High-resolution topography for Digital Terrain Model (DTM) in Keller Peninsula, Maritime Antarctica.

Adriano L Schünemann,Pedro Henrique A Almeida,Antonio Batista Pereira,Elpídio I Fernandes Filho,André Thomazini,Carlos E.G.R Schaefer,Márcio R Francelino

doi:10.1590/0001-3765201820170296

Abstract

High resolution topography (HRT) surveys is an important tool to model landscapes, especially in zones subjected to strong environmental changes, such as Antarctica, where landform is highly influenced by cryoclasty and permafrost melting. The aim of this work was to obtain a high accurate DTM for Keller Peninsula, Maritime Antarctica. The survey study was assessed in the 2014/2015 and 2015/2016 during the austral summer, by using Terrestrial Laser Scanner (TLS). In order to cover 8 km² of the Peninsula, the TLS equipment was installed in 81 different points. Results of the DTM generated by TLS (hereafter, HRT-DTM), and the terrain variables Aspect, Slope and Hillshade obtained were compared with previous models generated by aerophotographic survey (hereafter, APG-DTM). RMSE for the HRT and APG-DTM were 0.726 and 2.397 m, respectively. Spatial resolution of the DTMs was 0.20 m. Morphometric variables obtained from the two methods presented visual differences on the thematic maps, especially related to the Aspect. Generalization was the main process, whereas interpolation occurred for the HRT survey, being the process of choice for the APG method. A large number of points are obtained by the TLS, providing a dense cloud of points, spatially well-distributed, enabling the generalization process to obtain surface models with high performance.

Highlights

The ability to predict the transfer of water, sediments and nutrients, map catastrophical natural events, identify the radiation balance, biophysical responses of the environment that influence the landscape and its functions, all have great importance to science and society
Results of the High resolution topography (HRT)-DIGITAL TERRAIN MODEL (DTM) were compared with the DTM generated by Mendes JR et al (2012)
The terrain variables Aspect, Slope, Contour and Hillshade were generated with the two DTMs, and theirs results were compared

Summary

Introduction

The ability to predict the transfer of water, sediments and nutrients, map catastrophical natural events, identify the radiation balance, biophysical responses of the environment that influence the landscape and its functions, all have great importance to science and society. Several studies are focused on Earth’s surface and its natural resources and changes, especially at the present, when mankind face severe climate changes and widespread modifications of the landscape (Passalacqua et al 2015). One of the advantages of HRT surveysis that it enables quantitative study of a phenomena (Tarolli 2014). This is important in zones subjected to strong environmental changes, such as Antarctica, where relief dynamic is highly influenced by physical weathering and permafrost melting (Francelino et al 2011). The Digital Elevation Model is a representation of a continuous surface elevation using points with well-known x, y and z coordinates. When the elevation represents the earth surface, it is called Digital Terrain Model (DTM) (Li et al 2004). The main interpolators to model the landscape or a phenomena, may be grouped in three basic categories as indicated by Wasklewicz et al (2013): i) local neighborhood (e.g., nearest neighbor, inverse distance weighted, triangulation); ii) geostatistics methods (e.g. kriging), and iii) spline methods

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Discussion

Conclusion