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GPS also helps analyze global water resources

ScienceDaily (March 19, 2014)

GPS also helps analyze global water resources

ScienceDaily (March 19, 2014)

WaterGAP is a hydrological model used to model water shortage, groundwater depletion, and floods and droughts over the land area of the globe. The Frankfurt hydrologist Professor Petra Döll has examined how good a fit this model provides, using GPS observations and data from the GRACE satellite, which measures the gravitational field of the Earth. The study indicates that WaterGAP needs to be modified.

On a daily basis and with a spatial resolution of approx. 50 km, WaterGAP measures various forms of water flux such as evaporation, groundwater recharge and water flow in rivers, as well as the amount of water stored in the ground, in groundwater, in surface water bodies and as snow. Here, water abstraction for drinking water, industry and agriculture is also taken into account. A variety of data is used in calculating the models : climatic data, data concerning vegetation and soil, as well as socioeconomic and many other data besides.

Due to the uncertain data that is fed in and the simplifications required in a global-scale model, the findings are unreliable. Until now, river flow data has been employed to calibrate and check the quality of the model, but unfortunately this data does not exist for all major rivers. Besides, a model also needs to accurately map the dynamics of the stored water in order, for example, to be able to detect water abstraction by humans.

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The above story is based on materials provided by Goethe University Frankfurt.

Pour en savoir plus (ScienceDaily)

Page publiée le 2 août 2014, mise à jour le 7 août 2014