Chapter 3 – Drainage System – Top 30 Q&A
- What is a drainage system?
A drainage system refers to the network formed by rivers, tributaries, and distributaries that drain water from an area into a sea, lake, or other body. - What are the two main types of drainage systems in India?
India has two main systems: the Himalayan Rivers (perennial) and the Peninsular Rivers (seasonal, rain-fed). - What is a river basin?
A river basin is the area drained by a river and its tributaries. Examples: Ganga basin, Brahmaputra basin, Godavari basin. - What is a catchment area?
It is the area from which a river collects its water. It includes rainfall, melting snow, and groundwater feeding the river system. - What is the difference between a tributary and a distributary?
A tributary joins a main river and adds water to it, while a distributary branches out from the main river and flows away, usually in delta areas. - What are the three major Himalayan river systems?
The Indus, Ganga, and Brahmaputra are the major Himalayan river systems, originating from snow-covered mountains and glaciers. - Where does the Indus River originate?
The Indus originates from Mansarovar Lake in Tibet and flows through Ladakh and Pakistan before emptying into the Arabian Sea. - What are the main tributaries of the Indus River?
Jhelum, Chenab, Ravi, Beas, and Sutlej are major tributaries, forming the famous Punjab river system. - Where does the Ganga River originate?
The Ganga originates from Gangotri Glacier in Uttarakhand as Bhagirathi. It meets Alaknanda at Devprayag to become the Ganga. - Name some tributaries of the Ganga River.
Yamuna, Son, Ghaghara, Gandak, and Kosi are important tributaries that increase the Ganga’s flow and flood potential. - Where does the Brahmaputra River originate?
It originates from Angsi Glacier near Mansarovar Lake in Tibet (called Tsangpo), enters India through Arunachal Pradesh as Dihang, and flows into Bangladesh. - How is the Brahmaputra different from the Ganga?
Brahmaputra carries more water and silt, causes more floods, and is a braided river in Assam. It also flows through drier regions in Tibet. - What are Peninsular rivers?
Older, seasonal rivers with fixed courses, flowing over hard rocks. They originate in central highlands and flow into the Bay of Bengal or Arabian Sea. - Name the major Peninsular rivers.
Godavari, Krishna, Narmada, Tapi, Mahanadi, and Kaveri are major rivers. Most flow eastwards, except Narmada and Tapi which flow westward. - Which is the longest Peninsular river?
The Godavari is the longest Peninsular river, flowing about 1,465 km and also called the “Dakshin Ganga.” - Where does the Godavari River originate?
It rises from Trimbakeshwar in Maharashtra and flows southeast through Telangana and Andhra Pradesh before entering the Bay of Bengal. - What are the west-flowing rivers of India?
Narmada, Tapi, Sabarmati, and Mahi are major rivers flowing west into the Arabian Sea, creating estuaries. - What is a delta?
A delta is a fan-shaped area of sediment deposited at the mouth of a river. Example: Sunderban Delta formed by Ganga and Brahmaputra. - What is an estuary?
An estuary is a coastal water body where river water mixes with sea water, formed by rivers like Narmada and Tapi which don’t form deltas. - Why do Peninsular rivers not form large deltas?
Due to short courses, hard rocks, and seasonal flow, many Peninsular rivers lack enough silt and water to form large deltas. - What is river rejuvenation?
When land is uplifted or sea level falls, a river gains energy and starts eroding its bed again. This process is called rejuvenation. - What are inland drainage rivers?
Rivers that do not reach the sea but disappear inland or end in lakes. Example: Luni River in Rajasthan. - What are river capture and piracy?
When a river or stream captures the flow of another due to headward erosion, it is called river capture or piracy. - How do Himalayan rivers differ from Peninsular rivers?
Himalayan rivers are perennial, have large basins, and form meanders. Peninsular rivers are seasonal, have smaller basins, and flow through rocky terrain. - What is the drainage pattern?
The pattern formed by streams and rivers over the Earth’s surface, influenced by slope, rock structure, and climate. - What are dendritic drainage patterns?
It resembles tree branches and occurs in regions with uniform rock structure. Example: Ganga and Godavari basins. - What is a trellis drainage pattern?
Formed when rivers follow a rectangular pattern due to folded or faulted rock structures. Common in the Narmada and Satpura region. - What is radial drainage?
Streams radiate outward from a central high point like a dome or volcanic cone. Found in Amarkantak Plateau and Western Ghats. - How do rivers help in economic development?
They provide water for irrigation, drinking, hydropower, transport, and support industries, agriculture, and settlements. - What is river pollution?
When harmful chemicals, waste, or sewage enter rivers, degrading water quality. Ganga and Yamuna are examples of polluted Indian rivers.