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3 Hydrologic Concepts of Variability and Scale

Part 1. Theory, Organization and Scale

  1. Ross Woods

Published Online: 15 APR 2006

DOI: 10.1002/0470848944.hsa002

Encyclopedia of Hydrological Sciences

Encyclopedia of Hydrological Sciences

How to Cite

Woods, R. 2006. Hydrologic Concepts of Variability and Scale. Encyclopedia of Hydrological Sciences. 1:3.

Author Information

  1. National Institute of Water and Atmospheric Research, Catchment Processes and Water Resources Group, Christchurch, New Zealand

Publication History

  1. Published Online: 15 APR 2006


All hydrological phenomena have significant variations in time and space. Typically, these variations are driven by variations in physiographic factors such as climate, soils, vegetation, topography, geology, as well as by human and animal activities. These externally driven variations then propagate through hydrological systems, leading to an extremely rich variety of hydrological variability apparent at different temporal and spatial scales, in different physical settings. Virtually any quantitative approach to this problem requires the selection of a limited set of spatial and temporal scales within a particular physiographic setting. Any particular choice of time and space scales has a major influence on which aspects of this hydrological variability are perceived. This article surveys hydrological variability in both time and space, across a range of scales.


  • variability;
  • scale;
  • spatial;
  • space;
  • temporal;
  • time;
  • climate;
  • soil;
  • vegetation;
  • geology;
  • topography;
  • precipitation;
  • soil moisture;
  • groundwater;
  • streamflow