UNIT 2 - Environmental Studies
What is Water Pollution?
Water pollution occurs when harmful substances contaminate bodies of water, making them unsafe for human use or the environment. These substances can include chemicals, microorganisms, trash, or energy in the form of heat or radioactivity.
Water Resources of India
India accounts for about 2.45 per cent of world's surface area, 4 per cent of the world's water resources and about 16 per cent of world's population.
The Hydrologic Cycle / Water cycle
The hydrologic cycle involves the continuous circulation of water in the Earth-Atmosphere system. At its core, the water cycle is the motion of the water from the ground to the atmosphere and back again.
Stages of the Hydrological Cycle:
- Evaporation: Water changes from liquid to gas due to the sun's heat.
- Transpiration: Release of water vapor from plants and soil.
- Condensation: Water vapor cools and changes back into liquid droplets.
- Precipitation: Water droplets fall to Earth as rain, snow, etc.
- Runoff: Movement of water across the Earth's surface.
Methods of Water Conservation & Management
Water conservation refers to the prudent management and preservation of water resources to ensure their sustainable use for present and future generations. It involves reducing wastage, improving efficiency in water usage, and implementing strategies to replenish and protect water sources.
Rain water harvesting and their Legal aspects
Rainwater harvesting is the simple process or technology used to conserve rainwater by collecting, storing, conveying and purifying of rainwater that runs off from rooftops, parks, roads, open grounds, etc. for later use.
Rainwater Harvesting Components:
- Catchment: Used to collect and store the captured rainwater.
- Conveyance system: Transports water from catchment to recharge zone.
- Flush: Flushes out the first spell of rain.
- Filter: Filters collected rainwater and removes pollutants.
- Tanks and recharge structures: Stores filtered water ready to use.
River Action Plans in India
India has implemented several River Action Plans to address the pollution and degradation of its rivers. These initiatives aim to improve water quality, restore ecosystems, and ensure sustainable management of river resources.
Major River Action Plans:
- National River Conservation Plan (NRCP): Launched in 1995, focused on preventing river pollution and enhancing water quality.
- Ganga Action Plan (GAP): Initiated in 1985 to combat pollution in the Ganga River.
- Namami Gange Programme: Launched in 2014 as an integrated conservation mission to rejuvenate the Ganga River.
- Yamuna Action Plan (YAP): Initiated in 1993 to reduce pollution in the Yamuna River.
- State-Specific Initiatives: Various state-level river conservation projects.
Ground and surface water pollution
Surface Water Pollution
Causes include:
- Industrial Waste
- Agricultural Runoff
- Municipal Waste
- Oil Spills
- Erosion and Sedimentation
Groundwater Pollution
Causes include:
- Agricultural Chemicals
- Leaking Storage Tanks
- Landfills and Waste Sites
- Septic Systems
- Mining Activities
Wastewater Management
Wastewater management involves the collection, treatment, and safe disposal or reuse of water that has been contaminated by human, industrial, or agricultural activities.
Key Components:
- Collection: Wastewater from households, industries, and agriculture is collected through a network of pipes and sewers.
- Treatment: Involves physical, chemical, and biological processes to remove contaminants.
- Disposal: Treated wastewater is either released into nearby water bodies or applied to land.
- Reuse and Recycling: Treated wastewater can be reused for non-potable applications.
AIR POLLUTION
Air Pollution and Air Pollutants
Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere. Household combustion devices, motor vehicles, industrial facilities and forest fires are common sources of air pollution.
Major Air Pollutants:
- Particulate matter
- Carbon monoxide
- Ozone
- Nitrogen dioxide
- Sulfur dioxide
Effects on Human Health
- Respiratory Issues
- Cardiovascular Problems
- Nervous System Effects
- Chronic Diseases
- Acute Health Effects
Effects on Vegetation
- Growth Inhibition
- Crop Yield Reduction
- Leaf Damage
- Reduced Nutrient Absorption
- Forest Decline
Prevention and Control of Air Pollution
- Use renewable energy sources like solar and wind.
- Promote public transportation and electric vehicles.
- Implement stricter industrial emission standards.
- Encourage afforestation and sustainable land use practices.
- Adopt cleaner cooking and heating solutions in households.
Greenhouse Effect
The greenhouse effect is a natural process that warms the Earth's surface by trapping heat from the sun in the atmosphere. This process is essential for life on Earth, keeping the planet's average temperature around 33°C warmer than it would be without it.
How the Greenhouse Effect Works:
- Sunlight: The sun's energy reaches the Earth's atmosphere.
- Absorption: Energy is absorbed by the Earth's surface and atmosphere.
- Radiation: Earth radiates heat back into space.
- Trapping: Some radiation is trapped by greenhouse gases.
Natural Causes
- Water Vapor (H₂O)
- Volcanic Eruptions
- Natural Methane Emissions
- Forest Fires
Human Activities
- Burning Fossil Fuels
- Deforestation
- Industrial Processes
- Landfills and Waste Management
- Transportation
Effects of Greenhouse Effect:
- Global Warming: Gradual increase in Earth's average temperature.
- Depletion of Ozone Layer: Allows harmful UV rays to reach Earth.
- Smog and Air Pollution: Combination of smoke and fog.
- Acidification of Water Bodies: Greenhouse gases mix with rainwater forming acid rain.
