Science and Technology Class 9 Notes Chapter 9 Maharashtra Board

Environmental Management

Introduction to Weather and Climate

What is Weather? Weather is the condition of the atmosphere at a specific time and place, like temperature, rain, or wind on a given day.

What is Climate? Climate is the average weather pattern of a region over many years, staying mostly the same for a long time.

Difference Between Weather and Climate:

• Weather changes quickly and is specific to a place and time (e.g., “It’s raining now”).
• Climate is a long-term average (e.g., “This area has a hot climate”).

Factors Affecting Weather and Climate (Figure 9.1):

• Temperature (how hot or cold it is)
• Rainfall (amount of rain)
• Humidity (moisture in the air)
• Sunlight (brightness and heat from the sun)
• Clouds (cover that affects rain and temperature)
• Atmospheric pressure (weight of air)
• Visibility (how far you can see)
• Wind (direction and speed)

Importance of Climate

Role in Daily Life:

• Climate affects our food, clothes, and houses (e.g., warm clothes in cold regions like Kashmir).
• It influences jobs, especially farming in India.

Impact on the Environment:

• Helps form soil by weathering rocks.
• Affects water cycles, ocean currents, and marine salinity.
• Supports microbes that make organic matter in soil.

Human Progress:

• People plan their lives (e.g., farming seasons) based on climate.
• Scientists study climate to improve agriculture and predict changes.

Construction:

• Factors like wind and temperature are considered when building bridges, airports, or tall buildings.

Meteorology

What is Meteorology? Meteorology is the science of studying weather, climate, air components, and natural cycles like rain or storms.

Purpose:

• Helps predict weather for farmers, pilots, and fishermen.
• Studies thunder, lightning, and clouds to warn about dangers.

Key Organizations:

• World Meteorological Organization (WMO): Started on March 23, 1950, by the UN to manage weather data globally.
• India Meteorological Department (IMD): Founded in 1875 by the British, with its head office in New Delhi. It has regional offices in Guwahati, Mumbai, Kolkata, Chennai, and Nagpur. IMD uses satellites and radar to forecast weather and disasters like floods or tsunamis.

Monsoon Prediction Models:

• Historical Models: H.F. Blanford (1877) used Himalayan snowfall, and Sir Gilbert Walker (1930s) linked global climate to monsoons.
• Vasantrao Govarikar Model (1990-2002): Used 16 global parameters to predict monsoons.

Current Models:

• • Mathematical Model: Uses supercomputers like Param to analyze current weather data.
  • Statistical Model: Compares today’s data with past records (e.g., ocean temperature).
  • Holistic Model: Combines the best parts of all models for accurate predictions.

Challenges:

• Climate forecasting is hard because it involves many changing factors.
• It’s easier in stable areas but tough where changes are rapid.

Solid Waste Management

What is Solid Waste?

• Solid waste is unwanted material from daily activities, like food scraps or plastic.

Types of Solid Waste:

• Biodegradable Waste: Organic waste (e.g., vegetable peels, dung) that microbes break down. Also called “wet waste.” Can be turned into compost or biofuel.
• Non-Biodegradable Waste: Materials like plastic or metal that take a long time to degrade. Called “dry waste.”

Harmful Effects (Figure 9.4):

• Causes air, water, and soil pollution.
• Spreads diseases, produces toxic gases, and ruins natural beauty.
• Example: Mumbai floods in 2005 worsened due to poor waste management.

Need for Management:

• Prevents pollution and keeps surroundings clean.
• Produces energy (e.g., biogas) and jobs.
• Reduces strain on natural resources and improves health.

Management Methods (Figure 9.5):

• Composting: Turns wet waste into fertilizer.
• Vermicomposting: Uses earthworms to make compost.
• Incineration: Burns biomedical waste at high temperatures.
• Pyrolysis: Produces energy from waste.
• Safe Landfills: Stores waste safely to avoid pollution.

7 Principles of Waste Management:

1. Refuse: Avoid using non-degradable items like plastic.
2. Reduce: Use fewer resources and avoid waste.
3. Reuse: Use items again for other purposes.
4. Recycle: Make new products from waste (e.g., paper).
5. Rethink: Change habits to reduce waste impact.
6. Research: Find new ways to reuse waste.
7. Regulation: Follow rules and spread awareness.

Good Habits:

• Use cloth bags instead of plastic.
• Throw wrappers in dustbins.
• Reuse paper and avoid “use and throw” items.

Degradation Time:

• Organic waste breaks down in weeks, but plastic takes hundreds of years.

Disaster Management

What are Disasters?

• Natural (e.g., floods, lightning) and man-made (e.g., accidents, riots) events that damage life and property.

First Aid Principles (ABC):

• Airway: Keep the breathing passage open by tilting the head back.
• Breathing: Give mouth-to-mouth resuscitation if breathing stops.
• Circulation: Perform CPR (chest presses) to restart the heart.

Specific First Aid:

• Bleeding: Apply pressure with an antiseptic pad for 5 minutes.
• Fracture: Immobilize with a rod and avoid moving the back.
• Burns: Hold under cold water for 10 minutes.
• Sprains (RICE): Rest, ice, compress, and elevate the injured part.

Transporting Victims:

• Cradle Method: For children.
• Piggy Back: For unconscious patients.
• Human Crutch: For leg injuries.
• Stretcher: Use bamboo or blankets in emergencies.

Disaster Management Steps:

1. Prevent losses with planning.
2. Build tolerance to disasters.
3. Provide relief and reduce harm.
4. Prepare for emergencies.
5. Act quickly during disasters.
6. Assess damage and intensity.
7. Rescue and help victims.
8. Rebuild and rehabilitate.

Emergency Tools:

• Boats for floods, fire extinguishers for fires, and makeshift stretchers.