Rainwater Harvesting Techniques and Benefits

Rainwater Harvesting

• Aims to meet water demand across domestic, industrial, and agricultural sectors.
• Contributes to groundwater recharge, raising the water table.
• Helps minimize groundwater pollution and reduces soil erosion, flooding, and runoff.
• Techniques include dug wells, percolation pits, lagoons, check dams, and tanks.
• Two primary methods: surface runoff harvesting and rooftop rainwater harvesting.

Watershed Management

• A watershed drains water to a common location and varies in size from small streams to ocean areas.
• Ensures ecological balance and stabilizes income despite adverse weather conditions.
• Reduces risks of natural disasters such as droughts, floods, and landslides.
• Encourages efficient land use on marginal or waste lands for various activities including domestic water supply and hydropower generation.
• Aids in rural development to enhance regional economies.

Soil Formation and Characteristics

• Soil is a dynamic body composed of weathered rocks, water, oxygen, and organic materials, supporting plant life.
• Formation processes involve physical, chemical, and biological weathering.
• Influencing factors include parent material, living organisms, climate, topography, and time.

Deforestation: Causes and Effects

• Primary causes include logging, road construction, agriculture expansion, overgrazing, mining, hydropower projects, and forest fires.
• Key effects include wildlife endangerment, biodiversity loss, hydrological cycle disruption, soil erosion, and increased risks of natural disasters.
• Socio-economic consequences include displacement, cultural threats, and revenue loss.

Deforestation Control Methods

• Prohibiting mining in protected forests and enforcing sustainable logging practices.
• Implementing extensive reforestation and afforestation initiatives.
• Promoting community involvement in forest conservation programs and raising public awareness.

Energy Resources Overview

• Energy defined as the capacity to perform work; major resources include coal, hydroelectric, wind, solar, biomass, and nuclear.
• In India (2017):
  • Coal contributes 72%-76.5% of energy.
  • Hydroelectric plants account for 9.9%, and wind energy for 3.7%.

Renewable vs. Non-renewable Energy

• Non-renewable sources: coal, oil, natural gas, nuclear energy, face challenges like pollution and resource depletion.
• Renewable sources include solar, wind, hydro, tidal, geothermal, and biomass, offering cleaner alternatives.

Coal Types and Emissions

• Types of coal:
  • Anthracite (hard, high carbon content).
  • Bituminous (common for electricity generation).
  • Subbituminous (higher heating value than lignite).
  • Lignite (lowest grade, brown coal).
• Emissions from coal burning include sulfur dioxide, nitrogen oxides, particulates, carbon dioxide, and heavy metals, linking to health and environmental issues.

Petroleum and Natural Gas

• Petroleum is a mixture of hydrocarbons used in fuels like petrol, diesel, and plastics, refined through fractional distillation.
• Natural gas is the cleanest fossil fuel, primarily methane, with high calorific value, increasingly used as an alternative to traditional fuels.

Nuclear Energy

• Nuclear energy derives from fission and fusion processes, with uranium and thorium as primary elements.
• Advantages include high energy output from minimal fuel.
• Limitations involve potential accidents, waste management, and reactor lifespan.

Tidal Energy

• Captures energy from tidal movements for electricity generation, requiring significant tide height.
• Advantages: predictable, minimal pollutants, and manageable land use.
• Notable sites for tidal energy in India include the Gulf of Khambhat and the Gulf of Kutch.

Geothermal Energy

• Harnesses Earth's internal heat, using natural geysers or drilled wells.
• Advantages include low emissions and reliable production; disadvantages involve high investment and possible harmful emissions.
• India holds untapped potential for over 10,000 MW of geothermal energy.