Hydrology explains how rainfall becomes streamflow, floods, soil moisture and groundwater. In this field it links atmospheric hazards to their effects on land, through catchment models, flood frequency analysis and the propagation of drought.
Hydrology studies the movement, distribution and quality of water across the land surface, subsurface and atmosphere. It underpins the assessment of floods, droughts and water supply, which affect food, energy, health and infrastructure together. In climate and hazards and disaster and crisis, hydrological estimates set design standards for dams, levees and drainage and inform water allocation between competing users. They link climate hazards to downstream effects on power generation, crops and public health. The canonical description is onSTEM Commons.
Catchment flood modelling
Rainfall-runoff and hydraulic models simulate how a storm becomes river flow and inundation, calibrated against gauged events.
Drought propagation
Deficits are traced from rainfall to soil moisture, streamflow and groundwater, with the lag at each stage estimated for the catchment.
Flood frequency with changing climate
Flood peaks are analysed with methods that allow change over time, and design floods are compared under present and projected conditions.
03Erdnîgarî
Water now worldwide.
Rain, flood water and root-zone soil moisture across the world, from NASA GIBS. Each layer carries its own date.
Nexşeya înteraktîf JavaScript hewce dike; lîsteya qatan û çavkanî li jêr in.
Texmîna peykî, hema hema di dema rast de. Rasterê peykî an modelî wekî peydakar diweşîne. Ewr, valahiyên şeritê û çewtiya wergirtinê valahî û xîrecir dihêlin; nirx nîşander in, ne pîvanên li cihekî ne.
Bi vê rêyê tê gihîştin
gibs.earthdata.nasa.gov, tenê piştî ku hûn nexşeya zindî destûr bidin
rojane; Tesbîtkirina bi peykê; ewr valahiyan dihêlin
Nûtirîn di dema avakirinê de
2026-10-14
Çareserî
tora nêzîkî 250 m
Nediyarî
Tesbîtkirina bi peykê; ewr valahiyan dihêlin. Rasterê peyk an modelê wekî pêşkêşker diweşîne. Ewr, valahiyên şeritê û xeletiya wergirtinê valahî û lerzê dihêlin; nirx nîşander in, ne pîvandinên li cihekî ne.
Bi vê rêyê tê gihîştin
gibs.earthdata.nasa.gov, tenê piştî ku hûn nexşeya zindî destûr bidin
Model with satellite data assimilated. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Bi vê rêyê tê gihîştin
gibs.earthdata.nasa.gov, tenê piştî ku hûn nexşeya zindî destûr bidin
Wêneyê peykî. Rasterê peykî an modelî wekî peydakar diweşîne. Ewr, valahiyên şeritê û çewtiya wergirtinê valahî û xîrecir dihêlin; nirx nîşander in, ne pîvanên li cihekî ne.
Bi vê rêyê tê gihîştin
gibs.earthdata.nasa.gov, tenê piştî ku hûn nexşeya zindî destûr bidin
Derbarê vê qatê
Delîl
Modelkirî (sala herî dawî ya ku GIBS diweşîne)
Çavkanî
Vegirtina rûyê erdê ya MODIS Terra û Aqua (MCD12Q1) (NASA LP DAAC)
Satellite gravimetry; latest month GIBS publishes. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Bi vê rêyê tê gihîştin
gibs.earthdata.nasa.gov, tenê piştî ku hûn nexşeya zindî destûr bidin
Bikişîne da ku bilivîne. Ctrl an ⌘ û zivirandin, pincandin an bişkojkan ji bo nêzîkkirinê; ji bo nirxên di bin nîşanderê de li ser bisekine; vegerandin vedigere herêmê.
Water now, framed on the world.Berhemên peyk û modelê wekî NASA diweşîne, her yek bi dîroka xwe. Nîşander in, ne nirxandinên tu cihî ne.
We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified).Daneyên vekirî yên NASA
We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified).Daneyên vekirî yên NASA
Barana GPM IMERG, NASA Precipitation Processing System; ji aliyê NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) ve tê belavkirin; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a weşandî dîsa hatine xêzkirin; nirx li cihên ku têne nîşandan di şaneyên şeşgoşe de hatine navînkirin (guherandî).Daneyên vekirî yên NASA
Berhemên VIIRS yên hema hema di dema rast de (lehî, germahiya rûyê erdê, vegirtina berfê, refleksiyona rastkirî), NASA LANCE; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a hatî weşandin ji nû ve hatine xêzkirin; nirx li cihê nîşandayî di şaneyên şeşgoşe de hatine navgîn kirin (guhertî).Daneyên vekirî yên NASA
Şiliya axê û girseya berfê ya SMAP Level 4, NASA Global Modeling and Assimilation Office; ji aliyê NASA National Snow and Ice Data Center DAAC ve tê belavkirin; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a hatî weşandin ji nû ve hatine xêzkirin; nirx li cihê nîşandayî di şaneyên şeşgoşe de hatine navgîn kirin (guhertî).Daneyên vekirî yên NASA
Berhemên rûyê erdê yên MODIS (îndeksên nebatiyê, hilberîna seretayî ya giştî, vegirtina rûyê erdê), NASA LP DAAC û LANCE; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a hatî weşandin ji nû ve hatine xêzkirin; nirx li cihê nîşandayî di şaneyên şeşgoşe de hatine navgîn kirin (guhertî).Daneyên vekirî yên NASA
Çareseriya mascon a GRACE û GRACE-FO JPL, NASA Jet Propulsion Laboratory; ji aliyê NASA Physical Oceanography DAAC (PO.DAAC) ve tê belavkirin; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a weşandî dîsa hatine xêzkirin; nirx li cihên ku têne nîşandan di şaneyên şeşgoşe de hatine navînkirin (guherandî).Daneyên vekirî yên NASA
ASTER GDEM berhemek METI û NASA ye (ASTER Global Digital Elevation Model V003, NASA LP DAAC); wêne bi riya NASA GIBS. Reng ji nexşeya rengan a weşandî dîsa hatine xêzkirin; nirx li cihên ku têne nîşandan di şaneyên şeşgoşe de hatine navînkirin (guherandî). Bi vî awayî binivîse: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003.doi:10.5067/ASTER/ASTGTM.003. Daneyên vekirî yên NASA
Bi Natural Earth hatiye çêkirin. Daneyên nexşeyê yên vektor û raster ên belaş @ naturalearthdata.com.Giştî
Blue Marble, NASA Earth Observatory; wêne bi riya NASA GIBS. Reng ji nexşeya rengan a weşandî dîsa hatine xêzkirin; nirx li cihên ku têne nîşandan di şaneyên şeşgoşe de hatine navînkirin (guherandî).Daneyên vekirî yên NASA
Bûyerên zindî: NASA Earth Observatory Natural Event Tracker (EONET); bûyer nîşanî ne û girêdanên çavkaniya xwe ya orîjînal diparêzin.
Zindî: Bûyerên NASA EONET nîşander in, ne hişyariyên desthilatê ne.
Live: NASA GPM IMERG Early. We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
Observed (EO): NASA JPL OPERA DIST-ALERT (contains modified Copernicus Sentinel data 2026). We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
NASA GIBS: We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
Pêşbîniya herikîna çemê, 30 roj bi navber (GloFAS bi riya Open-Meteo): Agahiyên Copernicus Emergency Management Service yên guhertî dihewîne 2026; ne hişyariya lehiyê ye.
Salek borî, germahiya rojane (ERA5 bi riya Open-Meteo): Agahiyên Copernicus Climate Change Service yên guhertî dihewîne 2026.
Salek borî, germahî û tava rojane (NASA POWER): Ev dane ji NASA Langley Research Center (LaRC) POWER Project hatine wergirtin ku ji aliyê NASA Earth Science/Applied Science Program ve tê fînansekirin..
Daneyên hewayê ji Open-Meteo.com (https://open-meteo.com/), bi lîsansa CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
Qatên bijartî (14 çavkanî di lîsteya qatan de: zindî, pêşbînî, çavdêrîkirî û çarçoveyî) dema ku têne vekirin krediya peydakar li ser nexşeyê û li vir çap dikin; pêşbînî encamên modelê ne û nîşanderên derxistî texmîn in.
Datasets and records used by hydrology and water science on this platform, with the role each plays and the label its values carry. Sources are listed inthe source register.
Dane
Rol
Nîşan
River gauging networks
Discharge records
ÇAVDÊRÎKIRÎ
GloFAS reanalysis
Simulated discharge where gauges are absent
MODELKIRÎ
Groundwater monitoring wells
Aquifer levels
ÇAVDÊRÎKIRÎ
Digital elevation and land cover
Catchment properties
ÇAVDÊRÎKIRÎ
05Çavdêrî bike
Forecast verification.
The screen a team would use to follow this method: its measures, states and decisions. Names are examples and values are illustrative.
Piştrastkirina pêşbîniyê
Climate and hazards · Hydrology for climate hazards · Run R-8921
Skill above referenceGCRI · Climate and Hazards
Forecast with range
Method card
Rêbaz
Hîdrolojî û zanista avê
Reference
climatology
Lead times
1 to 9 steps
Nîşan
MODELKIRÎ
Verification by lead time
held-out period
T+2
0.11
0.28
0.26
Skilful
T+4
0.12
0.26
0.34
Marginal
T+6
0.43
0.19
0.15
Skilful
T+8
0.44
0.25
0.24
Marginal
Forecast verification: the screen’s structure, terms and states for Climate and hazards.Nav û nirxên nimûneyî; sêwiran e, ne qeyd an pergaleke zindî ye.
06Erêkirin
How results are checked.
Models are calibrated on one period of observed flows and tested on an independent period or neighbouring catchment. Skill scores and comparison with surveyed flood extents are used to judge performance.
Kontrol bikin
How it is done
Split-sample testing
Models are calibrated on one period and tested on another
Rating curve review
Discharge derived from stage is checked for rating curve uncertainty at high flows
Multi-model comparison
Several hydrological models are compared before relying on one
Assumptions of stationarity weaken as climate and land use change. Ungauged basins, karst aquifers and rapid urbanisation are poorly represented by parameters fitted elsewhere.
07Simulator
Route a storm through a river network.
Rain becomes runoff by the curve number method, drains each sub-catchment through a linear reservoir and travels down the main stem by Muskingum routing; play it to watch the flood wave move and flatten. Teaching model with stated illustrative values, not a prediction.
Kontrol
Storm rainfall depth
120 mm
Storm duration
12 saet
Curve number (soil and land cover)
78
Catchment area
800 km²
Reaches on the main stem
5
Travel time per reach (Muskingum K)
6.0 h
Muskingum X (storage weighting)
0.20
Channel capacity per unit area
300 L/s per km²
Xwendin
Peak discharge at the outlet
452 m³/s
Time to peak
21.6 h
Attenuation by the channel
61%
Hours over capacity
26.4 h
Runoff coefficient
52%
Jimar, rêbaz û çavkanî
Hour
Outlet (m³/s)
Unrouted (m³/s)
Upper reach (m³/s)
2.4
0.0
678.9
0.0
12.0
308.3
1,151.4
181.8
21.6
452.4
35.1
73.7
31.2
363.3
1.1
11.1
40.8
198.8
0.0
1.5
50.4
79.3
0.0
0.2
60.0
25.4
0.0
0.0
69.6
6.9
0.0
0.0
79.2
1.7
0.0
0.0
88.8
0.4
0.0
0.0
98.4
0.1
0.0
0.0
108.0
0.0
0.0
0.0
117.6
0.0
0.0
0.0
127.2
0.0
0.0
0.0
136.8
0.0
0.0
0.0
Rêbaz
Curve number runoffUSDA Soil Conservation Service (1972), National Engineering Handbook, Section 4: Hydrology
Linear reservoirNash (1957), The form of the instantaneous unit hydrograph, IAHS 45
Muskingum channel routingMcCarthy (1938); Cunge (1969), Journal of Hydraulic Research 7
Pankeya nediyarîyê (Monte Carlo ya parametreyan)Spiegelhalter, Pearson and Short (2011), Visualising uncertainty about the future, Science 333
Hesasiyeta yek-yek (tornado)Saltelli and others (2008), Global Sensitivity Analysis: The Primer, Wiley
Dane
The model runs on the teaching values set by the controls. To calibrate it for a place, read it against these admitted layers and series, which this page’s map can draw:
Surface water, 30 m (OPERA DSWx-HLS)NASA JPL OPERA DSWx-HLS (contains modified Copernicus Sentinel data 2026) · register nasa.gibs.context-live-layers
Surface water through cloud, 30 m (OPERA DSWx-S1 radar)NASA JPL OPERA DSWx-S1 (contains modified Copernicus Sentinel-1 data 2026) · register nasa.gibs.context-live-layers
Route a storm through a river network. Illustrative teaching model: it runs on the values set by the controls, not on measured data. Methods: Curve number runoff (USDA Soil Conservation Service (1972), National Engineering Handbook, Section 4: Hydrology); Linear reservoir (Nash (1957), The form of the instantaneous unit hydrograph, IAHS 45); Muskingum channel routing (McCarthy (1938); Cunge (1969), Journal of Hydraulic Research 7).
Li seranserê şeş stûnan, bi pêşengiya Nexus Consortium
Model hydrology for climate hazards as a system. Run the cascade.
Assembled from theNexus Standardsarea profileStandardên xetera avhewa: the hazards it names, thepergalanand sectors that carry the loss, the controls that dampen it and the data that observe it. Choose the components, pick an initiating hazard and step through the cascade. The Map view places the run on an example geography with open data. Every coupling weight is a stated assumption you can change. A teaching model, not a forecast, an assessment or a certification. To model a place of your own choosing, open the fullSystem Builder.
Nirxên fêrkirinê ji bo herêmeke bajarî ya tîpîk, ne pîvanên ji bo ti cihekî. Girêdan berhevoka hêza têkiliyên di lîstikê de ye, wekî para hemû pazdehan.
12Girêdayî
Ev rûpel li ser Konsorsiyûmê te ber bi kû ve dibe.
How hydrology for climate hazards is modelled, measured and tested.
Model, texmînên wî, daneyên wî û nediyariya wî, bi şeweyê ku zanyar an endezyar kontrol bike. Avahî rêbazên weşandî dişopînin. Nirxên hatine xêzkirin nimûneyî ne, ne encam in.
Bandên nediyarîyê
How far the outlook for hydrology for climate hazards could spread, shown as ranges rather than a single line.
Texmîna navendî
navîna ansamblê
Rêze
muhtemel û pir muhtemel, bi zimanê kalîbrekirî yê IPCC
Ansambl
endam, senaryo û şertên destpêkê hatine diyarkirin
Bi vê re bixwîne
hesasiyeta encamê ya li hember her têketinê
Belavbûna ansamblê ya nimûneyî li ser pîvana indeksê; form rêwerzên nediyarî yên IPCC dişopîne. Ne pêşbînî ye.
Prensîbên rêber ên FAIR · GO FAIR û FORCE11W3C PROV · World Wide Web ConsortiumRêwerzên ji bo birêvebirina hevgirtî ya nediyarîyan · IPCCCEOS Analysis Ready Data · Committee on Earth Observation Satellites
14Pirs
Pirs û bersiv.
What are the limits of hydrology and water science in this field?
Assumptions of stationarity weaken as climate and land use change. Ungauged basins, karst aquifers and rapid urbanisation are poorly represented by parameters fitted elsewhere.
How are results checked?
Models are calibrated on one period of observed flows and tested on an independent period or neighbouring catchment. Skill scores and comparison with surveyed flood extents are used to judge performance.
Are the values on this page real?
The data names, roles and checks are real descriptions of practice. The canvas shows a design of the method’s use, not a run; no result is reported here.
rêzeya Pergalên Stratejîkis the Consortium’s quarterly publication. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work.
GCRIAvhewa û metirsîXetera pergalên gerdûnî û berxwedanSînyala ÇavdêrxaneyêSenaryo û ceribandina stresê
Tu carî daneyên şexsî, hûrgiliyên binesaza hesas an tiştekî ku mafê we yê parvekirinê tune ne neşînin. Beşdarî berî bikaranînê tê nirxandin; şandina wê nivîskarî an mafên edîtorî nade û sponsorî tu carî encamekê nakire.
Avhewa û metirsî
Rêbazek, danehevek an pirsek bîne.
Agahî û pirs îro vekirî ne. Pirsek referansekê distîne û gava piştî wê dide nasîn; serlêdan, drav, veqetandina hesabkirinê û tomarkirin tenê dema ku tîm, mercên wê û kapasîteya vekolînê hebin vedibin.
Nexşe, dane û jimarên vê malperê ji bo çarçoveyê û agahiyên giştî têne nîşandan. Ew ne şîret, ne pêşbînî û ne hişyarî ne; sînorên agahiyê di Daxuyaniyên Berpirsiyariyê û Daxuyaniyên Daneyê de hatine diyarkirin.
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