Skip to main content

Definitions

Learning Objectives

  1. Define Hydrology as a discipline within the Earth Sciences.

  • "The geoscience that describes and predicts the occurence, circulation, and distribution of the water of the earth and its atmosphere, with two principal focuses: the global hydrological cycle (distribution and spatial & temporal variations of water substance in the terrestrial, oceanic, and atmospheric compartments of the global water system) and the land phase of the hydrologic cycle (movement of water substance on and under the earth's land surfaces, the physical and chemical interactions with earth materials accompanying that movement, and the biological processes that conduct or affect that movement." (Dingman, 2002)

  • "An earth science that encompasses the occurence, distribution, movement, and properties of the waters of the earth" (Viessmann & Lewis, 1996

  1. Define and differentiate Forest Hydrology from the broader study of Hydrology
  • Forest hydrology studies the effects of vegetation and land management on water quantity and quality, erosion, and sedimentation.
  1. List at least three practical applications of Hydrology
  • Knowledge of the behavior of water (or hydrology) is essential to silviculturists, ecologists, range managements
  1. Explain and provide examples of the five functions of water
  2. List at least five current global water resources issues.

The Planting - Harvesting paradox

People don't want trees as they "will consume all the water", people do not want the trees harvested as it "protects the water resources"

Broad functions of hydrology

  • Resolve issues of water quantity and quality
  • Study interrelations between water and the environment
  • Assess the impact of human activity on the occurrence, circulation and distribution of water.
  • Make predictions of water-related events and problems
  • Adjust, manage, and operate water and water resources to benefit society.
  • Prevent destruction

The Future

  • Real-time monitoring
  • Cleaning up the water
  • Recovering aquifer storages
  • Facing the challenges of increasing population
  • Integrating different scales
  • Larger scale understanding

Functions of water

Biological * Physiology * Habitat * Hydrotherapy

Chemical * Solvent * Medium

Physical * Moderator of climate (water vapour causes 90% of greenhouse affect) * Agent of destruction * Energy and power * Standard for measurement (1 L water = 1 kg, 1 cal = heat required to raise 1 g of liquid water 1 C, freezing (0 C), boiling (100 C) * Medium of transport

Socioeconomic * Recreation * Inspiration for creativity * Agriculture * Tools for industry

Political * World peace and stability * Regional conflicts * International conflicts * Military weapon and target

Global water resources & current issue * Fresh water: 410 km diameter

  • Groundwater, rivers, lakes: 249 km diameter * Accessible surface freshwater: 96 km diameter * Global water use for annual food production: 23 km diameter

Water withdrawal: water that is mostly circulated back to the body from which it was taken.

Water consumption: water withdrawn and not returned to its original source.