EVS full note

Unit 1: Introduction to Environmental Studies

Definition of Environment

  • Etymology: The word 'environment' derives from the Old French word 'environer' meaning to surround or encircle.

  • Concept: It refers to the aggregate of conditions and surroundings where living beings (humans, animals, plants) exist alongside non-living things.

  • Mutual Interaction: All living beings and their environments are mutually reactive, influencing each other significantly.

Major Components of Environment

  • Biotic and Abiotic Factors:

    • Biotic factors: Living components (e.g., organisms like plants and animals).

    • Abiotic factors: Non-living components (e.g., physical conditions like temperature, humidity; and chemical agents like gases and minerals).

Four Major Environmental Components

  • Lithosphere: The crust of the Earth, composed of various minerals, reaches depths of up to 100 kilometers. It includes:

    • Tectonic Plates: The main elements of the lithosphere.

    • Pedosphere: The uppermost part of the lithosphere that chemically interacts with the atmosphere, hydrosphere, and biosphere through soil formation.

  • Hydrosphere: Contains all forms of water (e.g., oceans, rivers, lakes).

    • Coverage: Occupies 70% of the Earth's surface.

    • Freshwater Availability: Only 2.5% of the total Earth's water is freshwater.

  • Atmosphere: The gaseous layer enveloping Earth, primarily composed of:

    • Components: 78.08% nitrogen, 20.95% oxygen, and other trace gases.

    • Structure: Divided into five major layers — troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

  • Biosphere: The regions on Earth where life exists, extending from polar ice caps to the equator, comprising all living matter (biomass).

Natural vs Man-Made Environment

Natural Environment

  • Definition: Natural environments are complex and arise from interactions amongst physical and biological processes, with aspects like climatology and geology influencing them.

Man-Made Environment

  • Definition: Human-created environments that facilitate living in geographical environments, involving alterations via urbanization and agriculture.

Scope of Environmental Studies

  • Multidisciplinary Approach: Incorporates aspects of anthropology, science, sociology, economics, ecology, and others.

  • Importance: Helps in understanding physical, social, cultural, and biological aspects of environmental changes, addressing issues like pollution, conservation of resources, and biodiversity.

Importance of Environmental Studies

  1. Awareness: Increases knowledge about current environmental issues.

  2. Ecological Balance: Maintains equilibrium in ecosystems.

  3. Conservation: Promotes preservation of biodiversity and natural resources.

  4. Human Responsibilities: Educates on our roles towards environmental protection and sustainable practices.

Sustainability and Development

  • Definition: Development that meets present needs without compromising future generations’ ability to meet their own needs.

  • Key Principles: Equal resource distribution, consideration of the poor, and attention to environmental quality.

Strategies for Sustainable Development

  1. Use of non-conventional energy sources (solar, wind, etc.).

  2. Implementation of LPG and Gobar gas plants for rural energy needs.

  3. Adoption of cleaner fuels (CNG) in urban transport.

  4. Wind and solar power development to harness natural energy efficiently.

  5. Encouragement of bio composting and organic waste utilization.

Conclusion

  • Economic development has led to increased pressure on natural resources, necessitating sustainable strategies that minimize environmental degradation while supporting human needs.

Unit 2: Ecosystem

Introduction to Ecosystem

  • Definition: An ecosystem is a complex network of living organisms and their physical environment interacting in a specific area.

  • Types of Ecosystems: Includes aquatic, marine, freshwater, and terrestrial ecosystems.

  • Aquatic Ecosystems: Characterized by bodies of water and include marine (oceans, coral reefs) and freshwater (lakes, rivers).

  • Terrestrial Ecosystems: Exist primarily on land and include forests, grasslands, deserts, etc.

Structure of Ecosystem

  • Biotic Components: Organisms within the ecosystem, classified into producers, consumers, and decomposers.

  • Abiotic Components: Non-living factors such as soil, water, sunlight, and nutrients.

Functions of Ecosystem

  • Food Circulation: Describes energy flow via food chains and webs, demonstrating interdependence among species.

  • Energy Flow: Primarily unidirectional; starts from producers through to various trophic levels ending in decomposers.

  • Nutrient Cycling: Continuous cycle of nutrients through biogeochemical cycles, maintaining ecosystem health.

Conclusion

The interconnectivity of life forms within ecosystems demonstrates the delicate balance maintained through energy flow and nutrient cycling, emphasizing the necessity for conservation efforts due to increasing human impact on these systems.