University of Twente Student Theses
Modelling the impact of highways on impedance of movement and mortality locations of Badger (Meles meles) and Roe Deer (Capreolus capreolus): A Case Study of the A73 in The Netherlands
Khatavkar, Parag Prasad (2009) Modelling the impact of highways on impedance of movement and mortality locations of Badger (Meles meles) and Roe Deer (Capreolus capreolus): A Case Study of the A73 in The Netherlands.
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Abstract: | Wildlife mortality due to vehicular collision is one of the most important threats of road development and operation. Though sufficient research has been conducted on factors affecting road kill, the identification of mortality locations as a key to developing mitigation measures such as wildlife crossings has largely been ignored. Studies to identify the locations of wildlife crossings need extensive wildlife datasets and collection of such data is not always possible. On the other hand road development is a continuously growing process worldwide. Hence it is important to develop and validate a model which can identify relative mortality locations for wildlife using limited wildlife data. The A73 highway in The Netherlands was selected to develop a model using badger (Meles meles) and roe deer (Capreolus capreolus) as indicator species. Data on wildlife mortality and developed mitigation measures such as wildlife overpass/underpass was used for validation The first step to identify relative mortality along the A73 highway was the creation of an impedance map for the two species, based on analysis of expert knowledge. Impedance is the resistance offered by different landuse and landcover types to animal movements. The impedance map was rasterised and circular buffers of 250 meter radius were developed. Using zonal statistics the circular buffers were divided into four categories – no, low, medium and high impedance. Secondly, a traversability equation from Jaarsma et al., (2006) was used to estimate the probability of road kill for the indicator species. The A73 highway was divided into mortality threat zones of low, medium and high probability. Overlay analysis of the impedance map and the mortality threat map was performed using two scenarios. The impedance model showed high impedance values for human settlements and industrial areas and only medium impedance for the A73 highway itself for both species. High probability of road kill was estimated in four continuous lanes of roads while relatively low probability was estimated if four lanes were divided in 2x2 lanes. In case of badger (Meles meles), scenario 2 identified 77 high mortality circular buffers. Likewise for roe deer (Capreolus capreolus), scenario 2 identified 71 high mortality circular buffers. Validation showed that scenario 2 predicted results better than scenario 1. The developed model is able to predict relative wildlife mortality locations using only species presence data. Validation of the model has shown satisfactory results. Using the output from current model, a separate functional model has been developed in STELLA for first time to estimate animal mortality. Future focus should be on applying and validating the model in other locations for other species |
Item Type: | Essay (Master) |
Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
Programme: | Geoinformation Science and Earth Observation MSc (75014) |
Link to this item: | https://purl.utwente.nl/essays/92726 |
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