Preprints
Filtering by Subject: Geography
Multi-scale segmentation algorithm for pattern-based partitioning of large categorical rasters
Published: 2018-01-28
Subjects: Computer Sciences, Earth Sciences, Geography, Numerical Analysis and Scientific Computing, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science
Analyzing large Earth Observation (EO) data on the broad spatial scales frequently involves regionalization of patterns. To automate this process we present a segmentation algorithm designed specifically to delineate segments containing quasi-stationary patterns. The algorithm is designed to work with patterns of a categorical variable. This makes it possible to analyze very large spatial [...]
Impacts of land-use and land-cover change on stream hydrochemistry in the Cerrado and Amazon biomes
Published: 2018-01-28
Subjects: Chemistry, Computer Sciences, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Fresh Water Studies, Geography, Hydrology, Natural Resources and Conservation, Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Physics, Social and Behavioral Sciences, Soil Science
Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental [...]
Effects of spatial resolution on slope and aspect derivation for regional-scale analysis
Published: 2017-11-01
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science
This paper investigates differences between morphometric parameters (slope and aspect) derived from a resampled DEM and resampled morphometric data derived from a medium resolution DEM, with examples for three study areas in South America selected to represent flatlands, hilly terrain, and mountain ranges. Using a low resolution DEM for regional scale morphometric analysis is not an optimal [...]
Geological applications of digital terrain analysis
Published: 2017-11-01
Subjects: Earth Sciences, Geochemistry, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Volcanology
Editorial to the IJGIS Special Issue on "Geological applications of digital terrain analysis". In this volume, the modern advances in the field of geological terrain analysis are presented, while emphasis is given to the quantitative analysis of modern datasets.
Influence of cell size on volume calculation using digital terrain models: A case of coastal dune fields
Published: 2017-11-01
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Remote Sensing, Sedimentology, Social and Behavioral Sciences, Spatial Science
In this work, we analyze how variation in cell size influences the volume calculated from Digital Terrain Models (DTMs) derived from a LiDAR (Light Detection and Ranging) survey in two coastal Late Holocene dune fields in southern Brazil. Cell size varied from 1 to 100 m. The RMSE (Root Mean Square Error) of the resampled DTMs from the original LiDAR (with 0.5 m resolution) increases linearly [...]
Multi-scale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Surface roughness is an important geomorphological variable which has been used in the earth and planetary sciences to infer material properties, current/past processes and the time elapsed since formation. No single definition exists, however within the context of geomorphometry we use surface roughness as a expression of the variability of a topographic surface at a given scale, where the scale [...]
Análise digital de terreno e evolução de longo-termo de relevo do centro-leste brasileiro
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Geomorphological theories for long-term relief evolution postulate the existence of planation surfaces, created by the con- tinuous work of erosion/deposition during periods of tectonic quiescence and recognized as extensive areas of very gentle relief disturbed only locally by residual elevations, or by the apparent leveling of summit heights in a given region. After decades since the [...]
Comparison of roving-window and search-window techniques for characterising landscape morphometry
Published: 2017-10-31
Subjects: Computer Sciences, Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Theory and Algorithms
Neighbourhood analysis in a Geographical Information System (GIS) calculates the value of a given raster cell from the values of its neighboring cells. Common operations include filtering (high-pass, low-pass, etc) and smoothing (mean, mode) of data, operations that can be done by means of roving-windows or search-windows. Digital terrain analysis (or geomorphometry) relies on neighbourhood [...]
SRTM resample with short distance-low nugget kriging
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
The Shuttle Radar Topography Mission (SRTM), was flow on Space Shuttle Endeavour in February 2000, with the objective of acquire a digital elevation model of all land between 60º north latitude and 56º south latitude, using Interferometric Synthetic Aperture Radar (InSAR) techniques. SRTM data is distributed at horizontal resolution of 1 arc-second (aprox. 30m) for areas within the USA and at 3 [...]
Aplicações dos modelos de elevação SRTM em geomorfologia
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science
A missão Shuttle Radar Topography Mission (SRTM) foi realizada para mapear o relevo da área continental da Terra com interferometria de radar entre 60º de latitude norte e 54º de latitude sul. A utilização de Modelos Digitais de Elevação (MDEs) em geomorfologia permite o cálculo de variáveis associadas ao relevo com rapidez e precisão. Neste artigo, apresenta-se uma visão geral de aplicações dos [...]
SRTM-based morphotectonic analysis of the Poços de Caldas Alkaline Massif, southeastern Brazil
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
An evaluation of SRTM 03” data applicability in geomorphology and morphotectonics analysis is proposed, considering the morphometric parameters slope, aspect, surface roughness and isobase surface. The study area, in southeastern Brazil, comprises the Poços de Caldas Alkaline Massif, a 33km-diameter Late Cretaceous collapsed volcanic caldera. Morphometric indices evaluated showed the correlation [...]
Resampling SRTM 03”-data with kriging
Published: 2017-10-30
Subjects: Computer Sciences, Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science
The purpose of this article is to present the steps necessary to improve the resolution of a DEM us- ing variogram modelling and kriging, as well as a brief comparison of the results with those obtained with interpolation by Regularised Splines with Ten- sion (RST).
r.roughness – a new tool for morphometric analysis in GRASS
Published: 2017-10-30
Subjects: Computer Sciences, Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Theory and Algorithms
This article briefly describes r.roughness, a shell script written to calculate the surface roughness of raster surfaces. The method is based on Hobson (1972), where roughness is defined as the ratio be- tween surface and plan area of square cells.
Trend-surfaces analysis of morphometric parameters: A case-study in southearstern Brazil
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Trend-surface analysis was carried out on data from morphometric parameters isobase and hydraulic gradient. The study area, located in the eastern border of Quadrilátero Ferrífero, southeastern Brazil, presents four main geomorphological units, one characterized by fluvial dissection, two of mountainous relief, with a scarp of hundreds of meters of fall between them, and a flat plateau in the [...]
Morphometric analysis in Geographic Information Systems: applications of free software GRASS and R
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Development and interpretation of morphometric maps are important tools in studies related to neotectonics and geomorphology; Geographic Information Systems (GIS) allows speed and precision to this process, but applied methodology will vary according to available tools and degree of knowledge of each researcher about involved software. A methodology to integrate GIS and statistics in morphometric [...]