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| Titel |
Extensive validation of the global water resources model PCR-GLOBWB 2.0: the added value of human impacts |
| VerfasserIn |
Stefanie Peßenteiner, Rens van Beek, Edwin Sutanudjaja, Marc Bierkens |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102691
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| Publikation (Nr.) |
 EGU/EGU2015-2086.pdf |
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| Zusammenfassung |
| With growing populations, economic expansion, and rising standards of living the demand for
water is increasing across the globe. Demographic developments and a changing climate will
further aggravate the pressure on global water resources. In the EU FP7 project
EartH2Observe in-situ data, earth observations, and models will be assimilated to provide a
comprehensive reanalysis of the global water resources system, accounting for all
components of the global water cycle including information on the impacts of human
activities, e.g., through water consumption and man-made reservoirs. Synthesizing as many
sources of information as possible bears great potential to improve global water balance
estimates and to consequently allow for consistent and informed decisions in water
management.
One of the modelling suites participating in EartH2Observe is the global hydrological
model PCR-GLOBWB (Van Beek et al., 2011) which already accounts for anthropogenic
perturbations in the water cycle. Here we present an extensive validation of the latest model
version PCR-GLOBWB 2.0 (Sutanudjaja et al., 2014) which comprises dynamic withdrawal,
allocation and consumptive use of ground- and surface water resources, irrigation, return
flows of unconsumed water to surface water and groundwater resources, and more than 6000
reservoirs of the GRanD database.
This study presents the first step towards a full reanalysis merging earth observations,
in-situ data and models. We focus on human activities altering the hydrologic cycle over the
past 30 years by evaluating PCR-GLOBWB “natural” and “humanly-modified” simulations
in 0.5°x 0.5° spatial and daily temporal resolution. To this end our model is forced
with the newly available WFDEI (WATCH Forcing Data methodology applied to
ERA-Interim data) data set. PCR-GLOBWB 2.0 simulations of river discharge, water
abstraction and water use are validated against observations from the Global Runoff
Data Centre as well as available national and globally reported statistics on human
water consumption (e.g.ÂAQUASTAT, USGS water data). Terrestrial water storage
(TWS) simulated by our model is compared with TWS-signals from the GRACE
satellite observation to analyze anthropogenic impacts particularly in highly regulated
basins.
The first evaluation results indicate that “humanly-modified” simulations are overall in
better agreement with the observed reference data. However, for some areas of the world the
introduction of man-made components in the water cycle reduces the model performance.
This could be attributed to simplistic process representation (of e.g.Âabstraction and
reservoirs) for some catchments but still has to be investigated in more depth. The
presented simulations serve as important benchmark. Their performance will allow for
constant evaluation of planned improvements in the representation of water cycle
processes through forcing, modelling, and assimilation of earth observation data. |
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