Chapter 14 — Natural Resources

What are natural resources? Natural resources are materials and components (air, water, soil, minerals, forests, sunlight, wildlife, etc.) that occur in nature and are used by humans for survival and economic activity. They form the basis of life and all human activities.

Classification

• Based on origin: Biotic (living or once-living: forests, animals, fossil fuels) and Abiotic (non-living: water, air, minerals, sunlight).
• Based on renewability:
  • Renewable — resources that can be replenished naturally within human time scales (e.g., solar energy, wind, biomass, surface water under sustainable use).
  • Non-renewable — resources that form very slowly or not at all on human time scales (e.g., coal, petroleum, natural gas, many minerals).

Why they are important
Natural resources provide food, clean water, air, raw materials for industry, energy, and ecosystem services such as climate regulation, soil formation, and pollination.

Key issues and threats

• Overuse and depletion: extraction faster than replenishment leads to resource depletion (e.g., groundwater pumping causing falling water tables).
• Pollution: contamination of air, water and soil reduces resource quality (e.g., industrial effluents, plastic pollution).
• Habitat loss and biodiversity decline: deforestation and land-use change destroy ecosystems.
• Inequitable distribution: unequal access causes social and economic problems.

Conservation and sustainable use
Conservation aims to use resources so they are available for future generations. Key approaches: sustainable harvesting (not exceeding replenishment), afforestation and reforestation, rainwater harvesting, pollution control, recycling, efficient technologies, and legal/regulatory frameworks.

Link to human population and development
Resource pressure rises with population and consumption per person. Managing both population growth and per-capita consumption is critical to sustainability.

Takeaway: Natural resources are limited and interdependent. Understanding their types, rates of renewal, and threats helps plan their wise use and conservation for long-term sustainability.

What is air? Air is the mixture of gases that surrounds the Earth and is essential for life. It is invisible, tasteless and odourless (when pure), and extends up to several hundred kilometres above the Earth as the atmosphere.

Composition

• Permanent gases (approx. by volume): Nitrogen ~78%, Oxygen ~21%, Argon ~0.93%, Carbon dioxide ~0.04% (variable), and traces of neon, helium, methane, krypton).
• Variable components: Water vapour (0–4% by volume depending on temperature and location), dust particles, pollen, smoke and other pollutants.

Properties of air

• Air has mass and density: a column of air has weight that produces atmospheric pressure.
• Air exerts pressure in all directions (atmospheric pressure ≈ 101.3 kPa at sea level).
• Air expands on heating and contracts on cooling (thermal expansion), and it diffuses (mixes) readily.
• Air supports combustion by supplying oxygen and participates in many chemical cycles (e.g., nitrogen cycle, carbon cycle).

Role of air in nature and daily life

• Respiration: Animals and humans breathe oxygen; plants use CO2 for photosynthesis and release oxygen.
• Photosynthesis: Plants convert CO2 and water to glucose and O2 using sunlight.
• Weather and climate: Air movement (wind), water vapour, and pressure differences determine weather systems and rainfall.
• Protection: The ozone layer (part of the atmosphere) absorbs harmful ultraviolet (UV) radiation.
• Transport and technology: Air is used in pneumatic systems, flight (lift), balloons, and engines.
• Pollution: Harmful gases and particulate matter in air cause health problems and ecological damage; controlling emissions and planting trees help reduce pollution.

Common demonstrations and phenomena

• Diffusion: Smell of perfume spreading across a room.
• Air pressure effects: A collapsing can after heating and rapid cooling; wind produced by pressure differences.
• Buoyancy: Hot-air balloons rise as heated air inside is less dense than outside air.
• Cloud formation: Cooling of moist air causes condensation of water vapour forming clouds and rain.

Air pollution & mitigation

• Major pollutants: Particulate matter (PM2.5/PM10), CO, SO₂, NOₓ, hydrocarbons, and excess CO₂.
• Effects: Respiratory diseases, acid rain, global warming and ozone depletion.
• Prevention: Use clean energy, reduce vehicle emissions, regulate industries, afforestation, and use public transport.

Water

Definition: Water is a chemical substance with formula H2O. It is a colourless, odourless, tasteless liquid at room temperature and is vital for all known forms of life.

Physical and chemical properties

• Compound: H2O (two hydrogen atoms covalently bonded to one oxygen atom).
• States: Exists naturally in three states – solid (ice), liquid (water), gas (water vapour).
• Density: Maximum density about 1 g/cm3 (1000 kg/m3) at 4°C.
• High specific heat: 4.18 J/g°C (4184 J/kg°C), so it moderates climate and stores heat.
• High latent heats: fusion ~334 kJ/kg, vaporisation ~2256 kJ/kg.
• Universal solvent: dissolves many ionic and polar substances, important for biological and geological processes.

Occurrence and distribution

Over 97% of Earths water is in the oceans (saline). Of the remaining freshwater (~3%): most is locked in glaciers and ice caps; a smaller fraction is groundwater; only a tiny fraction is available as surface water in rivers and lakes for direct human use.

Water cycle (hydrologic cycle)

The continuous movement of water on, above and below the surface of the Earth. Main processes:

• Evaporation: liquid water becomes vapour from oceans, lakes, soil.
• Transpiration: water vapour released by plants.
• Condensation: vapour forms clouds.
• Precipitation: rain, snow, hail returns water to Earth.
• Infiltration and percolation: water moves into soil and recharges groundwater (aquifers).
• Runoff: water flows over land into rivers, lakes and oceans.

Groundwater and water table

Groundwater occupies pores and fractures in soil and rock. The water table is the upper surface of saturated zone. Wells tap groundwater; overuse can lower the water table and cause problems like drying of wells and land subsidence.

Uses of water

• Domestic: drinking, cooking, cleaning.
• Agriculture: irrigation (largest use worldwide).
• Industry: cooling, processing, manufacturing.
• Ecological: habitat for aquatic life, maintaining wetlands.
• Energy: hydropower generation.

Water quality and purification

Potable water must be free from harmful microbes and within acceptable physical and chemical limits (pH, turbidity, dissolved salts). Common purification steps include sedimentation, filtration, and disinfection (e.g., chlorination). Boiling and household filtration are simple methods to make water safe.

Water scarcity and conservation

Freshwater is limited and unevenly distributed. Causes of scarcity include overuse, pollution, population growth and climate change. Conservation measures: rainwater harvesting, watershed management, efficient irrigation (drip), recycling and reuse, fixing leaks, and public awareness.

Importance in everyday life and environment

Water supports life processes (metabolism, transport of nutrients), shapes landscapes via erosion and deposition, and influences weather and climate. Protecting water resources ensures health, food security and sustainable development.

What is soil?
Soil is the uppermost layer of the Earth’s crust that supports plant life. It is a mixture of mineral particles, organic matter (humus), water, and air. Soil forms over long periods by the weathering of rocks and the action of climate, organisms and time.

How soil is formed (soil formation)

• Parent rock (source material) breaks down by physical, chemical and biological weathering.
• Climate (rain, temperature) affects the rate of weathering and organic decay.
• Organisms (plants, microbes, earthworms) add organic matter and mix the material.
• Topography (slope, drainage) influences erosion and accumulation.
• Time: longer periods lead to deeper, more developed soils.

Soil profile and horizons

• O horizon: organic litter (leaves, plant debris).
• A horizon (topsoil): dark, rich in humus and nutrients; most biological activity.
• B horizon (subsoil): accumulation of leached minerals (clays, iron).
• C horizon: partially weathered parent rock.
• R horizon: unweathered bedrock.

Components and properties of soil

• Mineral particles: sand (coarse), silt (medium), clay (fine) — determine texture.
• Organic matter (humus): improves fertility, water retention and structure.
• Soil air and water: important for root respiration and nutrient transport.
• pH: acidity or alkalinity affects nutrient availability (pH ~6–7.5 is ideal for most crops).
• Soil structure and colour: indicate aeration, drainage and organic content.

Types of soil (common in India) and typical crops

• Alluvial soil: found in plains and river valleys — fertile; crops: rice, wheat, sugarcane.
• Black (Regur) soil: retains moisture, rich in clay — cotton, millets.
• Red soil: well-drained but low in humus — pulses, millets.
• Laterite soil: poor and acidic, formed in high rainfall areas — plantation crops (tea, coffee after improvement).
• Arid (Desert) soil: saline, low organic matter — sparse vegetation; needs irrigation and reclamation.

Importance of soil

• Supports agriculture and food production.
• Habitat for many organisms (microbes, insects, earthworms).
• Stores water and filters pollutants.
• Provides raw materials (clay for pottery, sand for construction).

Soil erosion and conservation

• Erosion types: water erosion (rills, gullies), wind erosion (dust storms), and human-induced degradation (deforestation, overgrazing, unsuitable tillage).
• Conservation methods: contour ploughing, terracing, afforestation, strip cropping, cover crops, crop rotation, mulching, check dams, windbreaks and adding organic manure.

Practical tips (classroom & everyday)

• Test soil texture by the ‘ribbon test’ (sand gritty, clay forms long ribbon, silt feels smooth).
• Use compost or farmyard manure to improve soil fertility and structure.
• Avoid over-irrigation to prevent salinization and waterlogging.

Summary: Soil is a dynamic natural resource formed by rock weathering and biological activity; its texture, structure, moisture, and fertility determine its suitability for plants. Protecting soil from erosion and maintaining its organic content are crucial for sustaining agriculture and ecosystems.

Introduction

Natural vegetation means the plant cover that grows naturally in an area without human intervention. Wildlife refers to all wild animals, birds, insects and other organisms living in natural habitats. Both are integral parts of natural resources and are interdependent: vegetation provides food and shelter for wildlife, and animals help in pollination, seed dispersal and nutrient cycling.

Factors Affecting Distribution

• Climate (temperature and rainfall) — most important factor; determines type and density of vegetation.
• Soil — texture, depth and fertility influence plant growth.
• Altitude — temperature and oxygen change with height; vegetation changes from tropical at low levels to alpine at high levels.
• Topography and drainage — slope and water availability affect vegetation.
• Human activities — deforestation, agriculture, urbanisation modify natural vegetation and wildlife habitats.

Major Types of Natural Vegetation (with characteristics)

• Tropical Evergreen Forests: Found in areas with heavy rainfall (>200 cm) and high temperature throughout the year. Trees are tall, dense, with broad leaves and no definite season for leaf shedding. Examples of plants: rubber, cinchona, ebony, rosewood. Typical animals: elephants, monkeys, tiger, hornbills.
• Tropical Deciduous (Monsoon) Forests: Found where rainfall is moderate (70–200 cm) and there is a distinct dry season. Trees shed leaves in dry season. Subtypes: moist deciduous (sal, teak) and dry deciduous (teak, acacia). Animal life: deer, bison (gaur), tigers, various birds.
• Thorny and Scrub Vegetation: Occurs in regions with low and erratic rainfall (deserts and semi-arid). Plants are short, thorny and have small or no leaves to reduce water loss (cactus, acacia/khejri, ber). Animals adapted to aridity: camel, desert fox, lizards.
• Montane (Himalayan/Temperate) Vegetation: Vegetation changes with altitude. At lower montane: broad-leaved forests; higher up: coniferous forests (pine, deodar, fir); near snowline: alpine meadows and dwarf shrubs (rhododendron). Fauna: snow leopard, Himalayan tahr, musk deer.
• Mangrove Vegetation: Found in tidal zones of river mouths and deltas (e.g., Sundarbans). Plants (mangroves) can tolerate saline water and have aerial roots (Rhizophora, Avicennia, Sundari). Animals include estuarine crocodiles, mudskippers, many fish and bird species.
• Grasslands: Dominated by grasses rather than trees. Occur in areas with moderate rainfall and periodic fires or grazing. Examples: savannas, temperate grasslands and alpine meadows. Typical animals: herbivores like deer, bison, antelope and predators like lions or wolves (region dependent).

Wildlife: Adaptations, Importance and Threats

• Adaptations: Structural (thick fur, long roots), physiological (water conservation), behavioural (migration, hibernation) help organisms survive in specific vegetation zones.
• Importance: biodiversity maintains ecosystem services — pollination, nutrient cycling, soil formation, climate regulation and providing food, medicines and raw materials.
• Major threats: habitat loss (deforestation, land conversion), poaching, pollution, invasive species, climate change and fragmentation of habitats.

Conservation and Protection

Conservation is done by two main approaches: in-situ (protecting species in their natural habitats — national parks, wildlife sanctuaries, biosphere reserves) and ex-situ (zoos, botanical gardens, seed banks). Important measures in India: Wildlife Protection Act (1972), Project Tiger, Project Elephant, protected areas like the Sundarbans (mangrove), Jim Corbett National Park, Kanha, Kaziranga (one-horned rhinoceros).

Interdependence and Examples of Ecological Relationships

• Food chains and food webs show energy flow: plant (producer) → herbivore (primary consumer) → carnivore (secondary consumer) → top predator.
• Seed dispersal by birds and mammals maintains forest regeneration; pollination by insects and birds is essential for reproduction of many plants.

Summary (Key points)

• Natural vegetation types are primarily determined by climate and soil.
• Each vegetation type supports characteristic wildlife adapted to local conditions.
• Human actions greatly modify vegetation and threaten wildlife; conservation is essential.

Note for students: When studying examples, relate each plant and animal to the climate/soil/altitude of its habitat to understand adaptation and distribution.

Introduction
Minerals are naturally occurring, homogeneous substances with a definite chemical composition and crystalline structure. Energy resources are sources from which we obtain energy to do work — they can be stored (fossil fuels) or continuously replenished (renewables).

Types of Minerals

• Metallic minerals: Contain metals — e.g., iron ore (Fe), copper (Cu), bauxite (Al). Used in construction, transport, electrical wiring.
• Non-metallic minerals: Do not yield metals — e.g., limestone, mica, kaolin, gypsum. Used in cement, ceramics, electrical insulation.

Occurrence and Formation

Minerals form through igneous, sedimentary and metamorphic processes. Fossil fuels (coal, petroleum, natural gas) form from buried plant and animal remains undergoing heat and pressure over millions of years.

Extraction and Processing

• Mining methods: Open-cast (surface) mining for shallow deposits; underground mining for deep deposits.
• Ore dressing (beneficiation): Concentration methods like gravity separation and froth flotation remove gangue from ore.
• Pyrometallurgy and hydrometallurgy: Roasting, smelting and electrolytic refining yield pure metals from concentrated ores.

Energy Resources: Classification

• Non-renewable (exhaustible): Coal, petroleum (crude oil), natural gas, nuclear fuels (uranium). These form slowly and can be depleted.
• Renewable (inexhaustible or replenishable): Solar, wind, hydro (water), biomass, geothermal, tidal.

Uses and Importance

Minerals provide raw materials for industries (iron for steel, bauxite for aluminium). Energy resources power homes, industries and transport: coal and gas for electricity, petrol and diesel for vehicles, solar panels and wind turbines for renewable electricity.

Environmental Impacts

• Mining: land disturbance, soil erosion, habitat loss, acid mine drainage and water pollution.
• Fossil fuels: air pollution, greenhouse gas (CO2) emissions causing climate change.
• Hydro and large projects: displacement of people, ecological changes; renewable systems have smaller but present impacts (land use, material use).

Conservation and Sustainable Use

• Reduce, reuse and recycle minerals (e.g., recycling metals and glass).
• Improve energy efficiency (LEDs, efficient motors), develop public transport and energy-saving appliances.
• Shift to renewables (solar rooftops, wind farms) and enforce responsible mining regulations and reclamation.

Key Concepts to Remember

• Ore: Rock containing minerals of economic value.
• Gangue: Waste material in an ore.
• Reserve life (useful for planning): how long a resource will last at current rates.

CBSE tip: Understand examples of minerals and fuels, differences between renewable and non-renewable, simple processing steps (concentration, smelting, refining), and environmental effects with conservation methods.

Overview: Problems associated with resource use arise when natural resources are consumed faster than they can be replenished or are used in ways that degrade the environment. These problems include depletion of non‑renewable resources, over‑exploitation of renewable resources, pollution, habitat loss and reduced biodiversity, soil degradation and water scarcity. They threaten human well‑being and the environment.

• Over‑exploitation and depletion: Excessive use of minerals, fossil fuels, forests and fisheries reduces available stocks. Non‑renewable resources (coal, petroleum, minerals) get exhausted; renewable resources (forests, fish) collapse when use exceeds regeneration.
• Pollution: Use of resources often generates pollutants — air (SOx, NOx, particulate matter), water (industrial effluents, sewage, agricultural runoff), and soil (pesticide residues, heavy metals). Pollution degrades ecosystems and human health.
• Deforestation and habitat loss: Clearing forests for agriculture, timber and urbanization destroys habitats, causes biodiversity loss, increases soil erosion and changes local climate and water cycles.
• Soil degradation and erosion: Unsustainable agriculture, deforestation and overgrazing reduce soil fertility and increase erosion. Topsoil loss reduces agricultural productivity.
• Groundwater depletion and water scarcity: Excessive groundwater extraction for irrigation and industry lowers water tables, causing wells to dry, land subsidence, and salinization in coastal areas.
• Waste generation and disposal problems: Growing consumption creates large volumes of solid and hazardous waste (including e‑waste and radioactive waste) that are difficult to manage safely.
• Climate change: Burning fossil fuels and deforestation increase greenhouse gas concentrations, leading to global warming and associated impacts (sea level rise, extreme weather, changing rainfall patterns).
• Social and economic consequences: Resource depletion and pollution cause health problems, reduce livelihoods (e.g., fishing collapse), create conflicts over resources and can force migration.

Causes: population growth, rising per‑capita consumption, wasteful technologies, inefficient resource use, market failures (externalities), and lack of regulations or enforcement.

Simple mitigation approaches: reduce (use less), reuse, recycle; adopt renewable energy; sustainable agriculture and fisheries (regulate harvests, quotas); afforestation and watershed management; rainwater harvesting and groundwater recharge; pollution control technologies and strict regulation; public awareness and changing consumption patterns.

What it means: Conservation and sustainable management aim to use natural resources so that they meet present needs without compromising availability for future generations. Conservation reduces waste and damage; sustainable management balances use and natural regeneration.

Why it is needed: Overuse, pollution and habitat destruction cause depletion of forests, water, soil and wildlife, leading to loss of biodiversity, reduced agricultural productivity and water scarcity.

Important principles:

• Use resources at or below their regeneration rate (sustainable yield).
• Follow the 3R approach: Reduce, Reuse, Recycle.
• Prevent pollution at source and restore degraded ecosystems.
• Integrate community participation, scientific management and policy support.

Methods and practices (by resource):

• Forests & wildlife: Afforestation and reforestation; protected areas (national parks, wildlife sanctuaries); wildlife corridors; community forest management; laws against poaching; sustainable harvesting of forest produce.
• Water: Rainwater harvesting; watershed management; check dams and percolation tanks to recharge groundwater; efficient irrigation (drip, sprinkler); fixing leaks and reducing wastage; recycling and treating wastewater.
• Soil: Contour ploughing, terracing, strip cropping, cover crops, mulching, preventing overgrazing and deforestation to reduce erosion and maintain fertility.
• Agriculture: Crop rotation, organic fertilisers, integrated pest management (IPM), reduced chemical use, agroforestry and sustainable yield planning.
• Energy & materials: Use of renewable energy (solar, wind, biomass), energy-efficient appliances, extended producer responsibility, recycling of metals, paper, plastics and circular economy measures.

Role of stakeholders: Individuals conserve water, segregate waste, plant trees; communities manage common lands and adopt local conservation practices; governments create policies, protected area networks, incentives (subsidies for drip irrigation, renewable energy) and enforcement.

Outcomes of sustainable management: Stable or recovering forest and wildlife populations, reliable water supply, less soil erosion, sustained agricultural output and healthier ecosystems that support human well‑being.