Morphometric analysis in Geographic Information Systems: applications of free software GRASS and R

Abstract

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 analysis is presented for the most usual morphometric parameters -hypsometry, slope, aspect, swath profiles, lineaments and drainage density, surface roughness, isobase and hydraulic gradient.The GIS used was the Geographic Resources Analysis Support System (GRASS-GIS), an opensource project that offers an integrated environment for raster and vector analysis, image processing and maps/graphics creation. Statistical analysis of parameters can be carried out on R, a system for statistical computation and graphics, through an interface with GRASS that allows raster maps and points files to be treated as variables for analysis.The basic element for deriving morphometric maps is the digital elevation model (DEM). It can be interpolated from scattered points or contours, either in raster or vector format; it is also possible to use DEMs from NASA's Shuttle Radar Topographic Mission, with 30m of ground resolution for the USA and 90m for other countries.Proposed methodology can be adapted according to necessities and available tools. The use of free and open-source tools guarantees access to everyone, and its increasing popularization opens new development perspectives in this research field.

Morphometric analysis of river basins using GIS and remote sensing of an Andean section of Route 150, Argentina. A comparison between manual and automated delineation of basins

“…Some recent examples are: Topaloglu, 2002;Moussa, 2003;Sreedevi et al, 2004Sreedevi et al, , 2013Srinivasa Vittala et al, 2004;Mesa, 2006;Esper Angillieri, 2008, 2012Perucca and Esper Angillieri, 2011. Recent studies using digital GIS-derived basin are: Verstappen, 1983;Rinaldo et al, 1998;Farr and Kobrick, 2000;Macka, 2001;Grohmann, 2004;Gangalakunta, 2004;Godchild and Haining 2004;Grohmann et al, 2007;Korkalainen et al, 2007;Yu and Wei, 2008;Hlaing et al, 2008;Ozdemir and Bird, 2009;Panhalkar, 2014. In addition, studies that compare delineation methods are: Stanton, 2001;Baker et al, 2006.…”

Morphometric Characterization of Yamuna River basin around Agra, Firozabad and Etawah Districts, Uttar Pradesh, using Remote Sensing and GIS Techniques

“…The use of SRTM data and GIS technique shows precision, fast and inexpensive to calculate morphometric parameters [6], [7], [8] and [9]. The present study is carried out to analyse various morphometric attributes of Yamuna river basin in and around Agra, Firozabad and Etawah districts of Uttar Pradesh.…”

Tectônica transcorrente mesozoica-cenozoica na Borda Leste da Bacia do Paraná, Estado de Santa Catarina

“…It was constructed based on drainage of second and higher orders (as indicated by Grohmann, 2004) and for each component a pair of points was assigned, at the source and at the drainage mouth, which combined with DEM, allowed the generation of a network with the values of the different altitudes. Each drainage section had its length calculated, and then the value of the hydraulic gradient was calculated using equation [1] and assigned to its midpoint.…”

“…The Hydraulic Gradient (HG) map Modenesi-Gauttieri et al, 2002;Grohmann, 2004Grohmann, , 2005 was generated to determine areas with similar hydraulic behaviour with the aim of relating them to structural lineaments. It was constructed based on drainage of second and higher orders (as indicated by Grohmann, 2004) and for each component a pair of points was assigned, at the source and at the drainage mouth, which combined with DEM, allowed the generation of a network with the values of the different altitudes.…”

“…Morphometric maps were first used in tectonic analysis by Filosofov (1960), and since then methods of construction and assessment of morphometric parameters have been constantly improved with the development of new techniques (Zuchiewicz, 1991;Golts and Rosenthal, 1993;Rodrigues, 1993;Grohmann, 2004;. Particularly in this last decade, remotely sensed data coupled with Geographical Information System (GIS) have promoted significant improvement of these methods, giving them greater agility and precision in interpretation (Jordan et al, 2005;Guth, 2006;Valeriano et al, 2006;Grohmann et al, 2007).…”