
PRELIMS
Dehradun Flash Floods
Why in News: 13 killed, 16 missing after torrential rain and flash floods hit Dehradun; IMD red alert issued.

Torrential Rain
- Very heavy rainfall (>100 mm in few hours).
- Causes: monsoon bursts, cloudbursts, orographic effect, cyclonic systems.
- Impacts: flash floods, landslides, erosion, urban flooding.
- IMD issues Red/Orange alerts for such events.
Flash Floods
- Sudden flooding within <6 hrs of intense rain/dam breach/GLOF.
- Causes: cloudbursts, glacial lake outburst, dam release, poor urban drainage.
- Characteristics: high velocity, destructive force, minimal warning time.
- Impacts: severe damage to lives, infrastructure, crops, communication lines.
- Vulnerable regions: Himalayan states (Uttarakhand, HP, J&K, Sikkim, Arunachal).
- Preparedness: IMD Flash Flood Guidance (2020), NDMA guidelines, early warning, afforestation.
Portable ion chromatograph
Why in News: Scientists at the University of Tasmania, Australia, demonstrated a portable ion chromatograph (Aquamonitrix) for students to analyse nitrate and nitrite ions in soil pore water directly in the field.

About Ion Chromatography
- Analytical technique to separate and measure ions by passing a sample through a column.
- Conventional devices: long columns, high-pressure pumps, sophisticated, cost >$100,000.
- Portable version: low-pressure, short column, environmentally friendly (NaCl as carrier solution).
Aquamonitrix (Portable Device)
- Low-cost (~$10,000), portable, battery-run.
- Detects nitrate & nitrite ions using UV absorbance detector (both absorb in low UV).
- Produces simple chromatogram → less interference from other ions.
- Students collected soil pore water using portable vacuum pump → filtered & injected sample on-site.
- Benefits: accuracy, low cost, rapid results, real-world practice outside labs.
Environmental & Educational Significance
- Detects pollutants: nitrate, nitrite, ammonia (linked to nitrogen cycle monitoring in soils & water treatment).
- Future instruments: arsenic detection → important for India, Bangladesh (groundwater contamination).
- Enhances “hands-on” learning in analytical chemistry (per 2023 ACS guidelines).
- Bridges classroom theory with real-world field applications.
BIND Scheme
Why in News: Union MoS for Information & Broadcasting announced establishment of Akashvani Kendra in Ujjain under the BIND Scheme. Doordarshan to celebrate its 66th foundation day on Sept 15, 2025 with cultural event “Shabdanjali: DD@66”.

Broadcasting Infrastructure and Network Development (BIND) Scheme
- Type: Central Sector Scheme.
- Launched: 2023.
- Nodal Ministry: Ministry of Information & Broadcasting.
- Aim: Modernize and strengthen Prasar Bharati infrastructure (AIR & Doordarshan).
Key Objectives
- Digitalisation of broadcasting equipment.
- Replacement of old systems, modernization of studios & transmitters.
- Introduction of new broadcasting technologies.
- Expand reach of AIR FM transmitters.
- Increase capacity of DD Direct-To-Home (DTH) platform.
- Free distribution of DD Free Dish Set Top Boxes in remote, tribal, border & LWE-affected areas.
Coverage Target
AIR FM transmitters coverage:
- Geographical area → ↑ from 59% to 66%.
- Population coverage → ↑ from 68% to 80%.
Andhra Pradesh UNESCO bid
Why in News: Andhra Pradesh’s Erra Matti Dibbalu (Red Sand Dunes) & Tirumala Hills (with Eparchaean Unconformity) have been added to UNESCO’s Tentative List of World Heritage Sites (Aug 2025 update).
Erra Matti Dibbalu (Red Sand Dunes)

- Location: Near Visakhapatnam, Andhra Pradesh.
- Declared: National Geo-heritage Monument.
- Spread: ~1,500 acres along the coast.
- Formation: Sand, silt, clay → red colour from natural oxidation.
Geological significance:
- Shows dendritic drainage patterns, sediment layers → record of sea level & climate changes (Late Quaternary).
- First studied (1886) by British geologist William King.
- Only 3 such coastal geomorphological formations globally.
- Threats: Tourism, filming → risk to fragile dunes.
Tirumala Hills & Eparchaean Unconformity
- Location: Tirupati district, Andhra Pradesh.
- Geological significance:
- Eparchaean Unconformity → boundary between 2.5-billion-year-old Archaean rocks and younger Proterozoic rocks.
- Natural Arch (Silathoranam): Rare rock formation, ~1.5 billion years old, near Tirumala temple.
- Ecological importance:
- Part of Seshachalam Biosphere Reserve & Venkateswara National Park.
- Rich biodiversity: endangered Red Sanders, Jerdon’s Courser.
- Dense forests, seasonal waterfalls, unique flora & fauna.
- Cultural value: Associated with Tirumala temple.
UNESCO Relevance
- Erra Matti Dibbalu: Fits under tectonic & coastal systems themes.
- Tirumala Hills: Fits under Earth history & evolution of life themes.
- Tentative List: First mandatory step before full World Heritage Site nomination.
Gyan Bharatam Portal & Mission

Why in News: PM Narendra Modi launched the Gyan Bharatam Portal (Sept 2025) at the International Conference on Gyan Bharatam in New Delhi.
Aim: Digitise & preserve India’s vast manuscript heritage (~1 crore manuscripts in ~80 languages).
Gyan Bharatam Mission
- Announced in Budget 2025.
- Focus: Cataloguing & digitising manuscripts in and abroad.
- Central platform for public access.
- Promotes collaboration with global institutions for preservation & research.
India’s Manuscript Heritage
- World’s largest collection of manuscripts.
- Subjects: Philosophy, science, medicine, art, astronomy, architecture.
- Examples:
- Gilgit texts (Kashmir history).
- Kautilya’s Arthashastra.
- Buddhist texts (Sarnath).
- Charaka & Sushruta Samhitas (Ayurveda).
- Bakhshali Manuscript (earliest use of zero).
Knowledge Traditions
- Four pillars: Preservation, Innovation, Addition, Adaptation.
- Oral traditions (Vedas), innovations (Ayurveda, metallurgy), additions (regional Ramayanas), debates (Shastrarth).
Institutions & International Cooperation
- Key role: Asiatic Society (Kolkata), Saraswati Mahal Library, Dharohar Udaipur.
- 10+ lakh manuscripts digitised so far.
- MoUs with Thailand & Vietnam universities (training in Pali, Lanna, Cham).
- Manuscripts digitised & repatriated from Mongolia.
- Indian manuscripts preserved in Japan’s Horyu-ji Monastery.
Technology & Youth Engagement
- Use of AI & digital tools for preservation.
- Supports global cultural & creative industries ($2.5 trillion value).
- 70% participants are youth, universities encouraged to contribute.
Cultural Diplomacy
- Reinforces India as a custodian of heritage.
- Complements repatriation of hundreds of ancient idols.
- Led by Ministry of Culture; focus on legal frameworks, decipherment, diplomacy.