the state of hydrological observation...

The State of Hydrological The State of Hydrological Observation NetworksObservation Networks

Status of Hydrological inStatus of Hydrological in--situ Networks situ Networks and Future Developments and Future Developments Including Including

SpaceSpace--Based Observations Based Observations ..an overview..an overview

W. E. GrabsW. E. GrabsChief, Water Resources DivisionChief, Water Resources Division

World Meteorological OrganizationWorld Meteorological OrganizationWMO, GenevaWMO, Geneva

[email protected]@wmo.int

The challengeThe challenge

Increased water demandFloods and droughtsImpacts of climate changeReduction or deterioration of available resourcesManagement of shared resources

AddressingAddressing UncertaintyUncertainty in in HydrologicalHydrologicalForecastingForecasting and and PredictionPrediction

Quantifying the uncertainty in hydrologic predictions is becoming increasingly important in decision-making

Reduction of uncertainty might be achieved in three ways:[1] providing new, more and higher quality information due

to improved measurements (quantity, quality, timeliness) and measurement techniques;

[2] developing improved model structures based on better understanding of physical processes and better mathematical representation; and

[3] improving the use of the available information during model identification and prediction.

Focus of this presentation is on hydrological observations

Developments in Hydrological Observations

FromFrom staff gauge observationsstaff gauge observations……

FLOAT TYPE GAUGE

PRESSURE SENSOR

BUBBLE SYSTEM

……to to otherother conventionalconventional water water levellevelobservationsobservations……

……usingusing advancedadvanced radar techniquesradar techniques

Pulse Radar

Measure water levelwithout contact

……..ComplementComplement terrestrialterrestrial withwithsatellite (radar satellite (radar altimetryaltimetry) observations) observations

…….Arriving at multi.Arriving at multi--platform integrated platform integrated observationsobservations……

Red indicates area where NRT products are currently generated

Blue indicates area where products may be generated in the future.

Source: ESA, De Montford University, UK

…Integration of Gravimetric observations of large Groundwater Bodies …..

Data Transmission and Data Transmission and TelemetryTelemetry: : FromFromconventionalconventional systemssystems toto……

GSM Modem

Data logger with display

Cable to connect water level sensor « bubble-in principle »

Hydrological station with GSM remote transmission; Volta-HYCOS project

StateState--ofof--thethe--Art Data Collecting Art Data Collecting Platforms (Ghana)Platforms (Ghana)

Bubble Sensor NIMBUS

Source: Jean-Marie Briquet

Use of Satellite–based TelecommunicationSystems such as….

ObservedObserved generalgeneral trend: trend: FromFrom offoff--lineline to to ((nearnear) real time ) real time hydrologicalhydrological observationsobservations

Source: http://water.usgs.gov/nsip/history.html

Nearly 90 percent of the USGS stream gauges deliver real-time streamflowinformation at the end of 2004. The real-time technology used at the majority of stream gauges is satellite transmission, but some stream gauges are equipped with telephone or radio transmitters. Nearly all of the USGS real-time stream gauges display the streamflow information on the Internet within 4 hours of the observation taken.

Satellite datacollection platforms

Other types ofhydrological station

Server of the satell iteoperator

Regional DatabaseWeb site of the project

REGIONAL CENTREREGIONAL CENTREMETEOSAT,METEOSAT, GOEs GOEs, etc., etc.

NATIONAL HYDROLOGICALNATIONAL HYDROLOGICALSERVICESSERVICES

National Databases

END USERSEND USERS

Flow of hydrological data and informationwithin a HYCOS regional project

Hydrological Information Systems…

Information Sharing in Forecasting: A Information Sharing in Forecasting: A Regional Flood Information NetworkRegional Flood Information Network

Source: NOAA 24-hr rainfall forecast for July 27 (6:00Z).

• Rainfall Forecasts

• Flood loss

• Likely damburst

• Situation Report

Source: ICIMODKey for success: Integration of multi-platforminformation in a single system

• Inadequate / deteriorating systems for collecting and managing water-resources related information

• Little or no-quality assurance & control standards applied to instruments, data reduction methods and procedures

• Insufficient basic capabilities to access, interpret, and apply water cycle information available from satellite systems

Declining ability of the National Hydrological Services (NHSs) and related water agencies to provide information

on the status and trend of water resources

Current Situation of Data Collection Current Situation of Data Collection Systems (I)Systems (I)

Current Situation of Data Collection Current Situation of Data Collection Systems (II)Systems (II)

« Rationalization » of networks: Stations with long-term records are abandoned because it is felt that no incremental hydrological information can beobtained for i.e. engineering/design purposes.

This neglects the potentially changing hydrologicalregime as a result of climate change.

Long-term hydrological records are indispensible to assess impacts of climate change and to deriveadaptive measures.

Current Situation of Data Collection Current Situation of Data Collection Systems (III)Systems (III)

Hydrological stations are abandoned for the followingreasons:Available records fulfill present hydrologicalinformation requirements;No direct economically justifiable use of hydrologicalinformation is apparent (i.e. in pristine basins!)Logistical problems to maintain the stationsBudgetary/resource problems to maintain the stationClimate issues have largely not yet been taken into

account in decisions regardingestablishment/maintenance & operation of

hydrological networks!

DecliningDeclining HydrologicalHydrological Networks: Networks: USGS USGS exampleexample

Source: http://water.usgs.gov/nsip/history.html

From 1980 to 2004, 2,051 stream gauges with 30 or more years of streamflow record were discontinued. At the end of 2005, 7360 stations were active

DeclineDecline of of hydrologicalhydrological stations in stations in Kirgizstan Kirgizstan (Aral (Aral SeaSea Basin) 1985Basin) 1985--20052005

147 146 145137 135

127 128120123 118

97 96

85 8575 75 75 76 76 76 76 76

0

20

40

60

80

100

120

140

160

1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005Годы

Динамика сокращения наблюдений гидрологической сети Кыргызгидромета

Гидропосты

Number of hydrologicalstations declined by 48% in the period 1985-2005

Obstacles for Sharing Obstacles for Sharing HydrologicalHydrologicalDataData

• Fragmented data holdings, limited or no access procedures in place

• Interoperability of systems to support data exchange

• Commerical use of data

• Security considerations

• Political conflict between ripariancountries

Trends in the Trends in the DevelopmentDevelopment of of HydrologicalHydrological Networks (I)Networks (I)

Many new networks are project-oriented, especiallyin developing countries, serving specific project-objectives;

Development of new networks mainly in support of early warnings for disaster prevention;

Expansion of networks to obtain short time series of data while often neglecting stations with a view to long time series;

Trends in the Trends in the DevelopmentDevelopment of of HydrologicalHydrological Networks (II)Networks (II)

Short-term economic considerations lead to an increased« rationalization » of networks that invetably lead to a general decline of the number of observations;

Consideration of the development of Hydrological Networks in support of climate issues is at its beginning;

Little preparedness by national agencies and donors to investin Multipurpose Hydrological Networks expanding to regional networks or upscaling to global hydrologicalnetworks.

International Efforts Initiated to International Efforts Initiated to Address these IssuesAddress these Issues

1993 - World Hydrological Cycle Observing System (WHYCOS) - WMO

2002 - Global Terrestrial Network – Hydrology (GTN-H), effort of WMOand GCOS Implementation Plan

• development of baseline network in support of UNFCCC

2003 - GEO and its 10-Year Implementation Plan for GEOSS• with water cycle observations and related research activities

2004 - Global Water Cycle Observations Theme (IGWCO) by IGOS – P• develop & promote strategies for continuity of global water cycle observing systems

Detailed understanding of the components of the global water cycle not yet achieved

Global Global StatusStatus of of HydrologicalHydrological Networks Networks –– The The GRDC GRDC ExampleExample, August 2007, August 2007

IncreasingIncreasing hydrologicalhydrological information in information in GRDC 1993 GRDC 1993 -- 20062006

TimeTime--wisewise distribution of GRDC Data distribution of GRDC Data Holdings 1993 Holdings 1993 -- 20062006

FRIEND Flow Regimes of International and

Experimental Network Data….a UNESCO IHP Programme…

Objectives

“To develop a better understanding of hydrological variability and similarity…through the mutual exchange of data,

knowledge and techniques...

… to improve practical water resource and flood design methods”

FRIEND: A global perspective

WHYCOS WHYCOS -- The goalsThe goals

A WMO global framework programme aiming at:

Improving the availability, accuracy and dissemination of water related data and information

Strengthening international cooperation and data exchange

Facilitating water related data and information use for sustainable socio-economic development

Need for WHYCOSNeed for WHYCOS

Shortage or lack of data and information on freshwater resourcesAgeing and inadequacy of observing networksInadequate data management capabilitiesInstitutional weakness of National Hydrological Services

WHYCOS WHYCOS –– The ConceptThe Concept

Strengthen the capacity for water resources assessment and management at the national, river basin, regional and global levels

Promoting regional and international cooperation in the collection, transmission, processing, archiving and use of hydrological data and information

WHYCOS componentsWHYCOS components

ImplementationImplementation on a Global Basison a Global Basis

River discharge contribution to the GTN-H project sponsored by GCOS and HWRP of WMO

GCOS baseline river discharge network, supported by the Implementation Plan for the Global Observing Systems for Climate in Support of the UNFCCC

Basis for GRDC co-operation with the UN GEMS/WaterProgramme Office of UNEP/DEWA in Burlington/Ontario for biogeochemical flux computations

Basis for future versions of the GRDC product "Long Term Mean Annual Freshwater Surface Water Fluxes into the World Oceans“

StepsSteps towardstowards ImplementationImplementationInceptionWorkshop, Geisenheim, Germany, June 2000: Global Hydrological Observation Network for Climate

Expert Meeting, Koblenz, Germany, June 2001: Implementation of a Global Terrestrial Network for Hydrology (GTN-H)

Expert + Coordination Meeting Toronto, Canada, November 2002: Hydrological Data for Global Studies

Second GTN-H Coordination Panel meeting, Koblenz, Germany, July 2005

Third GTN-H Coordination Panel meeting, Koblenz, Germany, September 2007

Global Terrestrial NetworkHydrology(GTN-H)

"Network of Networks"

Snow cover*Glaciers and ice

caps*

NSIDCWGMS / GTN-G

Precipitation*

GPCCGPCPNCDC / GSN

River discharge*

GRDC / GTN-R

Water vapour*

WMO WWW

Ground water*

IGRAC

GEMS/Water

In-situ Soil Moisture Network (planned);SMOS

Soil moisture

Water quality / BGC fluxes

FAO/AQUASTAT

Water use*

FLUXNET

Evapotranspiration

HYDROLARE / GTN-L

Lake level/area*

IAEA / GNIP

Isotopes

GTN-H Configuration as of November 2007

Global network/coverage defined and contact establishedGlobal network/coverage partly existing/identified and/or contact to be improvedNo global network/coverage identifiedGCOS Essential Climate Variable*

Global Global TerrestrialTerrestrial Network Network -- RunoffRunoff

Network consists of 380 gaugingstations worldwide

HydrologicalHydrological Information for Information for ClimateClimateStudiesStudies: : PristinePristine BasinsBasins

Attempt to develop a global hydrological reference database on climate sensitive, pristine river basins. Some 21 countries have responded positively up to now. Based on the information obtained, GRDC will develop a metadata catalogue that also will allow the display of the geographical location of the stations.

ResponseResponse of Countries to of Countries to PristinePristineBasins for Basins for HydroclimaticHydroclimatic StudiesStudies DataData

21 countries so far provided information on 240 stations in pristine basins (August 2007)

1700

New! 30-08-2007

Global monitoring of runoff and lake storage:

- important elements of Integrated Global ObservingSystems

- integral parts of water resources management including prevention of water-induced disasters

New Project, facilitated by GEO:Hydrological Applications – Runoff Project

(HARON)Basic Rationale of the Initiative

IGWCOIGWCO GCOSGCOS

Provision of near real-time monitoring data and products of large scale rivers and lakes from:

•in-situ gauge observations, and •satellite observations (based on developing altimetry technology)

Will fulfill goal of observing / analyzing surface runoff and lake storage variations over time.

IGWCOIGWCO GCOSGCOS

HARON: Basic Rationale (cont.)

• Development of new in-situ and remote sensing sensors for water cycle measurements• Near real-time regional and global computation of the water balance, as input for climate models and seasonal forecasting• Validation of large-area precipitation fields against basin-wide hydrological records to validate GCMs• Detection of climate variability signal in changing hydrological patterns of river runoff on seasonal and inter-annual scales• Estimation of bio-geochemical fluxes from continents into world oceans•Variation of freshwater fluxes from the continents and influenceon thermohaline circulation / ocean currents

HARON Project: Raison dHARON Project: Raison d’’êtreêtre

Main Goals • Support water resources management while contributing in a cross-cutting fashion to all societal benefit areas of GEO

• Improve & support the closure of the global water budget, in line with requirements of GCOS and the Global Water Cycle Experiment (GEWEX)

Main ObjectiveIntegrate, in a phased approach, dedicated river gauging networks of existing hydrological stations into a global runoff observation network

Goals & ObjectivesGoals & Objectives

Strengthening of in-situ and satellite monitoring networks of estuaries, rivers, lakes, reservoirs, and groundwater levels

Expected ResultsExpected Results

PHASE I – Upgrade & sustained maintenance of major global run-off stations, monitoring continental freshwater fluxes into the world’s oceans

PHASE II – Integration of hydro-meteorological and related in-situcomponents with satellite observations

PHASE III – Consolidation of integrated hydrological observation network development and application of user-oriented information products made available by HARON

Production of an implementation plan for a broad global water cycle data integration system, combining water cycle in-situ, satellite, and model output data

Implementation PhasesImplementation Phases

Main Global Groundwater Regions

Phase 2 (Phase 2 (exampleexample I)I)

Establishment of phased connections with relevant existing or proposed networks

GEMS-Water Stations: Global Distribution

Establishment of phased connections with relevant existing or proposed networks

Phase 2 (Phase 2 (exampleexample II)II)

Rehabilitation of the in-situ observational infrastructure

• Technical upgrade, as required, of the major run-off stations which monitor continental freshwater fluxes into the world’s oceans of the GTN – R network

Linkage with relevant research and development activities

• Use of satellite altimeters to measure inland water heights for major rivers - relevant research issue to supplement in-situ observations for the derivation of discharge data

• Continuous follow-up on results of national and regional initiatives for application during project implementation

Main ElementsMain Elements

SpaceSpace--based hydrological based hydrological observations: Outlook (1)observations: Outlook (1)

High priority for additional observations should be High priority for additional observations should be focused on datafocused on data--poor regions, poorlypoor regions, poorly--observed observed parameters, regions sensitive to change.parameters, regions sensitive to change.The need for complementary inThe need for complementary in--situ baseline situ baseline observations for satellite measurements should be observations for satellite measurements should be appropriately recognized. The integration of inappropriately recognized. The integration of in--situ and situ and space based observations for hydrological space based observations for hydrological applications have to be undertaken in a comparable applications have to be undertaken in a comparable space and time domain and under tight quality control. space and time domain and under tight quality control. The latter would require The latter would require increased efforts to assess increased efforts to assess observation quality through intercomparison and (re)observation quality through intercomparison and (re)--calibration projects.calibration projects.


There is the need for coordinated data management of observational data streams from multiple observation platforms for basin-scale studies.The broader modelling community requires coordinated ground, atmospheric and satellite measurements for coupled modelling, intercomparison purposes and the derivation of problem-specific scenarios.


The need for long-term historical records has long since recognized by the hydrological community. Efforts need to be enhanced to ensure long termstorage and archiving of key satellite-basedobservations beyond the lifetime of a specificmission.

Speficially, this means that suitable hosts need to be found that take up full data centre functions

ThankThank youyou for for youryour attention !attention !

the state of hydrological observation...

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