Science Class - 8th CH02: Natural Resources: Soil, Water and Wildlife

By Pratap Sanjay Sir

• Introduction
• Land
• Soil
• Water
• Natural Vegetation
• Wildlife

Introduction

• Natural Resources are anything that people can use which comes from nature such

Land

One of the most important natural resources, land covers about thirty percent of the total area of the earth’s surface, however, all parts are not habitable.

Land Use

The different purposes such as agriculture, forestry, mining, building houses, roads, and setting up industries for which land is used is known as Land Use.

The factors that determine the use of land are:

• Topography
• Soil
• Climate
• Minerals
• Availability of water

Causes of degradation of land resources:

• Deforestation
• Overgrazing
• Mining activities
• Climate change

Conservation of land resources:

• Afforestation
• Control on overgrazing
• Control of mining activities
• Proper management of wasteland

Soil

The thin layer of grainy substance covering the surface of the earth is called soil. Soil is made up of organic matter, minerals, and weathered rocks found on the earth.

Types of Soil in India

• Alluvial Soil
  • Formation: Formed by the deposition of sediments brought by rivers, especially in the Indo-Gangetic plain.
  • Characteristics: Rich in potash and phosphoric acid but deficient in nitrogen and organic matter. Highly fertile and suitable for agriculture.
  • Crops: Rice, wheat, sugarcane, and pulses.
  • Regions: Northern plains, coastal plains, and deltas.
• Black Soil (Regur Soil)
  • Formation: Derived from the weathering of volcanic basalt rocks.
  • Characteristics: High clay content, retains moisture, and becomes very sticky when wet. Rich in calcium carbonate, magnesium, potash, and lime but poor in nitrogen and organic matter.
  • Crops: Cotton (hence also called 'cotton soil'), soybean, sorghum, and groundnut.
  • Regions: Deccan Plateau (Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh, and Tamil Nadu).
• Red Soil
  • Formation: Formed from the weathering of ancient crystalline and metamorphic rocks.
  • Characteristics: Red color due to the presence of iron oxide. Poor in nitrogen, phosphorus, and humus, but rich in potash.
  • Crops: Millets, rice, groundnut, and tobacco.
  • Regions: Eastern and southern parts of the Deccan Plateau, Tamil Nadu, Karnataka, southern Maharashtra, and parts of Odisha.
• Laterite Soil
  • Formation: Result of intense leaching due to heavy rainfall and high temperature.
  • Characteristics: Rich in iron and aluminum but poor in organic matter, nitrogen, phosphate, and calcium. Acidic in nature and low fertility.
  • Crops: Tea, coffee, cashew nuts, and rubber.
  • Regions: Western Ghats, Eastern Ghats, parts of Karnataka, Kerala, Tamil Nadu, and the northeastern states.
• Arid and Desert Soil
  • Formation: Formed under arid and semi-arid conditions with high temperatures and low rainfall.
  • Characteristics: Sandy texture, low moisture content, and poor in organic matter. Contains high salt content and is alkaline in nature.
  • Crops: Millets, barley, and pulses with irrigation.
  • Regions: Rajasthan, parts of Gujarat, Punjab, and Haryana.
• Mountain Soil
  • Formation: Found in mountainous regions and formed by the deposition of organic matter.
  • Characteristics: Varies from region to region, often rich in humus but poor in potash, phosphorus, and lime.
  • Crops: Tea, coffee, spices, and various fruits.
  • Regions: Himalayan regions, Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh.

Factors of Soil Formation

• Major Factors:
  • Nature of the parent rock
  • Climate
• Other Factors:
  • Topography
  • Role of organic material
  • Time

Degradation of Soil

Soil erosion and depletion are the major threats to soil as a resource. Factors for soil degradation:

• Deforestation
• Overgrazing
• Overuse of chemical fertilizers or pesticides
• Rain wash
• Landslides
• Floods

Soil Conservation

• Afforestation: Planting more trees to prevent soil erosion.
• Terracing: Creating terraces on slopes to reduce runoff and soil erosion.
• Contour Plowing: Plowing along the contour lines to slow down water runoff and prevent soil erosion.
• Crop Rotation: Growing different crops in succession to maintain soil fertility.
• Cover Crops: Planting cover crops to protect the soil between main crops.
• Windbreaks: Planting trees or shrubs to reduce wind erosion.
• Mulching: Covering the soil with organic materials to retain moisture and prevent erosion.
• Gully Plugging: Filling gullies with vegetation or other materials to prevent further erosion.
• Conservation Tillage: Reducing the amount of tilling to maintain soil structure and reduce erosion.
• Controlled Grazing: Managing livestock grazing to prevent overgrazing and soil degradation.

Water

Importance of Water

• Essential for Life: All living beings need water to survive.
• Daily Uses: Drinking, cooking, cleaning, and bathing.
• Agriculture: Used for irrigation to grow crops.
• Industry: Used in factories for cooling, cleaning, and as a solvent.

Sources of Water

• Surface Water: Rivers, lakes, and ponds.
• Groundwater: Water stored underground in aquifers, accessed via wells and tube wells.
• Rainwater: Main source that replenishes both surface and groundwater.

Water Cycle

• Evaporation: Water from oceans, rivers, and lakes turns into vapor due to the sun's heat.
• Condensation: Water vapor cools down to form clouds.
• Precipitation: Clouds release water as rain, snow, or hail.
• Collection: Water collects in oceans, rivers, lakes, and the cycle repeats.

Factors Responsible for Shortages in Supply of Fresh Water

• Increasing population
• Rising demands for food and cash crops
• Increasing urbanization
• Rising standards of living

Water Conservation

• Rainwater Harvesting: Collecting and storing rainwater for future use.
• Fixing Leaks: Repairing dripping taps and pipes to save water.
• Using Buckets: Using buckets instead of hoses for washing cars and watering plants.
• Efficient Appliances: Using water-saving devices like low-flow showers and toilets.
• Awareness: Educating others about the importance of saving water.

Pollution of Water

Causes:

• Industrial waste: Factories release harmful chemicals into water bodies.
• Sewage: Untreated waste from homes and cities.
• Agricultural runoff: Pesticides and fertilizers washed into rivers and lakes.

Effects:

• Harm to aquatic life: Fish and other creatures are poisoned.
• Health problems: Contaminated water can cause diseases in humans.
• Ecosystem damage: Disruption of the natural balance.

How to Keep Water Clean

• Proper Disposal: Do not throw garbage into water bodies.
• Treatment Plants: Use sewage treatment plants to clean wastewater.
• Reducing Chemicals: Use fewer chemicals in farming and cleaning.
• Community Clean-ups: Participate in or organize clean-up drives for rivers and lakes.

Multipurpose Projects in India

• Bhakra Nangal Project
  • Location: Sutlej River, Himachal Pradesh.
  • Purpose: Irrigation, power, flood control.
  • Features: Bhakra & Nangal Dams, Gobind Sagar Reservoir.
  • Benefits: Water for Punjab, Haryana, Rajasthan; hydroelectricity.
• Damodar Valley Project
  • Location: Bihar, West Bengal.
  • Purpose: Flood control, irrigation, power, industry.
  • Features: Dams on Damodar River.
  • Benefits: Controls floods, supports agriculture, industry.
• Hirakud Dam
  • Location: Mahanadi River, Odisha.
  • Purpose: Flood control, irrigation, power.
  • Features: Longest dam, Hirakud Reservoir.
  • Benefits: Prevents flooding, supports agriculture, power.
• Nagarjuna Sagar Project
  • Location: Krishna River, Telangana, Andhra Pradesh.
  • Purpose: Irrigation, power, water supply.
  • Features: Nagarjuna Sagar Dam.
  • Benefits: Irrigation, hydroelectric power.
• Sardar Sarovar Project
  • Location: Narmada River, Gujarat, Madhya Pradesh, Maharashtra.
  • Purpose: Irrigation, drinking water, power.
  • Features: Sardar Sarovar Dam.
  • Benefits: Irrigation, drinking water, electricity.
• Tehri Dam Project
  • Location: Bhagirathi River, Uttarakhand.
  • Purpose: Power, irrigation, flood control.
  • Features: Tehri Dam.
  • Benefits: Electricity, flood control, irrigation.
• Indira Gandhi Canal Project
  • Location: Rajasthan.
  • Purpose: Irrigation, drinking water.
  • Features: Canals from Sutlej, Beas rivers.
  • Benefits: Supports agriculture, drinking water in arid regions.

Natural Vegetation

Refers to the plant life that grows in a particular region without any human interference. Determined by factors like climate, soil, altitude, and topography.

Types of Natural Vegetation

• Tropical Rainforests: Found near the Equator, characterized by dense and tall trees, receives heavy rainfall.
• Deciduous Forests: Found in regions with moderate rainfall, trees shed leaves in the dry season.
• Coniferous Forests: Also known as taiga, found in colder regions, dominated by cone-bearing trees like pine and spruce.
• Grasslands: Found in both tropical and temperate regions, dominated by grasses, suitable for grazing animals.
• Deserts: Found in arid regions, characterized by sparse vegetation adapted to survive in dry conditions.

Wildlife

Refers to the animal life found in a particular region. Adapted to the natural vegetation and climatic conditions of their habitat.

Types of Wildlife

• Mammals: Include a wide variety of animals like tigers, elephants, deer, and bears.
• Birds: Range from small songbirds to large birds of prey like eagles and vultures.
• Reptiles: Include snakes, lizards, crocodiles, and turtles, adapted to various habitats.
• Amphibians: Include frogs, toads, and salamanders, often found near water bodies.
• Fish: Found in freshwater rivers, lakes, and oceans, include a diverse range of species.
• Insects: Abundant and diverse group of animals, play crucial roles in pollination and ecosystem balance.

Conservation of Natural Vegetation and Wildlife

• Protected Areas: National parks, wildlife sanctuaries, and biosphere reserves established to conserve natural habitats and species.
• Afforestation and Reforestation: Planting trees and restoring degraded forests to enhance natural vegetation.
• Wildlife Protection Laws: Enactment and enforcement of laws to protect endangered species from poaching and habitat destruction.
• Sustainable Practices: Promoting sustainable agriculture, fishing, and forestry to reduce negative impacts on natural ecosystems.
• Public Awareness: Educating people about the importance of preserving natural habitats and wildlife for future generations.

© 2024 Pratap Sanjay Sir - All rights reserved.