DEM generation and hydrologic modelling using LiDAR data

Kilpatrick, Glen R (2015) DEM generation and hydrologic modelling using LiDAR data. [USQ Project]

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Abstract

Communities and governments in flood prone areas around the globe seek to prevent the disastrous effects of major floods. There are plenty of examples of such events in the 21st century occurring around the globe. A particular event of significance to southeast Queensland is the floods of December 2010 and January 2011 which did much damage to communities in affected regions of the state. Airborne LiDAR has provided a sophisticated method of capturing data for digital elevation models (DEM) which provides a basis for flood flow and inundation predictions to inform the design of future developments and mitigation measures to reduce the consequences of major floods.

This dissertation investigated the use of Airborne LiDAR for hydrologic modelling, the accuracy of LiDAR data, its use as a tool for terrain change analysis and its effectiveness for basic flood extent modelling. LiDAR data captured in 2010 and 2012 covering the East Creek catchment in Toowoomba was obtained for this project. Hydrologic models were created and results were compared between the 2010 and 2012 LiDAR datasets. It was found that hydrologic flow lines and watershed boundaries varied on side streams. This variation was also found to be less in undeveloped areas than in developed areas.

A conventional field survey was carried out over a small area on East Creek to validate the LiDAR datasets and it was found that both LiDAR datasets were within the specified accuracies overall, though there was a tendency to overestimate elevations in areas covered by vegetation. The datasets and validation analysis were used to search for terrain changes between the periods of data capture and several areas of definite probable terrain change were found. The results highlighted the potential of LiDAR data for this application.

A basic flood surface extent analysis was done in the same area and LiDAR was found to perform well with minor effects of elevation overestimation errors due to vegetation. This dissertation shows some of the capabilities and limitations of LiDAR. Future research should make use of more sophisticated hydraulic modelling software and techniques. However the use of two independent LiDAR datasets provided a useful independent check which would be helpful for future studies of a similar topic.


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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Spatial Science (Surveying) project
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Supervisors: Liu, Xiaoye
Date Deposited: 07 Jun 2016 00:10
Last Modified: 07 Jun 2016 00:10
Uncontrolled Keywords: LiDAR, Terrain Analysis, Hydrologic Modelling
Fields of Research : 09 Engineering > 0909 Geomatic Engineering > 090906 Surveying (incl. Hydrographic Surveying)
URI: http://eprints.usq.edu.au/id/eprint/29263

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