scholarly journals Topographic Exposure and its Practical Applications

2010 ◽  
Vol 3 (1) ◽  
pp. 42-51 ◽  
Author(s):  
Tomáš Mikita ◽  
Martin Klimánek
Keyword(s):  
Detailed Knowledge ◽  
Climatic Data ◽  
Practical Applications ◽  
Degree Of Protection ◽  
Power Stations ◽  
Snow Storage ◽  
Vegetation Zones ◽  
Digital Elevation ◽  
The Creation ◽  
Elevation Model

Topographic Exposure and its Practical ApplicationsTopographic exposure is a topographic characteristic representing a degree of protection by a surrounding topography of a certain site. Detailed knowledge of topographic exposure has broad use in a number of applications ranging from studying forest wind damage through research on snow storage dynamics to optimisation in positioning wind power stations. This paper describes a method for creation of topographic exposure on the basis of a digital elevation model (DEM) using GIS. In combination with other climatic data on wind direction and speed, this factor is used to define the degree of terrain ventilation. Low terrain ventilation has, among other things, a significant influence on the creation of valley inversions and related vegetation zoning inversions. By combining the degree of terrain ventilation with DEM and forest vegetation zones in the area of the Training Forest Enterprise Křtiny, a clear relationship between the influence of topographic exposure, or terrain ventilation, and the creation of the vegetation zoning inversion was determined.

scholarly journals Spatial Downscaling of GPM Annual and Monthly Precipitation Using Regression-Based Algorithms in a Mountainous Area

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Chesheng Zhan ◽  
Jian Han ◽  
Shi Hu ◽  
Liangmeizi Liu ◽  
Yuxuan Dong
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Mountainous Area ◽  
Monthly Precipitation ◽  
Practical Applications ◽  
Precipitation Measurement ◽  
Digital Elevation ◽  
Elevation Model ◽  
Global Precipitation ◽  
Spatial Downscaling

As a fundamental component in material and energy circulation, precipitation with high resolution and accuracy is of great significance for hydrological, meteorological, and ecological studies. Since satellite measured precipitation is often too coarse for practical applications, it is essential to develop spatial downscaling algorithms. In this study, we investigated two downscaling algorithms based on the Multiple Linear Regression (MLR) and the Geographically Weighted Regression (GWR), respectively. They were employed to downscale annual and monthly precipitation obtained from the Global Precipitation Measurement (GPM) Mission in Hengduan Mountains, Southwestern China, from 10 km × 10 km to 1 km × 1 km. Ground observations were then used to validate the accuracy of downscaled precipitation. The results showed that (1) GWR performed much better than MLR to regress precipitation on Normalized Difference Vegetation Index (NDVI) and Digital Elevation Model (DEM); (2) coefficients of GWR models showed strong spatial nonstationarity, but the spatial mean standardized coefficients were very similar to standardized coefficients of MLR in terms of intra-annual patterns: generally NDVI was positively related to precipitation when monthly precipitation was under 166 mm; DEM was negatively related to precipitation, especially in wet months like July and August; contribution of DEM to precipitation was greater than that of NDVI; (3) residuals’ correction was indispensable for the MLR-based algorithm but should be removed from the GWR-based algorithm; (4) the GWR-based algorithm rather than the MLR-based algorithm produced more accurate precipitation than original GPM precipitation. These results indicated that GWR is a promising method in satellite precipitation downscaling researches and needed to be further studied.

scholarly journals Modelling Snowmelt Runoff from Tropical Andean Glaciers under Climate Change Scenarios in the Santa River Sub-Basin (Peru)

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3535
Author(s):  
Elmer Calizaya ◽  
Abel Mejía ◽  
Elgar Barboza ◽  
Fredy Calizaya ◽  
Fernando Corroto ◽  
...  
Keyword(s):  
Climate Change ◽  
Climatic Data ◽  
Climate Change Scenarios ◽  
Snowmelt Runoff ◽  
Snow Covered Area ◽  
Covered Area ◽  
Digital Elevation ◽  
Rcp 8.5 ◽  
Andean Glaciers ◽  
Elevation Model

Effects of climate change have led to a reduction in precipitation and an increase in temperature across several areas of the world. This has resulted in a sharp decline of glaciers and an increase in surface runoff in watersheds due to snowmelt. This situation requires a better understanding to improve the management of water resources in settled areas downstream of glaciers. In this study, the snowmelt runoff model (SRM) was applied in combination with snow-covered area information (SCA), precipitation, and temperature climatic data to model snowmelt runoff in the Santa River sub-basin (Peru). The procedure consisted of calibrating and validating the SRM model for 2005–2009 using the SRTM digital elevation model (DEM), observed temperature, precipitation and SAC data. Then, the SRM was applied to project future runoff in the sub-basin under the climate change scenarios RCP 4.5 and RCP 8.5. SRM patterns show consistent results; runoff decreases in the summer months and increases the rest of the year. The runoff projection under climate change scenarios shows a substantial increase from January to May, reporting the highest increases in March and April, and the lowest records from June to August. The SRM demonstrated consistent projections for the simulation of historical flows in tropical Andean glaciers.

Boots on the Ground at Yaxnohcah

2016 ◽  
Vol 4 (3) ◽  
pp. 314-338 ◽  
Author(s):  
Kathryn Reese-Taylor ◽  
Armando Anaya Hernández ◽  
F. C. Atasta Flores Esquivel ◽  
Kelly Monteleone ◽  
Alejandro Uriarte ◽  
...  
Keyword(s):  
Surface Model ◽  
Large Area ◽  
Vegetation Zones ◽  
Digital Elevation ◽  
Major Species ◽  
Ground Truthing ◽  
Elevation Model ◽  
Accuracy Of Results ◽  
Type 2 Errors

AbstractThis study proposes a sampling method for ground-truthing LiDAR-derived data that will allow researchers to verify or predict the accuracy of results over a large area. Our case study is focused on a 24 km2area centered on the site of Yaxnohcah in the Yucatan Peninsula. This area is characterized by a variety of dense tropical rainforest and wetland vegetation zones with limited road and trail access. Twenty-one 100 x 100 m blocks were selected for study, which included examples of several different vegetation zones. A pedestrian survey of transects through the blocks was conducted, recording two types of errors. Type 1 errors consist of cultural features that are identified in the field, but are not seen in the digital elevation model (DEM) or digital surface model (DSM). Type 2 errors consist of features that appear to be cultural when viewed on the DEM or DSM, but are caused by different vegetative features. Concurrently, we conducted an extensive vegetation survey of each block, identifying major species present and heights of stories. The results demonstrate that the lidar survey data are extremely reliable and a sample can be used to assess data accuracy, fidelity, and confidence over a larger area.

Analysis of the potential evapotranspiration demands in the Czech Republic between 1961–1990

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Jan Pivec ◽  
Václav Brant ◽  
Dalibor Moravec
Keyword(s):  
Czech Republic ◽  
Potential Evapotranspiration ◽  
Area Ratio ◽  
Climatic Data ◽  
The Czech Republic ◽  
Cylindrical Projection ◽  
Digital Elevation ◽  
Previous Decade ◽  
Elevation Model ◽  
The Many

AbstractDynamics of the evapotranspirational demands in the Czech Republic within three decades from 1961 to 1990 has been studied. The determination of the levels of influence of the respective natural components depends on the regionalized modelling techniques. The project of regionalized modelling is theoretically based on the potential evapotranspiration values (ET 0) calculated by FAO methodology (eqs. 1, 2) and the series of temperature and rainfall observations obtained by climatologic stations during a 30-year period from 1961 to 1990 and its relation to the absolute altimetric. The DMR-2 military digital elevation model of the Czech Republic relief consisting of a regular network of points with their altitudes specified in meters was used for the purpose of regionalized modelling. One step of the network in the S-42 coordinate system with the Gauss conforms cylindrical projection is equal to 100 meters; this implies that the smallest area for which the data can be processed is 1 hectare. The digital relief model can be linked to both direct (temperature, precipitation) and derived (evapotranspiration) quantities, which is one of the many novelties of regionalized modelling. The climatic data used in regionalized modelling records daily measurements were obtained by 85 climatologic and rainfall-monitoring stations from 1961 to 1990. Our results showed an appreciable decrease of the most drying area (ratio P/ET0 up to 0.755) in the last decade 1981–90; half as less amounts compared with the previous decade 1971–80 (about 500,000 hectares). On the other hand, an apparent increase (more than 500,000 hectares in comparison with the previous decade 1971–80) of the wettest area (ratio P/ET0 over 1.508) through the last decade was observed. Both first decades 1961–70 and 1971–80 look similar. The project mentioned in this article has made it possible to create models for the different time intervals which have showed higher reliability for heterogeneous application.

scholarly journals Geração de Modelo Digital de Elevação utilizando dados do SRTM como subsídio ao planejamento e gestão territorial do município de Lucena(PB)/Generation of Digital Elevation Model using SRTM data as grant to territorial planning and management (...)

2015 ◽  
Vol 26 (45) ◽  
pp. 151
Author(s):  
Erika Rodrigues Dias
Keyword(s):  
Digital Elevation Model ◽  
Three Dimensional ◽  
Shuttle Radar Topography Mission ◽  
Google Earth ◽  
Detailed Knowledge ◽  
Radar Images ◽  
Territorial Planning ◽  
Planning And Management ◽  
Digital Elevation ◽  
Elevation Model

<p>Uma das grandes preocupações da atualidade encontra-se no uso racional das terras, conciliando aspectos sociais, econômicos e ambientais tornando necessário o planejamento territorial através de um conhecimento detalhado da superfície territorial. Dessa forma, é de fundamental importância a representação do terreno. Assim, este trabalho teve por objetivo gerar um modelo digital de elevação – MDE, utilizando imagens de radar SRTM com a finalidade de servir como subsídio à gestão e planejamento territorial. Os materiais utilizados nesse trabalho foram imagens de radar da missão Shuttle Radar Topography Mission – SRTM, imagens obtidas do Google Earth e softwares específicos. Como resultados foram gerados diversos produtos cartográficos que possibilitaram o reconhecimento territorial do município como os mapas de hipsometria e clinografia da área em estudo e a representação tridimensional do relevo visando servir como subsídio à gestão territorial e planejamento do meio físico.</p><p><strong>Palavras-Chave</strong>: Modelo Digital de Elevação, SRTM, Geotecnologias.</p><p><strong>Abstract</strong></p><p>A major concern of today is in the rational use of land, combining social, economic and environmental aspects making it necessary to territorial planning with a detailed knowledge of land area. Thus, it is fundamental to representation of the terrain. Thus, this study aimed to generate a digital elevation model - MDE using SRTM radar images in order to serve as a resource management and territorial planning. The materials used in this work were the mission radar images Shuttle Radar Topography Mission - SRTM, images obtained from Google Earth and specific software. The results were generated several cartographic products enabled the territorial recognition of the city as hypsometry maps and clinografia of the study area and the three-dimensional relief representation to serve as subsidy for territorial planning and management of the physical environment.<strong> </strong></p><p><strong> Keywords</strong>:Digital Elevation Model, SRTM, Geotechnology.</p><p> </p><p> </p>

Derivation of terrain covariates for digital soil mapping in Australia

Soil Research ◽  
2015 ◽  
Vol 53 (8) ◽  
pp. 895 ◽  
Author(s):  
John C. Gallant ◽  
Jenet M. Austin
Keyword(s):  
Soil Properties ◽  
Spatial Patterns ◽  
Data Access ◽  
Soil Mapping ◽  
Digital Soil Mapping ◽  
Data Discovery ◽  
Digital Elevation ◽  
The Creation ◽  
Elevation Model ◽  
Mapping Exercise

Digital soil mapping is founded on the availability of covariates that are used as surrogates for the spatial patterns in soil properties. One important subset of covariates represents the patterns due to terrain, and these are typically derived from a digital elevation model at a suitable resolution. When each digital soil mapping exercise requires the calculation of terrain covariates, there is a clear potential for inconsistent methods and for choosing the covariates that are easiest to derive rather than those that are most relevant. The creation of open repositories of relevant terrain covariates that are correctly derived avoids these problems and fosters the application of digital soil mapping and other modelling activities that benefit from landscape properties. This paper describes the creation of a suite of commonly used terrain covariates from the 1-arcsecond (~30 m) resolution digital elevation models for Australia that were released through CSIRO’s Data Access Portal and the TERN Data Discovery Portal. The methods used to derive the terrain covariates are described and their characteristics are identified.

scholarly journals Sliding Windows Method Based on Terrain Self-Similarity for Higher DEM Resolution in Flood Simulating Modeling

2021 ◽  
Vol 13 (18) ◽  
pp. 3604
Author(s):  
Qian Yin ◽  
Ziyi Chen ◽  
Xin Zheng ◽  
Yingjun Xu ◽  
Tianxue Liu
Keyword(s):  
High Resolution ◽  
Earth Science ◽  
Small Scale ◽  
Self Similarity ◽  
Flood Simulation ◽  
Sliding Windows ◽  
Practical Applications ◽  
Digital Elevation ◽  
Elevation Model ◽  
Matching Window

A digital elevation model (DEM) is a quantitative representation of terrain and an important tool for Earth science and hydrological applications. A high-resolution DEM provides accurate basic Geodata and plays a crucial role in related scientific research and practical applications. However, in reality, high-resolution DEMs are often difficult to obtain. Due to the self-similarity present within terrains, we proposed a method using the original DEM itself as a sample to expand the DEM using sliding windows method (SWM) and generate a higher resolution DEM. The main processes of SWM include downsampling the original DEM and constructing mapping sets, searching for the optimal matching, window replacement. Then, we repeat these processes with the small-scale expansion factor. In this paper, the grid resolution of the Taitou Basin was expanded from 30 to 10 m. Overall, the superresolution reconstruction results showed that the method could achieve better outcomes than other commonly used techniques and exhibited a slight deviation (root mean square error (RMSE) = 3.38) from the realistic DEM. The generated high-resolution DEM prove to be significant in the application of flood simulation modeling.

scholarly journals Creation of Sumy oblast tourist GIS by means of GIS technologies

2021 ◽  
Vol 41 (I) ◽  
pp. 140-150
Author(s):  
V. SHEVCHUK ◽  
◽  
Z. KUZYK ◽  
L, AVDASOVA ◽  
◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Web Applications ◽  
Block Diagram ◽  
Satellite Image ◽  
Tourism Industry ◽  
Layer By Layer ◽  
Gis Technologies ◽  
Digital Elevation ◽  
The Creation ◽  
Elevation Model

Goal. The purpose of this paper is to create a tourist GIS of the Sumy oblast using cartographic materials and remote sensing data, as well as the development of new tourist routes in the Sumy oblast by means of modern geoinformation technologies and ArcGIS, ArcGIS Online, and AllTrails software. Method. The main stages of the creation of Sumy oblast tourist GIS were: search and analysis of the of input materials, necessary for the creation of a tourist GIS; create of the structural block diagram of research works; Satellite image processing, in particular the creation of synthesized images and the use of the Pansharpening technique for a better interpretation of objects; building a digital elevation model for tourist GIS; processing of cartographic materials in ArcGIS; creation of a graphical and attributive database; classification and layer-by-layer data visualization; development of tourism routes by means of ArcGIS Online and AllTrails web applications; analysis of the created of Sumy oblast tourist GIS. Results. As a result of the research: a structural diagram of the main stages of the research has been developed; a graphical-attributive database with information about tourist objects was organized; created a digital elevation model based on SRTM data of Sumy oblast, made the topographic basis of GIS; by means of the ArcGIS 10.3 software a tourist GIS of the Sumy oblast was created, which includes 255 tourist objects of various profiles; using web applications ArcGIS Online and AllTrails, 5 automobile tourist routes with a total length of 1234 kmand 1 pedestrian route 11 kmlong, which pass through the territory of Sumy oblast, have been developed. Scientific novelty. The novelty of the research lies in the methodology for creating a Sumy oblast tourist GIS, the development of new excursion tourist routes and objects, and their visualization based on the use of cartographic materials and satellite images by means of modern GIS, in particular ArcGIS 10.3, ArcGIS Online and AllTrails. Practical value. The research results can be used in the tourism industry, where the priority task is to provide tourists with modern highquality overview, cognitive and cartographic materials, including traditional maps, schematic maps, booklets, and digital maps, 3D models, web applications, audio, video and virtual tours, which are created using the latest digital and GIS technologies, as well as to popularize the tourist and recreational potential of the Sumy oblast among the population.

scholarly journals Risk assessment of soil erosion by using CORINE model in the western part of Syrian Arab Republic

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alaa Khallouf ◽  
Swapan Talukdar ◽  
Endre Harsányi ◽  
Hazem Ghassan Abdo ◽  
Safwan Mohammed
Keyword(s):  
Soil Erosion ◽  
Agricultural Sector ◽  
Climatic Data ◽  
Natural Ecosystem ◽  
Good Tool ◽  
Erosion Risk ◽  
Digital Elevation ◽  
Syrian Arab Republic ◽  
Gis Environment ◽  
Elevation Model

Abstract Background Soil erosion is a major threat to the natural ecosystem and agricultural sector in the western part of Lattakia Governorate, Syrian Arab Republic. The main goals of this research are to investigate erosion risk by using the Coordination of Information on the Environment (CORINE) Model and to prioritize areas for conservation practices. To achieve these goals, soil samples were collected from the field, the climatic data (i.e., rainfall) and Digital Elevation Model (DEM) were obtained and utilized to perform CORINE model in Geographic Information System (GIS) environment. Results The results showed that only 13.2% of the study area was classified as high erodible. In addition, 45.24%, 49.15% and 5.29% of the study area were under low, moderate and high actual erosion risk, respectively. This research identified slope and land use/land cover as key factors responsible for soil erosion in the study area. Conclusions The CORINE model acknowledged as a good tool for predicting soil erosion and highlighting the areas affected by soil erosion in the study area with high precision.

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