Editing Spring (hydrology) (section)

=== Classification ===
[[Image:La Sorgue, Fontaine-de-Vaucluse.JPG|thumb|[[Fontaine de Vaucluse (spring)|Fontaine de Vaucluse]] or Spring of Vaucluse in France discharges about {{convert|470|e6USgal|m3}} of water per day at a rate of {{convert|727|ft3|m3|abbr=on}} per second.]]

Springs fall into three general classifications: perennial (springs that flow constantly during the year); intermittent (temporary springs that are active after rainfall, or during certain seasonal changes); and periodic (as in geysers that vent and erupt at regular or irregular intervals).<ref name="Classification">{{cite journal |last1=Bryan |first1=Kirk |title=Classification of Springs |journal=The Journal of Geology |date=November 1919 |volume=27 |issue=7 |pages=522–561 |doi=10.1086/622677 |jstor=30058415 |bibcode=1919JG.....27..522B |s2cid=129936821 |url=https://www.jstor.org/stable/30058415 |access-date=14 November 2021}}</ref>

Springs are often classified by the volume of the water they discharge. The largest springs are called "first-magnitude", defined as springs that discharge water at a rate of at least 2800 liters or {{convert|100|cuft|m3}} of water per second. Some locations contain many first-magnitude springs, such as [[Florida]] where there are at least 27 known to be that size; the [[Missouri]] and [[Arkansas]] [[Ozarks]], which contain 10<ref>Vineyard and Fender, 1982. p. 12</ref><ref name="waterdata.usgs.gov"/> known of first-magnitude; and 11<ref name=ui>{{cite web |url=http://www.if.uidaho.edu/~johnson/ifiwrri/1000spgs.html |title=Thousand Springs Research Project |date=9 May 2006 |url-status=dead |archive-url=https://archive.today/20121212171529/http://www.if.uidaho.edu/~johnson/ifiwrri/1000spgs.html |archive-date=12 December 2012 |via=University of Idaho }}</ref> more in the [[Thousand Springs State Park|Thousand Springs]] area along the [[Snake River]] in [[Idaho]]. The scale for spring flow is as follows:

{|class="wikitable"
|-
! Magnitude !! Flow (ft<sup>3</sup>/s, gal/min, pint/min) !! Flow (L/s)
|-
| 1st magnitude  ||  > 100&nbsp;ft<sup>3</sup>/s || 2800 L/s
|-
| 2nd magnitude  || 10 to 100&nbsp;ft<sup>3</sup>/s || 280 to 2800 L/s
|-
| 3rd magnitude  || 1 to 10&nbsp;ft<sup>3</sup>/s || 28 to 280 L/s
|-
| 4th magnitude  || 100 US gal/min to 1&nbsp;ft<sup>3</sup>/s (448 US gal/min) || 6.3 to 28 L/s
|-
| 5th magnitude  || 10 to 100 gal/min || 0.63 to 6.3 L/s
|-
| 6th magnitude  || 1 to 10 gal/min || 63 to 630 mL/s
|-
| 7th magnitude  || 1 pint to 1 gal/min || 8 to 63 mL/s
|-
| 8th magnitude  || Less than 1 pint/min || 8 mL/s
|-
| 0 magnitude  || no flow (sites of past/historic flow) || 
|}