Prof. Gunnar Lischeid, Dr Christoph Merz, Miaomiao Ma, Yongbo Gao
China Scholarship Council
The Quillow-catchment in the Uckermark region (ca. 100 km NE of Berlin) is one of the main investigation areas of the ZALF Institute of Landscape Hydrology and the Helmholtz project TERENO. The catchment is characterized by a complex regional hydrogeological situation with heterogenic soil and sediment structures in the underground and massive water management measures like pipe drainage, surface drainage with ditches and channels. To date, no hydrological model is available to describe this complexity.
Therefore, it is necessary to adapt and parameterize a hydrological model that can response to this complex structure and allows the assessment of water management effects calculated on the base of climate change scenarios. This hydrological model should be developed during the project. Beside the interpretation and implementation of existing data sets, e.g. with non linear statistical methods, additional data should be taken in the region.
More over, it is well known that different rainfall-runoff-models or even the same model parameterized in different ways often give indistinguishable results with respect to the simulated hydrograph (model equifinality; Beven and Freer 2001). However, if these models are used for process identification or as a basis for the modeling of reactive solute transport they exhibit substantial variety, irrespective of any superior performance on a calibration or validation data set.
It has been argued that most of the available hydrological models are highly over-parameterized with respect to available data. On the other hand, a minimum of model complexity is required to account for the expected changes, e.g., land use, water management strategies or climate. This is a serious obstacle to using models for water resources planning and management.
Thus, there is urgent need for more sophisticated approaches to evaluate model performance. This project aims at testing and developing different approaches. Different statistical methods have been applied to a variety of observed hydrographs, their potential for model performance evaluation has not been investigated in a systematic way so far.
Mr. Gao Yongbo: Integrated hydrological Modelling in the Quillow-catchment to assess the influence of water management measures in the Uckermark region
Ms Miaomiao Ma: Equilibrating data and model complexity