Water Chapter Notes | Eureka Plus Class 6: Book Solutions, Notes & Worksheets PDF Download

Introduction

• The Earth is often referred to as the "Blue Planet" because three-fourths of its surface is covered with water.
• Only one-fourth of the Earth's surface is land.

Distribution of Water

• 97.5% of all water is in the oceans, making it salty and unsuitable for human use.
• Only 2.5% of freshwater is available on Earth.
• 1.5% of freshwater is frozen in polar regions.
• Human activities have polluted a small percentage of the remaining 1% freshwater.

Uses of Water

In Homes

• Water is essential for various daily activities such as cooking, drinking, bathing, and washing clothes.
• Potable water, safe for consumption, is mainly obtained from rivers, dams, lakes, wells, and groundwater.

For Agriculture

• Farmers use water for irrigation, but using polluted water can harm crops and health.

In Industries

• Water is crucial for manufacturing processes in industries.
• Releasing untreated wastewater is a punishable act.

To Produce Electricity

• Large dams store river water, preventing it from flowing into oceans.
• Hydroelectric power plants use the force of flowing water to generate electricity.

States of Water

• Water exists in three states: solid (ice and snow), liquid (rivers, lakes), and gaseous (water vapour in the air).
• Evaporation turns water into water vapour, and condensation changes water vapour back into water.

Water Cycle

• Continuous process involving evaporation, condensation, cloud formation, and precipitation is called the water cycle.
• Clouds form when water vapour in warm air condenses at higher altitudes, leading to rain or snowfall.

Where Does Rainwater Go?

• Rainwater flows into ponds, lakes, rivers, and some evaporates or percolates into the ground.
• Groundwater reservoirs and wells receive fresh water during the rainy season.

Sources of Freshwater

• Rain, wells, lakes, and rivers are the primary sources of freshwater.
• Wells and lakes are replenished by rain, emphasizing the importance of seasonal rainfall.

Groundwater

• Rainwater seeps into the soil, forming groundwater.
• The water table represents the level of water beneath the ground.
• Groundwater is a crucial source of clean drinking water.

Droughts

• Inadequate rainfall over successive years leads to drought.
• Droughts adversely affect agriculture, causing water shortages and impacting vegetation and animal life.

Floods

• Continuous heavy rainfall causes excess water to accumulate, resulting in floods.
• Floods damage crops, infrastructure, and can lead to waterborne diseases.

Conservation of Water

• Increasing human population leads to freshwater scarcity.
• Water conservation is essential to prevent depletion of freshwater sources.

Rainwater Harvesting

• Collecting and storing rainwater for future use.
• Increases availability of potable water, raises the water table, prevents soil erosion, and benefits plant growth.

Check Dams

• Structures built to impede the flow of rainwater.
• Collects rainwater, allows seepage into the ground, and increases water availability.

In conclusion, understanding the distribution, uses, and conservation of water is crucial for ensuring a sustainable and sufficient water supply for all.