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Friction Of Distance
Friction of distance is a core principle of Geography that states that movement incurs some form of cost, in the form of physical effort, energy, time, and/or the expenditure of other resources, and that these costs are proportional to the distance traveled. This cost is thus a resistance against movement, analogous (but not directly related) to the effect of friction against movement in classical mechanics. The subsequent preference for minimizing distance and its cost underlies a vast array of geographic patterns from economic agglomeration to wildlife migration, as well as many of the theories and techniques of spatial analysis, such as Tobler's first law of geography, network routing, and cost distance analysis. To a large degree, friction of distance is the primary reason why geography is relevant to many aspects of the world, although its importance (and perhaps the importance of geography) has been decreasing with the development of transportation and communication technolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography
Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of Earth. The first recorded use of the word γεωγραφία was as a title of a book by Greek scholar Eratosthenes (276–194 BC). Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. While geography is specific to Earth, many concepts can be applied more broadly to other celestial bodies in the field of planetary science. One such concept, the first law of geography, proposed by Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." Geography has been called "the world discipline" and "the bridge between the human and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Christaller
Walter Christaller (April 21, 1893 – March 9, 1969), was a German geographer whose principal contribution to the discipline is central place theory, first published in 1933. This groundbreaking theory was the foundation of the study of cities as systems of cities, rather than simple hierarchies or single entities. He was primarily concerned with the urban space and worked on the role of towns as geographic-economic units, besides analyzing the relationships between towns of the same region. Life Walter Christaller was born to Erdmann Gottreich and Helene Christaller, an author of Christian-themed children's novels at Berneck (today part of Altensteig in Germany. His paternal grandfather Johann Gottlieb Christaller was a linguist and a Christian missionary in West Africa. Before 1914, Christaller began studies in philosophy and political economics and subsequently served in the German Army during World War I. He was homeschooled and educated at the Universities of Heidelb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multivariate Interpolation
In numerical analysis, multivariate interpolation is interpolation on functions of more than one variable; when the variates are spatial coordinates, it is also known as spatial interpolation. The function to be interpolated is known at given points (x_i, y_i, z_i, \dots) and the interpolation problem consists of yielding values at arbitrary points (x,y,z,\dots). Multivariate interpolation is particularly important in geostatistics, where it is used to create a digital elevation model from a set of points on the Earth's surface (for example, spot heights in a topographic survey or depths in a hydrographic survey). Regular grid For function values known on a regular grid (having predetermined, not necessarily uniform, spacing), the following methods are available. Any dimension * Nearest-neighbor interpolation * n-linear interpolation (see bi- and trilinear interpolation and multilinear polynomial) * n-cubic interpolation (see bi- and tricubic interpolation) * Kriging * Inverse d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cost Distance Analysis
In spatial analysis and geographic information systems, cost distance analysis or cost path analysis is a method for determining one or more optimal routes of travel through unconstrained (two-dimensional) space.de Smith, Michael, Paul Longley, Michael Goodchild (2018Cost Distance ''Geospatial Analysis'', 6th Edition The optimal solution is that which minimizes the total cost of the route, based on a field of cost density (cost per linear unit) that varies over space due to local factors. It is thus based on the fundamental geographic principle of Friction of distance. It is an optimization problem with multiple deterministic algorithm solutions, implemented in most GIS software. The various problems, algorithms, and tools of cost distance analysis operate over an unconstrained two-dimensional space, meaning that a path could be of any shape. Similar cost optimization problems can also arise in a constrained space, especially a one-dimensional linear network such as a road ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer (GIS)
In geographic information systems (GIS) and spatial analysis, buffer analysis is the determination of a zone around a geographic feature containing locations that are within a specified distance of that feature, the buffer zone (or just buffer). A buffer is likely the most commonly used tool within the proximity analysis methods.Wade, T. and Smmer, S. eds. A to Z GIS' History The buffer operation has been a core part of GIS functionality since the original integrated GIS software packages of the late 1970s and early 1980s, such as ARC/INFO, Odyssey, and MOSS. Although it has been one of the most widely used GIS operations in subsequent years, in a wide variety of applications, there has been little published research on the tool itself, except for the occasional development of a more efficient algorithm. Basic algorithm The fundamental method to create a buffer around a geographic feature stored in a vector data model, with a given radius ''r'' is as follows: * Single point: C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deterministic Algorithm
In computer science, a deterministic algorithm is an algorithm that, given a particular input, will always produce the same output, with the underlying machine always passing through the same sequence of states. Deterministic algorithms are by far the most studied and familiar kind of algorithm, as well as one of the most practical, since they can be run on real machines efficiently. Formally, a deterministic algorithm computes a mathematical function; a function has a unique value for any input in its domain, and the algorithm is a process that produces this particular value as output. Formal definition Deterministic algorithms can be defined in terms of a state machine: a ''state'' describes what a machine is doing at a particular instant in time. State machines pass in a discrete manner from one state to another. Just after we enter the input, the machine is in its ''initial state'' or ''start state''. If the machine is deterministic, this means that from this point onwards, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Information System
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, software tools for managing, Spatial analysis, analyzing, and Cartographic design, visualizing those data. In a broader sense, one may consider such a system to also include human users and support staff, procedures and workflows, body of knowledge of relevant concepts and methods, and institutional organizations. The uncounted plural, ''geographic information systems'', also abbreviated GIS, is the most common term for the industry and profession concerned with these systems. It is roughly synonymous with geoinformatics and part of the broader geospatial field, which also includes GPS, remote sensing, etc. Geographic information science, the academic discipline that studies these systems and their underlying geographic principles, may also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ian McHarg
Ian L. McHarg (20 November 1920 – 5 March 2001) was a Scottish landscape architect and writer on regional planning using natural systems. McHarg was one of the most influential persons in the environmental movement who brought environmental concerns into broad public awareness and ecological planning methods into the mainstream of landscape architecture, city planning and public policy. He was the founder of the department of landscape architecture at the University of Pennsylvania in the United States. His 1969 book ''Design with Nature'' pioneered the concept of ecological planning. It continues to be one of the most widely celebrated books on landscape architecture and land-use planning. In this book, he set forth the basic concepts that were to develop later in geographic information systems. Biography Formative years His father was a manager and later a salesman in the industrial city of Glasgow, Scotland. McHarg showed an early talent for drawing and was advised to consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantitative Revolution
The quantitative revolution (QR) was a paradigm shift that sought to develop a more rigorous and systematic methodology for the discipline of geography. It came as a response to the inadequacy of regional geography to explain general spatial dynamics. The main claim for the quantitative revolution is that it led to a shift from a descriptive ( idiographic) geography to an empirical law-making (nomothetic) geography. The quantitative revolution occurred during the 1950s and 1960s and marked a rapid change in the method behind geographical research, from regional geography into a spatial science. "The ‘Quantitative Revolution’", GG3012(NS) Lecture 4, University of Aberdeen, 2011, webpage: AB12 In the history of geography, the quantitative revolution was one of the four major turning points of modern geography – the other three being environmental determinism, regional geography and critical geography. It culminated in the emergence of the technical geography branch of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Model
Gravity models are used in various social sciences to predict and describe certain behaviors that mimic gravitational interaction as described in Isaac Newton's laws of gravity. Generally, the social science models contain some elements of mass and distance, which lends them to the metaphor of physical gravity. A gravity model provides an estimate of the volume of flows of, for example, goods, services, or people between two or more locations. This could be the movement of people between cities or the volume of trade between countries. A gravity model cannot accurately predict flows, but is instead a measure against which actual observed values can be compared, highlighting where those flows are unexpectedly high or low. Social science gravity models: *Gravity model of trade *Trip distribution *Gravity model of migration *Two-step floating catchment area (2SFCA) method The two-step floating catchment area (2SFCA) method is a method for combining a number of related types of infor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Decay
Distance decay is a geographical term which describes the effect of distance on cultural or spatial interactions. The distance decay effect states that the interaction between two locales declines as the distance between them increases. Once the distance is outside of the two locales' activity space, their interactions begin to decrease. It is thus an assertion that the mathematics of the inverse square law in physics can be applied to many geographic phenomena, and is one of the ways in which physics principles such as gravity are often applied metaphorically to geographic situations. Mathematical models Distance decay is graphically represented by a curving line that swoops concavely downward as distance along the x-axis increases. Distance decay can be mathematically represented as an inverse-square law by the expression I = const. \times d^ or I \propto 1/d^2, where is interaction and is distance. In practice, it is often parameterized to fit a specific situation, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newton's Law Of Universal Gravitation
Newton's law of universal gravitation is usually stated as that every particle attracts every other particle in the universe with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers.It was shown separately that separated spherically symmetrical masses attract and are attracted as if all their mass were concentrated at their centers. The publication of the law has become known as the " first great unification", as it marked the unification of the previously described phenomena of gravity on Earth with known astronomical behaviors. This is a general physical law derived from empirical observations by what Isaac Newton called inductive reasoning. It is a part of classical mechanics and was formulated in Newton's work '' Philosophiæ Naturalis Principia Mathematica'' ("the ''Principia''"), first published on 5 July 1687. When Newton presented Book 1 of the unpublished text in April 1686 to the Ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
