scholarly journals The Construction of a Flood Monitoring System with Alert Distribution Using Google Earth and 3D GIS

2013 ◽  
Vol 8 (3) ◽  
pp. 512-518
Author(s):  
Yili Chan ◽  
◽  
Masatoshi Mori ◽  
Keyword(s):  
Monitoring System ◽  
Local Governments ◽  
Google Earth ◽  
Surface Model ◽  
3D Gis ◽  
Geographical Survey Institute ◽  
Digital Elevation ◽  
Flood Monitoring ◽  
Elevation Data ◽  
Flood Simulations

Locations of floods are not always known. Persons nearby for whom there is a possibility of danger due to flooding need information with which to predict flooding and to find refuge quickly and accurately. A Webbased Flood Monitoring System (FMS) using Google Earth and 3D GIS has been developed by employing Google Earth pro v. 6.0 and ArcGIS 10.0 (ESRI). The FMS provides a viewer for Windows PCs and smart phones. This viewer provides information consisting of digital elevation data from a 2 m Digital Surface Model (DSM) integrating 1:2500 digital topographic maps from the Geographical Survey Institute of Japan with official river information from the Ministry of Land, Infrastructure, Transport and Tourism of Japan and local river offices. It includes flood simulations and hazard maps from local governments. Users are able to download KML file data and/or Shape file data for private use. In addition, a reporting system for preregistered users who want immediate information has been prepared for alert and flood information.

scholarly journals Geomorphological Characterization of Rivers Using Virtual Globes and Digital Elevation Data: A Case Study from the Naryn River in Kyrgyzstan

2021 ◽  
pp. 47-55
Author(s):  
F. Betz ◽  
M. Lauermann ◽  
B. Cyffka
Keyword(s):  
New Technologies ◽  
Google Earth ◽  
River Systems ◽  
Catchment Scale ◽  
Digital Elevation ◽  
Elevation Data ◽  
Digital Elevation Data ◽  
Virtual Globes ◽  
Cost Efficient

In recent years, fluvial geomorphology included a range of new technologies for the characterization of riverine landscapes in the pool of methods. LIDAR, the analysis of drone imagery or satellite remote sensing improved the ability to analyze river systems in manifold ways. However, the high demand for (often expensive) data and processing skills limit the application commonly to smaller study reaches or to regions where data is already available. In contrast, a range of conceptual frameworks for the geomorphological characterization of river systems highlights the relevance of integrating the catchment scale context. Against this background, virtual globes such as Google Earth are cost-efficient alternatives as they make high resolution satellite imagery available almost worldwide. Merging the information mapped from virtual globes with digital elevation data allows the interpretation of riverscape attributes in the context of the longitudinal profile. In our study, we present the geomorphological mapping of the more than 600 km long Naryn River in Kyrgyzstan based on different virtual globes and the SRTM-1 digital elevation model. The experience from this mapping exercise suggests that the combination of virtual globe imagery and elevation data is a powerful and cost-efficient approach for river research and application in the context of data-scarce river corridors.

scholarly journals Aboveground Biomass Changes in Tropical Montane Forest of Northern Borneo Estimated Using Spaceborne and Airborne Digital Elevation Data

2020 ◽  
Vol 12 (22) ◽  
pp. 3677
Author(s):  
Ho Yan Loh ◽  
Daniel James ◽  
Keiko Ioki ◽  
Wilson Vun Chiong Wong ◽  
Satoshi Tsuyuki ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Surface Model ◽  
Managed Forests ◽  
Mean Values ◽  
Tropical Regions ◽  
Digital Elevation ◽  
Elevation Data ◽  
Digital Elevation Data

Monitoring anthropogenic disturbances on aboveground biomass (AGB) of tropical montane forests is crucial, but challenging, due to a lack of historical AGB information. We examined the use of spaceborne (Shuttle Radar Topographic Mission Digital Elevation Model (SRTM) digital surface model (DSM)) and airborne (Light Detection and Ranging (LiDAR)) digital elevation data to estimate tropical montane forest AGB changes in northern Borneo between 2000 and 2012. LiDAR canopy height model (CHM) mean values were used to calibrate SRTM CHM in different pixel resolutions (1, 5, 10, and 30 m). Regression analyses between field AGB of 2012 and LiDAR CHM means at different resolutions identified the LiDAR CHM mean at 1 m resolution as the best model (modeling efficiency = 0.798; relative root mean square error = 25.81%). Using the multitemporal AGB maps, the overall mean AGB decrease was estimated at 390.50 Mg/ha, but AGB removal up to 673.30 Mg/ha was estimated in the managed forests due to timber extraction. Over the 12 years, the AGB accumulated at a rate of 10.44 Mg/ha/yr, which was attributed to natural regeneration. The annual rate in the village area was 8.31 Mg/ha/yr, which was almost 20% lower than in the managed forests (10.21 Mg/ha/yr). This study identified forestry land use, especially commercial logging, as the main driver for the AGB changes in the montane forest. As SRTM DSM data are freely available, this approach can be used to estimate baseline historical AGB information for monitoring forest AGB changes in other tropical regions.

scholarly journals WORLDDEM – A NOVEL GLOBAL FOUNDATION LAYER

2015 ◽  
Vol XL-3/W2 ◽  
pp. 183-187 ◽  
Author(s):  
G. Riegler ◽  
S. D. Hennig ◽  
M. Weber
Keyword(s):  
Digital Terrain Model ◽  
Current Status ◽  
Disruptive Technology ◽  
Surface Model ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
German Aerospace

Airbus Defence and Space’s WorldDEM™ provides a global Digital Elevation Model of unprecedented quality, accuracy, and coverage. The product will feature a vertical accuracy of 2m (relative) and better than 6m (absolute) in a 12m x 12m raster. The accuracy will surpass that of any global satellite-based elevation model available. WorldDEM is a game-changing disruptive technology and will define a new standard in global elevation models. <br><br> The German radar satellites TerraSAR-X and TanDEM-X form a high-precision radar interferometer in space and acquire the data basis for the WorldDEM. This mission is performed jointly with the German Aerospace Center (DLR). Airbus DS refines the Digital Surface Model (e.g. editing of acquisition, processing artefacts and water surfaces) or generates a Digital Terrain Model. Three product levels are offered: WorldDEMcore (output of the processing, no editing is applied), WorldDEM™ (guarantees a void-free terrain description and hydrological consistency) and WorldDEM DTM (represents bare Earth elevation). <br><br> Precise elevation data is the initial foundation of any accurate geospatial product, particularly when the integration of multi-source imagery and data is performed based upon it. Fused data provides for improved reliability, increased confidence and reduced ambiguity. This paper will present the current status of product development activities including methodologies and tool to generate these, like terrain and water bodies editing and DTM generation. In addition, the studies on verification & validation of the WorldDEM products will be presented.

scholarly journals Integration von hochauflösenden Fernerkundungs- und Geländemodelldaten für die Landschaftsvisualisierung

1997 ◽  
Vol 52 (1) ◽  
pp. 21-26
Author(s):  
P. Pirchl ◽  
P. Hirtz ◽  
M. Suter ◽  
D. Nüesch
Keyword(s):  
Land Cover ◽  
Aerial Photographs ◽  
Surface Model ◽  
Northern Switzerland ◽  
Transition Zones ◽  
Gis Tools ◽  
Digital Elevation ◽  
Elevation Data ◽  
Digital Elevation Data ◽  
Elevation Model

Abstract. This paper presents experiments for realistic landscape visualization using high resolution digital aerial photographs and elevation modeis. The natural environment of a river in northern Switzerland is visualized. Photogrammetrically measured digital elevation data and ortho-rectified remote sensing imagery (Landsat Thematic Mapper/TM and aerial photographs) are combined to compute realistic 3D views of the landscape. To renderthe landscape more realistically, the digital elevation model (DEM) is transformed to a digital surface model (DSM), representing the surface and including objects like forests or bushes. For this transformation land cover information and GIS tools were used. Unnaturally looking vertical borders between different land cover classes were suppressed by interpolating transition zones. Additionally, 3D objects (trees) are used in the foreground to increase the realism of the views.

Urban Flood Mapping

2017 ◽  
Author(s):  
Indra Riyanto ◽  
Lestari Margatama
Keyword(s):  
Natural Disasters ◽  
Satisfying Condition ◽  
Three Dimensions ◽  
Urban Flood ◽  
Digital Elevation ◽  
Elevation Data ◽  
Recent Occurrence ◽  
Elevation Model ◽  
Digital Elevation Model Data ◽  
Potential Area

The recent degradation of environment quality becomes the prime cause of the recent occurrence of natural disasters. It also contributes in the increase of the area that is prone to natural disasters. Flood history data in Jakarta shows that flood occurred mainly during rainy season around January – February each year, but the flood area varies each year. This research is intended to map the flood potential area in DKI Jakarta by segmenting the Digital Elevation Model data. The data used in this research is contour data obtained from DPP–DKI with the resolution of 1 m. The data processing involved in this research is extracting the surface elevation data from the DEM, overlaying the river map of Jakarta with the elevation data. Subsequently, the data is then segmented using watershed segmentation method. The concept of watersheds is based on visualizing an image in three dimensions: two spatial coordinates versus gray levels, in which there are two specific points; that are points belonging to a regional minimum and points at which a drop of water, if placed at the location of any of those points, would fall with certainty to a single minimum. For a particular regional minimum, the set of points satisfying the latter condition is called the catchments basin or watershed of that minimum, while the points satisfying condition form more than one minima are termed divide lines or watershed lines. The objective of this segmentation is to find the watershed lines of the DEM image. The expected result of the research is the flood potential area information, especially along the Ciliwung river in DKI Jakarta.

scholarly journals MAT: GIS-Based Morphometry Assessment Tools for Concave Landforms

2021 ◽  
Vol 13 (14) ◽  
pp. 2810
Author(s):  
Joanna Gudowicz ◽  
Renata Paluszkiewicz
Keyword(s):  
Rapid Development ◽  
Assessment Tools ◽  
Lidar Data ◽  
Automatic Extraction ◽  
Sensing Technology ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
Morphometric Assessment ◽  
Morphometric Evaluation

The rapid development of remote sensing technology for obtaining high-resolution digital elevation models (DEMs) in recent years has made them more and more widely available and has allowed them to be used for morphometric assessment of concave landforms, such as valleys, gullies, glacial cirques, sinkholes, craters, and others. The aim of this study was to develop a geographic information systems (GIS) toolbox for the automatic extraction of 26 morphometric characteristics, which include the geometry, hypsometry, and volume of concave landforms. The Morphometry Assessment Tools (MAT) toolbox in the ArcGIS software was developed. The required input data are a digital elevation model and the form boundary as a vector layer. The method was successfully tested on an example of 21 erosion-denudation valleys located in the young glacial area of northwest Poland. Calculations were based on elevation data collected in the field and LiDAR data. The results obtained with the tool showed differences in the assessment of the volume parameter at the average level of 12%, when comparing the field data and LiDAR data. The algorithm can also be applied to other types of concave forms, as well as being based on other DEM data sources, which makes it a universal tool for morphometric evaluation.

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