Chapter: 05—Water

Short Answer Questions

1. What is a polar ice cap?

A polar ice cap is a large, thick layer of ice that covers the land or sea at the Earth’s
polar regions. These ice caps are found at the Arctic (North Pole) and Antarctic
(South Pole) and play a crucial role in regulating the Earth’s climate.

2. Why are the polar ice caps shrinking?

The polar ice caps are shrinking due to global warming and climate change. Rising
global temperatures cause ice to melt faster than it can refreeze, leading to a
reduction in the volume and area of the ice caps. Human activities such as the
burning of fossil fuels and deforestation contribute to greenhouse gas emissions,
which accelerate this warming process.

3. What is the difference between surface water and groundwater?

Surface water is water found in bodies of water on the Earth’s surface, such as
lakes, rivers, and oceans. Groundwater, on the other hand, is water found beneath
the Earth’s surface in aquifers and underground reservoirs. Groundwater is often
accessed through wells and is a significant source of fresh water.

4. What makes the problem regarding water pollution more sensitive and severe
than air pollution?
Water pollution is more sensitive and severe than air pollution because it directly
affects ecosystems and human health by contaminating water supplies essential for
drinking, agriculture, and sanitation. Polluted water can spread diseases, harm
aquatic life, and impact food sources. Unlike air pollution, which can disperse and
break down, polluted water bodies can remain contaminated for long periods and
accumulate toxins, causing long-term ecological damage.

5. What is rainwater harvesting?

Rainwater harvesting is the collection and storage of rainwater from rooftops,
surfaces, or natural catchment areas to use as a source of water for various
purposes. This method helps manage water resources efficiently and reduces
dependence on other water sources.

6. Why should rainwater be harvested?

Rainwater should be harvested to conserve water, reduce water bills, replenish
groundwater levels, prevent flooding, and provide a sustainable water supply,
especially in areas with water scarcity. It also helps mitigate the effects of droughts
and can be used for irrigation, household use, and other non-potable needs.

7. What is artificial eutrophication?

Artificial eutrophication is the process by which water bodies become nutrient-rich
due to the excessive addition of nutrients like nitrogen and phosphorus, often from
agricultural runoff, sewage, and industrial waste. This leads to rapid growth of algae
and aquatic plants, which can deplete oxygen levels in the water and harm aquatic
life.

8. What do you understand by desalting of sea?

Desalting of sea, or desalination, is the process of removing salt and other
impurities from seawater to produce freshwater. This is done through methods like
distillation or reverse osmosis and is essential in areas with limited access to fresh
water.
 9. Name the sources from which direct contamination of water sources takes
place.
Direct contamination of water sources takes place from sources such as industrial
discharge, sewage treatment plants, agricultural runoff, mining operations, oil spills,
and improper waste disposal. These contaminants can include toxic chemicals,
heavy metals, pathogens, and nutrients that harm aquatic ecosystems and human
health.

10. What is thermal pollution?

Thermal pollution is the increase in water temperature due to human activities such
as industrial discharges, which can affect aquatic life. Higher water temperatures
reduce oxygen levels and can lead to the death of fish and other aquatic organisms,
altering the ecosystem balance.

Long Answer Questions

1. Why is freshwater considered precious to life?

Freshwater is considered precious because it is essential for the survival of all living
organisms. It is required for drinking, sanitation, agriculture, and industrial
processes. Unlike saltwater, freshwater is not abundant, making it a limited
resource. Freshwater also plays a critical role in maintaining ecosystems, supporting
biodiversity, and sustaining human life. With the increasing demands and pollution,
the availability of clean freshwater is under constant threat, emphasizing its
precious nature.

2. How can rainwater be harvested?

Rainwater can be harvested through various methods such as collecting rainwater
from rooftops using a network of gutters and pipes that channel the water into
storage tanks or underground reservoirs. This stored water can be filtered and used
for various purposes, including irrigation, flushing toilets, and even for potable uses
if properly treated. Other techniques include creating rain gardens or catchment
basins to allow rainwater to infiltrate into the soil and recharge groundwater levels.

3. What is water conservation? Give reasons to justify the need to conserve

water.
Water conservation is the practice of using water efficiently to reduce waste and
ensure its sustainable use for future generations. Water conservation is necessary
because water is a finite resource, and with rising populations, climate change, and
pollution, many regions face water scarcity. Conserving water helps maintain
healthy ecosystems, supports agricultural productivity, prevents water shortages,
and reduces the energy used in water treatment and distribution. Proper water
management also helps protect natural resources and maintain biodiversity.

4. What are the point sources of water pollution? Discuss.

Point sources of water pollution refer to identifiable, single sources of pollution that
discharge contaminants directly into a water body. Examples include sewage
treatment plants, industrial facilities, and wastewater discharge pipes. These sources
are regulated and monitored, making it easier to control and manage pollution.
Point source pollution can introduce pollutants such as heavy metals, pathogens,
and chemicals that can have severe impacts on water quality and aquatic life.

5. Give four measures to prevent ocean pollution.

Four measures to prevent ocean pollution include:

Reducing plastic waste: Implementing policies to limit plastic production and

encouraging recycling and use of biodegradable materials.

Proper waste disposal: Ensuring that industrial and domestic waste is treated and
disposed of responsibly, preventing it from reaching the oceans.
Regulating industrial discharge: Enforcing laws to limit the amount and type of
pollutants released by factories and refineries into the ocean.

Promoting sustainable fishing practices: Preventing overfishing and using nets that
do not entangle marine animals to help maintain the health of marine ecosystems.