Modeller subjectivity and calibration impacts on hydrological model applications: an event-based comparison for a road-adjacent catchment in South-East Norway

Publisher's full text
Zahra Kalantari
Steve Lyon
Per-Erik Jansson
Jannes Stolte
Lennart Folkeson
Helen French
Mona Sassner

Identifying a ‘best’ performing hydrologic model in a practical sense is difficult due to the potential influences of modeller subjectivity on, for example, calibration procedure and parameter selection. This is especially true for model applications at the event scale where the prevailing catchment conditions can have a strong impact on apparent model performance and suitability. In this study, two lumped models (CoupModel and HBV) and two physically-based distributed models (LISEM and MIKE SHE) were applied to a small catchment upstream of a road in south-eastern Norway. All models were calibrated to a single event representing typical winter conditions in the region and then applied to various other winter events to investigate the potential impact of calibration period and methodology on model performance. Peak flow and event-based hydrographs were simulated differently by all models leading to differences in apparent model performance under this application. In this case-study, the lumped models appeared to be better suited for hydrological events that differed from the calibration event (i.e., events when runoff was generated from rain on non-frozen soils rather than from rain and snowmelt on frozen soil) while the more physical-based approaches appeared better suited during snowmelt and frozen soil conditions more consistent with the event-specific calibration. This was due to the combination of variations in subsurface conditions over the eight events considered, the subsequent ability of the models to represent the impact of the conditions (particularly when subsurface conditions varied greatly from the calibration event), and the different approaches adopted to calibrate the models. These results indicate that hydrologic models may not only need to be selected on a case-by-case basis but also have their performance evaluated on an application-by-application basis since how a model is applied can be equally important as inherent model structure.

MEET US


25-26
Apr

Cost Benefit Analysis (CBA) workshop in Stockholm

An open seminar and workshop in Stockholm will be held on 25-26 April 2018. The workshop deals with the use of CBA as a basis for decision-making in the public sector. The workshop is organized by, among others, Professor Jan-Eric Nilsson, VTI.
13-14
Jun

The 6st Humanist Conference

The 6th HUMANIST Conference will take place 13-14 June 2018 in the Hague, The Netherlands. The scope of the conference covers a wide range of topics on Human Factors in Transport. Tania Willstrand and Alexander Eriksson will present their research results.

LATEST NEWS


2018-04-17

VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


2018-04-12

Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...


2018-04-11

Swedish road safety spreads internationally

Sweden is a leading country in terms of road safety, and the research conducted by the Swedish National Road and Transport Research Institute (VTI) has contributed to increased safety. VTI’s remit includes disseminating research results and keeping up to date...


2018-04-06

A greater understanding of cyclists' behaviour

Cyclists are often accused of not following traffic rules and being hooligans on the road. New research shows that there is no support for this perception. "Our observations reveal no such general anarchy" says Sonja Forward, researcher at VTI.


2018-03-28

New technology for road surface measurement tested

VTI has tested a new scanning-laser technology for road surface measurement. The tests show the new technology for comprehensive transverse-profile measurement provides dependable values in measuring transverse profile and rut depth.


2018-03-15

Ulf Sandberg has been presented with the TTI Lifetime Achievement Award 2018

VTI’s Senior Research Leader Ulf Sandberg has been presented with the TTI Lifetime Achievement Award 2018 for his work on research into tyres and road surface.