Landslide inventories are routinely compiled by means of aerial photo interpretation (API). When examining photo pairs, the forest canopy (notably in old-growth forest) hides a population of "not visible" landslides. In the present study, we attempt to estimate how important is the contribution of landslides not detectable from aerial photographs to the global mass of sediment production from mass failures on forested terrain of the Capilano basin, coastal British Columbia. API was coupled with intensive fieldwork for identification and measurement of all landslides. A 30-year framework was adopted. We show that "not visible" landslides can represent up to 85% of the total number of failures and account for 30% of the volume of debris mobilised. Such percentages display high sub-basin variability with rates of sediment production varying by one order of magnitude between two sub-basins of the study area. This is explained qualitatively by GIS-based analysis of slope frequency distributions, drainage density, and spatial distribution of surficial materials. Such observations find further support in the definitions of transport-limited and supply-limited basins. As a practical consideration to land managers, we envisage that supplementary fieldwork for landslide identification is mandatory in transport-limited systems only. Fieldwork has demonstrated that gully-related failures have a greater importance than one could expect from API. © 2002 Elsevier Science B.V. All rights reserved.

Brardinoni, F., Slaymaker, O., Hassan, M. (2003). Landslide inventory in a rugged forested watershed: a comparison between air-photo and field survey data. GEOMORPHOLOGY, 54(3-4), 179-196 [10.1016/S0169-555X(02)00355-0].

Landslide inventory in a rugged forested watershed: a comparison between air-photo and field survey data

BRARDINONI, FRANCESCO;
2003

Abstract

Landslide inventories are routinely compiled by means of aerial photo interpretation (API). When examining photo pairs, the forest canopy (notably in old-growth forest) hides a population of "not visible" landslides. In the present study, we attempt to estimate how important is the contribution of landslides not detectable from aerial photographs to the global mass of sediment production from mass failures on forested terrain of the Capilano basin, coastal British Columbia. API was coupled with intensive fieldwork for identification and measurement of all landslides. A 30-year framework was adopted. We show that "not visible" landslides can represent up to 85% of the total number of failures and account for 30% of the volume of debris mobilised. Such percentages display high sub-basin variability with rates of sediment production varying by one order of magnitude between two sub-basins of the study area. This is explained qualitatively by GIS-based analysis of slope frequency distributions, drainage density, and spatial distribution of surficial materials. Such observations find further support in the definitions of transport-limited and supply-limited basins. As a practical consideration to land managers, we envisage that supplementary fieldwork for landslide identification is mandatory in transport-limited systems only. Fieldwork has demonstrated that gully-related failures have a greater importance than one could expect from API. © 2002 Elsevier Science B.V. All rights reserved.
Articolo in rivista - Articolo scientifico
Landslide identification, Air-photo interpretation, Interbasin variability, Forested terrain, Coastal British Columbia
English
2003
54
3-4
179
196
none
Brardinoni, F., Slaymaker, O., Hassan, M. (2003). Landslide inventory in a rugged forested watershed: a comparison between air-photo and field survey data. GEOMORPHOLOGY, 54(3-4), 179-196 [10.1016/S0169-555X(02)00355-0].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/12544
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