scholarly journals A 2D hydrodynamic-sedimentological model for gravel bed rivers. Part II, Case study: the Brenta River in Italy

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Gabriel Kaless ◽  
Johnny Moretto ◽  
Fabio Delai ◽  
Luca Mao ◽  
Mario A. Lenzi
Keyword(s):  
Low Frequency ◽  
Channel Changes ◽  
Gravel Bed ◽  
Digital Terrain ◽  
Terrain Models ◽  
Extensive Field ◽  
Subsurface Material ◽  
Sediment Flow ◽  
Imaging Detection

A 2D depth average model has been used to simulate water and sediment flow in the Brenta River so as to interpret channel changes and to assess model predictive capabilities. The Brenta River is a gravel bed river located in Northern Italy. The study reach is 1400 long and has a mean slope of 0.0056. High resolution digital terrain models has been produced combining laser imaging detection and ranging data with colour bathymetry techniques. Extensive field sedimentological surveys have been also carried out for surface and subsurface material. The data were loaded in the model and the passage of a high intense flood (R.I. > 9 years) was simulated. The model was run under the hypothesis of a substantial equilibrium between sediment input and transport capacity. In this way, the model results were considered as a reference condition, and the potential trend of the reach was assessed. Low-frequency floods (R.I. » 1.5 years) are expected to produce negligible changes in the channel while high floods may focalize erosion on banks instead than on channel bed. Furthermore, the model predicts well the location of erosion and siltation areas and the results promote its application to other reaches of the Brenta River in order to assess their stability and medium-term evolution.

scholarly journals Detection of earthflow dynamics using medium-resolution digital terrain models: Diachronic perspective of the Jovac earthflow, Southern Serbia

2021 ◽  
Vol 61 (2) ◽  
pp. 187-206
Author(s):  
Marko Milošević ◽  
Dragoljub Štrbac ◽  
Jelena Ćalić ◽  
Milan Radovanović
Keyword(s):  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Landslide Volume ◽  
Medium Resolution ◽  
Before And After ◽  
Movement Mechanism ◽  
Research Procedure ◽  
Definition Of

The paper presents and discusses the landslide research procedure related to the topography before and after its occurrence, using the comparative analysis of two medium-resolution digital terrain models. The case study is the Jovac mega-landslide—the largest landslide to occur in Serbia in the last 100 years, active for three days in February 1977. The indicators used to determine the volume and movement mechanism were the spatial distribution of elevation differences within the two digital terrain models (DTM), and the analysis of geomorphological features before the landslide. The obtained elevation differences allowed the definition of the approximate landslide volume: 11.6 × 106 m3. All the data obtained indicate that the movement mechanism falls into the category of earthflow.

scholarly journals Digital Deforestation: Comparing Automated Approaches to the Production of Digital Terrain Models (DTMs) in Agisoft Metashape

Quaternary ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Matthew D. Howland ◽  
Anthony Tamberino ◽  
Ioannis Liritzis ◽  
Thomas E. Levy
Keyword(s):  
Point Cloud ◽  
Archaeological Sites ◽  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Cloud Classification ◽  
Classification Tool ◽  
Point Cloud Classification ◽  
User Friendly

This paper tests the suitability of automated point cloud classification tools provided by the popular image-based modeling (IBM) software package Agisoft Metashape for the generation of digital terrain models (DTMs) at moderately-vegetated archaeological sites. DTMs are often required for various forms of archaeological mapping and analysis. The suite of tools provided by Agisoft are relatively user-friendly as compared to many point cloud classification algorithms and do not require the use of additional software. Based on a case study from the Mycenaean site of Kastrouli, Greece, the mostly-automated, geometric classification tool “Classify Ground Points” provides the best results and produces a quality DTM that is sufficient for mapping and analysis. Each of the methods tested in this paper can likely be improved through manual editing of point cloud classification.

Ending the Cinderella Status of Terraces and Lynchets in Europe

2020 ◽  
Author(s):  
Daniel Fallu ◽  
Tony Brown ◽  
Kevin Walsh ◽  
Sara Cucchiaro ◽  
Paolo Tarolli ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Holistic Approach ◽  
Theoretical Background ◽  
New Techniques ◽  
Erosion Rates ◽  
Digital Terrain ◽  
Terrain Models ◽  
Calcium Oxalates ◽  
Demographic Fluctuations

<p>Terraces and lynchets are not only ubiquitous worldwide and within Europe but can provide increasingly important Ecosystem Services (ESs), which may be able to mitigate aspects of climate change. They are also probably a major cause of non-linearity between climate and erosion rates in agricultural systems as noted from alluvial and colluvial studies. In this paper we review the theoretical background of terraces and lynchets, present a modified classification, and show how new techniques are transforming the study of these widespread and often ancient anthropogenic landforms. Indeed the problems of dating terraces and also the time-consuming nature and costly surveys has held back the archaeological study of terraces until now. The applicable suite of techniques available now includes the creation of Digital Terrain Models (DTMs) from Structure from Motion (SfM) photogrammetry, Airborne and Terrestrial Laser Scanning (ALS-TLS); the use of OSL and pOSL, pXRF, FTIR, phytoliths, calcium oxalates from plants and potentially sedaDNA. Examples will be drawn from a recently started ERC project (TerrACE; ERC-2017-ADG: 787790, 2018-2023; https://www.terrace.no/) which is working at over 10 sites in Europe ranging from Norway to Greece.</p><p>This paper explains the development of a new holistic approach to terrace archaeology driven by a modern conceptualisation of human-landscape relationships, and facilitated by new scientific developments. We explain the rationale for our choice of case study areas, for example, the range of bio-climatic zones. In addition, this multi-regional approach allows us to address contingent regional and local historical/socioeconomic processes; from demographic fluctuations to the development of specific forms of agricultural techniques. Examples of DTM creation, field analyses and selected results will be given from Martleburg in Belgium and sites in Italy. We will then move on to explain how this combination of a comprehensive suite of modern field and laboratory methods and an interpretive strategy informed by the environmental humanities will yield exciting and groundbreaking results.</p>

USE OF AERIAL IMAGES IN RESEARCH OF MASS MOVEMENTS – A CASE STUDY OF THE LACHOWICE LANDSLIDE (WESTERN CARPATHIANS, BESKID MAKOWSKI MTS)

2016 ◽  
pp. 115-122 ◽  
Author(s):  
Krzysztof Karwacki
Keyword(s):  
Horizontal Displacement ◽  
Aerial Images ◽  
Rock Masses ◽  
Aerial Photos ◽  
Digital Terrain ◽  
Terrain Models ◽  
Displacement Vectors ◽  
Digital Elevation

The article presents the application of photogrammetric digital elevation models in the study of the Lachowice landslide. For this purpose, aerial photos taken in 1977, 2003, 2009 have been used. Digital terrain models (DTM) have been produced from the point cloud generated on the aerial images, using images matching. Generated models allowed calculating the volume of displaced rock masses. Zones of loss and accumulation of rock masses have also been identified. The presence of identifiable points on all images enabled the determination of the values and directions of horizontal displacement vectors.

scholarly journals Estimated Land and Building Tax using Aerial Photography (Case Study: Tingkir District, Salatiga City)

2020 ◽  
Vol 4 (2) ◽  
pp. 372-378
Author(s):  
Josef Allen ◽  
Frederik Samuel Papilaya
Keyword(s):  
Aerial Photographs ◽  
Digital Terrain Models ◽  
Raster Calculator ◽  
Digital Terrain ◽  
Terrain Models ◽  
Surface Models ◽  
Building Area ◽  
The City ◽  
Area Data

Salatiga, a city that borders directly and is surrounded by Semarang Regency. It has an area of ​​56.78 km2, with four sub-districts including, Sidorejo Regency, Argomulyo Regency, Tingkir Regency, and Sidomukti Regency, which covers 23 villages. The city of Salatiga has a fairly high population density with a proportion of more than 3300 inhabitants / km2. In this study took place in the Central Tingkir and Tingkir Lor areas by taking several points that are considered as housing as a case study. This study aims to estimate the price of land and building tax on an object of land and building tax. The process of this research uses aerial photo processing, where aerial photographs will be processed using professional software Agisoft photoscan to become an orthophoto, digital surface models and digital terrain models to obtain building area and land area data, then digital surface models and digital terrain models are processed . with ArcGIS 10.6 software using a raster calculator to get the height of the object to be used as the height of the building. The data obtained will be used to perform land and building tax calculations. The results of this study estimate the estimated land and building tax prices of at least IDR 37,313.00 and a maximum value of IDR 3,809,763.00.  

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