33:
146:
year to year is the smallest is the time with the minimum storage level and minimum flow. However, the practical considerations also affect the water year definitions. For example, in Canada the water year starts in
October, apparently to coincide with the US one, although better measurement conditions exist in winter.
145:
One way to identify a water-year is to find the successive 12-month period that most consistently, year after year, gives the highest correlation between precipitation and streamflow and negligible changes in storage (i.e., soil water and snow). Usually, the time when the variation of storage from
141:
in the US to have the lowest stream flow and consistent ground water levels. The water year is designated by the calendar year in which it ends, so the 2024 water year started on
October 1, 2023, and will end on September 30, 2024.
172:) are used to present the historical hydrological data in a simplified form. These indices help to categorize similar water years for the planning of the rule-based water operations. A typical set includes:
256:
All indices by nature reflect the historic values and therefore cannot capture the variations in climate that are known to cause the distribution of water year types to be non-stationary in time.
253:("normal" years in California are extremely rare). These California indices were not created "through a systematic statistical analysis of historic basin conditions and river flows".
137:(USGS) defines it as the period between October 1 of one year and September 30th of the next, as late September to early October is the time for many
515:
192:
in the water year. The methods of calculation (and the set of types) naturally vary by the region, therefore many indices exists, for example:
43:
773:
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W. C. Palmer, “Meteorological
Drought,” Research Paper No. 45. US Department of Commerce Weather Bureau, Washington DC, 1965.
350:
77:
17:
279:
134:
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686:
390:
196:
367:
Likens, G. E. (2013). Biogeochemistry of a forested ecosystem. Springer
Science & Business Media.
59:
528:
272:
133:
Due to meteorological and geographical factors, the definition of the water years varies. The
779:
567:"Characterization of hydrologic conditions to support Platte river species recovery efforts"
229:, runoff for the rest of the year, and the result for the previous year, calculated for few
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698:
641:
402:
8:
721:
740:
702:
645:
406:
199:(PDSI). Proposed by W. C. Palmer in 1965, PDSI is extensively used in the US since then;
815:
760:
672:
594:
582:
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during the water year is attributable to the precipitation during the same water year.
118:
because part of the precipitation that falls in late autumn and winter accumulates as
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The
Saskatchewan river basin, Canada: a geographical appraisal of the water resources
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51:
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United States
Geological Survey, "Explanations for the National Water Conditions",
222:
788:
55:
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project as an opportunity for observers to audit and verify data for their site.
149:
To accommodate the regional and climatic variations, some researchers use a per-
337:
127:
798:
518:. 8th Conference on Applied Climatology, Anaheim, 17–22 January 1993, 179-184.
809:
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138:
115:
111:
566:
202:
Standardized
Precipitation Index (SPI) was proposed by McKee et al. in 1993;
189:
188:. The years are characterized through setting numerical thresholds for the
414:
230:
226:
150:
431:
391:"Trends in Global Flood and Streamflow Timing Based on Local Water Year"
654:
629:
157:
107:
630:"In bad waters: Water year classification in nonstationary climates"
286:
123:
516:
The
Relationship of Drought Frequency and Duration to Time Scales
687:"The Palmer Drought Severity Index: Limitations and Assumptions"
787:
Johnstone, Don; Cross, William Perry (1949). "The Water Year".
680:. Somerville, MA: Stockholm Environment Institute, U.S. Center.
317:
315:
218:
209:
605:
389:
Wasko, Conrad; Nathan, Rory; Peel, Murray C. (31 July 2020).
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Used to compare precipitation from one water year to another.
312:
712:
10.1175/1520-0450(1984)023<1100:TPDSIL>2.0.CO;2
532:
462:
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119:
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and does not drain until the following spring or summer's
729:
JAWRA Journal of the
American Water Resources Association
571:
JAWRA Journal of the
American Water Resources Association
455:
370:
126:. The goal is to ensure that as much as possible of the
282:(USGS) as a term that deals with surface-water supply.
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565:
Anderson, Donald M.; Rodney, Mark W. (8 June 2007).
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477:
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totals are measured. Its beginning differs from the
628:Null, Sarah E.; Viers, Joshua H. (February 2013).
558:
382:
514:McKee, T.B., Doesken, N.J. and Kleist, J. (1993)
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156:that starts in the month with the lowest average
110:to describe a time period of 12 months for which
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388:
786:
691:Journal of Applied Meteorology and Climatology
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321:
40:The examples and perspective in this article
221:. For example, California River Indices are
722:"Hydropower Relicensing and Climate Change"
338:http://water.usgs.gov/nwc/explain_data.html
271:Used to define a period of examination for
233:separately to classify the water year as a
217:Many practically used indices were created
793:. Ronald Press Company. pp. 102–103.
710:
653:
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611:
466:
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285:The end of the water year is used by the
78:Learn how and when to remove this message
14:
808:
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332:
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719:
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264:Examples of how water year is used:
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720:Viers, Joshua H. (30 March 2011).
583:10.1111/j.1752-1688.2006.tb05308.x
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749:10.1111/j.1752-1688.2011.00531.x
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280:United States Geological Survey
135:United States Geological Survey
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1:
790:Elements of Applied Hydrology
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197:Palmer Drought Severity Index
106:) is a term commonly used in
340:, Retrieved 16 October 2011.
7:
293:
54:, discuss the issue on the
10:
832:
621:
529:"California River Indices"
322:Johnstone & Cross 1949
205:Reclamation Drought Index;
634:Water Resources Research
395:Water Resources Research
351:"The hydrological year"
278:Used in reports by the
259:
772:Duncan, Craig (1955).
780:Ohio State University
685:Alley, W. M. (1984).
614:, pp. 1137–1138.
612:Null & Viers 2013
467:Null & Viers 2013
168:Water year types (or
415:10.1029/2020WR027233
225:of the estimates of
60:create a new article
52:improve this article
42:may not represent a
741:2011JAWRA..47..655V
703:1984JApMe..23.1100A
646:2013WRR....49.1137N
407:2020WRR....5627233W
379:, pp. 110–111.
273:hydrologic modeling
655:10.1002/wrcr.20097
357:. 31 October 2012.
223:weighted averages
96:hydrological year
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62:, as appropriate.
18:Hydrological year
16:(Redirected from
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697:(7): 1100–1109.
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735:(4): 655–661.
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164:Classification
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139:drainage areas
128:surface runoff
100:discharge year
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68:September 2016
46:of the subject
44:worldwide view
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116:calendar year
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112:precipitation
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243:below normal
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239:above normal
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231:river basins
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190:water runoff
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377:Duncan 1955
227:spring melt
799:1150788749
553:Viers 2011
503:Alley 1984
306:References
158:streamflow
92:water year
816:Hydrology
757:1093-474X
664:0043-1397
599:128988784
591:1093-474X
482:WEAP 2015
449:225359722
441:0043-1397
423:1944-7973
275:purposes.
108:hydrology
104:flow year
56:talk page
810:Category
538:7 August
355:Water UK
294:See also
287:CoCoRaHS
251:critical
182:wet year
178:dry year
124:snowmelt
50:You may
778:(PhD).
765:3065925
737:Bibcode
699:Bibcode
642:Bibcode
622:Sources
403:Bibcode
210:deciles
170:indices
797:
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662:
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447:
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249:, and
219:ad-hoc
761:S2CID
725:(PDF)
678:(PDF)
595:S2CID
445:S2CID
419:eISSN
401:(8).
151:gauge
58:, or
795:OCLC
753:ISSN
660:ISSN
587:ISSN
540:2022
533:CAWR
437:ISSN
260:Uses
120:snow
745:doi
707:doi
650:doi
579:doi
427:hdl
411:doi
247:dry
235:wet
102:or
812::
759:.
751:.
743:.
733:47
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695:23
693:.
689:.
658:.
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569:.
531:.
474:^
457:^
443:.
435:.
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417:.
409:.
399:56
397:.
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353:.
329:^
314:^
245:,
241:,
237:,
184:,
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