TY  - JOUR
A1  - Pilz, Tobias
A1  - Francke, Till
A1  - Baroni, Gabriele
A1  - Bronstert, Axel
T1  - How to Tailor my process-based hydrological model?
BT  - dynamic identifiability analysis of flexible model structures
JF  - Water resources research
N2  - In the field of hydrological modeling, many alternative representations of natural processes exist. Choosing specific process formulations when building a hydrological model is therefore associated with a high degree of ambiguity and subjectivity. In addition, the numerical integration of the underlying differential equations and parametrization of model structures influence model performance. Identifiability analysis may provide guidance by constraining the a priori range of alternatives based on observations. In this work, a flexible simulation environment is used to build an ensemble of semidistributed, process-based hydrological model configurations with alternative process representations, numerical integration schemes, and model parametrizations in an integrated manner. The flexible simulation environment is coupled with an approach for dynamic identifiability analysis. The objective is to investigate the applicability of the framework to identify the most adequate model. While an optimal model configuration could not be clearly distinguished, interesting results were obtained when relating model identifiability with hydro-meteorological boundary conditions. For instance, we tested the Penman-Monteith and Shuttleworth & Wallace evapotranspiration models and found that the former performs better under wet and the latter under dry conditions. Parametrization of model structures plays a dominant role as it can compensate for inadequate process representations and poor numerical solvers. Therefore, it was found that numerical solvers of high order of accuracy do often, though not necessarily, lead to better model performance. The proposed coupled framework proved to be a straightforward diagnostic tool for model building and hypotheses testing and shows potential for more in-depth analysis of process implementations and catchment functioning.
KW  - identifiability analysis
KW  - flexible model
KW  - numerics
KW  - model structure
KW  - WASA-SED
KW  - ECHSE
Y1  - 2020
U6  - https://doi.org/10.1029/2020WR028042
SN  - 0043-1397
SN  - 1944-7973
VL  - 56
IS  - 8
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - THES
A1  - Rottler, Erwin
T1  - Implementation of a snow routine into the hydrological model WASA-SED and its validation in a mountainous catchment
T1  - Einbau einer Schneeroutine in das hydrologische Modell WASA-SED und deren Validierung in einem gebirgigen Einzugsgebiet
N2  - In many regions of the world, snow accumulation and melt constitute important components of the hydrologic cycle. With the objective to improve model performance of the hydrological model WASA-SED (Water Availability in Semi-Arid environments - SEDiments) in catchments affected by snow and ice, a physically-based snow routine has been implemented into the model. The snow routine bases on the energy-balance method of the ECHSE (Eco-hydrological Simulation Environment) software. A first test application has been conducted in two sub-basins of the Isábena river catchment (Central Spanish Pre-Pyrenees). Results were validated using satellite-derived snow cover data. Furthermore, a rainfall gauge correction algorithm to restore the liquid precipitation signal of measurements affected by solid precipitation was applied. The snow module proved to be able to capture the dynamics of the snow cover forming during the cold months of the year. The temporary storage of water in the snow cover is able to improve simulations of river discharge. General patterns of the temporal evolution of observed and simulated snow cover fractions coincide. The work conducted only represents a first step in the process of implementation and evaluation of a physically-based snow routine into WASA-SED. Future work is necessary to further improve and test the snow routine and to resolve difficulties that occurred during model applications in the catchment.
N2  - In vielen Gebieten der Erde stellen die Prozesse Schneeakkumulation und -schmelze einen wichtigen Bestandteil des Wasserkreislaufs dar. Im Bestreben, Simulationen des hydrologischen Modells WASA-SED (Water Availability in Semi-Arid environments - SEDiments) in Gebieten mit Schnee und Eis zu verbessern, wurde eine physikalisch basierte Schneeroutine in die Modellstruktur implementiert. Die Schneeroutine beruht auf der Energiebilanz-Methode der ECHSE-Software (Ecohydrological Simulation Environment). Eine erste Anwendung wurde in zwei Teileinzugsgebieten des Flusses Isábena (zentrale, spanische Pre-Pyrenäen) durchgeführt. Die Validierung der Ergebnisse erfolgte anhand satellitengestützter Schneebedeckungsdaten. Außerdem wurde ein Korrekturalgorithmus zur Wiederherestellung des Signals flüssigen Niederschlags angewendet. Die Schneeroutine konnte die Dynamik der winterlichen Schneedecke erfassen. Die temporäre Speicherung des Niederschlags in der Schneedecken konnte Simulationen des Abflusses im Gebiet verbessern. Das generelle Muster der zeitlichen Entwicklung simulierter und beobachteter Schneebedeckungsgrade stimmt überein. Die durchgeführte Arbeit ist nur ein erster Schritt im Prozess der Implementierung und Validierung einer physikalisch begründeten WASA-SED Schneeroutine. Zukünftige Forschungsarbeit ist nötig, um die Schneeroutine weiter zu verbessern, zu testen und aufgetretene Schwierigkeiten bei der Modellanwendung im Gebiet zu lösen.
KW  - WASA-SED
KW  - snow routine
KW  - energy balance
KW  - MODIS snow cover
KW  - Pyrenees
KW  - WASA-SED
KW  - Schneeroutine
KW  - Energiebilanz
KW  - MODIS Schneebedeckung
KW  - Pyrenäen
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-504963
ER  -