Hypsometry

picture info	Hypsometry Hypsometry () is the measurement of the elevation and depth of features of the Earth's surface relative to mean sea level. On Earth, the elevations can take on either positive or negative (below sea level) values. The distribution is theorised to be bimodal due to the difference in density between the lighter continental crust and denser oceanic crust. On other planets within this solar system, elevations are typically unimodal, owing to the lack of oceans on those bodies. Hypsometric curve A hypsometric curve is a histogram or cumulative distribution function of elevations in a geographical area. Differences in hypsometric curves between landscapes arise because the geomorphic processes that shape the landscape may be different. When drawn as a 2-dimensional histogram, a hypsometric curve displays the elevation (''y'') on the vertical, y-axis and area above the corresponding elevation (''x'') on the horizontal or x-axis. The curve can also be shown in non-dimensional or s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Bathymetry Bathymetry (; ) is the study of underwater depth of ocean floors (''seabed topography''), lake floors, or river floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of water depth measurements are from Ancient Egypt over 3000 years ago. Bathymetric (or hydrographic) charts are typically produced to support safety of surface or sub-surface navigation, and usually show seafloor relief or terrain as contour lines (called depth contours or isobaths) and selected depths ('' soundings''), and typically also provide surface navigational information. Bathymetric maps (a more general term where navigational safety is not a concern) may also use a Digital Terrain Model and artificial illumination techniques to illustrate the depths being portrayed. The global bathymetry is sometimes combined with topography data to yield a global relief model. Paleobathymetry is the study of past underwater depths. Seabed topography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Terrain Terrain or relief (also topographical relief) involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level. The Latin word (the root of ''terrain'') means "earth." In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns. Importance The understanding of terrain is critical for many reasons: * The terrain of a region largely determines its suitability for human settlement: flatter alluvial plains tend to have better farming soils than steeper, rockier uplands. * In terms of environmental quality, agriculture, hydrology and other interdisciplinary sciences; understanding the terrain of an area assists the understanding of watershed boundaries, dra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Hypsometric Integral Hypsometric is a scientific term relating to the measurement of heights. The term originates from the Greek word "hypsos" meaning height and the word ''metre'' is from the Greek (''métron''), "a measure". Hypsometric curve is a histogram of elevations of a landscape Hypsometric equation relates pressure to height in the atmosphere Hypsometric tints are a technique of showing elevation on maps A Hypsometer A hypsometer is an instrument for measuring height or elevation. Two different principles may be used: trigonometry and atmospheric pressure. Etymology The English word ''hypsometer'' originates from the Ancient Greek words ὕψος (húpsos, ... is an instrument for measuring altitude using the boiling point of a liquid. {{disamb ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]
picture info	Hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth or environmental science, civil or environmental engineering, and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation, natural disasters, and water management. Hydrology subdivides into surface water hydrology, groundwater hydrology (hydrogeology), and marine hydrology. Domains of hydrology include hydrometeorology, surface hydrology, hydrogeology, drainage-basin management, and water quality, where water plays the central role. Oceanography and meteorology are not included because water is only one of many important aspects within those fields. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Physical Geography Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere, hydrosphere, biosphere, and geosphere. This focus is in contrast with the branch of human geography, which focuses on the built environment, and technical geography, which focuses on using, studying, and creating tools to obtain,analyze, interpret, and understand spatial information. The three branches have significant overlap, however. Sub-branches Physical geography can be divided into several branches or related fields, as follows: * Geomorphology is concerned with understanding the surface of the Earth and the processes by which it is shaped, both at the present as well as in the past. Geomorphology as a field has several sub-fields that deal with the specific landforms of various environments e.g. desert geomorphology and fluvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Levelling Levelling or leveling (American English; American and British English spelling differences#Doubled in British English, see spelling differences) is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum. It is widely used in geodesy and cartography to measure vertical position with respect to a vertical datum, and in construction to measure height differences of construction artifacts. Optical levelling Optical levelling, also known as spirit levelling and differential levelling, employs an ''optical level'', which consists of a precision telescope with crosshairs and stadia marks. The cross hairs are used to establish the level point on the target, and the stadia allow range-finding; stadia are usually at ratios of 100:1, in which case one metre between the stadia marks on the levelling staff represents 100metres from the target. The complete unit is normally mounted on a Tripod (surveying), tripod, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Hypsometer A hypsometer is an instrument for measuring height or elevation. Two different principles may be used: trigonometry and atmospheric pressure. Etymology The English word ''hypsometer'' originates from the Ancient Greek words ὕψος (húpsos, “height”) and μέτρον (métron, “measure”). Scale hypsometer A simple scale hypsometer allows the height of a building or tree to be measured by sighting across a ruler to the base and top of the object being measured, when the distance from the object to the observer is known. Modern hypsometers use a combination of laser rangefinder and clinometer to measure distances to the top and bottom of objects, and the angle between the lines from the observer to each to calculate height. An example of such a scale hypsometer is illustrated here, and can be seen to consist of a sighting tube, a fixed horizontal scale, and an adjustable vertical scale with attached plumb line. The principle of operation of such a scale hypsometer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Hypsometric Equation The hypsometric equation, also known as the thickness equation, relates an atmospheric pressure ratio to the equivalent thickness of an atmospheric layer considering the layer mean of virtual temperature, gravity, and occasionally wind. It is derived from the hydrostatic equation and the ideal gas law. Formulation The hypsometric equation is expressed as: h = z_2 - z_1 = \frac \, \ln \left(\frac\right), where: h = thickness of the layer /nowiki>, z = geometric height /nowiki>, R = specific gas constant for dry air, \overline = mean virtual temperature in Kelvin /nowiki>, g = gravitational acceleration /s2/nowiki>, p = pressure Pascal_(unit)">Pa.html" ;"title="Pascal_(unit).html" ;"title="/nowiki>Pascal (unit)">Pa">Pascal_(unit).html" ;"title="/nowiki>Pascal (unit)">Pa/nowiki>. In meteorology, p_1 and p_2 are wikt:isobaric, isobaric surfaces. In radiosonde observation, the hypsometric equation can be used to compute the height of a pressure level given the height of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Productivity Productivity is the efficiency of production of goods or services expressed by some measure. Measurements of productivity are often expressed as a ratio of an aggregate output to a single input or an aggregate input used in a production process, i.e. output per unit of input, typically over a specific period of time. The most common example is the (aggregate) labour productivity measure, one example of which is GDP per worker. There are many different definitions of productivity (including those that are not defined as ratios of output to input) and the choice among them depends on the purpose of the productivity measurement and/or data availability. The key source of difference between various productivity measures is also usually related (directly or indirectly) to how the outputs and the inputs are aggregated to obtain such a ratio-type measure of productivity. Productivity is a crucial factor in the production performance of firms and nations. Increasing national productivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Limnology Limnology ( ; from Greek λίμνη, ''limne'', "lake" and λόγος, ''logos'', "knowledge") is the study of inland aquatic ecosystems. The study of limnology includes aspects of the biological, chemical, physical, and geological characteristics of fresh and saline, natural and man-made bodies of water. This includes the study of lakes, reservoirs, ponds, rivers, springs, streams, wetlands, and groundwater.Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems, 3rd ed. Academic Press () Water systems are often categorized as either running (lotic) or standing (lentic). Limnology includes the study of the drainage basin, movement of water through the basin and biogeochemical changes that occur en route. A more recent sub-discipline of limnology, termed landscape limnology, studies, manages, and seeks to conserve these ecosystems using a landscape perspective, by explicitly examining connections between an aquatic ecosystem and its drainage basin. Recently, the need to underst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Arthur 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 (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ... 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 A ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]