Myanmar Matriculation Geography key terms

The angular distance of a place north or south of the Equator, measured in degrees from 0° at the Equator to 90° at the poles. It largely controls climate and day length.

The angular distance of a place east or west of the Prime Meridian at Greenwich, measured from 0° to 180°. Lines of longitude converge at the poles and fix local time.

The parallel at about 23.5° north of the Equator, the northern limit of the zone where the Sun can be directly overhead. It crosses Myanmar north of Mandalay.

A seasonal reversal of prevailing winds caused by unequal heating of land and sea. In Myanmar the southwest monsoon brings heavy rain from mid-May to October, while the northeast monsoon brings the dry season.

The dry leeward side of a mountain range, where descending air has already lost its moisture. In Myanmar the country east of the Arakan Yoma lies in the rain shadow of the southwest monsoon.

Rain produced when moist air is forced to rise over high land, cools, and condenses. It explains the very heavy rainfall on the windward slopes of the Arakan Yoma and the Shan Plateau.

An intense low-pressure storm system forming over warm tropical seas, with strong rotating winds and heavy rain. Such storms from the Bay of Bengal can strike the Myanmar coast, as Cyclone Nargis did in 2008.

An abnormal rise of sea level near the coast, driven by a storm's winds and low pressure. Surges accompanying cyclones in the Irrawaddy Delta cause severe flooding and loss of life.

The theory that the Earth's outer shell is divided into rigid plates that move over the mantle. Collision of the Indian and Eurasian plates uplifted the Himalayan and Arakan mountain ranges and makes Myanmar earthquake-prone.

A fracture in the Earth's crust along which rock masses have moved. The Sagaing Fault runs north to south through central Myanmar and is the source of many earthquakes.

A sudden shaking of the ground caused by the release of strain along faults or by volcanic activity. Myanmar lies in a seismically active zone, so tremors are a recurring natural hazard.

The breakdown of rocks in place by physical, chemical or biological processes, without transport of the material. It prepares rock for erosion and helps form the soils of Myanmar's uplands.

The wearing away and removal of rock or soil by moving agents such as water, wind or ice. Deforestation in Myanmar's hill areas greatly increases soil erosion and silting of rivers.

A low, flat area of sediment deposited where a river enters the sea or a lake. The Irrawaddy Delta is Myanmar's main rice-growing region and its most densely populated rural area.

Fine sediment of silt, sand and clay deposited by rivers on flood plains and deltas. Alluvial soils are fertile and support most of Myanmar's lowland agriculture.

The flat land beside a river that is covered when the river overflows its banks. Seasonal flooding of Myanmar's river plains enriches soils but can damage crops and settlements.

A hard, reddish soil rich in iron and aluminium oxides, formed in hot, wet tropical climates by heavy leaching. It occurs on parts of the Shan Plateau and is poor for farming.

The washing out of soluble nutrients from soil by downward-moving rainwater. Heavy monsoon rain leaches tropical soils, making many of Myanmar's upland soils less fertile.

A vertical section through soil showing its layers, or horizons, from topsoil to bedrock. Studying a profile reveals how climate and parent rock shape soils in a region.

The number of live births per 1,000 people in a population in one year. Together with the death rate it determines the natural rate of population increase.

The number of deaths per 1,000 people in a population in one year. Falling death rates, rather than rising birth rates, usually drive rapid population growth in developing countries.

The average number of people living in each square kilometre of an area. Myanmar's density is highest in the Irrawaddy Delta and lowest in the dry central zone and remote hill tracts.

The way people are spread over an area, whether clustered or sparse. It reflects differences in soil, water supply, relief, employment and transport in a country.

A graph showing the age and sex structure of a population, with males and females on opposite sides. A broad base indicates a young population with high birth rates.

The average number of years a person is expected to live, usually at birth. It is a key indicator of health care, living standards and nutrition in a country.

The growth in the proportion of a population living in towns and cities. In Myanmar it is driven by rural-to-urban migration towards Yangon and Mandalay.

The movement of people from villages to towns in search of work, education and services. It swells Myanmar's largest cities and can leave rural areas short of labour.

The reasons that drive people away from a place, such as poverty or conflict, and the attractions that draw them elsewhere, such as jobs. They explain migration patterns.

A city that is far larger than the second city of its country and dominates national economic and political life. Yangon, Myanmar's largest city, shows this pattern.

The growing of rice in flooded fields, or paddies, with seedlings transplanted by hand. It is the mainstay of Myanmar's rural economy and dominates the delta and river plains.

Farming that produces mainly food for the farmer's own family, with little left for sale. It is common in Myanmar's hill areas, where shifting cultivation is also practised.

A system in which farmers clear and burn a patch of forest, crop it for a few years, then move on. Also called taungya, it is practised by some hill peoples in Myanmar.

A crop grown mainly to be sold rather than consumed by the farmer. Myanmar grows cash crops such as rubber, pulses, sesame and sugarcane for export and trade.

Large-scale growing of a single crop, usually for export, often with hired labour. Rubber and oil palm estates in southern Myanmar are examples of this system.

The large-scale removal of forest cover, usually for timber, fuel or farmland. It causes soil erosion, loss of wildlife and worse flooding in Myanmar's watersheds.

A north-south mountain range in western Myanmar, also called the Rakhine Yoma, separating the coastal strip from the central lowlands. It causes heavy rain on its western slopes and a rain shadow to the east.

Myanmar's main river, flowing from north to south through the central lowlands to its delta on the Bay of Bengal. It is a vital route for transport, irrigation and rice farming.

A major active fault running roughly north to south through central Myanmar near Mandalay. Movement along it has caused damaging earthquakes and it is a key national hazard.

A coastal state in western Myanmar, separated from the central lowlands by the Arakan Yoma. It has a wet coastal plain and is prone to cyclones from the Bay of Bengal.

A high, largely flat upland in eastern Myanmar, drained by the Salween and Thanlwin systems. Its cool climate and poor lateritic soils favour crops such as tea, thanaka and some vegetables.

The hot, semi-arid belt of central Myanmar around Mandalay and Magway, lying in the rain shadow of the Arakan Yoma. It depends on irrigation for crops such as sesame, groundnut and cotton.

The ratio between a distance on a map and the real distance on the ground, shown as a statement, ratio or bar. It allows the map user to measure true distances between places.

A set of numbers locating a point on a map using numbered vertical and horizontal grid lines. In Myanmar school atlases, four-figure references give a square and six-figure references a precise point.

A line on a map joining points of equal height above sea level. Closely spaced contours show steep slopes; widely spaced ones show gentle slopes.

A number on a map giving the exact elevation of a point, such as a hilltop or road junction. It supplements contours in describing relief.

A profile drawn from a map showing the shape of the land along a chosen line. It helps interpret relief, slope steepness and intervisibility between points.

The arrangement of streams and rivers in an area, such as dendritic, trellis or radial. It reflects the underlying rock structure and relief shown on a map.

The boundary of high ground separating one river basin from another. On a map it can be traced along ridge lines, and in Myanmar it matters for forest and dam planning.

A map showing how land is used, for example for farming, forest, settlement or industry. Comparing such maps over time reveals changes such as deforestation or urban growth.