Calicis, Eva

Gomes, António Alberto

Marques, Miguel

Martins, Cátia

Pérez Alberti, Augusto

Silva, António

English

Repositório Aberto da Universidade do Porto

       →UAS4Enviro2017 small Unmanned Aerial Systems for Environmental Research  5th Edition           28 – 30 June 2017 | UTAD | Vila Real, PORTUGAL   ISBN: 978-989-704-241-6   ABSTRACT BOOK Small Unmanned Aerial Systems for Environmental Research – 5th Edition    98  UAVs ORTHOIMAGES FOR IDENTIFYING AN MAPPING GEOMORPHIC INHERITANCE OF THE QUATERNARY GLACIERS AT THE SOAJO-PENEDA MOUNTAIS, PORTUGAL Silva, António (1), Marques, Miguel (2), Calicis, Eva (3), Martins, Cátia (4), Péres-Alberti, (5), Gomes, Alberto (6), (1) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, mafalda.lopes7@gmail.com (2) Geolevação, geoelevacao@gmail.com (3) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, eva_calicis@hotmail.com (4) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, catia.martins.geographer.gis@gmail.com  (5) Universidade de Santiago de Compostela, xepalber@gmail.com (6) Centro de Estudos de Geografia e Ordenamento do Território (FLUP), Via Panorâmica, s/n 4150-564 Portugal, albgomes@gmail.com  Key-Words: UAV; orthoimage; glacial cirques; moraines; erratic blocks. ABSTRACT: High mountain landscapes in the Iberian Peninsula are a consequence of both Quaternary glaciations and post-glacial environmental dynamics driven (mainly) by periglacial, slope and alluvial processes and shallow or deep-seated landslides [1]. A long discussion about the existence/non existence of clear glaciation evidences at low altitudes in the NW of Iberia take a lot of research efforts and discussions about the two theories. This indefiniteness was linked with the presence of few and poor clear evidences of the glacial extent, in terms of undisputed erosive and/or depositional glacial forms. Nevertheless, for the Northwest of the Iberian Peninsula, several studies confirmed the presence of glacial forms at low altitudes [2]. In this way, the work done by other researchers [3,4,5,6,7], among others, is retaken by this study concerned with the geomorphic inheritance of the Pleistocene Glaciation at the Alto Vez spot, a sector of the Soajo-Peneda Mountains, placed in the Peneda-Gerês National Park. Located in the Northwest of Continental Portugal, in an area that covers part of the municipalities of Arcos de Valdevez, Melgaço and Monção, the Alto Vez spot has an altitude varying between 400m and 1416m, and slopes that surpass 600m of unevenness. The slopes are oriented 15% east and west and 14% southeast, with 71,4% of shady area. The fieldwork recognition and the geomorphological mapping already executed during 2013-14 allowed sketching a preliminary view of the glaciated area and the registering of more geomorphic elements that prove the extension of the Alto Vez glaciation [8]. This previous work allowed the identification and the morphometry analysis of 25 glacier cirques, as well as the geomorphological cartography associated with intensive fieldwork, allowed to establish comparisons with other glaciated areas, namely, regarding the orientation of the glacial cirques to the east, particularly, in the sector Branda de Gorbelas - Branda das Bosgalinhas.  Following this gaps, we present in this work the experimental results related with the Pleistocene glaciation in the Alto Vez sector, namely by the detailed analysis of the main cirque towards to east, the Ramisquedo Cirque (RC). Four main results are achieved: i) an high detailed orthoimage of sectors of the cirque; ii) a detailed map of the glacial inheritance forms; iii) a detailed geological map of the RC; iv) an update interpretation of the geomorphic inheritance of the low/medium size glacial forms existent on the RC.  Small Unmanned Aerial Systems for Environmental Research – 5th Edition    99 In April of 2017 it was performed a recent survey and UAV flights (one morning for the flights, 5 in total, and two days for the posterior fieldwork), in order to have a global orthoimage of the Ramisquedo Cirque (RC). It was an opportunity to realize the specific characteristics of flights with an UAV (low altitude flight), allowing images offering many advantages, such as: excellent resolution, large overlap and reduced execution time [9]. The flights took place at 50/70m of the ground and around noon, in order to have the sun as upright as possible. Wind conditions were not perfect (frequent bursts over 20 km/h), which compromises the quality and overlap of some photos and obliged to do flights with short duration (<10min).  It was used a self-construction UAV, an equipment of carbon with 900mm of maximum distance between the motors axes (class 900) with four motors (quadcopter) and pixhawk flight controller of the 3DR. This flight controller features inboard barometer and accelerometers, and a peripheral GPS antenna and compass. With a total weight in flight of about 2,5kg carries on board a Canon Powershot SX260 (12 Mp) conventional camera equipped with GPS. In order to provide the timer camera, which is indispensable for the acquisition of photographs during flight, this camera has a CHDK script on its memory card. For the flight planning, it was used the open source Mission Planner software, making it possible to plan the flight independently using various base maps, selecting the Google Satellite View for this work. At the field, it was used the differential GPS model Leica SR20, with a stationary and a mobile equipment allowing the positioning improvement by differential correction in post-processing. In addition, some control points (marked with red crosses on the terrain surface and in observable positions on aerial photos) were also collected. The photos obtained were processed with Agisoft software, resulting a global orthoimage with 5 cm of pixel size. Digital terrain and surface models were also processed as auxiliary base maps to identify and differentiate exposed inherited glacial forms from other types of erosional or deposition features/forms. Fieldwork recognition and referencing of the glacial forms was assisted by the orthoimage and complemented with a portable Garmin GPSMAP® 64st. Figure 1 shows the integration between the fieldwork data and the UAV orthoimage on a little sector of the Ramisquedo cirque. The UAV orthoimage (Fig. 1e) is the result of the third flight, covering an area of ~35000m2, performed 50m above ground, with a duration of 5 minutes, including 55 photos with a pixel resolution of 2m. Regarding the area lithology, since we cover a small area, the variations of colour and tonality are not significant, but allows distinguishing with great clarity the lithological differentiation. As it was already published in the Geological Map of Arcos de Valdevez, scale 1/50000 [10], the field knowledge acquired from the area reveals that there is only one type of granite with slight textured differences, and several metamorphic rock spots mainly at the base and specific slopes of the cirque. Plotting the contacts identified during the fieldwork it was obtained a rigorous geological map that reveals some differences (mainly, more precision) with previous maps and allows new interpretation about the cirque forms and the real displacement of erratic blocks. In relation with the geomorphic elements it was possible to identify sets of salient and polished quartz veins, flutes, polished granite surfaces in various cirque locations, an interior depression at the base of the circus (a former lake?), several erratic shale blocks placed along the flat granite surfaces. With all measured data it was possible to obtain the average direction of the grooves existing in various forms and thus define the relative movement of the ice mass on the surface of the circus. Concluding, the quality of the orthoimage obtained by the aerial photos of the UAV to perform detailed cartography on this former glaciated are was excellent. One great advantage comes from the precise and detailed characterization of geological and geomorphological features exposed along the cirque area, allowing rigorous position, detailed morphometric measures and establishing relations about ice mass dynamics on the cirque surface. Small Unmanned Aerial Systems for Environmental Research – 5th Edition    100   Figure 1. Drone orthoimage and field evidences of the quaternary glaciation at the Ramisquedo cirque: a) panoramic view of the Ramisquedo cirque; b) polished surfaces on the metamorphic basement and quartz veins; c) polished surfaces on granite outcrops; d) erratic granitic blocks over metamorphic basement; e) drone orthoimage of the central/bottom sector of the cirque, with many erratic blocks and polished/eroded surfaces, and clear quartz veins. The use of UAVs in comparison with other data acquisition techniques is very advantageous since the costs and time spent in collecting and processing the data are relatively short. Processing images can even be Small Unmanned Aerial Systems for Environmental Research – 5th Edition    101 carried out on-site, which allows an immediate result to be visualized and facilitates the correction of errors through repeated flights, which is very important for these places of difficult access. The great and sudden variety of wind conditions could be a difficulty to operate in this environment. Since the inherited glacial forms are dispersed over a large area (several kilometres), the use of UAV devices with low autonomy (covered area and flight duration) requires more efforts and flights to perform a good survey. Nevertheless, flights easiness repetition and speed of data processing makes it an accessible tool and very effective for detailed studies of the geomorphic evidences of low altitudes glaciation in the Iberian Mountains. References: 1. Oliva, M., Serrano, E., Gómez-Ortiz, A., González-Amuchastegui, M.J., Nieuwendam, A., Palacios, D., Pérez-Alberti, A., Pellitero-Ondicol, R.J., Ruiz-Fernández, J., Valcárcel, M., Vieira, G. & Antoniades, D., (2016). Spatial and temporal variability of periglaciation of the Iberian Peninsula, Quaternary Science Reviews, 137, 176-199. 2. Perez-Alberti, A.P., Rodríguez Guitián, M. & Valcárcel Díaz, M. (1993). Las formas y depósitos glaciares en las sierras orientales y septentrionales de Galicia (NW Península Ibérica). Xunta de Galicia, 61-90. 3. Coudé-Gaussen, G. (1981). Les Serras da Peneda et Gerês. Memórias do CEG, 5, 254 p. 4. Coudé, A., Coudé-Gaussen, G. & Daveau, S. (1983). Nouvelles observations sur la glaciation des montagnes du Nord-Ouest du Portugal. Cuadernos do Lab Xeolóxico de Laxe, 5, 381-393. 5. Moreira, A. & Farinha Ramos, J. (1981). Vestígios de glaciações na serra da Peneda (Noroeste de Portugal). Comunicações dos Serviços Geológicos de Portugal, 67 (1), 95-98. 6. Pereira P., Pereira D.I. & Casinhas P. (2009). Novos dados sobre a glaciação no sector Gorbelas-Junqueira (Serra da Peneda). Associação Portuguesa de Geomorfólogos, 6, 101-106. 7. Santos, J., Cunha, L., Vieira, A. & Bento-Gonçalves, A. (2013). Genesis of the Alto Vez glacial Valley Pleistocene moraines, Peneda Mountains, Northwest Portugal. Atas do VI Congresso Nacional de Geomorfologia, 57-62. 8. Martins, C., Pereira, J., Pérez-Alberti, A. & Gomes, A. (2014). A glaciação Plistocénica do Alto Vez (PNPG): morfometria dos circos, espessura da língua glaciária e esboço geomorfológico preliminar. Atas do XIV Colóquio Ibérico de Geografia, 2182-2187. 9. Humphrey, D. (2014). UAV and GIS, an emerging dynamic duo. Available at <http://www.esri.com/~/media/Files/Pdfs/news/arcuser/0314/uav-and-gis.pdf>. 10. Moreira, A. (1985). Carta Geológica de Arcos de Valdevez - folha 1D (escala 1/50000). Serviços Geológicos de Portugal. 

UAVs orthoimages for identifying and mapping geomorphic inheritance of the quaternary glaciers at the Soajo-Peneda mountains, Portugal

Open Repository of the University of Porto

  
 
 
 
 
 
→UAS4Enviro2017 
small Unmanned Aerial Systems for Environmental Research  
5th Edition 
 
 
 
 
 
 
 
 
 
 
28 – 30 June 2017 | UTAD | Vila Real, PORTUGAL 
 
 
ISBN: 978-989-704-241-6 
  
ABSTRACT BOOK 
Small Unmanned Aerial Systems for Environmental Research – 5th Edition  
 
 98 
 
UAVs ORTHOIMAGES FOR IDENTIFYING AN MAPPING GEOMORPHIC 
INHERITANCE OF THE QUATERNARY GLACIERS AT THE SOAJO-PENEDA 
MOUNTAIS, PORTUGAL 
Silva, António (1), Marques, Miguel (2), Calicis, Eva (3), Martins, Cátia (4), Péres-Alberti, (5), 
Gomes, Alberto (6), 
(1) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, 
mafalda.lopes7@gmail.com 
(2) Geolevação, geoelevacao@gmail.com 
(3) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, 
eva_calicis@hotmail.com 
(4) Faculdade de Letras da Universidade do Porto, Via Panorâmica, s/n 4150-564 Portugal, 
catia.martins.geographer.gis@gmail.com 
 (5) Universidade de Santiago de Compostela, xepalber@gmail.com 
(6) Centro de Estudos de Geografia e Ordenamento do Território (FLUP), Via Panorâmica, s/n 4150-564 
Portugal, albgomes@gmail.com 
 
Key-Words: UAV; orthoimage; glacial cirques; moraines; erratic blocks. 
ABSTRACT: 
High mountain landscapes in the Iberian Peninsula are a consequence of both Quaternary glaciations and 
post-glacial environmental dynamics driven (mainly) by periglacial, slope and alluvial processes and shallow 
or deep-seated landslides [1]. A long discussion about the existence/non existence of clear glaciation 
evidences at low altitudes in the NW of Iberia take a lot of research efforts and discussions about the two 
theories. This indefiniteness was linked with the presence of few and poor clear evidences of the glacial 
extent, in terms of undisputed erosive and/or depositional glacial forms. 
Nevertheless, for the Northwest of the Iberian Peninsula, several studies confirmed the presence of glacial 
forms at low altitudes [2]. In this way, the work done by other researchers [3,4,5,6,7], among others, is retaken 
by this study concerned with the geomorphic inheritance of the Pleistocene Glaciation at the Alto Vez spot, a 
sector of the Soajo-Peneda Mountains, placed in the Peneda-Gerês National Park. Located in the Northwest 
of Continental Portugal, in an area that covers part of the municipalities of Arcos de Valdevez, Melgaço and 
Monção, the Alto Vez spot has an altitude varying between 400m and 1416m, and slopes that surpass 600m 
of unevenness. The slopes are oriented 15% east and west and 14% southeast, with 71,4% of shady area. 
The fieldwork recognition and the geomorphological mapping already executed during 2013-14 allowed 
sketching a preliminary view of the glaciated area and the registering of more geomorphic elements that prove 
the extension of the Alto Vez glaciation [8]. This previous work allowed the identification and the morphometry 
analysis of 25 glacier cirques, as well as the geomorphological cartography associated with intensive 
fieldwork, allowed to establish comparisons with other glaciated areas, namely, regarding the orientation of 
the glacial cirques to the east, particularly, in the sector Branda de Gorbelas - Branda das Bosgalinhas.  
Following this gaps, we present in this work the experimental results related with the Pleistocene glaciation in 
the Alto Vez sector, namely by the detailed analysis of the main cirque towards to east, the Ramisquedo 
Cirque (RC). Four main results are achieved: i) an high detailed orthoimage of sectors of the cirque; ii) a 
detailed map of the glacial inheritance forms; iii) a detailed geological map of the RC; iv) an update 
interpretation of the geomorphic inheritance of the low/medium size glacial forms existent on the RC.  
Small Unmanned Aerial Systems for Environmental Research – 5th Edition  
 
 99 
In April of 2017 it was performed a recent survey and UAV flights (one morning for the flights, 5 in total, and 
two days for the posterior fieldwork), in order to have a global orthoimage of the Ramisquedo Cirque (RC). It 
was an opportunity to realize the specific characteristics of flights with an UAV (low altitude flight), allowing 
images offering many advantages, such as: excellent resolution, large overlap and reduced execution time [9]. 
The flights took place at 50/70m of the ground and around noon, in order to have the sun as upright as 
possible. Wind conditions were not perfect (frequent bursts over 20 km/h), which compromises the quality and 
overlap of some photos and obliged to do flights with short duration (<10min).  
It was used a self-construction UAV, an equipment of carbon with 900mm of maximum distance between the 
motors axes (class 900) with four motors (quadcopter) and pixhawk flight controller of the 3DR. This flight 
controller features inboard barometer and accelerometers, and a peripheral GPS antenna and compass. With 
a total weight in flight of about 2,5kg carries on board a Canon Powershot SX260 (12 Mp) conventional 
camera equipped with GPS. In order to provide the timer camera, which is indispensable for the acquisition of 
photographs during flight, this camera has a CHDK script on its memory card. For the flight planning, it was 
used the open source Mission Planner software, making it possible to plan the flight independently using 
various base maps, selecting the Google Satellite View for this work. 
At the field, it was used the differential GPS model Leica SR20, with a stationary and a mobile equipment 
allowing the positioning improvement by differential correction in post-processing. In addition, some control 
points (marked with red crosses on the terrain surface and in observable positions on aerial photos) were also 
collected. The photos obtained were processed with Agisoft software, resulting a global orthoimage with 5 cm 
of pixel size. Digital terrain and surface models were also processed as auxiliary base maps to identify and 
differentiate exposed inherited glacial forms from other types of erosional or deposition features/forms. 
Fieldwork recognition and referencing of the glacial forms was assisted by the orthoimage and complemented 
with a portable Garmin GPSMAP® 64st. Figure 1 shows the integration between the fieldwork data and the 
UAV orthoimage on a little sector of the Ramisquedo cirque. The UAV orthoimage (Fig. 1e) is the result of the 
third flight, covering an area of ~35000m2, performed 50m above ground, with a duration of 5 minutes, 
including 55 photos with a pixel resolution of 2m. 
Regarding the area lithology, since we cover a small area, the variations of colour and tonality are not 
significant, but allows distinguishing with great clarity the lithological differentiation. As it was already 
published in the Geological Map of Arcos de Valdevez, scale 1/50000 [10], the field knowledge acquired from 
the area reveals that there is only one type of granite with slight textured differences, and several 
metamorphic rock spots mainly at the base and specific slopes of the cirque. Plotting the contacts identified 
during the fieldwork it was obtained a rigorous geological map that reveals some differences (mainly, more 
precision) with previous maps and allows new interpretation about the cirque forms and the real displacement 
of erratic blocks. 
In relation with the geomorphic elements it was possible to identify sets of salient and polished quartz veins, 
flutes, polished granite surfaces in various cirque locations, an interior depression at the base of the circus (a 
former lake?), several erratic shale blocks placed along the flat granite surfaces. With all measured data it was 
possible to obtain the average direction of the grooves existing in various forms and thus define the relative 
movement of the ice mass on the surface of the circus. 
Concluding, the quality of the orthoimage obtained by the aerial photos of the UAV to perform detailed 
cartography on this former glaciated are was excellent. One great advantage comes from the precise and 
detailed characterization of geological and geomorphological features exposed along the cirque area, allowing 
rigorous position, detailed morphometric measures and establishing relations about ice mass dynamics on the 
cirque surface. 
Small Unmanned Aerial Systems for Environmental Research – 5th Edition  
 
 100 
 
 
Figure 1. Drone orthoimage and field evidences of the quaternary glaciation at the Ramisquedo cirque: a) 
panoramic view of the Ramisquedo cirque; b) polished surfaces on the metamorphic basement and quartz 
veins; c) polished surfaces on granite outcrops; d) erratic granitic blocks over metamorphic basement; e) 
drone orthoimage of the central/bottom sector of the cirque, with many erratic blocks and polished/eroded 
surfaces, and clear quartz veins. 
The use of UAVs in comparison with other data acquisition techniques is very advantageous since the costs 
and time spent in collecting and processing the data are relatively short. Processing images can even be 
Small Unmanned Aerial Systems for Environmental Research – 5th Edition  
 
 101 
carried out on-site, which allows an immediate result to be visualized and facilitates the correction of errors 
through repeated flights, which is very important for these places of difficult access. The great and sudden 
variety of wind conditions could be a difficulty to operate in this environment. Since the inherited glacial forms 
are dispersed over a large area (several kilometres), the use of UAV devices with low autonomy (covered 
area and flight duration) requires more efforts and flights to perform a good survey. Nevertheless, flights 
easiness repetition and speed of data processing makes it an accessible tool and very effective for detailed 
studies of the geomorphic evidences of low altitudes glaciation in the Iberian Mountains. 
References: 
1. Oliva, M., Serrano, E., Gómez-Ortiz, A., González-Amuchastegui, M.J., Nieuwendam, A., Palacios, D., 
Pérez-Alberti, A., Pellitero-Ondicol, R.J., Ruiz-Fernández, J., Valcárcel, M., Vieira, G. & Antoniades, D., 
(2016). Spatial and temporal variability of periglaciation of the Iberian Peninsula, Quaternary Science 
Reviews, 137, 176-199. 
2. Perez-Alberti, A.P., Rodríguez Guitián, M. & Valcárcel Díaz, M. (1993). Las formas y depósitos glaciares en 
las sierras orientales y septentrionales de Galicia (NW Península Ibérica). Xunta de Galicia, 61-90. 
3. Coudé-Gaussen, G. (1981). Les Serras da Peneda et Gerês. Memórias do CEG, 5, 254 p. 
4. Coudé, A., Coudé-Gaussen, G. & Daveau, S. (1983). Nouvelles observations sur la glaciation des 
montagnes du Nord-Ouest du Portugal. Cuadernos do Lab Xeolóxico de Laxe, 5, 381-393. 
5. Moreira, A. & Farinha Ramos, J. (1981). Vestígios de glaciações na serra da Peneda (Noroeste de 
Portugal). Comunicações dos Serviços Geológicos de Portugal, 67 (1), 95-98. 
6. Pereira P., Pereira D.I. & Casinhas P. (2009). Novos dados sobre a glaciação no sector Gorbelas-
Junqueira (Serra da Peneda). Associação Portuguesa de Geomorfólogos, 6, 101-106. 
7. Santos, J., Cunha, L., Vieira, A. & Bento-Gonçalves, A. (2013). Genesis of the Alto Vez glacial Valley 
Pleistocene moraines, Peneda Mountains, Northwest Portugal. Atas do VI Congresso Nacional de 
Geomorfologia, 57-62. 
8. Martins, C., Pereira, J., Pérez-Alberti, A. & Gomes, A. (2014). A glaciação Plistocénica do Alto Vez 
(PNPG): morfometria dos circos, espessura da língua glaciária e esboço geomorfológico preliminar. Atas 
do XIV Colóquio Ibérico de Geografia, 2182-2187. 
9. Humphrey, D. (2014). UAV and GIS, an emerging dynamic duo. Available at 
<http://www.esri.com/~/media/Files/Pdfs/news/arcuser/0314/uav-and-gis.pdf>. 
10. Moreira, A. (1985). Carta Geológica de Arcos de Valdevez - folha 1D (escala 1/50000). Serviços 
Geológicos de Portugal. 


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UAVs orthoimages for identifying and mapping geomorphic inheritance of the quaternary glaciers at the Soajo-Peneda mountains, Portugal

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