Conservation of Water and Soil: 23 MCQs with answers

D · Careful use of resources

Conservation means using resources wisely so they are not wasted, polluted, or destroyed.

C · Salty ocean water

Most of Earth's water is salty ocean water or frozen in glaciers and ice caps.

D · It is limited

Only a small fraction of Earth's water is fresh and accessible, so it is limited.

D · Turning off the tap while brushing

Turning off the tap while brushing teeth saves water at home.

B · Watering roots drop by drop

Drip irrigation delivers water directly to plant roots, drop by drop, reducing waste.

B · Storing rainwater

Rainwater harvesting collects and stores rainwater instead of letting it run off.

B · A complex mixture of particles, water, air and organisms

Soil is a mixture of rock particles, humus, water, air, and microorganisms.

A · Hundreds to thousands of years

Fertile soil forms through the extremely slow weathering of rock, taking hundreds to thousands of years.

A · Removal of topsoil by wind or water

Soil erosion is the removal of the fertile top layer of soil by water or wind.

C · Roots no longer hold soil

Tree roots normally grip and hold soil; without them, rain and wind wash or blow topsoil away.

C · Removing plant cover

Overgrazing removes the protective plant cover, leaving soil exposed to wind and water.

A · It removes fertile soil

Erosion removes the nutrient-rich topsoil, leaving less fertile soil and poorer harvests.

A · True

Only 1 cm of fertile soil can take 100 to 1,000 years to form, so it must be protected.

C · Terrace farming

Terrace farming creates flat, step-like platforms that slow water flow and reduce its ability to carry soil away.

C · Rainwater harvesting

Rainwater harvesting collects and stores rainwater, reducing dependence on other water sources.

B · More people need more water while the supply stays roughly the same

More people need more water for daily needs and farming, but the total available freshwater stays roughly the same.

D · Drip irrigation

Drip irrigation delivers water drop by drop directly to the roots of plants, making it highly efficient and minimizing water loss through evaporation and runoff.

C · By creating flat, step-like platforms

Terrace farming breaks a long slope into short, flat steps, which slows down water flow, reducing its ability to carry soil away and thus minimizing erosion.

A · They enhance soil structure and reduce water runoff.

The combination of terrace farming, contour ploughing, and afforestation enhances soil structure and reduces water runoff by slowing down water flow and holding the soil in place with roots.

C · It reduces surface runoff and recharges groundwater supplies.

Rainwater harvesting reduces surface runoff and recharges groundwater supplies, making it a valuable practice for urban water management.

A · Implementing afforestation, windbreaks, and contour ploughing.

Implementing afforestation, windbreaks, and contour ploughing addresses both the loss of vegetation and the erosion of soil, effectively reversing damage.

A · Drip irrigation delivers water directly to plant roots, minimizing waste.

Drip irrigation delivers water directly to plant roots, minimizing waste and allowing for more efficient water usage, which can lead to improved crop yields.

C · They slow down both water flow and wind, protecting the soil.

The combination of terrace farming and windbreaks effectively slows down both water flow and wind, providing dual protection for the soil against erosion.