際際滷

際際滷Share a Scribd company logo

Poster_2

Adri Descals
Adri Descals

This document summarizes a study that used aerial light detection and ranging (LiDAR) data and stereo-matched point clouds from aerial photos to analyze wind damage in Norway spruce forests in Poland's Tatra National Park. The study compared height data from 2012 LiDAR and 2014 stereo-matching to identify areas where 47.4% of spruce stems had been destroyed by a 2013 windstorm. Object-based image analysis of a high-resolution orthoimage detected over 16,000 downed stems pointing mostly north. The results provide detailed mapping of wind damage patterns and areas of natural forest gaps to help understand wind impacts on mountain vegetation.

1 of 1
Download to read offline
Introduction The upper heights (p95) of the Norway spruce stands derived automatically from ALS point clouds has become very important information in studies on mountain vegetation. The digital photogrammetry is offering nowadays 3D point clouds derived with the so called stereo- matching approach. The role of ALS is still important as information about DTM helping with CHM modeling. 50 m nDSM 2012 (ALS). Selected object 21,3 meters height nDSM 2014 (Stereomatching). Selected object 0,28 meters height Study area Lower part of Koscieliska Valley (Tatra National Park, Poland) in an area of approximately 164 ha of spruce forest, meadows (Polana Koscieliska) and wildlandurban interface (Kiry). Stereo-matching DSM was generated from stereo- matched of high resolution digital aerial photos (GSD 0,07 m; 2014) and DTM from ALS (ISOK project). Based on DTM the nDSM (CHM) was created. The windstorm damages in Kiry (Tatra Mts., Poland) were mapped using bi-temporal mean height data from ALS LiDAR (2012) and stereo-matching (2014). Vectorized stemsRGB digital aerial photo Image enhancement 15 m Stem detection Lying Norway spruce stems with roots systems were detected on the 7 cm orthoimage using Object-Based Image Analysis (OBIA). The characteristics of the windstormwereanalyzed. Segmentation stage Classi鍖cation 5 km Tatra National Park Study area Wind damages in spruce forest (Dolina Str甜yska; TNP) Land Cover map of Kocieliska Valley based on nDSM classification WIND DAMAGE CLASSIFICATION if nDSM_2012 > 5 m and nDSM_2014 < 5 m Wind damages and nDSM_2014 > 5 m Healthy forest if nDSM_2012 < 5 m and border index > 3 Forest gaps and border index < 3 Grassland Healthy forest Grassland Forest gaps Wind damages 150 m Results The windstorm from December 25, 2013 destroyed 47,4% of 110,52 ha analysed Norway spruce forest stands. The total area of the gaps located among Norway spruce stands was 17,4 ha, which represents the 15% of the forested area. The orthophoto from 2009 suggested that these gaps were previously caused also by natural damages. Automatically detected tree stems or its parts (16 192 in total) were overthrown pointing mostly to theNorth(mean azimuth 359,9属)inanareaof46,5ha - withoutanyrelationship toDTM surface. nDSM fromALS data (2012) Orthophoto (GSD 7cm) generated using DSM from stereomatching (2014) nDSM_2014 based on stereo-matching detected stems mean direction of stems Aspect Detected logs (n) Mean wind azimuth (属) N 1 569 1,0 NE 4 196 -2,4 E 7 239 2,6 SE 2 320 -1,7 S 302 -8,5 SW 107 -6,5 W 205 -16,1 NW 253 0,7 The detection of windfall and windbreak in Norway spruce stands using OBIA, LiDAR and aerial photo based 3D point clouds a case of study in Koscieliska Valley (Tatra National Park, Poland) Adria Descals, Pawe Hawryo, Piotr W甜yk Laboratory of Geomatics, Department of Forest Management, Geomatics and Forest Economics Institute of Forest Resources Management, Faculty of Forestry, University of Agriculture in Krakow Zakopane SK PL TPN *0 (North) / 90 (East) / -90 (West)

More Related Content

Poster_2

  • 1. Introduction The upper heights (p95) of the Norway spruce stands derived automatically from ALS point clouds has become very important information in studies on mountain vegetation. The digital photogrammetry is offering nowadays 3D point clouds derived with the so called stereo- matching approach. The role of ALS is still important as information about DTM helping with CHM modeling. 50 m nDSM 2012 (ALS). Selected object 21,3 meters height nDSM 2014 (Stereomatching). Selected object 0,28 meters height Study area Lower part of Koscieliska Valley (Tatra National Park, Poland) in an area of approximately 164 ha of spruce forest, meadows (Polana Koscieliska) and wildlandurban interface (Kiry). Stereo-matching DSM was generated from stereo- matched of high resolution digital aerial photos (GSD 0,07 m; 2014) and DTM from ALS (ISOK project). Based on DTM the nDSM (CHM) was created. The windstorm damages in Kiry (Tatra Mts., Poland) were mapped using bi-temporal mean height data from ALS LiDAR (2012) and stereo-matching (2014). Vectorized stemsRGB digital aerial photo Image enhancement 15 m Stem detection Lying Norway spruce stems with roots systems were detected on the 7 cm orthoimage using Object-Based Image Analysis (OBIA). The characteristics of the windstormwereanalyzed. Segmentation stage Classi鍖cation 5 km Tatra National Park Study area Wind damages in spruce forest (Dolina Str甜yska; TNP) Land Cover map of Kocieliska Valley based on nDSM classification WIND DAMAGE CLASSIFICATION if nDSM_2012 > 5 m and nDSM_2014 < 5 m Wind damages and nDSM_2014 > 5 m Healthy forest if nDSM_2012 < 5 m and border index > 3 Forest gaps and border index < 3 Grassland Healthy forest Grassland Forest gaps Wind damages 150 m Results The windstorm from December 25, 2013 destroyed 47,4% of 110,52 ha analysed Norway spruce forest stands. The total area of the gaps located among Norway spruce stands was 17,4 ha, which represents the 15% of the forested area. The orthophoto from 2009 suggested that these gaps were previously caused also by natural damages. Automatically detected tree stems or its parts (16 192 in total) were overthrown pointing mostly to theNorth(mean azimuth 359,9属)inanareaof46,5ha - withoutanyrelationship toDTM surface. nDSM fromALS data (2012) Orthophoto (GSD 7cm) generated using DSM from stereomatching (2014) nDSM_2014 based on stereo-matching detected stems mean direction of stems Aspect Detected logs (n) Mean wind azimuth (属) N 1 569 1,0 NE 4 196 -2,4 E 7 239 2,6 SE 2 320 -1,7 S 302 -8,5 SW 107 -6,5 W 205 -16,1 NW 253 0,7 The detection of windfall and windbreak in Norway spruce stands using OBIA, LiDAR and aerial photo based 3D point clouds a case of study in Koscieliska Valley (Tatra National Park, Poland) Adria Descals, Pawe Hawryo, Piotr W甜yk Laboratory of Geomatics, Department of Forest Management, Geomatics and Forest Economics Institute of Forest Resources Management, Faculty of Forestry, University of Agriculture in Krakow Zakopane SK PL TPN *0 (North) / 90 (East) / -90 (West)