scholarly journals Quaternary formations mapping in the region of Volta Grande do Rio Uruguai (Brazil)

2021 ◽  
Vol 41 ◽  
pp. e174174
Author(s):  
Sandra Cristina Deodoro ◽  
William Zanete Bertolini ◽  
Plinio da Costa Temba
Keyword(s):  
Particle Size Analysis ◽  
Size Analysis ◽  
Valley Bottom ◽  
Model Soil ◽  
Fluvial Dynamics ◽  
Digital Elevation ◽  
Topographic Attributes ◽  
History Of ◽  
Elevation Model

Quaternary formations (detrital and weathered materials) are an important natural resource for different areas of scientific investigation, from understanding their relation to erosive processes and morphodynamic processes that create landforms or to understanding the history of the first human settlements (geoarcheology). Quaternary coverings can be formed in situ or be transported by external geologic agents. Regarding soils, Quaternary formations are related to landscape topography and are transformed according to the characteristics of this topography. Hence, classifying and mapping these soils is not always easy. The present article aims to map the Quaternary formations along a stretch of the Uruguay River basin  known as Volta Grande (SC/RS-Brazil), by using  topographic attributes derived from the SRTM GL1-Up Sampled digital elevation model, soil particle-size analysis, and a generated Multiresolution Index of Valley Bottom Flatness (MRVBF) index . The results of the analysis show that: (i) colluvium is the predominant Quaternary formation in the study area; (ii) there is a predominance of clay, corroborating previous studies of the region; (iii) the spatial distribution of the study area’s  Quaternary formations reflect local slope dynamics based on morphology and topographic position; and, (iv) the existence of colluvium-alluvium on the Uruguay River’s banks indicates that slope attributes contributed to the pedogeomorphological dynamics of the study area and not only fluvial dynamics. Based on the results, the methodology applied in this study might be useful for pedogeomorphological studies, notably in the analysis and mapping of Quaternary formations, despite some of its limitations.

Length‐Scale‐Dependent Relationships between VS30 and Topographic Slopes in Southern California

2019 ◽  
Vol 109 (6) ◽  
pp. 2614-2625
Author(s):  
Jessica Lin ◽  
Seulgi Moon ◽  
Alan Yong ◽  
Lingsen Meng ◽  
Paul Davis
Keyword(s):  
Large Scale ◽  
Southern California ◽  
Length Scales ◽  
Motion Models ◽  
Digital Elevation ◽  
Seismic Site Effects ◽  
Topographic Attributes ◽  
Elevation Model ◽  
Ground Motion Models

Abstract In engineering seismology, the time‐averaged shear‐wave velocity (VS) of the upper 30 m of the crust (VS30) is the primary parameter used in ground‐motion models to predict seismic site effects. VS30 is typically derived from in situ recordings of VS, although proxy‐based approaches (using geologic and/or geomorphometric classifications) are provisionally adopted when measurement‐based VS30 are sparse or not readily available. Despite the acceptance of proxy approaches, there are limited studies that examine the empirical relationships between VS30 and topographic attributes measured from various length scales and different resolutions of the digital elevation model. In this study, we examine the relationships between compiled VS30 measurements from 218 sites in southern California and topographic metrics of slope and relief measured over various length scales. We find that the correlations between topographic metrics and VS30 are weak but statistically significant. The correlations are improved when topographic slopes and relief are measured over length scales longer than typical hillslopes and VS30 sites are separated by different geologic groups. This is likely because VS30, especially on the rock sites, is better reflected in topographic metrics that capture large‐scale topographic relief, as well as landscape positions such as hilltops and valley bottoms.

scholarly journals Soil Moisture Estimation Using Citizen Observatory Data, Microwave Satellite Imagery, and Environmental Covariates

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2160
Author(s):  
Daniel Kibirige ◽  
Endre Dobos
Keyword(s):  
Soil Moisture ◽  
Expert Knowledge ◽  
Coefficient Of Determination ◽  
Landsat 8 ◽  
Regression Kriging ◽  
Environmental Covariates ◽  
Observatory Data ◽  
Digital Elevation ◽  
Elevation Model

Soil moisture (SM) is a key variable in the climate system and a key parameter in earth surface processes. This study aimed to test the citizen observatory (CO) data to develop a method to estimate surface SM distribution using Sentinel-1B C-band Synthetic Aperture Radar (SAR) and Landsat 8 data; acquired between January 2019 and June 2019. An agricultural region of Tard in western Hungary was chosen as the study area. In situ soil moisture measurements in the uppermost 10 cm were carried out in 36 test fields simultaneously with SAR data acquisition. The effects of environmental covariates and the backscattering coefficient on SM were analyzed to perform SM estimation procedures. Three approaches were developed and compared for a continuous four-month period, using multiple regression analysis, regression-kriging and cokriging with the digital elevation model (DEM), and Sentinel-1B C-band and Landsat 8 images. CO data were evaluated over the landscape by expert knowledge and found to be representative of the major SM distribution processes but also presenting some indifferent short-range variability that was difficult to explain at this scale. The proposed models were evaluated using statistical metrics: The coefficient of determination (R2) and root mean square error (RMSE). Multiple linear regression provides more realistic spatial patterns over the landscape, even in a data-poor environment. Regression kriging was found to be a potential tool to refine the results, while ordinary cokriging was found to be less effective. The obtained results showed that CO data complemented with Sentinel-1B SAR, Landsat 8, and terrain data has the potential to estimate and map soil moisture content.

scholarly journals A multi-level strategy for anticipating future glacier lake formation and associated hazard potentials

2010 ◽  
Vol 10 (2) ◽  
pp. 339-352 ◽  
Author(s):  
H. Frey ◽  
W. Haeberli ◽  
A. Linsbauer ◽  
C. Huggel ◽  
F. Paul
Keyword(s):  
Swiss Alps ◽  
Bed Topography ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Lake Formation ◽  
Level 3 ◽  
Multi Level ◽  
Four Levels ◽  
Elevation Model

Abstract. In the course of glacier retreat, new glacier lakes can develop. As such lakes can be a source of natural hazards, strategies for predicting future glacier lake formation are important for an early planning of safety measures. In this article, a multi-level strategy for the identification of overdeepened parts of the glacier beds and, hence, sites with potential future lake formation, is presented. At the first two of the four levels of this strategy, glacier bed overdeepenings are estimated qualitatively and over large regions based on a digital elevation model (DEM) and digital glacier outlines. On level 3, more detailed and laborious models are applied for modeling the glacier bed topography over smaller regions; and on level 4, special situations must be investigated in-situ with detailed measurements such as geophysical soundings. The approaches of the strategy are validated using historical data from Trift Glacier, where a lake formed over the past decade. Scenarios of future glacier lakes are shown for the two test regions Aletsch and Bernina in the Swiss Alps. In the Bernina region, potential future lake outbursts are modeled, using a GIS-based hydrological flow routing model. As shown by a corresponding test, the ASTER GDEM and the SRTM DEM are both suitable to be used within the proposed strategy. Application of this strategy in other mountain regions of the world is therefore possible as well.

scholarly journals The 1513 Monte Crenone rock avalanche: numerical model and geomorphological analysis

2022 ◽  
Vol 77 (1) ◽  
pp. 21-37
Author(s):  
Alessandro De Pedrini ◽  
Christian Ambrosi ◽  
Cristian Scapozza
Keyword(s):  
Numerical Modelling ◽  
Rock Avalanche ◽  
Historical Reconstruction ◽  
Field Mapping ◽  
Digital Elevation ◽  
Lake Formation ◽  
Detachment Zone ◽  
Elevation Model ◽  
Geomorphological Analysis

Abstract. As a contribution to the knowledge of historical rockslides, this research focuses on the historical reconstruction, field mapping, and simulation of the expansion, through numerical modelling, of the 30 September 1513 Monte Crenone rock avalanche. Earth observation in 2-D and 3-D, as well as direct in situ field mapping, allowed the detachment zone and the perimeter and volume of the accumulation to be determined. Thanks to the reconstruction of the post-event digital elevation model based on historical topographic maps and the numerical modelling with the RAMMS::DEBRISFLOW software, the dynamics and runout of the rock avalanche were calibrated and reconstructed. The reconstruction of the runout model allowed confirmation of the historical data concerning this event, particularly the damming of the valley floor and the lake formation up to an elevation of 390 m a.s.l., which generated an enormous flood by dam breaching on 20 May 1515, known as the “Buzza di Biasca”.

scholarly journals Volkanostratigrafi Inderaan Jauh Kompleks Gunungapi Gede dan Sekitarnya, Jawa Barat, Indonesia

2019 ◽  
Vol 20 (1) ◽  
pp. 9
Author(s):  
Fitriani Agustin ◽  
Sutikno Bronto
Keyword(s):  
Remote Sensing ◽  
Geological Mapping ◽  
Lava Flows ◽  
Energy Resources ◽  
Visual Interpretation ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Digital Elevation ◽  
History Of ◽  
Elevation Model

Remote sensing technology greatly helps to identify the various of volcano features, including active, old and ancient volcanoes. The aim of this  paper is intended to introduce various volcanic features in the Gede Volcano Complexs (GVC) and souronding area; compose volcanostratigraphy; and estimate the history of the volcanoes. The method used is a visual interpretation 9 meters spatial resolution of Digital Elevation Model (DEM) TerraSar-x image. Indonesian Stratigraphy Nomenclature Guide 1996 was implemented in vocanostratigraphy unit classification, involving Arc, Super Brigate, Brigate, Crown and Hummockly. Based on the interpretation the DEM image, volcanostratigraphic unit the Gede Volcano Complex consists of Bregade Masigit (Br. M.), which consists of Joklok (Gm.J.) and Gegerbentang (Gm.G.) Hummocs; Crown Lingkung (Kh.L.) consisting of Pangrango (Gm.P.), Situ Gunung (Gm Sg.), Cikahuripan (Gm.Ck.), Pasir Prahu (Gm.Ph) Hummocs; Gege Crown (Kh.G.), which is located in the east of Lingkung Crown. The Gede Crown consists of Gumuruh humock (Gm.Gh.), Gunung Gede lava flows (LG 1,2,3,4,5), and giant debrise avalances (gv-G). The geological mapping based volcanostratigraphy is very useful for exploration of mineral and energy resources, as well as geological hazards.Keywords : volcanostratigraphy, DEM TerraSar-x image, Gunung Gede Complexs.

scholarly journals Digital Segusio: from models generation to urban reconstruction

2016 ◽  
Vol 7 (15) ◽  
pp. 87
Author(s):  
Antonia Spanò ◽  
Filiberto Chiabrando ◽  
Livio Dezzani ◽  
Antonio Prencipe
Keyword(s):  
Laser Scanning ◽  
Urban Landscape ◽  
Geographical Information ◽  
Innovative Methods ◽  
Digital Elevation ◽  
History Of ◽  
Land Survey ◽  
Aerial Vehicle ◽  
Elevation Model ◽  
The City

<p>The reconstructive study of the urban arrangement of Susa in the 4th century arose from the intention to exploit some resources derived from local studies, and survey activities, fulfilled by innovative methods from which the modelling of architectural heritage (AH) and virtual reconstructions are derived.  The digital Segusio presented in this paper is the result of intensive discussion and exchange of data and information during the urban landscape documentation activities, and due to the technology of virtual model generation, making it possible to recreate the charm of an ancient landscape. The land survey has been accomplished using aerial and terrestrial acquisition systems, mainly through digital photogrammetry from UAV (Unmanned Aerial Vehicle) and terrestrial laser scanning.  Results obtained from both the methods have been integrated into the medium scale geographical data from the regional map repository, and some processing and visualization supported by GIS (Geographical Information System) has been achieved. Subsequently, with the help of accurate and detailed DEM (Digital Elevation Model) and other architectural scale models related to the ancient heritage, this ancient landscape was modelled. The integration of the history of this city with digital and multimedia resources will be offered to the public in the city museum housed in the restored castle of Maria Adelaide (Savoy dynasty, 11th century), which stands in the place where the acropolis of the city of Susa lay in ancient times.</p>

scholarly journals Radiocarbon, Soil, and Artifact Chronologies for An Early Southern Oregon Coastal Site

Radiocarbon ◽  
2005 ◽  
Vol 47 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Roberta Hall ◽  
Loren G Davis ◽  
Samuel Willis ◽  
Matthew Fillmore
Keyword(s):  
Late Pleistocene ◽  
Texture Classification ◽  
Archaeological Site ◽  
Particle Size Analysis ◽  
Early Holocene ◽  
Size Analysis ◽  
Human Occupation ◽  
Radiocarbon Dates ◽  
Middle Holocene ◽  
History Of

Radiocarbon dates together with geoarchaeological, soil, and lithic analyses are presented to describe archaeological site 35-CS-9 in Bandon Ocean Wayside State Park, Oregon, northwestern USA. One of the few Oregon middle-Holocene coastal sites that includes sediments and artifacts dating to the early Holocene and possibly to the late Pleistocene, it was recorded in 1951 and surface surveyed by archaeologists in 1975, 1986, and 1991, but its depth and antiquity were not tested. In February 2002, we studied the site's stratigraphy and sediments and described 8 strata from the aeolian surface to bedrock at 350 cm depth. Soil samples taken from a cut bank for texture classification, particle size analysis, pH, carbon content, and chemical analysis suggested that the site represented a complete history of Holocene deposits. Excavation of 2 test units in August 2002 uncovered substantial lithic and charcoal remains that confirm a protracted middle-Holocene occupation and suggest that human occupation began in the early Holocene. Charcoal recovered at 235–245 cm dated to 11,000 14C BP, and the deepest lithic artifact was recovered in a level at 215–225 cm. Whether the human occupation was continuous throughout the Holocene, and whether it began in the early Holocene or in the late Pleistocene, can only be determined with further excavations.

Investigating the Impacts of DEM Type, Resolution, and Noise on Extracted Hydro-Geomorphologic Parameters of Watersheds via GIS

2018 ◽  
pp. 133-175
Author(s):  
Vahid Nourani ◽  
Safa Mokhtarian Asl ◽  
Maryam Khosravi Sorkhkolaee ◽  
Aida Hosseini Baghanam ◽  
Masoud Mehrvand
Keyword(s):  
Water Resources ◽  
Catchment Area ◽  
Hydrological Modeling ◽  
Integrated Management ◽  
Quality Data ◽  
Distributed Modeling ◽  
Digital Elevation ◽  
Topographic Attributes ◽  
Elevation Model

Water resources management is dependent on knowledge and understanding of water quantity and quality information with the latest developments in information technology such as geographic information system (GIS) to develop effective hydrological modeling within the water-based systems. The efficiency of such hydrological modeling relies on the accuracy of applied data. In this way, the application of low-quality data in developing models for integrated management of water resources can impose irreparable financial and human resources and environmental costs in the catchment area. Thus, in regions that shortage of data is the issue, semi-distributed modeling is a useful tool. In this chapter, three aims are followed: (1) effect of digital elevation model (DEM) type and resolution on extracted hydro-geomorphologic parameters, (2) effect of wavelet-based de-noising method on extracted hydro-geomorphologic parameters, (3) determination of the optimal cell size to extract topographic attributes with good agreement to the real features.

scholarly journals The first complete inventory of the local glaciers and ice caps on Greenland

2012 ◽  
Vol 6 (6) ◽  
pp. 1483-1495 ◽  
Author(s):  
P. Rastner ◽  
T. Bolch ◽  
N. Mölg ◽  
H. Machguth ◽  
R. Le Bris ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Climate Change Impacts ◽  
Mean Value ◽  
Ice Caps ◽  
Digital Elevation ◽  
Topographic Attributes ◽  
Baseline Information ◽  
The Mean ◽  
Mapping Techniques ◽  
Elevation Model

Abstract. Glacier inventories provide essential baseline information for the determination of water resources, glacier-specific changes in area and volume, climate change impacts as well as past, potential and future contribution of glaciers to sea-level rise. Although Greenland is heavily glacierised and thus highly relevant for all of the above points, a complete inventory of its glaciers was not available so far. Here we present the results and details of a new and complete inventory that has been compiled from more than 70 Landsat scenes (mostly acquired between 1999 and 2002) using semi-automated glacier mapping techniques. A digital elevation model (DEM) was used to derive drainage divides from watershed analysis and topographic attributes for each glacier entity. To serve the needs of different user communities, we assigned to each glacier one of three connectivity levels with the ice sheet (CL0, CL1, CL2; i.e. no, weak, and strong connection) to clearly, but still flexibly, distinguish the local glaciers and ice caps (GIC) from the ice sheet and its outlet glaciers. In total, we mapped ~ 20 300 glaciers larger than 0.05 km2 (of which ~ 900 are marine terminating), covering an area of 130 076 ± 4032 km2, or 89 720 ± 2781 km2 without the CL2 GIC. The latter value is about 50% higher than the mean value of more recent previous estimates. Glaciers smaller than 0.5 km2 contribute only 1.5% to the total area but more than 50% (11 000) to the total number. In contrast, the 25 largest GIC (> 500 km2) contribute 28% to the total area, but only 0.1% to the total number. The mean elevation of the GIC is 1700 m in the eastern sector and around 1000 m otherwise. The median elevation increases with distance from the coast, but has only a weak dependence on mean glacier aspect.

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