Hypsometry () is the measurement of the

elevation The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...

and depth of features of Earth's surface relative to mean

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. 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 plate tectonics on those bodies. EarthHypso

Hypsometric curve

A hypsometric curve is a

histogram A histogram is a visual representation of the frequency distribution, distribution of quantitative data. To construct a histogram, the first step is to Data binning, "bin" (or "bucket") the range of values— divide the entire range of values in ...

cumulative distribution function In probability theory and statistics, the cumulative distribution function (CDF) of a real-valued random variable X, or just distribution function of X, evaluated at x, is the probability that X will take a value less than or equal to x. Ever ...

of elevations in a geographical area. Differences in hypsometric curves between landscapes arise because the

geomorphic Geomorphology () is the scientific study of the origin and evolution of topography, topographic and bathymetry, bathymetric features generated by physical, chemical or biological processes operating at or near Earth#Surface, Earth's surface. Ge ...

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 standardized form by scaling elevation and area by the maximum values. The non-dimensional hypsometric curve provides a hydrologist or a geomorphologist with a way to assess the similarity of watersheds — and is one of several characteristics used for doing so. The hypsometric integral is a summary measure of the shape of the hypsometric curve. In the original paper on this topic, Arthur Strahler proposed a curve containing three parameters to fit different hypsometric relations: :

y = \left frac \cdot \frac\right z

, where ''a'', ''d'' and ''z'' are fitting parameters. Subsequent research using two-dimensional landscape evolution models has called the general applicability of this fit into question, as well as the capability of the hypsometric curve to deal with scale-dependent effects. A modified curve with one additional parameter has been proposed to improve the fit. Hypsometric curves are commonly used in

limnology Limnology ( ; ) is the study of inland aquatic ecosystems. It 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, ...

to represent the relationship between lake surface area and depth and calculate total lake volume. These graphs can be used to predict various characteristics of lakes such as

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 proce ...

, dilution of incoming chemicals, and potential for water mixing.

References

{{reflist

Hypsometric curve

See also

References

Further reading