Acid precipitation (Acid Rainfall): is now regarded as a serious problem in some European and Asian countries, the main cause and source of which is emissions of sulphur oxides and nitrogen oxides from thermal power plants and burn­ing of fossil fuels. These oxides dissolve in atmospheric water vapour and fall back on earth as acid rainfall. Acid rainfall can cause destruction of crops and trees; destruction of fish; and damage to buildings.
Agronomy: Soil manage­ment and production of field crops is known as Agronomy.
Aleurone layer: is that part of the grain in cereals where much of the protein lies.
Alluvial soil: is the richest and most fertile soil of India spread over large areas in north­ern plains of India.
Arakan Yoma: is the exten­sion of the Himalayas located in Myanmar.
Asthamudi Lake: is locat­ed in Kerala State.
Bailadila: in Bastar district of Madhya Pradesh, is known for its wealth of Manganese.
Barhara (Tribes): The Barhara tribes mentioned in the Mahabharata who had settled in the north-western regions of India, are associated with—(1) Ambashthas (a mixed Mongolian Aryan race); (2) Gandharas (Afghans); (3) Pavas.
Bhabhar region: in south of the Shivaliks, is an example of Piedmont situation i.e., belong­ing to or related to the foot of a mountain.
Bushmen (Tribes): They live in the Kalahari desert. They are probably the descendants of the earliest inhabitants of Africa. They rank among the most uncivilized and backward peo­ples in the world. Their food consists almost entirely of meat, often raw or decomposed, and in times of scarcity they will eat insects, snakes etc.
Cardamom: Karnataka is the largest producer of car­damom. India is the largest exporter of cardamom in the world.
Chinook: Warm, dry wind experienced along the eastern side of the Rocky Mountains in Canada and the U.S.A.
Climograph: is a graphical representation of the differentia­tion between various types of climate. It reveals the type of cli­mate at a glance—a climograph showing wet bulb temperatures and relative humidities  which are  high, for instance, depicts a constantly hot damp climate.
Coastline of India, Length of: The length of India’s coast­line is 7,516 km and its territory includes 1,256 islands. Tamil Nadu has the longest coastline in India.
Cosmic year: One cosmic year is equal to the time taken by the sun to complete one orbit around the galactic centre.
Cotopaxi: is the highest volcano in the world. It is situat­ed in Ecuador.
Date Line, International: International Date Line is an internationally agreed line drawn parallel to the 180° meridian. It divides the Pacific Ocean into two equal parts. A crossing of the International Date Line entails repeating one day when travelling westwards.
Detroit of India: Pithampur in Madhya Pradesh, where a large number of auto­mobile industries have been set up, is called the “Detroit of India”.
Doldrums Belt: is a zone of the tropics where the calm last­ing for some weeks prevails, broken at times by erratic squalls and baffling winds. It is an area of low pressure. The wind system in the Equatorial areas is known as doldrums.
Dust Devil: is a dusty whirlwind normally a few feet in diameter and about 100 feet tall, sometimes also wider and higher.
Earth mass: The mass of the earth is about 81 times that of the moon.
Earth’s core: is mainly composed of iron and nickel. Lithosphere is the innermost layer of the earth.
El Nino: is the weather phenomenon brewing in the tropical Pacific Ocean. It is the largest climate event of the 20th century setting off more global disasters than ever before. El Nino is warming of the waters off Equatorial South America which causes climate abnor­malities around the world. The impact can be flooding drought in California, Brazil, Africa and Australia, severe storms in the Central Pacific and a decline in hurricanes hitting the south-eastern United States.
Exfoliation: This type of weathering is common both in the cold as well as in the hot cli­mate regions.
Fertilizer plant, First: The first fertilizer plant in India was set up at Sindri (Bihar).
Garo (Tribes): Garos are the tribe of Garo Hills in Meghalaya.
Glacial lake—example in India: Dal Lake in Srinagar.
Great Circle: A circle on the earth’s surface whose plane passes through its centre, and bisects it into two hemispheres. Two opposing meridians together form a Great Circle. The shortest distance between any two points on the earth’s surface is the arc of the Great Circle which passes through them. 0° latitude forms a Great Circle. (The latitude or longi­tude 75°W should be combined with 75°E to obtain the Great Circle).
Horse Latitudes: Sub-trop­ical belts of high atmospheric pressure over the oceans situat­ed in both hemispheres. These are called Belts of Calm between regions of the Trade Winds and Westerlies of higher latitudes.
Hydroponics: means culti­vation of the plants without use of soil.
Hyetology: is the study of rainfall.
Indira Point: in Andaman and Nicobar Islands is the southern-most tip of India.
Irrigated area, Indian State having largest: The Indian State with the largest irrigated area is Uttar Pradesh.
Jhum: It is a slash and burn method of shifting cultivation (called jhum) practised on rain­fall-bed slopes of forest hills and dales in Arunachal Pradesh.
Kandla: is a sea port situat­ed at the head of the Gulf of Kuch in Gujarat State. It was the first port to be developed after independence. It has a free trade zone.
Khonds (Tribes): were primitive tribes living in Orissa.
Kikuyu (Tribes) : are a race of Bantu negroes who live to the north of Mount Kenya. These people combine agriculture with pastoralism.
Kirghiz (Tribes): of Central Asia are an example of people adapted to a grassland environment. The Kirghiz are pastoral nomads who move from pasture to pasture with the flocks and herds of horses, camels, oxen, sheep and goats. Meat forms only a small portion of their food. The Kirghiz are fearless horsemen, and even their children are expert riders
Lambadies (Tribes): are concentrated in Karnataka.
Lapse Rate: is the rate of change in temperature with increase of altitude.
Laterite soils: Laterite soils are formed by the weathering of laterite rocks. These can be dis­tinguished from other soils by their acidity.  Laterite soils are generally poor on the higher levels and cannot retain mois­ture. In the plains, however, they consist of heavy loams and clay and can retain moisture. Laterite soils occur in Madhya Pradesh, Assam and along the eastern and western Ghats. Tea plantation require acidity which is there in the laterite soil. It is, therefore, common in these areas.
Loams (loamy soil): Amix­ture of sand, clay and silt is known as loamy soil. Loams are formed where the soils have equal proportion of sand, silt and clay.
Local winds and their areas: Khamsin—Egypt; Zonda—Argentina; Santa Ana—California; Simoon—Iran.
Lushais (Tribes): are tribes of Mizoram.
Mansarover Lake: is in Tibet. Near it, the rivers having their source are the Brahamputra, the Sutlej and the Indus.
Maoris (Tribes): are the original inhabitants of New Zealand.
Masai (Tribes): of the East African plateau are the example of pastoral peoples. They are a tall, strong, warlike race, partly negroid in type. They treat their cattle with great respect and affection and do not kill them for food or for sale as meat.
Monsoon in India: is relat­ed to differential heating and cooling of the huge landmass of Asia and the Indian Ocean and the origin of cyclones in the Bay of Bengal. The term Monsoon was introduced by the Arabs.
Munda (Tribes): are most­ly located in Madhya Pradesh.
Negritos (Tribes): are the ancient tribes of Andamans.
Nutrification: is the process of conversion by action of bacteria, of nitrates in the soil.
Onges: are tribes of Andaman and Nicobar Islands.
Oraon (Tribes): are aborig­inal people of the Chhota Nagpur region in the State of Bihar. They call themselves Kurukh  and speak a Dravidian language.
Pangong Tso: is one of the world’s highest and brackish lakes in Jammu & Kashmir.
Pressure zones on earth: are created due to differential heating of the earth’s surface by the sun.
Proxima Centauri: is a star nearest to the earth.
Rare earths (Or Lignite and Monazite) : are found on the beaches of Kerala and Tamil Nadu. Monazite is an ore of tho­rium.
Roaring Forties: are west­erly winds.
Saddle peak: is the highest peak of Andaman and Nicobar islands, located in Great Nicobar.
Savannas: are found between latitudes 5° and 20° North and South of Equator. These are tropical grasslands bordering the equatorial forests in each hemisphere. The Llanos and Pampas of South America are chief examples of Savannas but extensive Savannas are in Africa. Savanna grasslands are also found in Australia. The three-tier growth of vegetation is found in these regions. The natural vegetation of Savannas consists of tall grass.
Selvas: The rain forest of Amazon basin is called Selvas. These are rainy tropical forests..
Semangs (Tribes): are trib­al people living in Malaysia.
Spring Tides: are caused when the sun and the moon are in a straight line. The tide on its maximum height is known as Spring Tide.
Taiga Belt: lies between the Tibet-type climate and the Tundras.
Telegu Ganga Project: in Tamil Nadu envisages optimal use of surplus water of the Krishna river. It is a joint ven­ture of Tamil Nadu, Andhra Pradesh and Karnataka.
Time Zone: A zone on the terrestrial globe that is 15° longi­tude wide and extends from pole to pole and within which a uniform clock time is used. Time zones are the functional basis of standard time. The world is divided into 24 time zones.
Tsunamis: are huge sea waves caused by earthquakes.
Willy Willy: is a tropical cyclone of the north-west Australia.