Geomorphological mapping using object-based analysis and ASTER DEM in the Paraíba do Sul Valley, Brazil

Abstract. Spatiotemporal geomorphological mapping of intertidal areas is essential for understanding system dynamics and provides information for ecological conservation and management. Mapping the geomorphology of intertidal areas is very challenging mainly because spectral differences are oftentimes relatively small while transitions between geomorphological units are oftentimes gradual. Also, the intertidal areas are highly dynamic. Considerable challenges are to distinguish between different types of tidal flats, specifically, low and high dynamic shoal flats, sandy and silty low dynamic flats, and mega-ripple areas. In this study, we harness machine learning methods and compare between machine learning methods using features calculated in classical Object-Based Image Analysis (OBIA) vs. end-to-end deep convolutional neural networks that derive features directly from imagery, in automated geomorphological mapping. This study expects to gain us an in-depth understanding of features that contribute to tidal area classification and greatly improve the automation and prediction accuracy. We emphasise model interpretability and knowledge mining. By comparing and combing object-based and deep learning-based models, this study contributes to the development and integration of both methodology domains for semantic segmentation.

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Using geomorphometry for hydro-geomorphological analysis in a Mediterranean research catchment

10.5194/hess-2016-68 ◽

2016 ◽

Author(s):

Domenico Guida ◽

Albina Cuomo ◽

Vincenzo Palmieri

Keyword(s):

Base Flow ◽

Storm Event ◽

Wet Season ◽

Time Step ◽

Geomorphological Mapping ◽

Object Based ◽

Flood Magnitude ◽

Geomorphological Units ◽

Specific Discharge ◽

Geomorphological Analysis

Abstract. The aim of the paper is to apply an object-based geomorphometric procedure to define the runoff contribution areas and support a hydro-geomorphological analysis on a 3-km2 Mediterranean research catchment (southern Italy). Daily and sub-hourly discharge and electrical conductivity data were collected and recorded based on three-year monitoring activity. Hydro-chemograph analyses on these data revealed a strong seasonal hydrological response in the catchment that were different from the stormflow events that occurred in the wet period and in dry periods. This analysis enabled us to define the hydro-chemograph signatures related to increasing flood magnitude, which progressively involves various runoff components (base flow, subsurface flow and surficial flow) and an increasing contributing area to discharge. Field surveys and water table/discharge measurements carried out during a selected storm event enabled us to identify and map specific runoff source areas with homogeneous geomorphological units previously defined as hydro-geomorpho-types (spring points, diffuse seepage along the main channel, seepage along the riparian corridors, diffuse outflow from hillslope taluses and concentrate sapping from colluvial hollows). Following the procedures previously proposed and used by authors for object-based geomorphological mapping, a hydro-geomorphologically-oriented segmentation and classification was performed with an e-Cognition (Trimble, Inc) package. The best agreement with the expert-based geomorphological mapping was obtained with weighted profile and plane curvature sum at different-size windows. Combining the hydro-chemical analysis and object-based hydro-geomorpho-type map, the variability of the contribution areas was graphically modelled for the selected event which occurred during the wet season by using the log values of flow accumulation that better fit the contribution areas. The results enabled us to identify the runoff component on hydro-chemograph for each time step and to calculate a specific discharge contribution from each hydro-geomorpho-type. This kind of approach could be usefull applied to similar, rainfall-dominated, forested and no-karst catchments in the Mediterranean eco-region.

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Object-Based Geomorphological Mapping: Application on an Alpine Deep-Seated Gravitational Slope Deformation Contest (Germanasca Valley, Western Alps—Italy)

Applied Sciences ◽

10.3390/app12020778 ◽

2022 ◽

Vol 12 (2) ◽

pp. 778

Author(s):

Maria Gabriella Forno ◽

Giandomenico Fubelli ◽

Marco Gattiglio ◽

Glenda Taddia ◽

Stefano Ghignone

Keyword(s):

Western Alps ◽

Slope Deformation ◽

Classical Representation ◽

Multiscale Representation ◽

Geomorphological Mapping ◽

Piedmont Zone ◽

Full Coverage ◽

Object Based ◽

Gis Environment ◽

Geomorphological Features

This research reports the use of a new method of geomorphological mapping in GIS environments, using a full-coverage, object-based method, following the guidelines of the new geomorphological legend proposed by ISPRA–AIGEO–CNG. This methodology is applied to a tributary valley of the Germanasca Valley, shaped into calcschist and greenschist, of the Piedmont Zone (Penninic Domain, Western Alps). The investigated sector is extensively affected by dep-seated gravitational slope deformation (DSGSD) that strongly influences the geological setting and the geomorphological features of the area. The mapping of these gravitational landforms in a traditional way creates some difficulties, essentially connected to the high density of information in the same site and the impossibility of specifying the relationships between different elements. The use of the full-coverage, object-based method instead is advantageous in mapping gravitational evidence. In detail, it allows for the representation of various landforms in the same sector, and their relationships, specifying the size of landforms, and with the possibility of multiscale representation in the GIS environment; and, it can progressively be update with the development of knowledge. This research confirms that the use of the full-coverage, object-based method allows for better mapping of the geomorphological features of DSGSD evidence compared to classical representation.

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Using object-based geomorphometry for hydro-geomorphological analysis in a Mediterranean research catchment

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3493-2016 ◽

2016 ◽

Vol 20 (9) ◽

pp. 3493-3509 ◽

Cited By ~ 4

Author(s):

Domenico Guida ◽

Albina Cuomo ◽

Vincenzo Palmieri

Keyword(s):

Storm Event ◽

Wet Season ◽

Time Step ◽

Riparian Corridors ◽

Geomorphological Mapping ◽

Object Based ◽

Flood Magnitude ◽

Geomorphological Units ◽

Specific Discharge ◽

Geomorphological Analysis

Abstract. The aim of the paper is to apply an object-based geomorphometric procedure to define the runoff contribution areas and support a hydro-geomorphological analysis of a 3 km2 Mediterranean research catchment (southern Italy). Daily and sub-hourly discharge and electrical conductivity data were collected and recorded during a 3-year monitoring activity. Hydro-chemograph analyses carried out on these data revealed a strong seasonal hydrological response in the catchment that differed from the stormflow events that occur in the wet periods and in dry periods. This analysis enabled us to define the hydro-chemograph signatures related to increasing flood magnitude, which progressively involves various runoff components (baseflow, subsurface flow and surficial flow) and an increasing contributing area to discharge. Field surveys and water table/discharge measurements carried out during a selected storm event enabled us to identify and map specific runoff source areas with homogeneous geomorphological units previously defined as hydro-geomorphotypes (spring points, diffuse seepage along the main channel, seepage along the riparian corridors, diffuse outflow from hillslope taluses and concentrate sapping from colluvial hollows). Following the procedures previously proposed and used by authors for object-based geomorphological mapping, a hydro-geomorphologically oriented segmentation and classification was performed with the eCognition (Trimble, Inc.) package. The best agreement with the expert-based geomorphological mapping was obtained with weighted plan curvature at different-sized windows. By combining the hydro-chemical analysis and object-based hydro-geomorphotype map, the variability of the contribution areas was graphically modeled for the selected event, which occurred during the wet season, by using the log values of flow accumulation that better fit the contribution areas. The results allow us to identify the runoff component on hydro-chemographs for each time step and calculate a specific discharge contribution from each hydro-geomorphotype. This kind of approach could be useful when applied to similar, rainfall-dominated, forested and no-karst catchments in the Mediterranean eco-region.

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