TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 2: Surface dynamics and basin analysis $ Faisal Shahzad à , Richard Gloaguen Remote Sensing Group, Institute of Geology, Freiberg University of Mining and Technology, Bernhard-von-Cotta-Strasse 2, 09599 Freiberg, Germany article info Article history: Received 2 March 2010 Received in revised form 9 June 2010 Accepted 18 June 2010 Available online 9 November 2010 Keywords: Tectonics Surface roughness Isobase map Basin tilting Hypsometry abstract We present the analytical capability of TecDEM, a MATLAB toolbox used in conjunction with Global DEMs for the extraction of tectonic geomorphologic information. TecDEM includes a suite of algorithms to analyze topography, extracted drainage networks and sub-basins. The aim of part 2 of this paper series is the generation of morphometric maps for surface dynamics and basin analysis. TecDEM therefore allows the extraction of parameters such as isobase, incision, drainage density and surface roughness maps. We also provide tools for basin asymmetry and hypsometric analysis. These are efficient graphical user interfaces (GUIs) for mapping drainage deviation from basin mid-line and basin hypsometry. A morphotectonic interpretation of the Kaghan Valley (Northern Pakistan) is performed with TecDEM and the findings indicate a high correlation between surface dynamics and basin analysis parameters with neotectonic features in the study area. & 2010 Elsevier Ltd. All rights reserved. 1. Introduction Landscape development is controlled by tectonic and climatic processes. Traces of this development are preserved in drainage network anomalies, rock weathering and discontinuities in relief patterns (Garrote et al., 2008; Grohmann, 2004; Shahzad et al., 2009; Strahler, 1957). Digital elevation models (DEMs) provide an oppor- tunity to quantify the influence of neotectonic processes on landscape development. Numerous studies have been carried out to investigate surface process models (SPMs) and how they influence and/or are influenced by tectonics (Alexandru et al., 2006). Thus SPMs can be investigated to discriminate the spatial distribution of tectonic processes. This paper presents part 2 of the paper series on TecDEM. For surface dynamics analysis topography is usually examined by studying the relationships between minimum and maximum elevations. Whilst for basin analysis extracted streams and drainage basins of similar Strahler (1957) order are used to identify the major tectonic units, structures and lithological boundaries (Golts and Rosenthal, 1992, 1993). Drainage analysis can also be a principal tool for interpreting active tectonics due to the variation in stream power (Garrote et al., 2008). It is important to study drainage dynamics at a suitable Strahler order as these streams can then be attributed to the same geological events. For example, short length streams of similar Strahler order exists on flanks of folds or elevated tectonic blocks and the inclination of the longest streams are attributed to synclinal troughs, graben structures and down faulted blocks (Filosofov, 1960; Golts and Rosenthal, 1992). Here we present the surface dynamics and basin processing options that are available in TecDEM. This includes algorithms for the preparation of morphometric maps for surface dynamics and basin analysis. In this second paper we extend the idea of TecDEM, and demonstrated how it can be used to implement algorithms for morphometric indices and produce maps of Isobase, Incision, Surface Roughness, Drainage Density, Basin asymmetry and Hypsometry (Garrote et al., 2008; Grohmann, 2004; Schumm et al., 2006). We include an overview of the methodology and algorithms used. This study also investigates the tectonics of the Kaghan Valley (Northern Pakistan). We show that parameters of surface dynamics strongly correlate to already identified neotectonic features in the study area. The relationship between the degree of basin tilt and the stage of the landscape’s response to tectonic perturbation was investigated using TecDEM. 2. Methodology Previous work has shown that morphometric basin analysis sheds light on surface dynamics and neotectonics (Cox, 1994; Day, 1979; Filosofov, 1960; Garrote et al., 2008; Golts and Rosenthal, 1992, 1993; Grohmann, 2004; Perez-Pena et al., 2009). Two data sets are used for the current work: DEM and an automatically extracted drainage network, as discussed in part one of this paper series (Shahzad and Gloaguen, in press). Both datasets were used to further implement the above stated morphometric indices in the framework of TecDEM. A data flow diagram for these analyses is shown in Fig. 1. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/cageo Computers & Geosciences 0098-3004/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.cageo.2010.06.009 $ Code available from server at http://www.rsg.tu-freiberg.de or at http://www.iamg.org/CGEditor/index.htm. à Corresponding author. Tel.: + 49 3731 44 59 29. E-mail addresses: geoquaidian@gmail.com (F. Shahzad), gloaguen@geo.tu-freiberg.de (R. Gloaguen). Computers & Geosciences 37 (2011) 261–271