Bihar Board Class 10 · Social Science · Matric exam 2027
Chapter 2: Flood and Drought — notes
The chapter’s 8 parts in the book’s order — the first idea of each and the points Medha Ma’am writes on the board — and the summary at the end. The full lesson and a check question for each part are in the app.
1. What is Flood and Drought?
Okay, so you often hear on the news that one part of the country has floods, and another part has drought.
- • Flood = excess rainfall in Monsoon -> rivers rise
- • Drought = scanty rainfall -> no water for fields/drinking
- • Both are natural disasters linked to rainfall
- • Indra = rain god in Indian epics (ancient belief)
2. Rivers Known for Floods and Bangladesh
Okay, so, monsoon rains don't come evenly every year.
- • Flood rivers: Kosi (Bihar), Damodar & Tista (WB), Brahmaputra (Assam), Mahanadi (Odisha), Krishna (AP), Narmada (Gujrat)
- • 2008: embankment break near Kusha changed Kosi's course
- • Bangladesh: yearly floods, yet fertile due to alluvial soil
3. Managing Floods: Dams and Embankments
Since the time of English rule, Dams and embankments have been constructed to check the destruction caused by floods, and this continued after independence too.
- • Dams/embankments built since English rule, continued after independence
- • Bhakhra Nangal Dam - Satluj river - Govind Sagar reservoir
- • Narmada Project - Narmada river - Sardar Sarovar reservoir
- • Nagarjun Sagar Project - Krishna river - Nagarjun Sagar
- • Highest Dam of world: on river Nile at Aswan
- • Embankments: not stable, dangerous if broken
4. Ecologically Suitable Flood Management and Early Warning
Okay, so embankments are not very stable.
- • Houses: cement-concrete, deep pillars, 250m from river bank
- • Remote sensing -> early warning before flood
- • Swimming training + swimming jackets in flood areas
- • After flood: D.D.T. + Bleaching powder, remove carcasses
- • Self help institutions: community help during epidemic
5. Drought: Its Problems and Prone Areas
Okay, so — what happens when rainfall falls short?
- • Drought causes 3 problems: food grain scarcity, drinking water scarcity, fodder scarcity
- • 77 drought prone districts: Rajasthan, Gujarat, Karnataka, MP, Chhattisgarh, Maharashtra, UP
- • 19th century drought years: 1877, 1899
- • 20th century drought years: 1918, 1966, 1987
- • 16% of country's area faces drought-like condition every year
6. Long Term Drought Management: Canals, Wells, Underground Water
Okay, so let's talk about managing drought.
- • Two types of drought planning: long term & short term
- • Long term: canals, ponds, wells, paine, Aahars
- • Punjab & Haryana: canal network solved drought permanently
- • Bihar canals: Kosi, Gandak, Chandan Kiul-Barua command areas
- • Underground water = rain water percolated below surface
- • Over-exploitation by tube wells -> lowers water table, ecological imbalance
7. Rainwater Harvesting and Watershed Management
Okay, so let's talk about water today.
- • Fresh water shortage = serious world problem
- • Rainwater harvesting + watershed management started
- • Watershed management: raise underground water, reduce soil erosion, increase forest cover
- • Rajasthan: up to 50 hectare watershed areas identified
- • Roof rainwater -> pipe -> tank -> drinking water, irrigation
- • Boon during drought, even with less rainfall
8. Drip and Sprinkle Irrigation
Okay, so let's talk about drip and sprinkle irrigation.
- • Drip & sprinkle irrigation: saves water in drought areas
- • Suitable crops: flowers, vegetables, oilseeds
- • Used where rainfall is less than 75 cm (rural development programme)
- • Also used where rainfall is more than 75 cm, during drought
- • Karnataka, MP, Rajasthan: part of rural development programme
- • Rajasthan: special financial help to farmers
Summary
Okay, so let's quickly look back at everything we covered. We started with floods and droughts — both natural disasters, both tied directly to rainfall. Too much rain gives floods, too little gives drought. Remember the rivers famous for floods? We also talked about the 2008 Kosi embankment break. And we saw how Bangladesh still stays fertile and heavily populated, even with floods every year. Then we moved to how floods are managed — dams and embankments like Bhakhra Nangal and the Narmada Project. We also spoke about safer measures, ones that work with nature — building houses the right way, and early warning systems. After that, we turned to drought. We saw its three major problems, the 77 drought prone districts, and some of the worst drought years in history. Finally, we looked at managing drought — both long term and short term. Canals, wells, underground water, rainwater harvesting, watershed management, and drip and sprinkle irrigation for growing the right crops. That's a lot we've covered today. Can you tell me — which one topic stayed with you the most?
AskMedha · Medha Ma’am — Bihar Board Class 10 Social Science, Chapter 2. Written from the textbook, checked twice.
Questions parents and students ask
- How do I get the "Flood and Drought" notes as a PDF?
- Press "Save as PDF" — the phone’s print sheet opens; choose "Save as PDF" there. The PDF holds the notes only.
- Where are these notes written from?
- From the chapter’s own textbook text, part by part, in the book’s own terms; a second, independent model then checked every part against the book. The full lesson, a check question for each part and the practice are in the AskMedha app.
The same preparation, with Medha Ma’am — on your phone
Every question of every chapter with its model answer, practice questions in the board’s own shapes, 60 minutes of class a day, written answers marked, a test every Sunday and a WhatsApp report to parents.
Medha Ma’am is an AI teacher, not a live tutor. Every answer is checked twice; a person takes responsibility.