationships between biotic and abiotic components. ### Key Concepts 1. **Regenerative Architecture**: Engaging the natural world as a medium for sustainable design. 2. **Urban Farming**: - Benefits: Local food production, reduced transportation emissions. - Challenges: Limited space in dense cities. 3. **Biophilic Design**: - Incorporates natural elements into urban spaces. - Improves air quality, reduces stress, and enhances aesthetics. Singapore’s "Gardens by the Bay" integrates greenery into urban design, creating a balance between nature and infrastructure. ### Resilience Planning - **Definition**: Preparing cities to adapt to climate change and other challenges. - **Examples**: - Flood defenses in coastal cities. - Heat-resistant infrastructure in hot climates. Resilience planning ensures cities can recover quickly from disasters, such as hurricanes or droughts. --- ## Systems Thinking in Urban Areas ### Urban Systems as Ecosystems - **Components**: 1. **Inputs**: Energy, water, raw materials. 2. **Processes**: Transportation, trade, cultural activities. 3. **Outputs**: Waste, pollution, goods, and services. - **Flows**: - Energy flows through power grids. - Water flows through supply and sanitation systems. In New York City: - **Input**: Electricity from power plants. - **Process**: Subway system transporting millions daily. - **Output**: Wastewater treated in sewage plants. Many students forget to include cultural and social components when analyzing urban systems. These are just as important as physical infrastructure! --- ## Practice Questions 1. **Define** the term "urban system." 2. **Explain** how an urban system is similar to a natural ecosystem. 3. **List** four key components of an urban system and describe their roles. 4. **Describe** the relationship between the inputs and outputs of an urban system, using a specific city as an example. 5. **Outline** three environmental impacts of urban sprawl. 6. **Explain** how green infrastructure contributes to sustainable urban planning. 7. **Describe** the benefits and challenges of urban farming in densely populated cities. --- ## Key Takeaways - Urban systems function like ecosystems, with interconnected biotic and abiotic components. - Urbanization and suburbanization significantly impact the environment, including habitat loss and pollution. - Sustainable urban planning integrates green infrastructure, renewable energy, and efficient transport systems. - Ecological urban planning treats cities as ecosystems, focusing on resilience and harmony with nature. - Systems thinking helps us understand the complex flows and interactions within urban areas. When designing or analyzing urban systems, always consider the balance between functionality, sustainability, and quality of life.