scholarly journals Digitalna analiza padina otoka Raba

Geoadria ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Mladen Pahernik
Keyword(s):  
Spatial Distribution ◽  
Comparative Analysis ◽  
Network Analysis ◽  
Slope Angle ◽  
Morphometric Parameters ◽  
Digital Elevation ◽  
Morphometric Features ◽  
Gis Environment ◽  
Valley Network ◽  
Elevation Model

The paper analyzes morphometric features of the slopes of Rab Island. Based on the digital elevation model, raster layers were calculated for the values of slope angle, aspect and curvature, as well as valley network, which was grouped using the Strahler method. A comparative analysis of the calculated values of morphometric parameters was conducted in the GIS environment. Spatial distribution of the values of each of the morphometric parameters was correlated to the structural and morphogenetic features of Rab Island. Differences between the slopes features within each of the morphogenetic types of the terrain were ascertained by comparing their morphometric features, and by using the valley network analysis. 

scholarly journals Compartimentação dos elementos do relevo da bacia hidrográfica do arroio Pantanoso – Canguçu/RS, através da proposta dos geomorphons

2020 ◽  
Vol 13 (2) ◽  
pp. 713
Author(s):  
Danilo Da Silva Dutra ◽  
André Ricardo Furlan ◽  
Luís Eduardo De Souza Robaina
Keyword(s):  
Digital Elevation Model ◽  
River Basin ◽  
Spatial Resolution ◽  
Advantages And Disadvantages ◽  
Digital Elevation ◽  
Relief Elements ◽  
Gis Environment ◽  
Elevation Model

O relevo é a base onde todas as populações vivem e desenvolvem suas atividades, derivando dessa relação vantagens e desvantagens, daí a importância de conhecê-lo através do estudo de suas diferentes formas e elementos. Nesse contexto insere-se a importância de metodologias para o seu estudo, sendo que atualmente vivencia-se a expressividade de dados disponíveis para aplicação de geoprocessamento. A partir das geotecnologias pode-se empreender diversas análises sobre o relevo, destacando-se nesse contexto, a proposta dos geomorphons a qual foi aplicada na bacia hidrográfica do arroio Pantanoso. O objetivo da pesquisa é a identificação e análise dos elementos do relevo definido por geomorphons, quais sejam: 1) Planos, 2) Picos, 3) Cristas, 4) Ressaltos, 5) Crista secundária, 6) Encostas, 7) Escavado, 8) Base de encosta, 9) Vales e 10) Fosso. A determinação dos geomorphons foi a partir do processamento em ambiente SIG do Modelo Digital de Elevação (MDE) do Shuttle Radar Topograph Mission (SRTM) com resolução espacial 3 arcsec (90 metros), “L” Lookup (distância em metros) definiu-se como de 20 pixels (1800 metros) e o “T” Theresholdt (nivelamento em graus) definiu-se em 2º. Para visualização do comportamento dos elementos do relevo na área de estudo realizaram-se trabalhos de campo, o que contribuiu para evidenciar a padronização desses elementos. Os quatro elementos geomorphons mais representativos são encostas, vales, cristas e planos. Subdivision of relief elements through the proposal of geomorphons: river basin of arroio Pantanoso - Canguçu/RS A B S T R A C TRelief is the basis where all populations live and develop their activities, deriving from this relation advantages and disadvantages, hence the importance of knowing it through the study of its different forms and elements. In this context, the importance of methodologies for its study is inserted and geoprocessing application for data available for is currently experienced. From the geotechnologies one can undertake several analyzes on the relief, highlighting in this context, the proposal of the geomorphons which was applied in Pantanoso stream basin. The objective of the research is to identify and analyze the elements of the relief defined by geomorphons, namely: 1) Flats, 2) Peaks, 3) Ridges, 4) Shoulders, 5) Spurs, 6)Slopes, 7) Hollows, 8) Footslope, 9) Valley and 10) Pits. The determination of the geomorphons was based on the GIS environment of the Shuttle Radar Topograph Mission (SRTM) Digital Elevation Model (DEM) with spatial resolution 3 arcsec (90 meters), "L" Lookup (distance in meters) was defined as of 20 pixels (1800 meters) and the "T" Theresholdt (leveling in degrees) was defined in 2º. In order to visualize the behavior of the relief elements in the study area, fieldwork was carried out, which contributed to the standardization of these elements. The four most representative geomorphons, which are: Slopes, Valleys, Ridges and Flat.Keywords: SIG, Geomorphons; Canguçu/RS; relief

Prioritization of Sub-Watersheds based on Morphometric parameters in Pare watershed, Arunachal Pradesh, India

2021 ◽  
pp. 53-64
Author(s):  
Waikhom Rahul Singh ◽  
Swapnali Barman ◽  
Nitesh Patidar
Keyword(s):  
Morphometric Parameters ◽  
Development Programs ◽  
Arunachal Pradesh ◽  
Watershed Development ◽  
Prioritization Process ◽  
Morphological Aspects ◽  
Management Measures ◽  
Digital Elevation ◽  
Mountainous Watersheds ◽  
Elevation Model

Mountainous watersheds are constantly under pressure of huge amount of soil loss due to soil erosion. Pare watershed is situated in the eastern Himalayan ranges of Arunachal Pradesh, India, which is subjected to such soil losses and its sub-watersheds are being degraded in many places. Watershed management programs are required in the area in which prioritization of sub-watersheds is one of the first steps. A study has been carried out to address this issue in the area to prioritize 26 sub-watersheds of Pare through morphometric analysis. The study used digital elevation model (DEM) to determine several morphometric parameters of the watershed. The analysis revealed that Pare river is of the 7th order comprising of 6127 stream segments running over the watersheds for about 2448 km. Based on the results obtained, the study area is an elongated well dissected watersheds with high relief and great presence of streams all over the watershed indicating faster runoff peak attainment which is synonymous to rapid transportation of sediment load. The analysis also revealed that SW25 required the top priority in dealing with soil, land and water management measures while least priority could be given to SW7 among all the sub-watersheds in the Pare basin. We suggest various stakeholders who are involved in watershed development programs in the region to take cues from the results obtained in this paper. The results of this study are quite satisfactory in understanding the various morphological aspects of the watershed. Nonetheless, efforts to improve the results can always be made through incorporation of land-use and soil information to enhance the prioritization process so that purpose utilization of the watershed may be reflected in the results.

scholarly journals The new remote-sensing-derived Swiss glacier inventory: I. Methods

2002 ◽  
Vol 34 ◽  
pp. 355-361 ◽  
Author(s):  
Frank Paul ◽  
Andreas Kääb ◽  
Max Maisch ◽  
Tobias Kellenberger ◽  
Wilfried Haeberli
Keyword(s):  
Satellite Data ◽  
Accuracy Assessment ◽  
Three Dimensional ◽  
Geographical Information ◽  
Glacier Inventory ◽  
Ratio Image ◽  
Digital Elevation ◽  
First Results ◽  
Gis Environment ◽  
Elevation Model

AbstractA new Swiss glacier inventory is to be compiled from satellite data for the year 2000. The study presented here describes two major tasks: an accuracy assessment of different methods for glacier classification with Landsat Thematic Mapper (TM) data and a digital elevation model (DEM); the geographical information system (GIS)-based methods for automatic extraction of individual glaciers from classified satellite data and the computation of three-dimensional glacier parameters (such as minimum, maximum and median elevation or slope and orientation) by fusion with a DEM. First results obtained by these methods are presented in Part II of this paper (Kääb and others, 2002). Thresholding of a ratio image from TM4 and TM5 reveals the best-suited glacier map. The computation of glacier parameters in a GIS environment is efficient and suitable for worldwide application. The methods developed contribute to the U. S. Geological Survey-led Global Land Ice Measurements from Space (GLIMS) project which is currently compiling a global inventory of land ice masses within the framework of global glacier monitoring (Haeberli and others, 2000).

scholarly journals Morphometric relief features of Kremenets Mountains

2015 ◽  
pp. 3-13 ◽  
Author(s):  
Andrii Bermes
Keyword(s):  
Spatial Modelling ◽  
Morphometric Parameters ◽  
Gis Analysis ◽  
Gis Technologies ◽  
Vertical Partitioning ◽  
Digital Elevation ◽  
Morphometric Features ◽  
Horizontal Partitioning ◽  
Geomorphological Features ◽  
Morphogenetic Analysis

Geomorphological structure and morphometric features of Kremenets Mountains are determined. The differences in geomorphic structure, morphometric parameters of individual sections of the study area are highlighted. The opportunity of the modelling of morphometric parameters using GIS technologies is considered. Certain regularities in the distribution of morphometric parameters on investigated area are revealed. Morphometric data processing and the construction of a series of morphometric maps using GIS-analysis and spatial modelling for Kremenets Mountains are done. A number of basic morphometric maps of the territory of Kremenets Mountains are constructed, namely horizontal and vertical partitioning of the territory, steepness of slopes and slope exposure. Based on the constructed maps certain regularities of geomorphological features of the territory of Kremenets Mountains, morphological features of the relief components are detected. The value of morphometric parameters could be used in complex morphogenetic analysis of the area of study. Key words: Kremenets Mountains, morphometric analysis, morphometric parameters, watershed, relict hills, GIS (geographic information systems), digital elevation models, horizontal partitioning, vertical partitioning, slopes, slope exposure.

scholarly journals Flood Impact Assessment Using HEC-RAS and GIS Techniques Dinder River, Southeast Sudan

2021 ◽  
Vol 1 (3) ◽  
pp. 14-19
Keyword(s):  
River Flow ◽  
Flow Behavior ◽  
Normal Height ◽  
Discharge Data ◽  
Four Seasons ◽  
Statistical Computation ◽  
Digital Elevation ◽  
Gis Environment ◽  
Flooded Area ◽  
Elevation Model

Abstract: Dinder River is largest tributary of the Blue Nile. It is seasonal river that flows from June to November and reaches its high peak in September. Frequently, the water level exceeds the normal height causing over bank flow and consequently floods. The floods generally ring about losses properties and crops close to river banks. This study is attempts to figure out the river flow behavior and find out the aerial extent of inundated lands in four flooding seasons. The investigated area is located in Sennar State, SE Sudan. Discharge data collected over the period from 2015 to 2018 and Digital Elevation Model (DEM) have been used to model the River flow regime, while land cover data was used to determine the affected LU/LC types in the area. HEC-RAS software was used to create 2D unsteady flow model in order to simulate Dinder River flooded area in four seasons. The largest flooded area extent in each season was used as input in GIS environment for further spatial analysis. Statistical computation for the affected area and consequent analysis revealed that: the affected urban area in 2018 was around 28.152km2, in 2017 was 29.205 km2, in 2016 was 16.531km2, and in 2015 was 10.422km2. Similar calculations were carried out for the other LU/LC types. According to the present study, the year 2017 witnessed the largest extent of flooding in the area.

A novel multiple flow direction algorithm for computing the topographic wetness index

2012 ◽  
Vol 43 (1-2) ◽  
pp. 135-145 ◽  
Author(s):  
Bin Yong ◽  
Li-Liang Ren ◽  
Yang Hong ◽  
Jonathan J. Gourley ◽  
Xi Chen ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Flow Direction ◽  
Contour Length ◽  
Topographic Wetness Index ◽  
Wetness Index ◽  
Digital Elevation ◽  
Surface Saturation ◽  
Mathematical Equations ◽  
Downslope Flow ◽  
Elevation Model

The topographic wetness index (TWI), frequently used in approximately characterizing the spatial distribution of soil moisture and surface saturation within a watershed, has been widely applied in topography-related geographical processes and hydrological models. However, it is still questionable whether the current algorithms of TWI can adequately model the spatial distribution of topographic characteristics. Based upon the widely-used multiple flow direction approach (MFD), a novel MFD algorithm (NMFD) is proposed for improving the TWI derivation using a Digital Elevation Model (DEM) in this study. Compared with MFD, NMFD improves the mathematical equations of the contributing area and more precisely calculates the effective contour length. Additionally, a varying exponent strategy is adopted to dynamically determine the downslope flow-partition exponent. Finally, a flow-direction tracking method is employed to address grid cells in flat terrain. The NMFD algorithm is first applied to a catchment located upstream of the Hanjiang River in China to demonstrate its accuracy and improvements. Then NMFD is quantitatively evaluated by using four types of artificial mathematical surfaces. The results indicate that the error generated by NMFD is generally lower than that computed by MFD, and NMFD is able to more accurately represent the hydrological similarity of watersheds.

scholarly journals Drainage basin morphometry: a global snapshot from the shuttle radar topography mission

2011 ◽  
Vol 15 (7) ◽  
pp. 2091-2099 ◽  
Author(s):  
P. L. Guth
Keyword(s):  
Digital Elevation Model ◽  
Drainage Basin ◽  
Shuttle Radar Topography Mission ◽  
Morphometric Parameters ◽  
Global Distribution ◽  
Drainage Basins ◽  
Basin Morphometry ◽  
Digital Elevation ◽  
Elevation Model

Abstract. A suite of 42 morphometric parameters for each of 26 272 drainage basins larger than 100 km2 from the Hydrosheds Shuttle Radar Topography digital elevation model shows the global distribution of Strahler order for streams and drainage basins. At the scale of 15 arc s spacing (232 to 464 m) the largest basins are order 9. Many common parameters depend both on the size of the basin, and the scale of the digital elevation model used for the computations. These drainage basins display the typical longitudinal stream profiles, but the major basins tend to be generally more concave than the smaller basins.

scholarly journals Using the geodetic and hydroacoustic measurements to investigate the bathymetric and morphometric parameters of Lake Hancza (Poland)

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Dariusz Popielarczyk ◽  
Tomasz Templin ◽  
Michał Łopata
Keyword(s):  
Digital Elevation Model ◽  
Measurement Techniques ◽  
Morphometric Parameters ◽  
Great Opportunity ◽  
Single Beam ◽  
Bathymetric Data ◽  
Digital Elevation ◽  
Hydroacoustic Measurements ◽  
Elevation Model ◽  
Bathymetric Map

Abstract Most of the inland lakes do not have up-to-date bathymetry. However, a significant progress in surveying technologies creates a possibility to quickly and accurately describe the underwater environment. Modern geodetic and global positioning techniques integrated with hydroacoustic systems provide a great opportunity to study the bottom shape with high resolution. Our study presents a reliable methodology for investigation of bathymetry and morphometric parameters with the use of GNSS positioning techniques and single beam echosounder. The research was implemented on the deepest, glacial reservoir in the central part of European Depression - Lake Hancza. Direct hydroacoustic and geodetic measurements completed by sediment study were conducted by the authors in 2010-2013. After performing a field survey the Digital Elevation Model was constructed and the new bathymetric map and morphometric card were elaborated. The maximum depth was confirmed to be 105.55 m. The final conclusions show that the available bathymetric data and morphometric parameters of lakes are highly dependent on the research methodology used, the precision and accuracy of measurement techniques, proper water level determination, digital elevation model and bathymetric map elaboration processes.

Sign in / Sign up

Export Citation Format

Share Document