# kb

id: glossary-of-geography-terms-a-m-20260505-19
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-19.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
headwall A steep slope or sheer cliff face at the upper end of a valley (e.g. at the back of a cirque), or at the active face of a mine, pit, or quarry. headwaters 1. Another name for the source of a river, stream, or other watercourse, i.e. the point or points furthest from the mouth of a particular channel at which precipitation, meltwater, or groundwater first accumulates into a persistent, identifiable, and/or named body of water whose contents ultimately empty into that particular channel; or all of the uppermost tributaries of a watershed considered collectively (of which there may be thousands), typically including all streams identified as first-order through third-order in conventional stream order systems. 2. The entire region, inclusive of land, surrounding these sources, often abutting the boundary of a drainage divide that separates distinct watersheds. hearth The source area of any innovation; the place from which an idea, crop, artifact, or good is diffused to other areas. heartland 1. The central or interior part of a region. 2. A part of a region considered essential to the viability and survival of the whole. heath Also heathland. A shrubland habitat found mainly on free-draining, infertile, acidic soils and


id: glossary-of-geography-terms-a-m-20260505-20
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-20.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
horizontal equivalent The distance between two points on a land surface when projected on to a perfectly horizontal (i.e. flat) plane, e.g. on a map, as opposed to measuring the actual physical length along the real-world surface, which can be greatly increased by slopes and other topographic variation. The distance between the start and end points of any route, even if at the same elevation, will often appear to be much shorter on a map than the shortest route that could actually be walked between them, because of the influence of real-world changes in vertical displacement along the path followed by the route. horn A mountain formed by the back-to-back abutment of three or four adjacent cirques, leaving a distinctly pyramidal peak. horst A raised block of the Earth's crust, bounded by parallel escarpments or faults, that has been displaced upward or has remained stationary while adjacent blocks on either side, known as grabens, have been displaced downward. Horsts and grabens often occur side-by-side in a repeated series of vertical displacements. hotspot An area in the middle of a lithospheric plate where magma rises from the mantle and erupts at the Earth's surface, despite being far from the plate's tectonic


id: glossary-of-geography-terms-a-m-20260505-21
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-21.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
igneous rock Rock formed when molten (melted) materials harden. immigration To move to another country. People that move to another country are called immigrants. impact crater A type of crater formed by the hypervelocity collision of a solid astronomical body, such as a meteor, with the Earth's surface. Unlike volcanic craters, impact craters typically have raised rims higher in elevation and depressed floors lower in elevation than the surrounding terrain. impoundment 1. Another name for a dam that impounds a body of water. 2. The reservoir created by such a dam. improved land Any land area which has been intentionally altered from its natural condition by human activity, such as ploughing, clearing, cultivation, or some other form of management, and thereby made more valuable or productive for human purposes (not necessarily to the benefit of any other organism or the environment in general). Legal definitions vary with location, but in most countries the term refers primarily to certain types of agricultural land or to property which has been developed for residential or commercial use. inclinometer Also clinometer, declinometer, tilt meter, gradient meter, slope gauge, and level gauge. An instrument used to measure angles of slope, elevation, or depression with respect


id: glossary-of-geography-terms-a-m-20260505-22
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-22.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
intermontane Also intermountain. Situated between mountains or mountain ranges, e.g. the high plateaus lying between the eastern and western ranges of the Andes. International Date Line A line of longitude generally 180 degrees east and west of the Prime Meridian. The date is one day earlier to the east of the line. international waters interpolation In geographic information science, the estimation of the values of spatially dependent variables at unsampled points based on known values of surrounding points, under the assumption that any unknown quantity can be calculated based on its distance to each surrounding quantity. Interpolation techniques such as spline and kriging are commonly raster operations, but can also be applied in vector environments using a triangulated irregular network to model a surface. interruption Any place where the contiguous geographic area represented in a map projection has been split, separating to distant parts of the projection certain features and locations which are in reality much closer to each other, in order to permit the representation of a three-dimensional space on a two-dimensional map. All world maps, for example, have at least one interruption, conventionally along the length of a single meridian, thus forming an east–west boundary despite that the


id: glossary-of-geography-terms-a-m-20260505-23
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-23.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
knickpoint Also nickpoint. 1. A point of abrupt inflection in the longitudinal profile of a river or its channel or valley, such as occurs at a waterfall. 2. Any interruption or break in the character of a slope. knob A peak or projection from the top of a hill or mountain, or any rounded protrusion of land, especially a small but prominent or isolated hill with steep sides; a boulder or an area of resistant rock protruding from the side of a hill or mountain. The term is used primarily in the southern United States. knoll See hillock. kolk Also colc and colk. 1. A violently rotating underwater vortex capable of plucking and scouring depressions in bedrock, which may leave behind distinct pits or lakes known as rock-cut basins or potholes. 2. Another name for a bog pond. kopje See tor. krai In Russia and other Slavic countries, a generic term for a region, historically and politically reserved for border regions in particular, and variously translated as march, frontier, or territory. The term is cognate with the name of Ukraine. kriging Also Gaussian process regression and Wiener–Kolmogorov prediction. In geostatistics, an interpolation technique in which, for a given spatially dependent


id: glossary-of-geography-terms-a-m-20260505-24
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-24.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
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parent: glossary-of-geography-terms-a-m-20260505-0
summary:
latitude A measure of distance north or south of the Equator. One degree of latitude equals approximately 111 kilometers (69 mi). Lines of latitude, also called circles of latitude or parallels, are the imaginary lines that cross the surface of the Earth in an east-west direction (parallel to the Equator) and measure how far north or south of the Equator a place is located. lava The term used for magma once it has erupted onto the Earth's surface. layer of no motion In oceanography, a hypothetical layer at some depth in the ocean within which the water is assumed to be at rest, implying that the isobaric surfaces within that layer are level and hence that such surfaces can be used as points of reference when calculating absolute-gradient currents. lea A pasture, meadow, or grassy field. leaching A process of soil nutrient removal through the erosive movement and chemical action of water. lee The side or slope of a physical feature (such as a hill or mountain) which faces downwind, i.e. away from the direction in which the wind is blowing, or which faces away from an advancing glacier or ice sheet. The lee side is often sheltered by the


id: glossary-of-geography-terms-a-m-20260505-25
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-25.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
magnetic declination Also magnetic variation. The angle on the horizontal plane between magnetic north and true north. Because compass needles always point to magnetic north, and because the Magnetic North Pole and the Geographic North Pole are not in precisely the same location, the north direction indicated by a compass may be slightly different from the direction of geographic north, depending on the user's location on the Earth. The user can compensate for this discrepancy by adding the known declination angle for their location to the magnetic bearing reported by their compass, yielding the true bearing with respect to true north. magnetic dip Also dip angle and magnetic inclination. The angle made with the horizontal by the Earth's magnetic field lines. Locations in the Northern Hemisphere usually have positive values of inclination, indicating that the magnetic field is angled downward, into the Earth; the angle increases as one approaches the North Magnetic Pole, where the field lines point vertically downward, perpendicular to the horizontal. Locations in the Southern Hemisphere usually have negative inclination, indicating that the field lines are angled upward, away from the Earth, with the maximum angle located at the South Magnetic Pole. Dip angle is in principle


id: glossary-of-geography-terms-a-m-20260505-26
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-26.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
margin 1. The line or edge along which the surface of a body of water meets the land. 2. In property law, the boundary of a piece of land which is bounded by a stream or watercourse, often with the center of the stream or the thalweg defining the legal boundary. 3. The mostly blank, unused space lying beyond the neatline of a map and completely surrounding the map area. See also surround. marginal land Land that is of low agricultural value because any crops produced from it would be worth the same or less than the costs paid to produce them, either because the rights or improvements required to cultivate it are very expensive, or the market prices for the crops are very low, or for any other reason. A change in economic conditions may allow formerly marginal lands to become profitable again. marginal sea 1. A sea or other large area of the ocean that is partially enclosed by land and/or submarine ridges yet still adjacent to, widely open to, and connected to the larger ocean at the surface; e.g. the Yellow Sea and Hudson Bay. 2. Also territorial sea, marine belt, and maritime belt.Those waters along a


id: glossary-of-geography-terms-a-m-20260505-27
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-27.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
Mercator projection Also equatorial cylindrical orthomorphic map projection. A conformal cylindrical map projection in which the equator is represented by a straight line true to scale and meridians are represented by parallel straight lines perpendicular to the equator and uniformly spaced according to the distances between them at the equator. Lines of latitude are also represented by a system of straight lines which are perpendicular to all of the meridians and therefore parallel to the equator, though their spacing is not uniform but rather increases with increasing distance from the equator in order to conform with the expanding scale resulting from the parallel representations of the meridians. The standard Mercator projection has long been popular in navigation because it represents north as up and south as down everywhere in the world while preserving local directions and shapes, though it also greatly inflates the size of objects near the geographic poles. mere A shallow pond, lake, or wetland. The term is used primarily in Great Britain and other parts of Western Europe. mereing A type of surveying in which boundaries are established with respect to ground features present at the time of the survey, which may include natural features and may


id: glossary-of-geography-terms-a-m-20260505-28
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)-28.md
category: reference
title: Glossary of geography terms (A–M)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(A–M)
date_saved: 2026-05-05T07:19:36.992630+00:00
instance: kb-cron
parent: glossary-of-geography-terms-a-m-20260505-0
summary:
mouth 1. The place where a river or stream flows into another body of water, such as a lake or another river but especially a sea or ocean. Deltas and estuaries occur near the mouths of rivers. 2. The lower or downstream end or the most accessible entrance of a valley, canyon, ravine, or cave. mudflat Also mud flat and tidal flat. A type of coastal wetland consisting of exposed layers of bay mud formed by the deposition of silts, clays, and marine animal detritus by tides or rivers. Mudflats usually form within the intertidal zone of relatively sheltered areas such as bays and lagoons. mudflow See lahar. multicultural Of, pertaining to, or including multiple distinct cultures. multilingual The ability to use more than one language when speaking or writing. This term often refers to the presence of more than two populations of significant size within a single political unit, each group speaking a different language as their primary language. municipal corporation The legal term for a government body at the local level, including but not necessarily limited to cities, counties, towns, townships, villages, and boroughs. municipality A type of general-purpose urban administrative subdivision having corporate status and powers of


id: glossary-of-geography-terms-n-z-20260505-0
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-0.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
This glossary of geography terms is a list of definitions of terms and concepts used in geography and related fields, including Earth science, oceanography, cartography, and human geography, as well as those describing spatial dimension, topographical features, natural resources, and the collection, analysis, and visualization of geographic data. It is split across two articles: Glossary of geography terms (A–M) lists terms beginning with the letters A through M. This page, Glossary of geography terms (N–Z), lists terms beginning with the letters N through Z. Related terms may be found in Glossary of geology, Glossary of agriculture, Glossary of environmental science, and Glossary of astronomy. == N == nadir narrows Also narrow. A land or water passage that is confined or restricted by its narrow breadth, often a strait or a water gap. nation A stable community of people formed on the basis of a common geographic territory, language, economy, ethnicity, or psychological make-up as manifested in a common culture. national mapping agency A governmental agency which manages, produces, and publishes topographic maps, geographic data, and sometimes cadastral information that is specific to an individual nation or political territory, such as the United Kingdom's Ordnance Survey. national park A type of


id: glossary-of-geography-terms-n-z-20260505-1
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-1.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
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parent: glossary-of-geography-terms-n-z-20260505-0
summary:
North Magnetic Pole Also called the Magnetic North Pole or Magnetic North. The point in the Northern Hemisphere at which the Earth's magnetic field points vertically downward. It is close to but distinct from the Geographic North Pole and the Geomagnetic North Pole, and its precise location varies considerably over time due to frequent magnetic changes in the Earth's core. Its counterpart in the Southern Hemisphere is the South Magnetic Pole, though the two poles are not directly opposite each other. Northern Hemisphere The half sphere of the Earth that is north of the Equator. It is opposite the Southern Hemisphere. northing nubbin A small, gentle hill consisting of a bedrock core dotted with rounded residual boulders. Nubbins form in a similar way to castle koppies and bornhardts. nunatak == O == oasis A combination of a human settlement and an area of cultivated vegetation in an otherwise desolate desert or semi-desert environment, made fertile when sources of fresh water, such as underground aquifers, irrigate the surface naturally or via man-made wells. oblate spheroid The approximate geometric shape of the Earth: a three-dimensional ellipsoid that is nearly but not exactly a true sphere, being instead slightly flattened at the poles


id: glossary-of-geography-terms-n-z-20260505-2
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-2.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
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parent: glossary-of-geography-terms-n-z-20260505-0
summary:
orographic rainfall Precipitation that results when moist air is lifted over a topographic barrier, such as a mountain range. orography A branch of physical geography and geomorphology concerned with the scientific study and description of the topographic relief of the Earth, particularly of mountains and hills, and more broadly of any elevated terrain. orthodrome See great circle. orthodromic distance See great-circle distance. orthophotograph Also orthophoto, orthoimage, or orthoimagery. An aerial photograph or satellite image that has been geometrically corrected or orthorectified such that the scale is uniform across all parts of the image, allowing the image to align with a particular map projection. In an uncorrected aerial photo, distances on the ground may be distorted by topographic relief, camera tilt, or the curvature of the Earth; techniques of digital image processing can compensate for these distortions, often by combining multiple images captured from slightly different perspectives into a single composite image. Orthophotos can be used to measure true distances because they accurately depict the relative sizes and positions of features on the Earth's surface. outback In Australia, the vast, remote, sparsely populated backcountry. See also bush. outcrop Also outcropping. Any visible exposure of bedrock or ancient superficial deposits on the


id: glossary-of-geography-terms-n-z-20260505-3
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-3.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
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parent: glossary-of-geography-terms-n-z-20260505-0
summary:
pediment An eroded, often bare rock platform, cut into the local bedrock, usually slightly concave and triangular in shape and extending over a considerable area at the foot of an abrupt mountain slope or face, the lower edge sloping gently away. Pediments form basal slopes of transport for weathered material derived from the steeper slope above, and are characteristic of arid and semi-arid lands. pediplain pedology The scientific study of the morphology, composition, and spatial distribution of soils, with an emphasis on classifying soils and understanding their formation and evolution. pedosphere The uppermost layer of the Earth's crust that is composed of soils and subject to pedological processes such as soil formation and erosion, a consequence of dynamic interactions between the lithosphere, atmosphere, hydrosphere, and biosphere. pelagic zone peneplain A low-relief plain leveled by long-term erosion, often implying a landscape that is in the final stages of fluvial erosion during an extended period of tectonic stability, i.e. approaching the point at which all initial topographic inequalities such as mountains and hills have been eroded and evenly redistributed into a broad, flat, uniform surface at or near sea level. peninsula A piece of land surrounded almost entirely by water while still


id: glossary-of-geography-terms-n-z-20260505-4
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-4.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
place A particular point on the Earth's surface, or the area surrounding such a point, having or encompassing a definite position; a location, often specifically named, that is identifiable in social interaction because humans have endowed it with meaning or purpose; or a mental representation of a physical space created from functional or emotional associations in the human mind. The concept of place – how places are created, identified, mapped, connected, and used – is fundamental to all of geography. place identity place utility The measure of approval or satisfaction accorded by an individual to a location in his or her action space; the value or usefulness of a particular place as perceived by a particular person. Dissatisfaction with place utility may result in migration. placename See toponym. placer 1. (mineral deposit) An accumulation of valuable minerals, particularly gold, formed by gravity separation from a source rock during natural sedimentary processes. The minerals, weathered from rocks or veins, are washed out by streams and mixed with alluvial deposits of sand or gravel, from which they can then be extracted by placer mining. 2. (reef) A flat, shallow sandbank or reef submerged beneath the ocean surface, often with a sandy bottom


id: glossary-of-geography-terms-n-z-20260505-5
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-5.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
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parent: glossary-of-geography-terms-n-z-20260505-0
summary:
polar ice cap Also polar ice sheet. Either of the two very large regions near the Earth's geographical poles that are seasonally or persistently covered in ice, which occurs because high-latitude regions receive less direct solar radiation than other regions and therefore experience much lower surface temperatures. The Earth's polar ice may cover both land and sea, and varies in size seasonally and with long-term climate change. They typically cover a much larger area than true ice caps and are more correctly termed ice sheets. polar region Either of the two high-latitude regions surrounding the Earth's geographical poles (the North and South Poles), which are characterized by frigid climates and extensive polar ice caps. The polar region of the Northern Hemisphere is often called the Arctic and that of the Southern Hemisphere is called the Antarctic. polder Also empolder. A low-lying tract of land enclosed by dikes, forming an artificial hydrological entity by creating land from a naturally inundated area, e.g. by reclaiming land from a lake or sea, or by building barriers around a floodplain or marsh and then draining it. All polders are eventually below the surrounding water table some or all of the time, making them especially


id: glossary-of-geography-terms-n-z-20260505-6
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-6.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
pothole Also pot, swirlhole, churn hole, evorsion, rock mill, and eddy mill. 1. Any smooth, bowl-shaped or cylindrical hollow, generally deeper than it is wide, that is carved into the rocky bed of a watercourse such as a stream or river. Fluvial potholes are created by the grinding action of stones or coarse sediment kept in perpetual motion in the same spot by the turbulence of the current. The term is also used to refer to plunge pools beneath waterfalls, which are created by similar processes. See also kolk. 2. A vertical or steeply inclined karstic shaft in a limestone deposit. 3. In the Great Plains of North America, a shallow depression, generally less than 10 acres (4.0 ha) in area, occurring between dunes or on morainic relief on a prairie and often filled by an intermittent pond or marsh. 4. Another name for a kettle. 5. Another name for a panhole. prairie A type of temperate grassland ecosystem dominated by a characteristic composition of grasses, herbs, and shrubs, rather than by trees. The term is used primarily in North America, but similar ecosystems can be found across the world. Precambrian rock The oldest rocks, generally more than 600 million


id: glossary-of-geography-terms-n-z-20260505-7
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-7.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
rake A sloping terrace on a mountainside or rock face. The term is used primarily in Scotland. rapid Also rapids or whitewater. A section of a river or stream where the riverbed is sufficiently steep, the rate of flow is sufficiently fast, and/or the channel is sufficiently narrow or obstructed by shallow or protruding rocks or other obstacles that the water at the surface is visibly swift, turbulent, and broken, often forming large white-capped breaking waves, eddies, whirlpools, and "holes", in contrast to other sections where relatively slow, steady, laminar flows predominate. Rapids can persist long enough to form distinct, stable patterns at particular locations, though they are ultimately dependent on water volume and thus may change seasonally, disappearing entirely if water levels are too low or too high. Generally, watercourses are more likely to form rapids closer to their source, where channels are relatively shallow and narrow and often pass through mountainous or highly eroded terrain, than to downstream portions near their mouth, where channels tend to be deeper and wider. raster A representation of spatial data within a two-dimensional image that defines space as a rectangular array or grid of equally sized cells arranged in rows and columns,


id: glossary-of-geography-terms-n-z-20260505-8
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-8.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
relief The actual physical surface of a region of the Earth, i.e. the specific shape, dimensions, and particularities of its terrain; or the deviation of a real-world surface from a reference surface such as the geoid, a sphere, or a plane. When only the patterns and contours of the natural surface are considered and man-made features are ignored, relief is more or less synonymous with topography. relief map See topographic map. religion The belief in a supernatural power that is regarded as the creator and maintainer of the universe, as well as the system of beliefs itself. remote (of a particular location) Isolated or inaccessible, either by being physically very distant from another location or by lacking connectivity to transportation or communication networks which would otherwise make exchange between locations convenient. remote sensing The gathering of information about an object or place from a remote location (i.e. without making physical on-site observations), most commonly by the use of satellite- or aircraft-based electromagnetic sensor technologies. representative fraction (RF) The fraction expressing the ratio between the distance measured between two points on a map and the corresponding actual distance measured between those points in the real world, used to indicate the map's


id: glossary-of-geography-terms-n-z-20260505-9
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-9.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
rose A diagram printed on a map consisting of a set of lines radiating from a point and marked so as to indicate velocity or some other quantity having direction; e.g. a compass rose or current rose. route 1. A way or course taken in getting from one place to another; an established or selected course of travel or action; a line of travel or means of access, especially when marked by a path, track, road, or rail. 2. A circuit traveled in delivering, selling, or collecting goods, e.g. by a mail carrier. routefinding The determination of a viable route or line of travel between two places, especially in rugged or unexplored areas such as mountainous terrain or in conditions of poor visibility, and especially when done without the benefits of prior knowledge of the area, maps, or other technology that might aid orienteering, instead relying entirely on recognition of natural features and landmarks and quick estimations of distance, scale, ease, and safety. rural An adjective describing any geographic area located outside areas of significant human population such as towns and cities; all population, housing, and territory not included within an urban area is often said to be rural. Rural


id: glossary-of-geography-terms-n-z-20260505-10
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-10.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
sea lane Also sea road, seaway, or shipping lane. A navigable route across a wide waterway such as an ocean, sea, or large lake that is regularly used for maritime trade by large vessels or ships because it is safe, direct, and economical. sea level The average level of the surface of one or more of Earth's oceans from which heights such as elevation and altitude are commonly measured. Often called mean sea level (MSL), it is a type of standardized geodetic vertical datum that is used in numerous applications, including surveying, cartography, and navigation. Mean sea level is commonly defined as the midpoint between the mean low and mean high tides at a particular location. sea stack See stack. seabed Also sea floor or ocean floor. The bottom of a sea or ocean. As with land terrain, the ocean floor may have ridges, mountains, valleys, and plains. seaboard Any extensive region of land adjacent to the sea, broadly synonymous with coast or coastline. seamount A mountain (often a volcano) rising from the ocean floor whose summit does not reach the water's surface and which is therefore entirely submerged and not an island or islet. search space In human geography,


id: glossary-of-geography-terms-n-z-20260505-11
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-11.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
shield volcano A class of volcano that resembles an inverted warrior's shield, with long gentle slopes produced by multiple eruptions of fluid lava flows. shoal Also sandbank, sandbar, or gravel bar. A natural submerged ridge, bank, or bar that consists of or is covered by sand or other unconsolidated material and rises from the bed of a body of water to just below or above the surface. shore Also shoreline. The fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. Compare coast. shore platform See wave-cut platform. shoulder 1. A rounded spur on a mountainside; or a bench on the side of a glacier-deepened U-shaped valley, demarcating an abrupt transition between the gentle upper slopes which have been largely unaffected by glacial erosion and the steep lower slopes of the heavily eroded inner valley. 2. The part of a roadway between the edge of the graded or paved driving surface and the top of the foreslope of an adjacent ditch or embankment. shoulder drop See topographic prominence. side valley A valley whose mouth opens onto a larger, lower-order valley to which its drainage is tributary. sighting compass A handheld magnetic


id: glossary-of-geography-terms-n-z-20260505-12
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-12.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
soil building process The creation of organic matter from weathered rock, air, and water. soil horizon A distinct layer of soil which can be distinguished from other layers in vertical cross-section. solstice The time when the Sun reaches its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around 20–22 June and 20–22 December. In many countries, the seasons of the year are defined by reference to the solstices and the equinoxes. solution pan See panhole. solubility The degree to which a substance can be dissolved in another substance. In a geographical context, solubility is a characteristic of soil minerals that describes their tendency to be carried away in solution by water. See also leaching. sound 1. A large inlet of a sea or ocean that is larger than a bay, deeper than a bight, and wider than a fjord. 2. A narrow sea or ocean channel between two landmasses. sounding 1. A measured depth in water, usually a measurement of the distance from an instrument on a vessel at the surface to the bottom of the bed or floor of the body of water at a point directly below the


id: glossary-of-geography-terms-n-z-20260505-13
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-13.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
spatiomap A map that is not merely a diagrammatic representation of a place but is based on an aerial orthophotograph, such that the map includes actual imagery of ground-level features which are often omitted from conventional maps. Spatiomaps are usually created by overlaying annotations directly upon an orthophoto, such as a north arrow or compass rose, a scale bar, political boundaries and labels, or other cartographical information. They are useful when reliable data from ground-based surveys are missing for a particular geographical area or when accurate maps must be produced very quickly, especially during disaster relief efforts where a natural disaster has dramatically changed ground-level detail but new surveys have not yet been conducted. spirit level spit Also sandspit. A type of bar or shoal extending from a beach into an ocean or lake and which develops by the deposition of sediment as a result of longshore drift. Spits form where the shoreline sharply changes direction, such as at a headland, and often develop a "hooked" or recurve shape at their distal ends. spot elevation Also spot height. A point on a map or chart whose height or elevation above a specified reference datum (often mean sea level) is explicitly


id: glossary-of-geography-terms-n-z-20260505-14
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-14.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
strip map A map covering only a narrow band of territory in which the user is interested, e.g. alongside each side of a trail or vehicle route. subcontinent A large landmass forming a contiguous part of an even larger continent, though often separable by physiographic or political boundaries, e.g. the Indian subcontinent; or a non-contiguous but still very large landmass that is smaller than one usually termed a continent, e.g. Greenland. subduction zone The place where two lithospheric plates come together, one riding over the other. Most volcanoes on land occur parallel to and inland from the boundary between the two plates. subglacial Of, relating to, or formed on or by the underside of a glacier. Contrast englacial and superglacial. sublittoral 1. Of or relating to the coastal area of the sea between the intertidal zone and the edge of the continental shelf. Compare littoral zone. 2. Of or relating to the deepest parts of a lake or other large body of freshwater, distant from the shore, where plants cannot root. See also aphotic zone. subsequent (of a stream, river, or any natural water flow) Flowing along a course determined by the structure of the local bedrock. Contrast consequent and


id: glossary-of-geography-terms-n-z-20260505-15
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-15.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
tectonic plate Any of several very large divisions of the Earth's crust consisting of solid rock which "floats" on top of the semi-solid mantle. temperate zone Traditionally, either of the two mid-latitude regions of the Earth defined by their latitudinal position between the tropics and the polar zones, i.e. the region between latitudes 23°30' N and 66°30' N, or that between 23°30' S and 66°30' S. In modern usage, the term may refer instead to regions of mild or temperate climate, regardless of latitude. temperature inversion An increase in temperature with height above the Earth's surface, a reversal of the normal pattern, often observed in deep valleys and basins that are mostly or entirely enclosed by high mountain ranges. tephra Solid material of all sizes explosively ejected from a volcano into the atmosphere. terminal moraine Also end moraine. A moraine that forms at the terminus or snout of a glacier, marking its furthest advance. Debris transported by plucking and abrasion accumulates at the glacier's leading edge, where it is deposited in an unsorted pile of sediment as the ice begins to retreat. terracette One of a series of regularly spaced, horizontal, step-like ridges forming a distinctive ribbed pattern on a


id: glossary-of-geography-terms-n-z-20260505-16
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-16.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
tidal creek Also tidal channel. A narrow inlet or estuary that is affected by the ebb and flow of tides from an adjacent ocean. Water in the lower portions of these channels tends to vary greatly in depth, salinity, electrical conductivity, and other hydrological properties over the course of the tidal cycle, but is often slow-moving and rich in organic sediment drained from upstream freshwater sources, making them important habitats for many species. tidal flat An extensive, nearly horizontal, and barren or sparsely vegetated tract of land at the edge of a sea or ocean that is alternately covered and uncovered by the tide. tidal prism The total volume of water that flows in and out of a coastal inlet or estuary with each cycle of the tides, excluding any freshwater discharges; i.e. the difference in the inlet's volume between the mean high and low tides. tidal range The difference in height between high tide and low tide at a given location. This range may vary over the course of the year, e.g. during neap tides and spring tides. tide The periodic rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the


id: glossary-of-geography-terms-n-z-20260505-17
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-17.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
township A type of populated place or administrative subdivision for which definitions vary widely between jurisdictions. In the United States, the township is the basic unit of land in the Public Land Survey System, a quadrangle with sides of approximately 6 miles (9.7 km) aligned to parallels and meridians and further subdivided into 36 one-square-mile sections. The location of each township is specified with respect to a designated reference parallel and a reference meridian. township and range The rectangular system of land subdivision used to plat real property for sale and settlement in much of the agriculturally settled United States west of the Appalachian Mountains, established by the Land Ordinance of 1785. towpath A road or path alongside a navigable river, canal, or other inland waterway designed to allow land vehicles, draught animals, or a team of human pullers to tow a boat or barge. trafficability The capacity of a soil or of a particular type of terrain to permit the movement of vehicles or pedestrians. trail transferability The extent to which a good or service can be moved from one location to another; the relative capacity for spatial interaction. transhumance The seasonal movement of people and animals in search


id: glossary-of-geography-terms-n-z-20260505-18
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-18.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
trough Any elongated, generally U-shaped valley, ravine, basin, or ditch, natural or artificial, dry or wet. Particularly common usages refer to a submarine trench or deep in the ocean floor, or to a geological syncline. true north Also geodetic north. The direction along the Earth's surface towards the Geographic North Pole. Geodetic true north differs from magnetic north and grid north, and also very slightly from astronomical true north, which is based on the direction of the north celestial pole. true south Also geodetic south. The direction along the Earth's surface that is exactly opposite (i.e. bearing 180 degrees) of true north, towards the Geographic South Pole. trunk See main stem. tsunami A giant ocean wave caused by an underwater earthquake or volcanic eruption with great destructive power. tundra A treeless plain characteristic of the Arctic and subarctic regions. tunnel valley A deep, greatly elongated, U-shaped valley carved from land beneath a mass of glacial ice, often near the margin of a continental ice sheet. Tunnel valleys may be up to 100 kilometres (62 mi) long, 2.5 kilometres (1.6 mi) wide, and 400 metres (1,300 ft) deep, and often occur side-by-side in a series of multiple parallel valleys. turlough In


id: glossary-of-geography-terms-n-z-20260505-19
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-19.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
volcanic avalanche Also debris avalanche. A large, chaotic mass of soil, rock, and volcanic debris moving swiftly down the slopes of a volcano. Volcanic avalanches can also occur without an eruption due to an earthquake, heavy rainfall, or unstable soil, rock, and volcanic debris. volcanic crater A type of crater created by volcanic activity, typically shaped like a bowl and containing one or more volcanic vents. Compare caldera. volcano A vent or opening in the Earth's surface through which magma erupts, or the landform that is constructed by the eruptive material. volcanology Also vulcanology. The scientific study of volcanoes, lava, magma, and the body of related geophysical phenomena known as volcanism. It is a branch of geology and Earth science which seeks to understand the formation, activity, and dormancy of volcanoes, their current and historic eruptions, and how to predict them. vrtače See doline. == W == wadi 1. A dry, ephemeral riverbed which contains water only when heavy rainfall occurs. 2. Another name for a valley, used primarily in Arabic-speaking parts of the world. warping 1. The slow, gentle deformation of the Earth's crust over a wide area, resulting in a raising or lowering of the surface. 2. (sedimentation)


id: glossary-of-geography-terms-n-z-20260505-20
file: data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-20.md
category: reference
title: Glossary of geography terms (N–Z)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)
date_saved: 2026-05-05T07:19:38.512543+00:00
instance: kb-cron
parent: glossary-of-geography-terms-n-z-20260505-0
summary:
wave-cut platform Also shore platform, wave-cut cliff, or coastal bench. A flat erosion surface along the shore of a lake, bay, or sea that is formed by the undercutting and eventual collapse of a sea cliff as a result of repetitive wave action. waypoint A reference point in physical space used for purposes of navigation, especially when plotted on a map or in a GIS application as part of a traveled route. weathering The breaking of rocks into smaller rocks, gradually becoming soil. weir Also low head dam. A man-made obstruction built across the width of a river that alters its flow and usually results in a change in the height of the river level, commonly by permitting water to flow freely over a low barrier before cascading down to a lower level. Weirs may serve many purposes, including decreasing or increasing the force of the current, maintaining water depth, or diverting or impounding flow, typically for navigation, irrigation, fishing, to generate a head for a water mill, or to control outflow from a lake or reservoir. Compare dam and barrage. welfare geography An approach in human geography which considers the areal differentiation and spatial organization of human activity from


id: abstract-space-20260505-0
file: data/en.wikipedia.org/wiki/Abstract_space-0.md
category: reference
title: Abstract space
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Abstract_space
date_saved: 2026-05-05T07:19:39.743891+00:00
instance: kb-cron
parent: abstract-space-20260505-0
summary:
Abstract space, in geography, is a hypothetical space characterized by equal and consistent properties; a geographic space that is completely homogeneous. All movement and activity would be equally easy or difficult in all directions and all locations within this space. This concept is useful for modeling or analyzing spatial activity and behavior by limiting or eliminating extraneous variables, such as terrain. For example, if researchers want to study the relationship between culture and trade, they don't want their model to be overwhelmed or influenced by factors such as mountainous barriers and rivers because these would detract from the purpose of modeling how culture alone effects trade. == See also == Central Place Theory == References ==


id: activity-space-20260505-0
file: data/en.wikipedia.org/wiki/Activity_space-0.md
category: reference
title: Activity space
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Activity_space
date_saved: 2026-05-05T07:19:40.952263+00:00
instance: kb-cron
parent: activity-space-20260505-0
summary:
In social science, the activity space designates the "set of places individuals encounter as a result of their routine activities in everyday life." The activity space can include all relevant locations that an individual routinely go to, such as the place of residence, the workplace (or the place of study), but also gyms, supermarkets, or cinemas. == Definition == Activity space research started in the field of geography and urban planning, where scholars investigated the effect of urban spatial structure on individual behavior. Horton and Reynolds define the activity space "as the subset of all urban locations with which the individual has direct contact as the result of day-to-day activities." They consider the activity space as a subset of one's "action space," which they define as "the collection of all urban locations about which the individual has information and the subjective utility or preference he associates with these locations". The "action space" is often use synonymously with the terms "awareness space," "mental map," and "cognitive map." The emergence of the cognitive science has broadened the scope of activity space beyond the realm of physicality. Scientists like David Kirsh define activity space as the blend of several components. These components include:


id: alfoz-territory-20260505-0
file: data/en.wikipedia.org/wiki/Alfoz_(territory)-0.md
category: reference
title: Alfoz (territory)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alfoz_(territory)
date_saved: 2026-05-05T07:19:42.153703+00:00
instance: kb-cron
parent: alfoz-territory-20260505-0
summary:
The geographical term alfoz (plural alfoces) was used in the Iberian Peninsula during the Middle Ages to describe the rural territory, including subordinate hamlets, under the jurisdiction of a corresponding town (villa in Spanish). The villa and its alfoz, under the authority of the town's local council (concejo), sometimes underpinned what was called a Comunidad de Villa y Tierra, an autonomous political division. At the center of this community, the town (or sometimes a city) comprised an urban area and usually boasted of a castle and a fortified wall. By the 12th century, the alfoces had fiscal, judicial and military functions. Furthermore, they lent themselves to the communal use of land for silvopastoral agriculture; however, in the year 1100, monarchs began to allocate portions of land to the Church and the nobility, an act that undermined the very purpose of the alfoz. The alfoz and its villa formed what would later be known as a municipality. The word alfoz comes from the Arabic al-hawz, meaning "rural district". It is currently preserved in several placenames in Spain as well as is occasionally used as a modern-day common noun. == Notes == == References == == Bibliography == Martínez Sopena, Pascual (2005).


id: alluvial-fan-20260505-0
file: data/en.wikipedia.org/wiki/Alluvial_fan-0.md
category: reference
title: Alluvial fan
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alluvial_fan
date_saved: 2026-05-05T07:19:43.613390+00:00
instance: kb-cron
parent: alluvial-fan-20260505-0
summary:
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than 1 square kilometer (0.4 sq mi) to almost 20,000 square kilometers (7,700 sq mi). Alluvial fans typically form where a flow of sediment or rocks emerge from a confined channel and are suddenly free to spread out in many directions. For example, many alluvial fans form when steep mountain valleys meet a flat plain. The transition from a narrow channel to a wide open area reduces the carrying capacity of flow and results in deposition of sediments. The flow can take the form of infrequent debris flows like in a landslide, or can be carried by an intermittent stream or creek. The reduction of flow is key to the formation of alluvial fans. If a river exits a mountain valley without any reduction in flow, it is more common to see the formation of an alluvial plain. The


id: alluvial-fan-20260505-1
file: data/en.wikipedia.org/wiki/Alluvial_fan-1.md
category: reference
title: Alluvial fan
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alluvial_fan
date_saved: 2026-05-05T07:19:43.613390+00:00
instance: kb-cron
parent: alluvial-fan-20260505-0
summary:
=== Debris flow === Debris flow fans receive most of their sediments in the form of debris flows. Debris flows are slurry-like mixtures of water and particles of all sizes, from clay to boulders, that resemble wet concrete. They are characterized by having a yield strength, meaning that they are highly viscous at low flow velocities but become less viscous as the flow velocity increases. This means that a debris flow can come to a halt while still on moderately tilted ground. The flow then becomes consolidated under its own weight. Debris flow fans occur in all climates but are more common where the source rock is mudstone or matrix-rich saprolite rather than coarser, more permeable regolith. The abundance of fine-grained sediments encourages the initial hillslope failure and subsequent cohesive flow of debris. Saturation of clay-rich colluvium by locally intense thunderstorms initiates slope failure. The resulting debris flow travels down the feeder channel and onto the surface of the fan. Debris flow fans have a network of mostly inactive distributary channels in the upper fan that gives way to mid- to lower-level lobes. The channels tend to be filled by subsequent cohesive debris flows. Usually only one lobe is active


id: alluvial-fan-20260505-2
file: data/en.wikipedia.org/wiki/Alluvial_fan-2.md
category: reference
title: Alluvial fan
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alluvial_fan
date_saved: 2026-05-05T07:19:43.613390+00:00
instance: kb-cron
parent: alluvial-fan-20260505-0
summary:
== Occurrences == Alluvial fans are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They have also been found on other bodies of the Solar System. === Terrestrial === Alluvial fans are built in response to erosion induced by tectonic uplift. The upwards coarsening of the beds making up the fan reflects cycles of erosion in the highlands that feed sediments to the fan. However, climate and changes in base level may be as important as tectonic uplift. For example, alluvial fans in the Himalayas show older fans entrenched and overlain by younger fans. The younger fans, in turn, are cut by deep incised valleys showing two terrace levels. Dating via optically stimulated luminescence suggests a hiatus of 70,000 to 80,000 years between the old and new fans, with evidence of tectonic tilting at 45,000 years ago and an end to fan deposition 20,000 years ago. Both the hiatus and the more recent end to fan deposition are thought to be connected to periods of enhanced southwest monsoon precipitation. Climate has also influenced fan formation in Death Valley, California, US, where


id: alluvial-fan-20260505-3
file: data/en.wikipedia.org/wiki/Alluvial_fan-3.md
category: reference
title: Alluvial fan
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alluvial_fan
date_saved: 2026-05-05T07:19:43.613390+00:00
instance: kb-cron
parent: alluvial-fan-20260505-0
summary:
=== Flood hazards === Alluvial fans are subject to infrequent but often very damaging flooding, whose unusual characteristics distinguish alluvial fan floods from ordinary riverbank flooding. These include great uncertainty in the likely flood path, the likelihood of abrupt deposition and erosion of sediments carried by the flood from upstream sources, and a combination of the availability of sediments and of the slope and topography of the fan that creates extraordinary hazards. These hazards cannot reliably be mitigated by elevation on fill (raising existing buildings up to a meter (three feet) and building new foundations beneath them). At a minimum, major structural flood control measures are required to mitigate risk, and in some cases, the only alternative is to restrict development on the fan surface. Such measures can be politically controversial, particularly since the hazard is not obvious to property owners. In the United States, areas at risk of alluvial fan flooding are marked as Zone AO on flood insurance rate maps. Alluvial fan flooding commonly takes the form of short (several hours) but energetic flash floods that occur with little or no warning. They typically result from heavy and prolonged rainfall, and are characterized by high velocities and capacity


id: alluvial-plain-20260505-0
file: data/en.wikipedia.org/wiki/Alluvial_plain-0.md
category: reference
title: Alluvial plain
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Alluvial_plain
date_saved: 2026-05-05T07:19:44.931749+00:00
instance: kb-cron
parent: alluvial-plain-20260505-0
summary:
An alluvial plain is a plain (an essentially flat landform) created by the deposition of sediment over a long period by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the smaller area over which the rivers flood at a particular time. In contrast, the alluvial plain is the larger area representing the region over which the floodplains have shifted over geological time. As the highlands erode due to weathering and water flow, the sediment from the hills is transported to the lower plain. Various creeks will carry the water further to a river, lake, bay, or ocean. As the sediments are deposited during flood conditions in the floodplain of a creek, the elevation of the floodplain will be raised. As this reduces the channel floodwater capacity, the creek will, over time, seek new, lower paths, forming a meander (a curved path). The leftover higher locations, typically natural levees at the margins of the flood channel, will be eroded by lateral stream erosion, local rainfall, and possibly wind transport if the climate is arid and does not support soil-holding grasses. These processes, over geologic time, will form the


id: americas-terminology-20260505-0
file: data/en.wikipedia.org/wiki/Americas_(terminology)-0.md
category: reference
title: Americas (terminology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Americas_(terminology)
date_saved: 2026-05-05T07:19:46.319434+00:00
instance: kb-cron
parent: americas-terminology-20260505-0
summary:
The Americas, also known as America, are lands of the Western Hemisphere, composed of numerous entities and regions variably defined by geography, politics, and culture. The Americas are recognized in the English-speaking world to include two separate continents: North America and South America. In parts of Europe and Latin America, America is considered to be a single continent, within which North and South America are subcontinents. == Physical geography == North America—the continent and associated islands of the Northern Hemisphere and (chiefly) Western Hemisphere. It lies northwest of South America and is bounded by the Atlantic, Arctic, and Pacific Oceans. Middle America—the territory between the southern Rocky Mountains and the northern tip of the Andes. This isthmus marks the transition between North and South America. It may also include the Caribbean. Central America—the narrow southern portion of mainland North America connecting with South America, extending from the Isthmus of Tehuantepec to the Isthmus of Panama; alternatively, the Trans-Mexican Volcanic Belt may delimit the region on the north. Caribbean—the region between southeastern North America and northern South America, consisting of the Caribbean Sea, its islands (most of which enclose the sea), and the surrounding coasts. The islands—composed of the Greater Antilles,


id: americas-terminology-20260505-1
file: data/en.wikipedia.org/wiki/Americas_(terminology)-1.md
category: reference
title: Americas (terminology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Americas_(terminology)
date_saved: 2026-05-05T07:19:46.319434+00:00
instance: kb-cron
parent: americas-terminology-20260505-0
summary:
=== Linguistic/cultural regions === Anglo-America—the region of the Americas having significant historical, linguistic, and cultural links to England or the British Isles, i.e., Anglophone; often just Canada and the United States. Latin America—the region of the Americas where Romance languages derived from Latin–namely Spanish, Portuguese, and variably French–are officially or primarily spoken. Though French is spoken in Quebec, it is typically not included due to Canada's links to Britain. Ibero-America—the region of the Americas having significant historical, linguistic, and cultural links to Spain or Portugal (both on the Iberian Peninsula), i.e., Hispanophone and Lusophone. Hispanic America (also Spanish America)—those countries inhabited by Spanish-speaking populations. French America—the Francophone region. Mesoamerica—a region of the Americas extending from central Mexico southeast to Nicaragua and Costa Rica; a term used especially in archaeology and ethnohistory for the region where an array of civilizations had flourished during the pre-Columbian era, and which shared a number of historical and cultural traditions. Mesoamerican Linguistic Area—a sprachbund, or linguistic region, defined as the area inhabited by speakers of a set of indigenous languages which have developed certain similarities as a result of their historic and geographical connections; roughly co-terminate with the archaeological/ethnohistorical Mesoamerica. Aridoamerica—an archaeological/ethnohistorical regional division, essentially


id: anatopism-20260505-0
file: data/en.wikipedia.org/wiki/Anatopism-0.md
category: reference
title: Anatopism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Anatopism
date_saved: 2026-05-05T07:19:47.579101+00:00
instance: kb-cron
parent: anatopism-20260505-0
summary:
An anatopism (from the Ancient Greek ἀνά, "against," and τόπος, "place") is something that is out of its proper place. The concept of anatopism is less widely familiar than that of anachronism, perhaps because much that is anatopic is also anachronistic. Yet the distinction is a valid one; not all that is anatopic is necessarily also anachronistic. The online Collins English Dictionary gives a synonym for "anatopism": anachorism (from Greek: ana- + khōros, "place"): "a geographical misplacement; something located in an incongruent position". == Examples == Catherine Hardwicke's 2006 film The Nativity Story shows a field of maize in a Nazareth farming scene. Maize is native to Mesoamerica, not to the Middle East, and in pre-Columbian times was grown only in the Americas. The use of maize in this film is an anatopism as well as an anachronism. The same anatopism appears in the first part ("The Warrior Pharaohs") of a three-part 2002 PBS documentary series on "Egypt's Golden Empire" depicting the history of ancient Egypt's New Kingdom: ears of maize corn are shown in a scene recreating the battle and siege of Megiddo in the 15th century BC. Ridley Scott's 2000 film Gladiator, set in 180 AD, features Roman


id: anthropization-20260505-0
file: data/en.wikipedia.org/wiki/Anthropization-0.md
category: reference
title: Anthropization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Anthropization
date_saved: 2026-05-05T07:19:48.874145+00:00
instance: kb-cron
parent: anthropization-20260505-0
summary:
In geography and ecology, anthropization is the conversion of open spaces, landscapes, and natural environments by human action. Anthropic erosion is the process of human action degrading terrain and soil. An area may be classified as anthropized even though it looks natural, such as grasslands that have been deforested by humans. It can be difficult to determine how much a site has been anthropized in the case of urbanization because one must be able to estimate the state of the landscape before significant human action. == Origin == The earliest known stages of anthropization can be found as early as the Neolithic era and the basic farmland created in that time. With the continually-growing population of humans, the land that the Earth provides has been appropriated over the years. The ecological footprint created by anthropization is continually growing despite efficiency and technique improvements made in anthropization.. Whether anthropized or not, all land seldom a few locations has been claimed. Outside of the largely inhospitable Arctic and Antarctic circles and large portions of other uninhabitable landscapes, much of the globe has been used or altered in some direct way by humans. Land has been appropriated for many different reasons, but ultimately


id: glossary-of-arabic-toponyms-20260505-0
file: data/en.wikipedia.org/wiki/Glossary_of_Arabic_toponyms-0.md
category: reference
title: Glossary of Arabic toponyms
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glossary_of_Arabic_toponyms
date_saved: 2026-05-05T07:19:50.237695+00:00
instance: kb-cron
parent: glossary-of-arabic-toponyms-20260505-0
summary:
The glossary of Arabic toponyms gives translations of Arabic terms commonly found as components in Arabic toponyms. A significant number of them were put together during the PEF Survey of Palestine carried out in the second half of the 19th century. == A == 'Ain, pl.: `Ayūn, ʿUyūn Spring, fountain, source. Examples: El Aaiún All pages with titles containing Ain All pages with titles containing Aiun Ab, Abu Father; as a geographical term it signifies "producing", "containing", etc.; All pages with titles containing Ab All pages with titles containing Abu Arak, pl.: Arkan Cavern or cliff (among various meanings); see All pages with titles containing Arak == B == Bab, pl.: Buwab Gate. Examples Bab el-Mandeb; see All pages with titles containing Bab Baḥr Arabic: بحر - Sea, large river. see All pages with titles containing Bahr Beit House. see All pages with titles containing Beit Balad Arabic: بلد (sometimes transliterated as Beled or Belled) - Town; see All pages with titles containing Balad Bir Arabic: بير, Well; see All pages with titles containing Bir Birkeh Artificial pool, tank; see All pages with titles containing Birkeh Buḥayra, Baḥeirah Arabic: بحيرة, Lake, lagoon; Diminutive of بَحْر (baḥr, “sea”). Burj Arabic: برج,


id: backcountry-20260505-0
file: data/en.wikipedia.org/wiki/Backcountry-0.md
category: reference
title: Backcountry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Backcountry
date_saved: 2026-05-05T07:19:51.538300+00:00
instance: kb-cron
parent: backcountry-20260505-0
summary:
In geography, a backcountry, back country or backwater is a geographical area that is remote, undeveloped, isolated, or difficult to access. These areas are typically rural or mountainous and sparsely populated. == Terminology == === Backcountry and wilderness within United States national parks === The National Park Service (NPS) generally uses the term "backcountry" to refer to "primitive, undeveloped portions of parks". Developments within backcountry areas are generally limited to trails, unpaved roads, and administrative facilities associated with dispersed recreational use. Dispersed recreational use is the most prevalent human use in backcountry areas, although research activities may also occur. The NPS defines wilderness within US national parks as any "backcountry areas which have been specifically designated as part of the National Wilderness Preservation System or any other area that has been determined to possess the characteristics of wilderness as defined by Section 2(c) of the Wilderness Act". Section 2(c) states in part that wilderness: (1) generally appears to have been affected primarily by the forces of nature, with the imprint of man's work substantially unnoticeable; (2) has outstanding opportunities for solitude or a primitive and unconfined type of recreation; (3) has at least five thousand acres of land or is


id: barrier-ridge-20260505-0
file: data/en.wikipedia.org/wiki/Barrier_ridge-0.md
category: reference
title: Barrier ridge
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Barrier_ridge
date_saved: 2026-05-05T07:19:54.171011+00:00
instance: kb-cron
parent: barrier-ridge-20260505-0
summary:
The terms barrier ridge, a term of art in the earth sciences, especially geology and sometimes barrier range (more common as a geography term) describing the existence of gross landforms describing long ridgelines which are particularly difficult to pass, especially in the context of being on foot or dependent upon other forms of animal powered transportation systems, in mountainous and sometimes hilly terrains. Barrier ridges such as the steep rising slopes or escarpments of the Allegheny Front, separating the ridge-and-valley Appalachians from the drainage divides of the uplands of the Appalachian Plateau. The ridge and valley region is filled with a succession of nearly impassible ridges from Northern Georgia, along the Appalachian chain all the way to Maine. == Notes == == References == == External links == Media related to Barrier ridge at Wikimedia Commons


id: binary-distribution-20260505-0
file: data/en.wikipedia.org/wiki/Binary_distribution-0.md
category: reference
title: Binary distribution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Binary_distribution
date_saved: 2026-05-05T07:19:55.509941+00:00
instance: kb-cron
parent: binary-distribution-20260505-0
summary:
Binary distribution is the presence of two or more very large and dominant cities in a country. == Countries with binary distribution == Australia (Melbourne, Sydney) Brazil (São Paulo, Rio de Janeiro) Canada (Toronto, Montréal) China (Shanghai, Beijing) India (Mumbai, Delhi) Italy (Rome, Milan) Japan (Tokyo, Osaka-Kobe-Kyoto) Netherlands (Amsterdam, Rotterdam) Russia (Moscow, Saint Petersburg) Spain (Madrid, Barcelona) Turkey (Ankara, Istanbul) USA (New York City, Los Angeles) Vietnam (Ho Chi Minh City, Hanoi) == References ==


id: boundary-real-estate-20260505-0
file: data/en.wikipedia.org/wiki/Boundary_(real_estate)-0.md
category: reference
title: Boundary (real estate)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Boundary_(real_estate)
date_saved: 2026-05-05T07:19:56.802552+00:00
instance: kb-cron
parent: boundary-real-estate-20260505-0
summary:
A unit of real estate or immovable property is limited by a legal boundary (sometimes also referred to as a property line, lot line or bounds). The boundary (in Latin: limes) may appear as a discontinuation in the terrain: a ditch, a bank, a hedge, a wall, or similar, but essentially, a legal boundary is a conceptual entity, a social construct, adjunct to the likewise abstract entity of property rights. A cadastral map displays how boundaries subdivide land into units of ownership. However, the relations between society, owner, and land in any culture or jurisdiction are conceived of in terms more complex than a tessellation. Therefore, the society concerned has to specify the rules and means by which the boundary concept is materialized and located on the ground. A 'Western' version of the boundary determination might be a legally specified procedure, performed by a chartered surveyor, supported by statements from neighbors and pertinent documents, and resulting in official recording in the cadastre as well as boundary markings in the field. Alternatively, indigenous people represent boundaries through ephemeral performances, such as song and dance, and, when in more permanent form, e.g. paintings or carvings, in an artistic or metaphorical manner. ==


id: butte-20260505-0
file: data/en.wikipedia.org/wiki/Butte-0.md
category: reference
title: Butte
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Butte
date_saved: 2026-05-05T07:19:58.123904+00:00
instance: kb-cron
parent: butte-20260505-0
summary:
In geomorphology, a butte ( BEWT) is an isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller landforms than mesas, plateaus, and tablelands. The word butte comes from the French word butte (French: [byt]), meaning 'knoll' (of any size); its use is prevalent in the Western United States, including the Southwest, where mesa (Spanish for 'table') is used for the larger landform. Due to their distinctive shapes, buttes are frequently landmarks in plains and mountainous areas. To differentiate the two landforms, geographers use the rule of thumb that a mesa has a top that is wider than its height, while a butte has a top that is narrower than its height. == Formation == Buttes form by weathering and erosion when hard caprock overlies a layer of less resistant rock that is eventually worn away. The harder rock on top of the butte resists erosion. The caprock provides protection for the less resistant rock below from wind abrasion which leaves it standing isolated. As the top is further eroded by abrasion and weathering, the excess material that falls off adds to the scree or talus slope around the base. On a much smaller


