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Brunner, Philip

Nom
Brunner, Philip
Affiliation principale
Fonction
Professeur ordinaire
Email
philip.brunner@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/165
_
0000-0001-6304-6274

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  • Publication
    Accès libre
    Uav-Based LIDAR High-Resolution Snow Depth Mapping in the Swiss Alps: Comparing Flat and Steep Forests
    (ISPRS Congress, 2021-11-10)
    Koutantou, Kalliopi 
    ;
    Mazzotti, Giulia
    ;
    Brunner, Philip 
    Snow depth mapping in Alpine forests is of high importance for hydrogeology, ecology, tourism, and natural hazards prevention. Different remote sensing approaches have been employed for the precise mapping of snow depth within forests. However, optical sensors cannot provide below-canopy information. While Airborne Laser Scanning (ALS) systems have been used successfully in this context and allow obtaining data below canopies, the costs of acquisitions are very high, not allowing frequent data acquisitions. UAV-based Lidar technology potentially can provide the critical below-canopy information at lower cost and allows for frequent acquisitions. First attempts to employ a UAV-based Lidar system in forests have proven promising, but they are limited to flat forests and to grid-level snow depth calculations. In this study, we present UAV-based Lidar data of both flat and steep forests. Different Lidar processing workflows are analyzed and compared, and snow depth algorithms are used both at the point and the grid level. Whereas the UAV-Lidar system proved capable of mapping snow in both environments, the steep forests' data processing comes with greater challenges, especially for the 3D registration, ground classification, and point-to-point snow depth calculations.
  • Publication
    Accès libre
    Implication of density-dependent flow on numerical modelling of SW-GW interactions
    (: S. Sauvage, J. M. Sánchez-Pérez, A. E. Rizzoli, 2015-7)
    Alaghmand, Sina
    ;
    Brunner, Philip 
    ;
    Graf, Thomas
    ;
    Simmons, Craig T.
    With the growing interest in the last decades in the modelling of hydrogeological processes involved in the water resources management, it has been recognized that the assumption of constantproperties water is no longer adequate in the analysis and simulation of the flow considered in these cases. In recent years, many studies used simplistic approaches that may not represent the aquifer flow dynamics realistically by not accounting for changing fluid density. This study explore the importance of understanding the impact of density-dependent flow on SW-GW interactions. To this aim two synthetic models was developed at large and small scales and various scenarios were defined to explore the impact of density-dependent flow on drivers including river and aquifer salinity ratio, hydraulic gradient and river geometry. The results shows that simplifying by excluding density-dependent flow leads to overestimation of solute mass accumulation, and eventually groundwater salinity and limited freshwater lens. Also, the simulated model without density-dependent flow is not able to represent the unsaturated zone properly. However, these impacts are limited to the river banks. In the small scale, when simulated with density-dependent flow, large salinity ratio between river and aquifer can significantly influence both solute and flow dynamics. Moreover, mixed-convention was observed when hydraulic gradient was towards river. Overall, it was concluded that density-dependent flow play an essential role in SW-GW interaction and needs to be taken in to account where the river and aquifer have significant salinity difference, particularly at the vicinity of the river banks.
  • Publication
    Accès libre
    Wireless Mesh Networks and Cloud Computing for Real Time Environmental Simulations
    (: Springer, 2014-4-22)
    Kropf, Peter 
    ;
    Schiller, Eryk 
    ;
    Brunner, Philip 
    ;
    Schilling, Oliver 
    ;
    Hunkeler, Daniel 
    ;
    Lapin, Andrei 
    Predicting the influence of drinking water pumping on stream and groundwater levels is essential for sustainable water management. Given the highly dynamic nature of such systems any quantitative analysis must be based on robust and reliable modeling and simulation approaches. The paper presents a wireless mesh-network framework for environmental real time monitoring integrated with a cloud computing environment to execute the hydrogeological simulation model. The simulation results can then be used to sustainably control the pumping stations. The use case of the Emmental catchment and pumping location illustrates the feasibility and effectiveness of our approach even in harsh environmental conditions.
  • Publication
    Accès libre
    Real-time Environmental Monitoring for Cloud-based Hydrogeological Modeling with HydroGeoSphere
    (: IEEE Computer Society, 2014)
    Lapin, Andrei 
    ;
    Schiller, Eryk 
    ;
    Kropf, Peter 
    ;
    Schilling, Oliver 
    ;
    Brunner, Philip 
    ;
    Jamakovic-Kapic, A.
    ;
    Braun, T.
    ;
    Maffioletti, S.
    This paper describes an architecture for real-time environmental modeling. It consists of a wireless mesh network equipped with sensors and a cloud-based infrastructure to perform real-time environmental sim- ulations using a physics-based model combined with an Ensemble Kalman Filter. The purpose of the system is to optimize groundwater abstraction close to a river. These initial studies demonstrate that the cloud infrastructure can simultaneously compute a large number of simula- tions, thus allowing for the implementation of Ensemble Kalman Filters in real-time.
  • Publication
    Accès libre
    Practical identifiability analysis of environmental models
    (: IEMSS society, 2014)
    Marsili-Libelli, Stefano
    ;
    Brunner, Philip 
    ;
    Croke, Barry
    ;
    Guillaume, Joseph
    ;
    Jakeman, Anthony J.
    ;
    Jakeman, John D.
    ;
    Keesman, Karel J.
    ;
    Stigter, Johannes D.
    Identifiability of a system model can be considered as the extent to which one can capture its parameter values from observational data and other prior knowledge of the system. Identifiability must be considered in context so that the objectives of the modelling must also be taken into account in its interpretation. A model may be identifiable for certain objective functions but not others; its identifiability may depend not just on the model structure but also on the level and type of noise, and may even not be identifiable when there is no noise on the observational data. Context also means that non-identifiability might not matter in some contexts, such as when representing pluralistic values among stakeholders, and may be very important in others, such as where it leads to intolerable uncertainties in model predictions. Uncertainty quantification of environmental systems is receiving increasing attention especially through the development of sophisticated methods, often statistically-based. This is partly driven by the desire of society and its decision makers to make more informed judgments as to how systems are better managed and associated resources efficiently allocated. Less attention seems to be given by modellers to understand the imperfections in their models and their implications. Practical methods of identifiability analysis can assist greatly here to assess if there is an identifiability problem so that one can proceed to decide if it matters, and if so how to go about modifying the model ( transforming parameters, selecting specific data periods, changing model structure, using a more sophisticated objective function). A suite of relevant methods is available and the major useful ones are discussed here including sensitivity analysis, response surface methods, model emulation and the quantification of uncertainty. The paper also addresses various perspectives and concepts that warrant further development and use.
  • Publication
    Métadonnées seulement
    What is a disconnected stream?
    (2010)
    Cook, Peter G
    ;
    Brunner, Philip 
    ;
    Simmons, Craig Trevor
    ;
    Lamontagne, Sebastien
  • Publication
    Métadonnées seulement
    Modelling for sustainable water management in arid and semi-arid environments
    (2010)
    Kinzelbach, Wolfgang
    ;
    Bauer, Peter
    ;
    Brunner, Philip 
    ;
    Siegfried, T
  • Publication
    Accès libre
    Using a fully coupled surface water-groundwater model to quantify streamflow components
    (2009-5-26)
    Joseph Partington, Daniel 
    ;
    Werner, AD
    ;
    Brunner, Philip 
    ;
    Simmons, Craig Trevor Trevor
    ;
    Dandy, Graeme Clyde
    ;
    Maier, Holger R
  • Publication
    Métadonnées seulement
    Uncertainty analysis of an integrated hydrological model using posterior covariance matrix from automatic calibration
    (: IAHS-AISH publication, 2009)
    Li, Haitao
    ;
    Kinzelbach, Wolfgang
    ;
    Hendricks Franssen, Harrie-Jan
    ;
    Brunner, Philip 
    ;
    Von Boetticher, Albrecht