Environmental Science

Concept: Rainwater harvesting is the process of collecting, storing, and utilizing rainwater for various purposes such as irrigation, groundwater recharge, and domestic use. It is an important sustainable practice in urban planning and environmental management.
Step 1: Understand the process.
Rainwater harvesting involves:

• Collection of rainwater from rooftops or surfaces
• Storage in tanks or reservoirs
• Reuse for domestic or agricultural purposes

Step 2: Differentiate from related terms.

• Water recycling – reuse of treated wastewater
• Rainwater harvesting – direct collection of rainwater (correct)
• Groundwater recharge – replenishing aquifers
• Water conservation – general reduction in water usage

Step 3: Select the correct answer.
Thus, the correct term is rainwater harvesting.

Concept: The Earth's atmosphere is divided into several layers based on temperature and altitude. The ozone layer, which protects life by absorbing harmful ultraviolet (UV) radiation from the sun, is located in the stratosphere.
Step 1: Understand atmospheric layers.

• Troposphere – lowest layer, weather occurs here
• Stratosphere – contains ozone layer
• Mesosphere – meteors burn here
• Thermosphere – very high temperatures, includes ionosphere

Step 2: Identify the correct layer.
The ozone layer is concentrated in the stratosphere at an altitude of about 10–50 km above Earth’s surface.
Step 3: Importance of ozone layer.

• Absorbs harmful UV-B and UV-C radiation
• Protects living organisms
• Plays a role in environmental and climatic balance

Step 4: Conclusion.
Thus, the correct answer is the Stratosphere.