Discharge year

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The year of discharge , also hydrological year or water management year , comes from the field of water science (hydrology). Drainage years are usually different from the calendar years. This classification is chosen in order to be able to record in the annual balance the precipitation that already fell in late autumn and early winter and was stored as snow or ice in the catchment area. However, this precipitation does not have an effect as meltwater until the following calendar year . In the Glaciology is called financial year or financial year of the glaciers.

Country-specific definitions

Germany: November 1st to October 31st

In Germany, DIN 4049 specifies the period from November 1st to October 31st for the reason that experience shows that the water reserves in Germany are the lowest at the end of October. The shift by two months (in relation to the calendar year) has the advantage that the water that precipitates in the form of snow and ice and flows off in the following calendar year can be included in the hydrological annual calculation.

The year of discharge is referred to as the calendar year in which the months of discharge from January to October occur. The discharge year 2008 begins on November 1 of the previous year and ends on October 31, 2008. The following discharge year 2009 begins on November 1, 2008. The discharge year is divided into the winter half-year (November to April) and the summer half-year (May to October) .

Switzerland: October 1 to September 30

In Switzerland, the period between October 1st and September 30th of the following year is the hydrological year (definition according to the Federal Office of Energy SFOE).

This definition takes into account the earlier onset of water binding through snow and ice in the high Alps .

Austria

In Austria, the regulation October 1 to September 30 was also in use, but the regulation November 1 to October 31 of the DIN 4049 standard is increasingly in use. In glacier research, the period from September 1 to August 31 is used as the budget year .

United States

In the USA, the United States Geological Survey defines the water year as the period from October 1 to September 30 of the following year. However, other definitions are also used.

Web links

Individual evidence

  1. ↑ The hydrological year begins in October , from SRF.ch, accessed on September 30, 2015
  2. ↑ Flood glossary. Lower Austrian Civil Protection Association (NÖZSV), accessed on February 9, 2014 .
  3. ↑ Gernot Patzelt: Glacier Report 2007/2008 . In: Collective report on the glacier measurements of the Austrian Alpine Club in 2008 (=  uphill ). Edition 02-2009. Oesterreichischer Alpenverein, Innsbruck 2009, p. 20–25 ( booklet archive alpenverein.at [PDF; accessed on February 9, 2014]).
  4. ^ Explanations for the National Water Conditions , United States Geological Survey, accessed October 16, 2011.