Water

Sources of water, water cycle, conservation, scarcity and water-borne diseases

---

Overview

Water is a foundational topic in Environmental Studies for UPTET Paper I, directly connecting to the child's everyday environment and broader concerns of health, geography and civic responsibility. Questions typically test factual recall (sources, diseases, conservation methods) alongside application-based scenarios where candidates must identify correct practices or explain natural phenomena like the water cycle.

Mastering this topic requires understanding three interconnected areas: (1) where water comes from and how it circulates in nature, (2) why water scarcity occurs and how communities can conserve water, and (3) how contaminated water causes diseases and what preventive measures exist. Expect 2–4 questions from this topic, often linked to pictorial diagrams of the water cycle or matching diseases with their causative agents.

---

Key Concepts

**Water covers about 71% of Earth's surface**, but only about 2.5% is freshwater; of this, less than 1% is easily accessible for human use (rivers, lakes, groundwater).

**Sources of water** are classified as surface water (rivers, lakes, ponds, streams) and groundwater (wells, tube-wells, springs). Rainwater is the ultimate source replenishing both.

**The water cycle (hydrological cycle)** is a continuous process with four main stages: evaporation, condensation, precipitation and collection. It ensures water is recycled naturally.

**Water scarcity** arises from unequal distribution, over-extraction of groundwater, pollution and increasing demand due to population growth and industrialisation.

**Rainwater harvesting** is the collection and storage of rainwater for later use—roof-top harvesting for homes and check-dams or percolation pits for community-level recharge.

**Water-borne diseases** spread through contaminated drinking water; major examples include cholera, typhoid, jaundice (Hepatitis A), dysentery and polio.

**Safe drinking water practices** include boiling, filtration, chlorination and using water purifiers to kill pathogens.

**3 Rs for water conservation**: Reduce usage, Reuse greywater, Recharge groundwater.

---

Formulas / Key Facts

| Fact | Detail | |------|--------| | Percentage of Earth covered by water | ~71% | | Freshwater percentage of total water | ~2.5% | | Accessible freshwater (rivers, lakes, groundwater) | <1% of total | | Main stages of water cycle | Evaporation → Condensation → Precipitation → Collection | | Safe chlorine dose for drinking water | 0.2–0.5 mg per litre (residual chlorine) | | Boiling time to purify water | At least 1–3 minutes at rolling boil | | Major water-borne diseases | Cholera (Vibrio cholerae), Typhoid (Salmonella typhi), Hepatitis A (virus), Dysentery (bacteria/amoeba), Polio (virus) | | India's annual rainfall | ~1,170 mm average; highly seasonal (monsoon-dependent) | | Groundwater contribution to India's irrigation | ~60% |

Practice this topic

Take a full mock →

Q1 · Water · EASY
Ramesh lives in a village where the only source of drinking water is a hand pump installed in the village square. During summer, the hand pump often runs dry. What is the MOST likely reason for this?
Q2 · Water · EASY
A teacher shows the class a diagram of the water cycle. She points to the process where water vapour in the air cools down and changes into tiny water droplets that form clouds. What is this process called?
Q3 · Water · MEDIUM
In a village in Uttar Pradesh, many children suffer from diarrhoea and stomach pain. A health worker finds that the village pond, which is used for drinking water, is contaminated with sewage. Which water-borne disease are the children MOST likely suffering from?
Q4 · Water · MEDIUM
A school in a city collects rainwater from its roof during the monsoon and stores it in an underground tank. Later, this water is used for watering plants and cleaning. This practice is an example of:
Q5 · Water · HARD
A diagram shows the water cycle with arrows indicating different processes. One arrow points from the ocean surface upward into the atmosphere, another arrow points from clouds to the ground, and a third arrow points from the ground back into the ocean through rivers. If the rate of evaporation from oceans decreases significantly due to a sudden drop in temperature, which of the following is the MOST likely long-term effect on the water cycle?

Ask Shishya to explain these →

Notes generated on 27 Jun 2026

Water

Water

Sources of water, water cycle, conservation, scarcity and water-borne diseases

Overview

Key Concepts

Formulas / Key Facts

Need more? Ask Shishya

Practice this topic

Worked Examples

Common Mistakes

Quick Reference