scholarly journals Inventory and Connectivity Assessment of Wetlands in Northern Landscapes with a Depression-Based DEM Method

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3355
Author(s):  
Emelie Stengård ◽  
Aleksi Räsänen ◽  
Carla Sofia Santos Ferreira ◽  
Zahra Kalantari
Keyword(s):  
Additional Data ◽  
Future Research ◽  
Hydrological Connectivity ◽  
Flow Paths ◽  
Digital Elevation ◽  
Wetland Connectivity ◽  
Resilience Management ◽  
Mapping Techniques ◽  
Elevation Model ◽  
Chemical Materials

Wetlands, including peatlands, supply crucial ecosystem services such as water purification, carbon sequestration and regulation of hydrological and biogeochemical cycles. Peatlands are especially important as carbon sinks and stores because of the incomplete decomposition of vegetation within the peat. Good knowledge of individual wetlands exists locally, but information on how different wetland systems interact with their surroundings is lacking. In this study, the ability to use a depression-based digital elevation model (DEM) method to inventory wetlands in northern landscapes and assess their hydrological connectivity was investigated. The method consisted of three steps: (1) identification and mapping of wetlands, (2) identification of threshold values of minimum wetland size and depth, and (3) delineation of a defined coherent area of multiple wetlands with hydrological connectivity, called wetlandscape. The results showed that 64% of identified wetlands corresponded with an existing wetland map in the study area, but only 10% of the wetlands in the existing map were identified, with the F1 score being 17%. Therefore, the methodology cannot independently map wetlands and future research should be conducted in which additional data sources and mapping techniques are integrated. However, wetland connectivity could be mapped with the depression-based DEM methodology by utilising information on upstream and downstream wetland depressions, catchment boundaries and drainage flow paths. Knowledge about wetland connectivity is crucial for understanding how physical, biological and chemical materials are transported and distributed in the landscape, and thus also for resilience, management and protection of wetlandscapes.

scholarly journals Controller for a Low-Altitude Fixed-Wing UAV on an Embedded System to Assess Specific Environmental Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Johannes von Eichel-Streiber ◽  
Christoph Weber ◽  
Jesús Rodrigo-Comino ◽  
Jens Altenburg
Keyword(s):  
Embedded System ◽  
Environmental Conditions ◽  
Plant Density ◽  
Future Research ◽  
Digital Elevation ◽  
Small Uav ◽  
Aerial Vehicle ◽  
Low Costs ◽  
Low Altitude ◽  
Elevation Model

The use of an appropriate sensor on an unmanned aerial vehicle (UAV) is vital to assess specific environmental conditions successfully. In addition, technicians and scientists also appreciate a platform to carry the sensors with some advantages such as the low costs or easy pilot management. However, extra requirements like a low-altitude flight are necessary for special applications such as plant density or rice yield. A rotary UAV matches this requirement, but the flight endurance is too short for large areas. Therefore, in this article, a fixed-wing UAV is used, which is more appropriate because of its longer flight endurance. It is necessary to develop an own controller system to use special sensors such as Lidar or Radar on the platform as a multifunctionality system. Thereby, these sensors are used to generate a digital elevation model and also as a collision avoidance sensor at the same time. To achieve this goal, a small UAV was equipped with a hardware platform including a microcontroller and sensors. After testing the system and simulation, the controller was converted into program code to implement it on the microcontroller. After that, several real flights were performed to validate the controller and sensors. We demonstrated that the system is able to work and match the high requirements for future research.

Impacts of peatland drainage on the properties of typical water flow paths determined from a digital elevation model

2008 ◽  
Vol 39 (5-6) ◽  
pp. 359-368 ◽  
Author(s):  
Timo Korkalainen ◽  
Ari Laurén ◽  
Harri Koivusalo ◽  
Teemu Kokkonen
Keyword(s):  
Digital Elevation Model ◽  
Water Flow ◽  
Water Body ◽  
Water Bodies ◽  
Flow Paths ◽  
Digital Elevation ◽  
The Mean ◽  
Growth Changes ◽  
Elevation Model ◽  
Water Flow Paths

Peatland drainage enhances tree growth, changes catchment hydrology and increases export of nutrients and suspended solids to water bodies. In this study, impacts of peatland drainage on the properties of water flow paths in terrestrial parts of catchments were assessed in terms of slope, elevation, length and soil type. Three study catchments (area 31.8–153.5 km2) were delineated using a 25 m × 25 m digital elevation model (DEM). Typical water flow paths were calculated for each catchment to characterize the mean elevation above the receiving water body as a function of distance along water flow paths. The resulting two-dimensional (2D) profile also allowed calculations of horizontally distributed properties of catchments as a function of distance to the water body. Peatland drainage decreased the length and elevation of the typical water flow path, and increased the area near water bodies. Increasing drainage from 10.7% to 55.4% of the total catchment area increased the area residing close to a water body (no farther than 25 m) from 17.1% to 60.7%. This area estimate is useful for assessing the costs of water protection, arising from restricting forestry operations in the vicinity of water bodies.

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.

scholarly journals The first complete glacier inventory for the whole of Greenland

2012 ◽  
Vol 6 (4) ◽  
pp. 2399-2436 ◽  
Author(s):  
P. Rastner ◽  
T. Bolch ◽  
N. Mölg ◽  
H. Machguth ◽  
F. Paul
Keyword(s):  
Strong Dependence ◽  
Ice Sheet ◽  
Climate Change Impacts ◽  
Watershed Analysis ◽  
Digital Elevation ◽  
User Communities ◽  
Baseline Information ◽  
Mapping Techniques ◽  
Elevation Model

Abstract. Glacier inventories provide important baseline information for the determination of water resources, glacier-specific changes in area and volume, climate change impacts, and the past, potential and future contribution of glaciers to sea-level rise. Though heavily glacierized and thus highly relevant for all of the above points, such an inventory of all local glaciers and icecaps (GIC) was not available so far for Greenland. Here we present the details and results of our inventory, that has been compiled from more than 70 Landsat scenes mostly acquired between 1999 and 2002 using semi-automated multispectral mapping techniques. A digital elevation model (DEM) was used to derive drainage divides from watershed analysis and topographic parameters for each glacier entity. We assigned to each entity one of three connectivity levels (CL0, CL1, CL2; i.e. no, weak, and strong connection) with the ice sheet to distinguish the local GIC from the ice sheet and its outlet glaciers and to serve the specific needs of different user communities. All GIC larger 0.05 km2 include ~20 300 entities (of which 900 are marine terminating), covering an area of 129 983 ± 4029 km2, or 89 273 ± 2767 km2 without the CL2 GIC. The latter is about 50% more than according to all previous estimates. Glaciers smaller 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. Most of the ice was located at elevations around 1000 m, except in the eastern sector with elevation arround 1700 m. In addition, a strong dependence of the median elevation to the distance from the ocean was found, but only a weak dependence on aspect. All data will be made available in the Global Land Ice Measurement from Space (GLIMS) glacier database.

scholarly journals Large-scale map and 3D modelling of the Henryk Arctowski Polish Antarctic Station

Polar Record ◽  
2017 ◽  
Vol 53 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Mariusz Pasik ◽  
Maria Elżbieta Kowalska ◽  
Sławomir Łapiński ◽  
Marcin Rajner ◽  
Krzysztof Bakuła
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Satellite System ◽  
Scientific Activity ◽  
3D Modelling ◽  
Future Research ◽  
Digital Elevation ◽  
The Mean ◽  
Elevation Model ◽  
Global Navigation Satellite

ABSTRACTThis paper presents survey measurements carried out during the 39th Polish Antarctic Expedition to the Henryk Arctowski Polish Antarctic Station in March 2015. The measurements were used to create a map on a 1:500 scale and for 3D modelling of the station buildings and vicinity. The paper also presents the geodetic control network established around the station. We discuss the issue of creating a digital elevation model for the station and its surroundings. The elevation models were generated using terrestrial laser scanning data integrated with Global Navigation Satellite System real time kinematic and tacheometric surveying. The accuracy of these models was estimated using height differences in relation to survey data. The mean height difference was 0.03 m and root mean square error was 0.05 m. Furthermore, an analysis of changes to the coastline was conducted using archival cartographic materials to assess the threat of Admiralty Bay to the station buildings. The results are important for continued scientific activity and safety at Arctowski Station, and may be useful for future research on King George Island.

scholarly journals Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

2008 ◽  
Vol 8 (3) ◽  
pp. 433-443 ◽  
Author(s):  
A. Casteller ◽  
M. Christen ◽  
R. Villalba ◽  
H. Martínez ◽  
V. Stöckli ◽  
...  
Keyword(s):  
Tree Ring ◽  
Model Simulation ◽  
Snow Avalanche ◽  
Future Research ◽  
Nothofagus Pumilio ◽  
Snow Avalanches ◽  
Northern Patagonia ◽  
Digital Elevation ◽  
History Of ◽  
Elevation Model

Abstract. The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1) to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2) to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

scholarly journals Geomorphology of the Mirador-Calakmul Karst Basin: A GIS-based approach to hydrogeologic mapping

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255496
Author(s):  
Ross Ensley ◽  
Richard D. Hansen ◽  
Carlos Morales-Aguilar ◽  
Josie Thompson
Keyword(s):  
Remote Sensing Data ◽  
Western Boundary ◽  
Drainage Basins ◽  
Flow Paths ◽  
Digital Elevation ◽  
Data Points ◽  
Thin Section Analysis ◽  
Karst Landscapes ◽  
Elevation Model ◽  
Karst Landforms

This paper classifies the karst landscapes of the Petén Plateau and defines the Mirador-Calakmul Karst Basin by illustrating the distribution of its karst hydrologic features. Archaeological and spatial research of the Mirador-Calakmul area of Guatemala and Mexico has shown it to be a karst basin with geopolitical implications. Current research characterizes the karst landscapes of the Petén Plateau, maps the distribution of karst hydrologic features, and delineates the basin in geomorphological terms. To further this aim, multiple forms of remote sensing data including orthophotographs, a satellite Digital Elevation Model, satellite multispectral images, and Light Detection and Ranging (LiDAR) data have been integrated to interpret the karst features in the study area. Outcrop study and thin section analysis of the upper Buena Vista Formation document that the dominant lithologies are a shallow water algal boundstone interbedded with terrestrial caliche. Karst landforms have been mapped over the Petén Plateau and we identify five karst landscapes, the largest of which is a fluviokarst landscape dominated by karst valleys. We further map karst hydrologic features including seasonal swamps, dolines, intermittent lakes, intermittent streams, solution-enhanced fractures, and springs all of which are characteristic of drainage basins. Boundaries of the karst basin are mapped from multiple lines of evidence including distribution of the karst valleys, a line of springs along the western boundary of the fluviokarst landscape, and a surface drainage analysis. We capture and classify hydrologic data points and develop a regional groundwater map that indicates subsurface flow from east to west within the basin. A drainage map illustrates the extensive system of karst valleys, boundaries, and inferred groundwater flow paths of the Mirador-Calakmul Karst Basin. It was within this geomorphological setting that the ancient Maya developed an extensive civilization during the Middle and Late Preclassic periods (1000 BCE-150 CE).

scholarly journals A Simplified, Object-Based Framework for Efficient Landslide Inventorying Using LIDAR Digital Elevation Model Derivatives

2019 ◽  
Vol 11 (3) ◽  
pp. 303 ◽  
Author(s):  
Michael Bunn ◽  
Ben Leshchinsky ◽  
Michael Olsen ◽  
Adam Booth
Keyword(s):  
Large Scale ◽  
Landslide Inventory ◽  
Sediment Delivery ◽  
Landslide Occurrence ◽  
Automated Method ◽  
Object Based ◽  
Digital Elevation ◽  
Input Parameters ◽  
Mapping Techniques ◽  
Elevation Model

Landslide inventory maps are critical to understand the factors governing landslide occurrence and estimate hazards or sediment delivery to channels. Numerous semi-automated approaches for landslide inventory mapping have been proposed to improve the efficiency and objectivity of the process, but these methods have not been widely adopted by practitioners because of the use of input parameters without physical meaning, a lack of transparency in machine-learning based mapping techniques, and limitations in resulting products, which are not ordinarily designed or tested on a large-scale or in diverse geologic units. To this end, this work presents a new semi-automated method, called the Scarp Identification and Contour Connection Method (SICCM), which adapts to diverse geologic settings automatically or semi-automatically using interventions driven by simple inputs and interpretation from an expert mapper. The applicability of SICCM for use in landslide inventory mapping is demonstrated for three diverse study areas in western Oregon, USA by assessing the utility of the results as a landslide inventory, evaluating the sensitivity of the algorithm to changes in input parameters, and exploring how geology influences the resulting landslide inventory results. In these case studies, accuracies exceed 70%, with reliability and precision of nearly 80%. Conclusions of this work are that (1) SICCM efficiently produces meaningful landslide inventories for large areas as evidenced by mapping 216 km2 of landslide deposits with individual deposits ranging in size from 58 to 1.1 million m2; (2) results are predictable with changes to input parameters, resulting in an intuitive approach; (3) geology does not appear to significantly affect SICCM performance; and (4) the process involves simplifications compared with more complex alternatives from the literature.

The influence of digital elevation model resolution on overland flow networks for modelling urban pluvial flooding

2009 ◽  
Vol 60 (12) ◽  
pp. 3137-3149 ◽  
Author(s):  
J. P. Leitão ◽  
S. Boonya-aroonnet ◽  
D. Prodanović ◽  
Č. Maksimović
Keyword(s):  
Digital Elevation Model ◽  
Overland Flow ◽  
Temporary Ponds ◽  
Flow Networks ◽  
Flow Paths ◽  
Digital Elevation ◽  
Pluvial Flooding ◽  
Generate Surface ◽  
Elevation Model ◽  
Urban Pluvial Flooding

This paper presents the developments towards the next generation of overland flow modelling of urban pluvial flooding. Using a detailed analysis of the Digital Elevation Model (DEM) the developed GIS tools can automatically generate surface drainage networks which consist of temporary ponds (floodable areas) and flow paths and link them with the underground network through inlets. For different commercially-available Rainfall–Runoff simulation models, the tool will generate the overland flow network needed to model the surface runoff and pluvial flooding accurately. In this paper the emphasis is placed on a sensitivity analysis of ponds and preferential overland flow paths creation. Different DEMs for three areas were considered in order to compare the results obtained. The DEMs considered were generated using different acquisition techniques and hence represent terrain with varying levels of resolution and accuracy. The results show that DEMs can be used to generate surface flow networks reliably. As expected, the quality of the surface network generated is highly dependent on the quality and resolution of the DEMs and successful representation of buildings and streets.

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