Double mass analysis

Double mass analysis

Double mass analysis [1] is a commonly used data analysis approach for investigating the behaviour of records made of hydrological or meteorological data at a number of locations. It is used to determine whether there is a need for corrections to the data to account for changes in data collection procedures or other local conditions. Such changes may result from a variety of things including changes in instrumentation, changes in observation procedures, or changes in gauge location or surrounding conditions. Double mass analysis for checking consistency of a hydrological or meteorological record is considered to be an essential tool before taking it for analysis purpose.

An example of a double mass analysis is a "double mass plot", or "double mass curve"[2]. For this, points and/or a joining line are plotted where the x- and y- coordinates are determined by the running totals of the values observed at two stations. If both stations are affected to the same extent by the same trends then a double mass curve should follow a straight line. A break in the slope of the curve would indicate that conditions have changed at one location but not at another.

Notes

  1. ^ Searcy, J.K. and C.H. Hardison (1960). Double-mass curves. U.S. Geological Survey Water-Supply Paper 1541-B'
  2. ^ Wilson, E.M. (1983) Engineering Hydrology, 3rd edition. Macmillan Press, London. p.27

Further reading

  • Dubreuil P. (1974). "Initiation à l'analyse hydrologique". Masson& Cie et ORSTOM, Paris.

Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph …   Universalium

  • Mass psychogenic illness — (MPI), also called mass sociogenic illness,[1] is “the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss or alteration of function, whereby… …   Wikipedia

  • Mass spectrum analysis — is an integral part of mass spectrometry.[1][2] Organic chemists obtain mass spectra of chemical compounds as part of structure elucidation and the analysis is part of every organic chemistry curriculum. Co …   Wikipedia

  • Double top and double bottom — are reversal chart patterns observed in the technical analysis of financial trading markets of stocks, commodities, currencies, and other assets. Double top Double top confirmation The double top is a frequent price formation at the end of a bull …   Wikipedia

  • analysis — /euh nal euh sis/, n., pl. analyses / seez /. 1. the separating of any material or abstract entity into its constituent elements (opposed to synthesis). 2. this process as a method of studying the nature of something or of determining its… …   Universalium

  • Double pendulum — A double pendulum consists of two pendulums attached end to end. In mathematics, in the area of dynamical systems, a double pendulum is a pendulum with another pendulum attached to its end, and is a simple physical system that exhibits rich… …   Wikipedia

  • Mass index — The mass index is an indicator, developed by Donald Dorsey, used in technical analysis to predict trend reversals. It is based on the notion that there is a tendency for reversal when the price range widens, and therefore compares previous… …   Wikipedia

  • Double layer (plasma) — This article is about the structure in plasma physics. For other uses, see Double layer. Saturnian aurora whose reddish colour is characteristic of ionized hydrogen plasma.[1] Powered by the Saturnian equivalent of (filamentary) Birkeland… …   Wikipedia

  • Mass Spectrometry Instruments — Infobox Company name = Mass Spectrometry Instruments Ltd. location = Dewberry, W. Yorkshire, U.K. industry = Mass Spectrometry products = High Resolution Mass Spectrometers homepage = http://www.massint.co.uk Mass Spectrometry Instruments Ltd. or …   Wikipedia

  • mass transit — a system of large scale public transportation in a given metropolitan area, typically comprising buses, subways, and elevated trains. Cf. rapid transit. * * * Transportation systems, usually publicly but sometimes privately owned and operated,… …   Universalium

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”