### Abstract

This study evaluates two common methods to represent landslide polygons as frequencies for use within GIS analysis. These methods are used to extract information from factor maps, such as a single value for slope angle for the landslide polygon, which is then used in hazard assessment. Understanding the errors associated with generating points to represent landslide polygons should be clearly understood to evaluate the effectiveness of these points. In this paper, the effectiveness of two representation techniques in gathering slope angle information is examined. The first technique evaluated is based on the centroid (a point feature) of each landslide polygon. The value of the landslide factor class beneath the centroid point, e.g. the slope value at that point, selects the landslide factor class. The second method is an area based technique which depends on the area covered by different landslide factor classes, e.g. the most common slope for the polygon. Here, the landslide factor class that occupies most of the landslide polygon is selected as the attribute for each landslide polygon. As demonstrated in this paper, the results favour the area based technique. While this paper explores this technique for slope information, the finding is applicable to other landslide causal factors, such as elevation and rock type.

Original language | English |
---|---|

Pages (from-to) | 775-784 |

Number of pages | 10 |

Journal | Electronic Journal of Geotechnical Engineering |

Volume | 18 D |

Publication status | Published - 2013 |

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### Keywords

- Area based technique
- Centroid point
- GIS
- Landslide

### ASJC Scopus subject areas

- Geotechnical Engineering and Engineering Geology

### Cite this

*Electronic Journal of Geotechnical Engineering*,

*18 D*, 775-784.

**Point based assessment : Selecting the best way to represent landslide polygon as point frequency in landslide investigation.** / Simon, Norbert; Crozier, Michael; de Roiste, Mairead; Rafek, Abdul Ghani.

Research output: Contribution to journal › Article

*Electronic Journal of Geotechnical Engineering*, vol. 18 D, pp. 775-784.

}

TY - JOUR

T1 - Point based assessment

T2 - Selecting the best way to represent landslide polygon as point frequency in landslide investigation

AU - Simon, Norbert

AU - Crozier, Michael

AU - de Roiste, Mairead

AU - Rafek, Abdul Ghani

PY - 2013

Y1 - 2013

N2 - This study evaluates two common methods to represent landslide polygons as frequencies for use within GIS analysis. These methods are used to extract information from factor maps, such as a single value for slope angle for the landslide polygon, which is then used in hazard assessment. Understanding the errors associated with generating points to represent landslide polygons should be clearly understood to evaluate the effectiveness of these points. In this paper, the effectiveness of two representation techniques in gathering slope angle information is examined. The first technique evaluated is based on the centroid (a point feature) of each landslide polygon. The value of the landslide factor class beneath the centroid point, e.g. the slope value at that point, selects the landslide factor class. The second method is an area based technique which depends on the area covered by different landslide factor classes, e.g. the most common slope for the polygon. Here, the landslide factor class that occupies most of the landslide polygon is selected as the attribute for each landslide polygon. As demonstrated in this paper, the results favour the area based technique. While this paper explores this technique for slope information, the finding is applicable to other landslide causal factors, such as elevation and rock type.

AB - This study evaluates two common methods to represent landslide polygons as frequencies for use within GIS analysis. These methods are used to extract information from factor maps, such as a single value for slope angle for the landslide polygon, which is then used in hazard assessment. Understanding the errors associated with generating points to represent landslide polygons should be clearly understood to evaluate the effectiveness of these points. In this paper, the effectiveness of two representation techniques in gathering slope angle information is examined. The first technique evaluated is based on the centroid (a point feature) of each landslide polygon. The value of the landslide factor class beneath the centroid point, e.g. the slope value at that point, selects the landslide factor class. The second method is an area based technique which depends on the area covered by different landslide factor classes, e.g. the most common slope for the polygon. Here, the landslide factor class that occupies most of the landslide polygon is selected as the attribute for each landslide polygon. As demonstrated in this paper, the results favour the area based technique. While this paper explores this technique for slope information, the finding is applicable to other landslide causal factors, such as elevation and rock type.

KW - Area based technique

KW - Centroid point

KW - GIS

KW - Landslide

UR - http://www.scopus.com/inward/record.url?scp=84876378547&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84876378547&partnerID=8YFLogxK

M3 - Article

VL - 18 D

SP - 775

EP - 784

JO - Electronic Journal of Geotechnical Engineering

JF - Electronic Journal of Geotechnical Engineering

SN - 1089-3032

ER -