| 1. |
- Brandt, S. Anders, 1970-, et al.
(författare)
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3D geovisualization as a communication and analysis tool in fluvial geomorphology
- 2004
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Ingår i: Geoinformatics 2004. - Gävle : Gävle University Press. - 919749481X ; , s. 339-346
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Konferensbidrag (refereegranskat)abstract
- The fields of hydrology and fluvial geomorphology get more and more attention in the general public. The reason for this is changed climate patterns with increased frequencies of storms and river flooding and as a result changed geomorphology and living conditions for the inhabitants of the area. With the development of 3D geovisualization, hydrological and geomorphological processes can be better simulated and visualized. Thus not only the domain specialists, but also the general public can appreciate very complex hydrological processes and resulting geomorphology. This is of great value since a high frequency of storms and flooding has been a big issue for politicians, planners, and the general public. It is in this sense that 3D geovisualization can be an important tool for analysis and communication. Complex hydrological and geomorphological processes can be effectively simulated and analyzed by the domain specialists while efficient and effective visualization provides a common platform for communication among domain specialists and the general public. This paper will discuss and illustrate these issues using a case study of geomorphology along the Reventazón River, downstream from the Cachí Reservoir in Costa Rica, due to the release of extreme amounts of sediment during flushing of the reservoir.
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| 2. |
- Brandt, S. Anders, 1970-, et al.
(författare)
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A harmonized GIS course curriculum for Swedish universities
- 2007
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Ingår i: EUC'07 HERODOT Proceedings. ; , s. 10 s.-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- With the implementation of the Bologna declaration, European and other universities must change or adjust courses and programmes so they fit into the Bologna model. In Sweden this will take place during 2007. The intention with the declaration, for example, is that a basic course in one subject at one university should be treated as equivalent to the same type of course at another university. Once a year, the recently formed section for education of the Swedish Cartographic Society gathers university lecturers and others for an education conference to discuss matters concerning higher education in geomatics, geoinformatics, geography, etc. Last year’s conference identified the need for a harmonized course curriculum in basic GIS. One of the advantages of such a course is easier transfer of study records for inclusion of course credits in study programmes at other universities. Therefore, an attempt has been made to write a harmonized course curriculum for basic GIS. The course will contain about 50% common content and about 50% of content decided by the individual university. The common content will be described as learning outcomes, and then it is up to the universities to place the learning outcomes into a context. Thanks to this common core, the course can be given for such diverse programmes as archaeology, land surveying, or economy, and still be able to include the required knowledge for students to continue on more advanced courses at other universities.
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| 3. |
- Brandt, S. Anders, 1970-
(författare)
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Conceptualization of hydraulic and sedimentary processes in downstream reaches during flushing of reservoirs
- 2005
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Ingår i: Proceedings of the XXXI IAHR Congress [Elektronisk resurs]. - Seoul : Korea Water Resources Association. - 8987898237 ; , s. 2577-2588
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Konferensbidrag (refereegranskat)abstract
- The main focus of this paper is to describe the active hydraulic and sedimentary processes in downstream river reaches during flushing of sediments from reservoirs. During flushing extreme amounts of sediment may be released. Therefore, these processes are different than those downstream from dams and reservoirs not subjected to flushing. Hence, also the effects differ, which knowledge of may be of value for biologists, etc. During flushing of a reservoir a wave will be released to the downstream reaches. This wave can be divided into one water part and one sediment part. Initially they are in phase with each other, but with increased distance downstream from the dam, the transported sediment lags behind the water due to different traveling velocities. The paper treats when and where sedimentation occurs, and how this is related to the different traveling velocities of water and sediment. Also included are discussions on how the downstream effects during flushing differ from non-flushing effects, how visualization of effects can enhance both the analysis and communication with planners, politicians, etc., as well as discussions on how the studies of these effects can benefit from improved field-work methods.
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| 4. |
- Brandt, S. Anders, 1970-, et al.
(författare)
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Harmonization of GI educations in Sweden and the Bologna process : viewpoints of University of Gävle
- 2006
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Ingår i: Fifth European GIS Education Seminar (EUGISES 2006). ; , s. 10-
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Konferensbidrag (refereegranskat)abstract
- With the implementation of the Bologna declaration, many study programmes and course curricula needs to be updated and revised. This paper describes the current situation in Sweden regarding GIT educations and courses and whether a harmonization is needed. A survey was made to see which GIT courses that are given and at which level they are given at the various universities. For some universities, interviews were conducted about their courses’ contents and their strategies for determining course levels. Discussions were also made about harmonization of courses between Swedish universities. Some problems due to lack of harmonization was noted, which probably will be more severe in the future due to increased student mobility. To harmonize courses, Bloom’s revised taxonomy is put forward as a tool which is used to clearly state the level of the course in relation to learning objectives.
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| 5. |
- Brandt, S. Anders, 1970-, et al.
(författare)
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Importance of river bank and floodplain slopes on the accuracy of flood inundation mapping
- 2012
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Ingår i: River Flow 2012. - Leiden, The Netherlands : CRC Press / Balkema (Taylor & Francis). - 9780415621298 - 9780203076354 - 9781466575523 ; , s. 1015-1020
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Konferensbidrag (refereegranskat)abstract
- Effective flood assessment and management depend on accurate models of flood events, which in turn are strongly affected by the quality of digital elevation models (DEMs). In this study, HEC-RAS was used to route one specificwater discharge through the main channel of the Eskilstuna River, Sweden. DEMs with various resolutions and accuracies were used to model the inundation. The results showed a strong positive relationship between the quality of theDEMand the extent of the inundation. However, evenDEMswith the highest resolution produced inaccuracies. In another case study, the Testebo River, the model settings could be calibrated, thanks to a surveyed old inundation event. However, even with the calibration efforts, the resulting inundation extents showed varying degrees of deviation from the surveyed flood boundaries. Therefore, it becomes clear that not only does the resolution of the DEM impact the quality of the results; also, the floodplain slope perpendicular to the river flow will impact the modelling accuracy. Flatter areas exhibited the greatest predictive uncertainties regardless of the DEM’s resolution. For perfectly flat areas, uncertainty becomes infinite.
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| 6. |
- Brandt, S. Anders, 1970-
(författare)
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Resolution issues of elevation data during inundation modeling of river floods
- 2005
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Ingår i: Proceedings of the XXXI IAHR Congress [Elektronisk resurs]. - Seoul : Korea Water Resources Association. - 8987898237 ; , s. 3573-3581
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Konferensbidrag (refereegranskat)abstract
- A case study of the Eskilstuna River in Sweden is presented. This study is carried out within the project KRIS-GIS®, a Swedish initiative of handling crisis situations, including flooding. The purpose is to show how different resolutions in input elevation data affect the resulting inundation maps. Terrain elevation points at the sides of the river were gathered from an airborne laser altimetry survey, and river bed elevations were gathered from an echosounding survey. The terrain model was constructed in ArcView GIS as a triangulated irregular network (TIN), which served as the base for all later modeling. The hydraulic modeling was done as one-dimensional steady flow in HEC-RAS flow routing software. High-resolution elevation data resulted in better inundation delineation than did lowresolution elevation data. If the mean water discharge was used in the modeling and if the river is narrow, a low resolution could even lead to that the river itself would not be marked as inundated. At high water discharges, the river was usually inundated, but there was great uncertainty if the riparian areas really would be flooded or not. With steep side slopes, the delineation of inundation becomes more certain, while at gentler side slopes, the flow is distributed on a larger surface with a risk that the raster cells will be incorrectly marked regarding inundation. Finally, the use of high-resolution elevation data compared with lowresolution data, makes estimates of friction factor, Manning’s n, relatively more important for correct results in inundation studies.
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| 7. |
- Brandt, S. Anders, 1970-, et al.
(författare)
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Visualising DEM-related flood-map uncertainties using a disparity-distance equation algorithm
- 2016
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Ingår i: IAHS-AISH Proceedings and Reports. - Göttingen : Copernicus Publications on behalf of International Association of Hydrological Sciences (IAHS). ; , s. 153-159
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Konferensbidrag (refereegranskat)abstract
- The apparent absoluteness of information presented by crisp-delineated flood boundaries can lead tomisconceptions among planners about the inherent uncertainties associated in generated flood maps. Even mapsbased on hydraulic modelling using the highest-resolution digital elevation models (DEMs), and calibrated withthe most optimal Manning’s roughness (n) coefficients, are susceptible to errors when compared to actual floodboundaries, specifically in flat areas. Therefore, the inaccuracies in inundation extents, brought about by thecharacteristics of the slope perpendicular to the flow direction of the river, have to be accounted for. Instead ofusing the typical Monte Carlo simulation and probabilistic methods for uncertainty quantification, an empiricalbaseddisparity-distance equation that considers the effects of both the DEM resolution and slope was used tocreate prediction-uncertainty zones around the resulting inundation extents of a one-dimensional (1-D) hydraulicmodel. The equation was originally derived for the Eskilstuna River where flood maps, based on DEM dataof different resolutions, were evaluated for the slope-disparity relationship. To assess whether the equation isapplicable to another river with different characteristics, modelled inundation extents from the Testebo Riverwere utilised and tested with the equation. By using the cross-sectional locations, water surface elevations, andDEM, uncertainty zones around the original inundation boundary line can be produced for different confidences.The results show that (1) the proposed method is useful both for estimating and directly visualising modelinaccuracies caused by the combined effects of slope and DEM resolution, and (2) the DEM-related uncertaintiesalone do not account for the total inaccuracy of the derived flood map. Decision-makers can apply it to alreadyexisting flood maps, thereby recapitulating and re-analysing the inundation boundaries and the areas that areuncertain. Hence, more comprehensive flood information can be provided when determining locations whereextra precautions are needed. Yet, when applied, users must also be aware that there are other factors that caninfluence the extent of the delineated flood boundary.
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| 8. |
- Harrie, Lars, et al.
(författare)
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Some strategic national initiatives for the Swedish education in the geodata field
- 2014
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Ingår i: Proceedings of the AGILE'2014 International Conference on Geographic Information Science. - : AGILE Digital Editions. - 9789081696043
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Konferensbidrag (refereegranskat)abstract
- This paper describes national cooperation in Sweden launched by its universities and authorities, aimed at improving geodata education. These initiatives have been focused upon providing common access to geodata, the production of teaching materials in Swedish and organizing annual meetings for teachers. We argue that this type of cooperation is vital to providing high quality education for a poorly recognized subject in a country with a relatively small population.
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