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Hydrological Code
A hydrological code or hydrologic unit code is a sequence of numbers or letters (a '' geocode'') that identify a hydrological unit or feature, such as a river, river reach, lake, or area like a drainage basin (also called watershed in North America) or catchment. One system, developed by Arthur Newell Strahler, known as the Strahler stream order, ranks streams based on a hierarchy of tributaries. Each segment of a stream or river within a river network is treated as a node in a tree, with the next segment downstream as its parent. When two first-order streams come together, they form a second-order stream. When two second-order streams come together, they form a third-order stream, and so on. Another example is the system of assigning IDs to watersheds devised by , known as the Pfafstetter Coding System or the Pfafstetter System. Drainage areas are delineated in a hierarchical fashion, with "level 1" watersheds at continental scales, subdivided into smaller level 2 watersheds, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocode
A geocode is a code that represents a geographic entity (location or Geographical feature, object). It is a unique identifier of the entity, to distinguish it from others in a finite set of geographic entities. In general the ''geocode'' is a human-readable and short identifier. Typical geocodes (in bold) and entities represented by it: * ''Country code'' and subdivision code. Polygon of the administrative boundaries of a country or a subdivision. The main examples are ISO codes: ISO 3166-1 alpha-2 code (e.g. AF for Afghanistan or BR for Brazil), and its subdivision conventions, such as ISO 3166-2:AF, subdivision codes (e.g. AF-GHO for Ghor province) or ISO 3166-2:BR, subdivision codes (e.g. BR-AM for Amazonas (Brazilian state), Amazonas state). * ''DGG cell ID''. Identifier of a cell of a discrete global grid: a Geohash code (e.g. ~0.023km2 cell 6vd23gq at Brazil's Geographical centre, centroid) or a Open Location Code, Plus Code (e.g. ~0.0002km2 cell 58Q8XXXX+XX with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from rainfall, the Runoff (hydrology), runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their Bank (geography), banks and flood the surrounding area, spreading nutrients to the surrounding area. Sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reach (geography)
A reach is a segment of a stream, river, or arm of the sea, usually suggesting a straight, level, uninterrupted stretch. They are traditionally defined by the capabilities of sailing boats, as a stretch of a watercourse which, because it is straightish, can be sailed in one " reach" (that is, without tacking). Reaches are often named by those using the river, and a reach may be named for landmarks, natural features, and historical reasons (see, for instance, Gallions' Reach, named after the family that once owned its banks). A reach may be an expanse, or widening, of a stream or river channel. This commonly occurs after the river or stream is dammed. A reach is similar to an arm, though an arm may bend and thus have multiple reaches. The term "reach" can also refer to a level stretch, as between river rapids or locks in a canal. The word may also be used more generally to refer to any extended portion or stretch of land or water, or even metaphorically. In fluvial hydrology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, as with other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Basin
A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the drainage divide, made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, " watershed" is used only in its original sense, that of the drainage divide line. A drainage basin's boundaries are determined by watershed delineation, a common task in environmental engineering and science. In a closed drainage basin, or endorheic basin, rather than flowing to the ocean, water converges toward the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Newell Strahler
Arthur Newell Strahler (February 20, 1918 – December 6, 2002) was a geoscience professor at Columbia University who in 1952 developed the Strahler Stream Order system for classifying streams according to the power of their tributaries. Strahler was largely responsible for the shift from qualitative to quantitative geomorphology Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ... during the mid 20th century. Significant works *Strahler, A. N. (1952). "Dynamic basis of geomorphology". ''Geological Society of America Bulletin'' 63: 923–938. *Strahler, A. N. (1952). "Hypsometric (Area-Altitude) analysis of erosional topography". ''Geological Society of America Bulletin'' 63: 1117–1142. *Strahler, A. N. (1957). "Quantitative analysis of watershed geomorphology". ''Eos, Transactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strahler Number
In mathematics, the Strahler number or Horton–Strahler number of a mathematical tree (graph theory), tree is a numerical measure of its branching complexity. These numbers were first developed in hydrology, as a way of measuring the complexity of rivers and streams, by and . In this application, they are referred to as the Strahler stream order and are used to define stream size based on a hierarchy of tributary, tributaries. The same numbers also arise in the analysis of L-systems and of hierarchical biological structures such as (biological) trees and animal respiratory and circulatory systems, in register allocation for compiler, compilation of high-level programming languages and in the analysis of social networks. Definition All trees in this context are directed graphs, oriented from the root towards the leaves; in other words, they are Arborescence (graph theory), arborescences. The degree (graph theory), degree of a node in a tree is just its number of children. One may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pfafstetter Coding System
The Pfafstetter Coding System is a hierarchical method of hydrologically coding river basins. It was developed by the Brazilian engineer in 1989. It is designed such that topological information is embedded in the code, which makes it easy to determine whether an event in one river basin will affect another by direct examination of their codes.Watershed Topology - The Pfafstetter System , by Jordan Furnans and Francisco Olivera History and use 
In the 1950s, Pfafstetter suggested the use of a hierarchical system of coding river ...
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Endorheic Basin
An endorheic basin ( ; also endoreic basin and endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water (e.g. rivers and oceans); instead, the water drainage flows into permanent and seasonal lakes and swamps that equilibrate through evaporation. Endorheic basins are also called closed basins, terminal basins, and internal drainage systems. Endorheic regions contrast with open lakes (exorheic regions), where surface waters eventually drain into the ocean. In general, water basins with subsurface outflows that lead to the ocean are not considered endorheic; but cryptorheic. Endorheic basins constitute local base levels, defining a limit of the erosion and deposition processes of nearby areas. Endorheic water bodies include the Caspian Sea, which is the world's largest inland body of water. Etymology The term ''endorheic'' derives from the French word , which combines ( 'within') and 'flow'. Endorheic lake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Sea
The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia (country), Georgia, Romania, Russia, Turkey, and Ukraine. The Black Sea is Inflow (hydrology), supplied by major rivers, principally the Danube, Dnieper and Dniester. Consequently, while six countries have a coastline on the sea, its drainage basin includes parts of 24 countries in Europe. The Black Sea, not including the Sea of Azov, covers , has a maximum depth of , and a volume of . Most of its coasts ascend rapidly. These rises are the Pontic Mountains to the south, bar the southwest-facing peninsulas, the Caucasus Mountains to the east, and the Crimean Mountains to the mid-north. In the west, the coast is generally small floodplains below foothills such as the Strandzha; Cape Emine, a dwindling of the east end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Hydrographic Organization
The International Hydrographic Organization (IHO) (French: ''Organisation Hydrographique Internationale'') is an intergovernmental organization representing hydrography. the IHO comprised 102 member states. A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters are properly surveyed and charted. It does this through the setting of international standards and through its capacity building programs and offices. The IHO enjoys observer status at the United Nations, where it is the recognized competent authority on hydrographic surveying and nautical charting. When referring to hydrography and nautical charting in conventions and similar instruments, it is the IHO standards and specifications that are normally used. History During the 19th century, many maritime nations established hydrographic offices to provide means for improving the navigation of naval and merchant vessels by providing nautical publications, nautical charts, and oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrologic Unit Modeling For The United States
The HUMUS project (or Hydrologic Unit Modeling of the United States) is a project that was funded by the Natural Resources Conservation Service to model the non-point source loading from 8-digit hydrologic unit cataloging units. History Most of the project activity took place from 1992–1996, and work continues to this day through the Conservation Effects Assessment Program (CEAP. The project was led within NRCS by Clive Walker. The modeling work used the Soil & Water Assessment Tool (SWAT) developed by Jeff Arnold, Jimmy Williams and others at USDA-Agricultural Research Service (ARS) in Temple, Texas Temple is a city in Bell County, Texas, United States. As of 2020, the city has a population of 82,073 according to the 2020 United States census, U.S. census. Temple lies in the region referred to as Central Texas and is a principal city in th .... Additional development support was provided by the Texas A&M Blackland Research & Extension Service AgriLife Center employees Ragh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
