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Publikation Comparing Q347 development and regionalization using recent data in two Swiss cantons(09.11.2024) Dups, Yanick; Lebrenz, HenningIn Switzerland, low flows are characterized by the discharge level corresponding to a 95% exceedance probability on a ten-year average flow duration curve, referred to as Q347. This threshold not only has significant implications for planning but also requires authorities to adjust the operation of relevant infrastructure to mitigate ecological impacts on watercourses. The value of Q347 can be determined from a flow duration curve if a discharge time series of at least ten years is available. However, for smaller catchments such time series are typically unavailable, necessitating the regionalization of Q347 values. In Switzerland, multiple linear regression has been established to estimate the area-specific discharge q347 for ungauged basins. The primary objective of this study was to regionalize Q347 values for small, ungauged catchments (383 in the Canton of Solothurn and 9'034 in the Canton of Zürich) each with an area of less than 100 km². Daily discharge, precipitation, and temperature time series were collected for a 30-year study period from 1990 to 2020 from 56 gauged catchments in Solothurn, and similarly for a ten-year study period from 2013 to 2023 in Zürich, focusing on catchments smaller than 500 km² surrounding the target areas. A total of 30 “static” parameters delineating geometry, topography, geology, land use, and drainage along with nine “climatic” parameters describing temperatures, precipitation distributions, and potential evapotranspiration were defined and computed to characterize both gauged and ungauged catchments. The temporal variability of low flow events was then analysed for observed catchments in the two study areas. Over the past 30 years, the frequency of low flow events below the threshold has systematically increased, while the ten-year Q347 values for these catchments have decreased during the same period. Three multiple linear regression methods were developed and implemented to be coupled with two adjustment techniques supplementing truncated discharge time series. Validation of the proposed models showed reduced errors and increased linear correlations between estimated and observed values compared to standard models. Notably, a spatially more homogeneous yet catchment-specific distribution of estimated values is observable. The proposed models yielded promising results, particularly when time series remain unadjusted, or adjustment is done using the Antecedent Precipitation Index (API) combined with the flow duration curve of a donor basin (Ridolfi et al., 2020). Using recent data for parameter selection and model fitting, especially in the Zürich study area (2013-2022), often resulted in lower Q347 values compared to standard models, reflecting an adaptation to current climatic trends.06 - PräsentationPublikation How popular will ride hailing and ride pooling be with autonomous vehicles?(18.09.2024) van Eggermond, Michael; Erath, Alexander; Tanner, Reto06 - PräsentationPublikation Veloerreichbarkeit Sisslerfeld für verschiedene Nutzendengruppen(Hochschule für Architektur, Bau und Geomatik FHNW, 17.09.2024) Minder, Nils; Erath, Alexander; Mühlich, Nicolas11 - Studentische ArbeitPublikation Bestimmung von Velohauptrouten im Kanton Basel-Stadt(Hochschule für Architektur, Bau und Geomatik FHNW, 21.08.2024) Fiabane, Noè; Erath, AlexanderIm Rahmen des ersten Vertiefungsprojektes im MSE befasst sich diese Arbeit mit der Bestimmung von Velohauptrouten. Durch die Auswertung von Velonetzen im In- und Ausland, das Studium von Fachliteratur und Interviews mit Expertinnen und Experten wurde eine Methodik entwickelt, um Velohauptrouten festzulegen. Diese Methodik wurde am Beispiel vom Kanton Basel-Stadt auf der Ebene des Netzentwurfes angewandt. Anhand des konkreten Beispiels Basel-Stadt zeigte sich, dass die Bestimmung von Velohauptrouten sowohl intuitiv als auch herausfordernd ist. Die Routenführung auf der Ebene der Hauptverbindungen ist in vielen Fällen durch äussere Rahmenbedingungen vorgegeben. Dazu gehören Zwangspunkte wie die Rheinbrücken sowie städtebauliche Hauptachsen. Wo eine solche Führung nicht offensichtlich ist, wurde ein Bewertungsschema entwickelt, das sich auf die Anforderungen des Gesetzes über Velowege und dessen Praxishilfe stützt. Bei unklaren Teilabschnitten einer Route konnte so mittels Varianten unterschiedliche Routenführungen erstellt werden. Anschliessend wurde durch das Bewertungsschema die Bestvariante eruiert und einer Sensitivitätsanalyse unterzogen. Aufgrund der zeitlichen Rahmenbedingungen wurde dies bei vier Abschnitten durchgeführt.11 - Studentische ArbeitPublikation Parkraumkonzept Dreispitz. Analyse Ist-Zustand(Hochschule für Architektur, Bau und Geomatik FHNW, 16.08.2024) Gedik, Kevin; Erath, Alexander; Christoph Merian StiftungDiese Arbeit untersucht die aktuelle Parkplatzsituation auf dem Dreispitzareal in Basel-Stadt, mit dem Fokus auf die Anzahl, Auslastung und Nutzergruppen der vorhandenen Parkplätze. Insgesamt wurden 1’339 aktive Parkplätze erfasst, die sich auf die Allmend, Baurechtsparzellen und das Parkhaus Leimgrube verteilen. Die Analyse zeigt, dass die Parkplatzauslastung insgesamt gering ist, wobei die Spitzenwerte (60 % belegte Parkfelder) um die Mittagszeit erreicht wer-den und die Belegung in der Nacht deutlich abnimmt. Die Arbeit zeigt anhand einer Fallstudie im Bereich der Stuttgartstrasse mögliche Verbesserun-gen bezüglich des Angebotskonzepts auf. Hier könnte durch Mehrfachnutzung die Anzahl der benötigten Parkplätze reduziert und die Flächen für nachhaltige Nutzungen, wie Grünflächen, freigegeben werden. Zudem wird die Anzahl bestehender Parkfelder mit den gemäss unterschiedlichen Reglementen für das Dreispitzareal berechneten maximal möglichen Anzahl Parkfelder verglichen. Dabei wird festgestellt, dass die gemäss der kantonalen Parkraumverordnung für Bauzone 7 errechnete Maximalzahl deutlich geringer liegt als die heute tatsächlich vorhandene Anzahl an Parkfeldern. Eine Umstellung auf Zone 6 würde eine der auf dem Areal tatsächlichen Nutzungen besser Rechnung tragen, auch wenn die damit berechnete Maximalzahl den tatsächlichen Bedarf überschätzt. Es wird empfohlen, zukünftig eine bedarfsorientierte Planung durchzuführen und zusätzlich das Verkehrsaufkommen mit einem Fahrtenmodell zu steuern, um die Parkraumplanung besser an die tatsächlichen Bedürfnisse anzupassen.11 - Studentische ArbeitPublikation Where to park your car at home?(18.07.2024) Erath, Alexander; van Eggermond, Michael; Tanner, RetoHow distric parking garages can complement existing parking options in dense urban neighborhoods06 - PräsentationPublikation Virtual reality and choice modelling. Existing applications and future research directions(Edward Elgar Publishing, 2024) van Eggermond, Michael; Mavros, Panos; Erath, Alexander; Hess, Stephane; Daly, AndrewResearch eliciting individuals’ preferences, including stated preference (SP) research, have long utilised imagery as stimuli to visualise either attributes or situations deemed too complex to be expressed verbally. The advent of Virtual Reality (VR) offers choice modelers with exciting new opportunities. This chapter outlines key concepts underlying VR and summarises previous research combining VR and choice modeling. It provides a framework of different dimensions that should be considered when developing VR experiments, including technological aspects (display technology and movement) and other aspects, such as survey duration, motion sickness and the representation of time. The chapter concludes with several ways to further combine choice modeling and VR.04A - Beitrag SammelbandPublikation Fliessgewässer im Nordwestschweizer Jura in Zeiten der Trockenheit und des Klimawandels(Geographisch-Ethnologische Gesellschaft Basel, 2022) Lüscher, Peter; Weingartner, Rolf; Pavia Santolamazza, Daniela; Lebrenz, HenningTrockenheit und Niedrigwasser sind aus hydrologischer Sicht der Gewässer eine der grössten Herausforderungen in der Schweiz. In diesem Beitrag werden die Niedrigwasserverhältnisse im Nordwestschweizer Jura untersucht. Dabei steht die Frage der heutigen und zukünftigen Trockenheitsanfälligkeit im Mittelpunkt. Die Resultate belegen, dass signifikante Unterschiede zwischen Ketten- und Tafeljura bestehen, wobei die Fliessgewässer im Tafeljura insgesamt trockenheitsanfälliger sind. Gelingt es nicht, die Treibhausgasemissionen wirkungsvoll zu begrenzen, wird die Trockenheitsanfälligkeit gemäss dem Szenario ohne Massnahmen (RCP 8.5) bis Ende des Jahrhunderts deutlich zunehmen.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Where to park your car at home? How distric parking garages can complement existing parking options in dense urban neighborhoods(18.07.2024) Erath, Alexander; van Eggermond, Michael; Tanner, Reto; Susilo, Yusak04B - Beitrag KonferenzschriftPublikation Event-based flood estimation using a random forest algorithm for the regionalization in small catchments(Eigenverlag des Instituts für Wasser- und Umweltsystemmodellierung, 07/2022) Pavía Santolamazza, DanielaThe hydrological cycle is a complex system, composed of multiple variables, which in most cases are not measured. This is one of the reasons why it is a challenge to have models that adequately represent the expected discharges. The PUB initiative reinforces the need on having models that capture the different catchment interactions and represent various catchment processes. These models are more robust and thus can be more reliable to transfer to the ungauged catchments. In recent years, the field of hydrological research has focused on understanding and explaining the different processes present in catchments. Nevertheless, few applications that include pre- cipitation, the main responsible of runoff change,are found.Further understanding of the temporal and spatial dependence of the meteorological event triggering the floods is needed. In this study, an analysis of the meteorological event triggering the floods was carried out. The concept of entropy was used to characterize the temporal distribution of precipitation. It was found that the precipitation temporal entropy is a better indicator of hydrograph shape than the duration or the intensity. Further, the geographical interdependence of the amount of precipitation and the temporal precipitation entropy causing the floods was described looking at the association of sta- tions triples. This suggested that, up until a given quantile, flood events are more likely caused by precipitation events of total coverage. However, for larger quantile values, it is observed that as the quantile increases the probability of observing joint occurrence in space decreases. The tem- poral distribution of precipitation events causing the floods showed to be more associated in space than the amount of precipitation triggering the floods. Nonetheless, this temporal distribu- tion is not constant over all flood events, what can be attributed to d ifferent flood mechanisms. The Antecedent Precipitation Index (API) was used to explain the soil moisture content. The em- pirical distribution of (API) at the time of a flood was compared with empirical distributions of unconditioned (API) data series. T o this end, the Wilcoxon statistic and the Kolmogorov -Smirnov distance were used to compare the empirical distributions. The re sults showed that the soil mois- ture triggering the floods is not an annual extreme, rather a value close to the monthly maximum (API). Further, it was observed that the longer memory of the catchment gives more information about the occurrence of the flood. Additionally, in order to estimate the catchment reaction at the time of a flood, a regiona lization of the flood wave hydrographs was carried out. T o this end, three methods of defining the simi- larity of the floods were considered. In all three methods, the similarity matrices were generated using the random forest algorithm. The novelty of this procedure was the use of a supervised random forest to describe the similarity of the floods events. It was supervised given that the algorithm was trained to estimate a target variable. The proximity matrix was obtained by calcu- lating the joint occurrence of floods in the random forest space. For evaluating the estimation the hydrograph peak and the time to peak were used. In all three methods, the same tendencies were observed, an overestimation of the peak and an underestimation of the time to peak. However, the bias was observed to be smaller when an ensemble of similarity matrices was used as com- pared to having a single similarity matrix. Moreover, an approach using an unsupervised random forest was compared to the supervised one. It was found that the unsupervised random forest yields larger estimation errors. Finally, to estimate the volume of the flood event a rainfall-runoff model was modified to represent the study region. The model chosen in this study was EPIC. The model was calibrated to be more representative of the study region. To this end, the estimation errors in the space of the model parameters were studied. This allowed to find the model parameters that can better represent the study area. The values obtained were considered reasonable. For example, it is observed that the longer memory of the catchment is more representative of the study catchments, which are the same results as when analyzing the meteorological phenomenon causing the floods. Further, the values obtained for the regional constant, parameter modifying the initial abstraction of the catchment, were found to be smaller than the original ones obtained for United States catchments, which agrees with other studies in European catchments.02 - Monographie