scholarly journals Penentuan Batas DAS Tojo Berbasis GIS Menggunakan Perangkat HEC HMS 4.4 dan QGIS 3.16

2021 ◽  
Vol 5 (3) ◽  
pp. 273-282
Author(s):  
Aswar Amiruddin ◽  
Asta Asta ◽  
Rosmalia Handayani

Watershed delineation is the process of determining an area that contributes to the flow of rainfall (precipitation) into runoff to the outlet. The watershed delineation analysis in this study used the HEC-HMS version 4.4 and QGIS 3.16 . HEC HMS version 4.4 has GIS tools that have been directly integrated to facilitate the watershed delineation process. The study area in this research is the Tojo watershed which is located in Central Sulawesi Province. The digital elevation model (DEM) data source used is DEMNAS BIG with a spatial resolution is 8,1 meters. The results of watershed delineation using HEC-HMS 4.4 software are the same as the results of watershed delineation using QGIS 3.16 software. There is a slight difference in the watershed boundary in some parts when zoomed in. The watershed area produced by each GIS Softwares are HEC-HMS 212,583 km2, QGIS 212,5404 km2. The HEC-HMS 4.4 software gives quite good results on the boundary analysis of the Tojo watershed, so the HEC-HMS 4.4 software can also be used in other researches in the field of water resources. 

2021 ◽  
Vol 5 (3) ◽  
pp. 1475-1491
Author(s):  
Gisele Marilha Pereira Reginatto ◽  
Regiane Mara Sbroglia ◽  
Camilo Andrade Carreño ◽  
Bianca Rodrigues Schvartz ◽  
Pâmela Betiatto ◽  
...  

In translational landslide susceptibility analysis with SHALSTAB (Shallow Landsliding Stability Model), the resolution of the digital elevation model (DSM) is determinant for defining the type of mapping generated (preliminary or not). In this study, in order to verify the influence of the SDM scale on the SHALSTAB stability classes, susceptibility maps were prepared at two scales: 1:50,000 and 1:10,000. The study area was the Garcia River watershed, belonging to the municipality of Blumenau, Santa Catarina, affected by landslides in the 2008 catastrophe, which enabled the validation of the simulations with the scars mapped in the field. Thus, the influence of scale on the distribution of the model's stability classes and on its performance was verified. SHALSTAB performed better at the 1:10,000 scale, predicting 70% of the instabilities in a percentage of unstable area approximately three times smaller than at the 1,50,000 scale.


2020 ◽  
Vol 13 (2) ◽  
pp. 713
Author(s):  
Danilo Da Silva Dutra ◽  
André Ricardo Furlan ◽  
Luís Eduardo De Souza Robaina

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


Author(s):  
M. Nishio ◽  
M. Mori

These The present study aims to simulate the hydrologic processes of a flood, based on a new, highly accurate Digital Elevation Model (DEM). The DEM is provided by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan, and has a spatial resolution of five meters. It was generated by the new National Project in 2012. The Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS) is used to simulate the hydrologic process of a flood of the Onga River in Iizuka City, Japan. A large flood event in the typhoon season in 2003 caused serious damage around the Iizuka City area. Precise records of rainfall data from the Automated Meteorological Data Acquisition System (AMeDAS) were input into the HEC-HMS. The estimated flood area of the simulation results by HEC-HMS was identical to the observed flood area. A watershed aggregation map is also generated by HEC-HMS around the Onga River.


2019 ◽  
Vol 11 (15) ◽  
pp. 1767 ◽  
Author(s):  
Francesca Pasquetti ◽  
Monica Bini ◽  
Andrea Ciampalini

The aim of this paper is to evaluate the usefulness of TanDEM-X DEM (digital elevation model) for remote geomorphological analysis in Argentinian Patagonia. The use of a DEM with appropriate resolution and coverage might be very helpful and advantageous in vast and hardly accessible areas. TanDEM-X DEM could represent an unprecedented opportunity to identify geomorphological features because of its global coverage, ~12 m spatial resolution and low cost. In this regard, we assessed the vertical accuracy of TanDEM-X DEM through comparison with Differential Global Positioning System (DGPS) datasets collected in two areas of the Patagonia Region during a field survey; we then investigated different types of landforms by creating the elevation profiles. The comparison indicates a high agreement between TanDEM-X DEM and reference values, with a mean absolute vertical error (MAE) of 0.53 m, and a root mean squared error (RMSE) of 0.73 m. The results of landform analysis show an appropriate spatial resolution to detect different features such as beach ridges, which are impossible to delineate with other lower resolution DEMs. For these reasons, TanDEM-X DEM constitutes a useful tool for detailed geomorphological analyses in Argentinian Patagonia.


Geosciences ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 360 ◽  
Author(s):  
Sansar Raj ◽  
Thimmaiah

Landslides are one of the most damaging geological hazards in mountainous regions such as the Himalayas. The Himalayan region is, tectonically, the most active region in the world that is highly vulnerable to landslides and associated hazards. Landslide susceptibility mapping (LSM) is a useful tool for understanding the probability of the spatial distribution of future landslide regions. In this research, the landslide inventory datasets were collected during the field study of the Kullu valley in July 2018, and 149 landslide locations were collected as global positioning system (GPS) points. The present study evaluates the LSM using three different spatial resolution of the digital elevation model (DEM) derived from three different sources. The data-driven traditional frequency ratio (FR) model was used for this study. The FR model was used for this research to assess the impact of the different spatial resolution of DEMs on the LSM. DEM data was derived from Advanced Land Observing Satellite-1 (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) ALOS-PALSAR for 12.5 m, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global for 30 m, and the Shuttle Radar Topography Mission (SRTM) for 90 m. As an input, we used eight landslide conditioning factors based on the study area and topographic features of the Kullu valley in the Himalayas. The ASTER-Global 30m DEM showed higher accuracy of 0.910 compared to 0.839 for 12.5 m and 0.824 for 90 m DEM resolution. This study shows that that 30 m resolution is better suited for LSM for the Kullu valley region in the Himalayas. The LSM can be used for mitigation and future planning for spatial planners and developmental authorities in the region.


Author(s):  
Michał Wasilewski ◽  
Jarosław Chormański

The Shuttle Radar Topography Mission Digital Elevation Model as an alternative data source for deriving hydrological characteristics in lowland catchment — Rogożynek catchment case study This paper describes possibility of supplementing digital topography data needed for hydrologic modeling (WetSpa model) of lowland catchment with existing, freely available DEM data obtained from Shuttle Radar Topography Mission launched on February 11th, 2000. Rogożynek basin (Upper Biebrza) as case study is given. Authors compared three DEMs: topographic — TOPO DEM 20 (20 m resolution), radar — SRTM DEM 90 (90 m res.) and resampled radar — SRTM DEM 20 (20 m res.). There were several characteristics compared and analyzed like: relative height differences, slopes, generated river network and generated subwatersheds (subbasins).


2014 ◽  
Vol 16 (6) ◽  
pp. 1343-1358 ◽  
Author(s):  
L. Cui ◽  
Y. P. Li ◽  
G. H. Huang ◽  
Y. Huang

Topography plays a critical role in controlling water dispersion and soil movement in hydrologic modeling for water resources management with raster-based digital elevation model (DEM). This study aims to model effects of DEM resolution on runoff simulation through coupling fuzzy analysis technique with a topography based rainfall–runoff model (TOPMODEL). Different levels of DEM grid sizes between 30 m and 200 m are examined, and the results indicate that 30 m DEM resolution is the best for all catchments. Results demonstrate that the DEM resolution could have significant influence on the TOPMODEL rainfall–runoff simulation. Fuzzy analysis technique is used to further examine the uncertain DEM resolution based on considering Nash, sum of squared error, and sum of absolute error values of TOPMODEL. The developed model is calibrated and validated against observed flow during the period 2010–2012, and generally performed acceptably for model Nash–Sutcliffe value. The proposed method is useful for studying hydrological processes of watershed associated with topography uncertainty and providing support for identifying proper water resources management strategy.


OSEANA ◽  
2018 ◽  
Vol 43 (4) ◽  
Author(s):  
Marindah Yulia Iswari ◽  
Kasih Anggraini

DEMNAS : NATIONAL DIGITAL ELEVATION MODEL FOR COASTAL APPLICATION. DEM is a digital data which contain information about elevation. In Indonesia, DEM can be generated from elevation points or contours in RBI (Rupabumi Indonesia). DEM can be performed to research of coastal application i.e. inundation or tsunami. DEM can help to analyze vulnerability or evacuation zone for coastal hazards. DEMNAS is one product of BIG (Geospatial Information Agency) which consist of elevation data from remote sensing images. DEMNAS data has not been widely used and is still being developed but DEMNAS has an advantage of spatial resolution. DEMNAS has spatial resolution 0.27 arc-second, which is bigger than the spatial resolution of global DEM.


Author(s):  
Aleksander Szmidt

The article presents an example of application of selected GIS methods for showing connections between the course of palaeovalleys and contemporary valleys in Central Poland. The analysed area was shaped in the conditions of environment as early as the Palaeogene and Neogene, but the greatest impact on the present-day landscape came from the morphogenetic processes which operated in the Quaternary.Palaeogeographic studies of the analysed area often point to the possible dependencies between the contemporary landscape and its substrate, particularly as regards the valley system. In order to verify this hypothesis, on the basis of archival cartographic materials and a Digital Elevation Model of the current terrain, a procedure for conducting analyses with the use of commonly available GIS tools was proposed. Results of the conducted analysis allow for stating that the major river valleys of Central Poland in large part correspond to the arrangement of the fossil valley system, and the relationships are most easily noticeable for the largest valleys.


2021 ◽  
Author(s):  
Jingming Hou ◽  
Xinyi Li ◽  
Zhanpeng Pan ◽  
Junhui Wang ◽  
Ruike Wang

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