➤ Only about 2.5% of the total water available on Earth is freshwater, suitable for human consumption, agriculture, and industry.
➤ The rest (97.5%) is saline water found in oceans and seas.
★ Of the 2.5% freshwater, the majority is locked in glaciers and ice caps, with only a small fraction available in rivers and lakes.

➤ The Jhelum River originates from Verinag in Jammu & Kashmir and flows into Wular Lake, then passes through Baramulla.
➤ It is a major tributary of the Indus River system.
★ Wular Lake, one of the largest freshwater lakes in India, is fed mainly by the Jhelum River.

➤ Montane forests occur in high-altitude areas and are home to cold-adapted species like the yak, snow leopard, and Himalayan bear.
➤ These forests are found in regions like the Himalayas.
★ Yak is a key animal adapted to the cold montane climate, especially in regions like Ladakh and Sikkim.

➤ The Himalayas were formed due to the collision of the Indian Plate with the Eurasian Plate, uplifting the Tethys geosyncline.
➤ This ancient sea existed between the two plates before the uplift.
★ The Tethys geosyncline is key in explaining the origin of the Himalayas and their marine fossil records.

➤ Tropical evergreen forests are found in areas with heavy rainfall and dense vegetation, like the Western Ghats.
➤ These forests remain green throughout the year due to consistent moisture.
★ Western Ghats is a biodiversity hotspot, rich in flora and fauna found in evergreen forests.

➤ Duns are flat-bottomed valleys found between the Lesser Himalayas and Siwalik ranges, formed by river deposits.
➤ Examples include Dehradun and Patlidun.
★ Duns are fertile and agriculturally productive, found mainly in Uttarakhand and Himachal Pradesh.

➤ ‘Aus’, ‘Aman’, and ‘Boro’ refer to three rice-growing seasons in West Bengal and eastern India.
➤ Aus (pre-monsoon), Aman (monsoon), and Boro (post-monsoon) are timed based on rainfall patterns.
★ These classifications help optimize rice cultivation across seasons in states like West Bengal and Assam.

➤ National Waterway-1 (Allahabad-Haldia) is the longest inland waterway in India, spanning over 1,620 km.
➤ It runs along the Ganga-Bhagirathi-Hooghly river system.
★ NW-1 connects major trade hubs and supports cheaper cargo transport.

➤ The Salal Hydroelectric Power Station is located on the Chenab River in Jammu and Kashmir.
➤ It is one of the earliest hydropower projects in the region, operational since the 1980s.
★ This project contributes significantly to the power supply of northern India.

➤ Lakshadweep Islands are coral atolls and reefs, not of volcanic origin.
➤ Andaman and Nicobar islands are believed to be elevated parts of submarine mountains, of volcanic and tectonic origin.
★ Andaman-Nicobar = volcanic origin; Lakshadweep = coral origin.

➤ Shyok River is a major tributary of the Indus, flowing through Ladakh and Gilgit-Baltistan.
➤ The others are tributaries of the Ganga-Brahmaputra system.
★ Shyok joins Indus near Skardu in Pakistan-administered territory.

➤ Chambal River flows northward and joins the Yamuna River in Uttar Pradesh.
➤ Chambal is known for its deep ravines and wildlife sanctuaries.
★ Chambal → Yamuna → Ganga.

➤ Malabar Coast (Kerala) and Konkan Coast (Maharashtra-Goa) lie along the Arabian Sea.
➤ Northern Circars and Coromandel lie along the Bay of Bengal on the east coast.
★ Arabian Sea coasts = Malabar + Konkan.

➤ Nile River, the longest river in the world, flows northward from East Africa to the Mediterranean Sea.
➤ It originates from Lake Victoria, near the equator.
★ Nile flows from south to north, rare among major rivers.

➤ Lichens are pioneer species that can grow on bare rocks, producing acids that break them into soil.
➤ They initiate primary succession in barren areas.
★ Lichens are symbiotic organisms (algae + fungi) and crucial for ecosystem formation.

➤ India has 13 major ports: 12 government-owned and 1 (Ennore/Kamarajar Port) as a corporation.
➤ These ports handle the majority of India’s cargo traffic.
★ Total = 13 major ports + 200+ minor/intermediate ports.

➤ Statement a is incorrect: Narmada originates from the Amarkantak Plateau, not Malwa.
➤ Godavari (Nashik), Mahanadi (Chhattisgarh), Krishna (Mahabaleshwar) origins are correct.
★ Narmada → Amarkantak; rest as stated.

➤ Cattle dung (used in biogas or burning) is a conventional source of energy used in rural India for centuries.
➤ Others are non-conventional/modern or renewable energy sources.
★ Conventional = age-old, widely used sources like wood, coal, dung.

➤ Statement a is correct: Western Ghats rise in height from Maharashtra towards Kerala.
➤ Statement b is incorrect: Mahendragiri is in Odisha (Eastern Ghats); Anamudi is the highest in the Western Ghats.
➤ Statement c is correct: Western Ghats are higher than Eastern Ghats.
★ Anamudi (2695 m) = highest peak in Western Ghats.

➤ PPM (Parts Per Million) is the standard unit to measure concentration of contaminants in soil, sediment, water, and air.
➤ DPMO is used in quality control; TDS measures total dissolved solids in water.
★ PPM = Common unit for pollutant measurement in environmental studies.

➤ Seshachalam Biosphere Reserve (in Andhra Pradesh) is rich in biodiversity, known for Red Sanders and Slender Loris.
➤ Cold Desert is in Himachal; Pachmarhi is in MP; Agasthyamalai is in Kerala-TN.
★ Seshachalam = Only biosphere reserve in Andhra Pradesh.

➤ Biogeochemical cycles involve movement of elements like carbon, nitrogen (gaseous) and phosphorus (sedimentary) through biosphere, lithosphere, atmosphere, and hydrosphere.
➤ Biochemical = within organisms; others are not valid terms.
★ Biogeochemical = life (bio) + earth (geo) + chemicals.

➤ Eastern Ghats are lower than Western Ghats, with an average elevation of around 600 metres.
➤ They are discontinuous and eroded compared to the Western Ghats.
★ Eastern Ghats = older, lower, broken hills running parallel to east coast.

➤ Eutrophication is the nutrient enrichment of water bodies (especially lakes) due to runoff of fertilizers, sewage, etc., causing excessive algal growth.
➤ It leads to oxygen depletion and aquatic life death.
★ Eutrophication = nutrient overload → algae bloom → oxygen drop.

➤ The hydrological cycle describes the continuous movement of water on, above, and below the surface of the Earth.
➤ It includes processes like evaporation, condensation, precipitation, infiltration, and runoff.
★ This cycle maintains Earth’s water balance and supports life and ecosystems.