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.

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

scholarly journals Development of RiverBox—An ArcGIS Toolbox for River Bathymetry Reconstruction

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1266 ◽  
Author(s):  
Tomasz Dysarz
Keyword(s):  
Cross Sections ◽  
River Flow ◽  
Computational Time ◽  
Fully Integrated ◽  
River Bed ◽  
Develop Software ◽  
Scripting Language ◽  
Gis Environment ◽  
Elevation Model ◽  
Model Preparation

The main purpose of the present research is to develop software for reconstruction of the river bed on the basis of sparse cross-section measurements. The tools prepared should support the process of hydrodynamic model preparation for simulation of river flow. Considering the formats of available data and the requirements of modern modeling techniques, the prepared software is fully integrated with the GIS environment. The scripting language Python 2.7 implemented in ArcGIS 10.5.1 was chosen for this purpose. Two study cases were selected to validate and test the prepared procedures. These are stream reaches in Poland. The first is located on the Warta river, and the second on the Ner river. The data necessary for the whole procedure are: a digital elevation model, measurements of the cross-sections in the form of points, and two polyline layers representing an arbitrary river centerline and river banks. In the presented research the concept of a channel-oriented coordinate system is applied. The elevations are linearly interpolated along the longitudinal and transversal directions. The interpolation along the channel is implemented in three computational schemes linking different tools available in ArcGIS and ArcToolbox. A simplified comparison of memory usage and computational time is presented. The scheme linking longitudinal and spatial interpolation algorithms seems to be the most advantageous.

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 Using a Particle Based Simulation to Visualize Sub-Catchments Contribution to Localized Flooding

10.29007/4lbl ◽  
2018 ◽  
Author(s):  
Mehdi Khoury ◽  
Dragan Savic ◽  
Lydia Vamvakeridou-Lyroudia ◽  
Albert Chen ◽  
Slobodan Djordjevic
Keyword(s):  
Rolling Ball ◽  
Simulation Engine ◽  
Digital Elevation ◽  
Natural Flow ◽  
Flow Pathways ◽  
Flooded Area ◽  
Elevation Model ◽  
The Uk ◽  
The Impact ◽  
The Village

Using the Nvidia off-the-shelf particle based “Flex” simulation engine, we visualize the impact of rainfall over different sub-catchments on flooding in the village of Millbrook in the UK. Stakeholders are able to see what part of the catchment contributes most to which flooded area in the village. Hundreds of thousands of colored particles (balls), whose color is based on the quadrant of the catchment area, are dropped above the terrain and left to roll down while interacting with each other. The approach is similar to the ‘rolling ball’ method, which identifies natural flow pathways by rolling a ball down a digital elevation model, but uses multiple balls instead. Although the visualized results of our approach are of limited hydraulic accuracy, this type of visualization explains causality when analyzing the contribution of different portions of the terrain to the flooding from rainfall. This is possible due to colored deposits resembling well the final flood extent. Consequently, it is a useful technique for implementation in Serious Gaming, with flooding related themes, targeting in improving the understanding of stakeholders/players.

scholarly journals Kajian Potensi Erosi Di Daerah Aliran Sungai Babon Menggunakan Permodelan GeoWEPP

G - SMART ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 98
Author(s):  
Revangga Dandha Pratama ◽  
Dimas Jalu Setyawan ◽  
Budi Santosa
Keyword(s):  
Erosion Rate ◽  
River Flow ◽  
Water Erosion ◽  
Climate Data ◽  
Erosion Prediction ◽  
Digital Elevation ◽  
Water Erosion Prediction Project ◽  
Type Data ◽  
Hazard Level ◽  
Elevation Model

At the time of the high intensity of rainfall in Semarang, the water contained in the Babon River had overflowed, resulting in flooding of parts of the area adjacent to the Babon river flow. This matter has many factors, there are erosion and sediment produced. This study aims to study erosion potential in the Babon watershed, using the Geospatial Interface for Water Erosion Prediction Project (GeoWEPP) modeling. The results of the modeling are the amount of erosion rate and erosion distribution in the study area. The erosion prediction period in this study is in 2006 - 2015. Data needed in GeoWEPP operation are Digital Elevation Model, climate data, land use data, and soil type data. Based on the GeoWEPP process in the Babon watershed the erosion rate was 36.1 tons / ha / year and the sediment yield was 26075.2 tons / year. From the results of the erosion rate produced divided by the reasonable erosion rate get the Erosion Hazard Level index (TBE) of 3.6 or including medium TBE. Based on the distribution of erosion maps produced, the area experienced the greatest erosion rate in the Ungaran region. This is due to the fact that it belongs to the highlands and has a high slope value.

Multidisciplinary approach to assess landslide hazards in alpine environment: the geomorphological map of the upper Maira Valley (Western Alps, Italy).

2020 ◽  
Author(s):  
Mauro Bonasera ◽  
Alessandro Petroccia ◽  
Fabiola Caso ◽  
Sara Nerone ◽  
Michele Morelli
Keyword(s):  
Western Alps ◽  
Local Analysis ◽  
Rock Falls ◽  
Stratigraphic Sequence ◽  
Aerial Photos ◽  
Digital Elevation ◽  
Multi Temporal ◽  
Gis Environment ◽  
Elevation Model ◽  
Cover Thickness

<p>The landscape evolution of the U-shaped Maira Valley was mainly led by glacial dynamics during Pleistocene. The Holocene linear fluvial erosion creates higher steepness slopes in a narrow valley in which gravitational phenomena involves buildings and facilities of Acceglio municipality (Piedmont, Italy). A geomorphological survey in an unmapped area of about 12 km<sup>2</sup> has been carried out and a new map at scale 1:10000 has been realised. In order to improve the accuracy of fieldwork data, several multidisciplinary techniques have been investigated. The landforms and slope evolution were analysed by using a 5-meters resolution ARPA Digital Elevation Model (DEM) in GIS environment. Discontinuities and geomorphological features were recognized and mapped observing aerial-photos provided by Regione Piemonte. Multi-temporal dataset of orthophotos were useful to examine the river pattern behaviour coupled with interdigitating polygenic fan deposition. The stratigraphic sequence knowledge was achieved using boreholes, inclinometers and piezometers evaluating eventual detrital cover thickness. Detailed field investigations allowed to understand the relationship between structural geology and landslide evolution, in particular concerning several detachment zones characterising the slope overlooking Acceglio town. In the uppermost range of that slope, the fracturation is intense and influences the rock-falls and rock avalanches trigger, whilst debris flows were identified throughout the detected area associated with a homogeneous presence of weathered cover. Widespread accumulation bodies suggest how avalanche and debris flow occurrences have affected Acceglio human activities, testified by historical archives documents as well. In the past, several trial to mitigate these risks were performed through engineering activities which could be refined and implemented with further local analysis on landslide susceptibility. Research on this issue, in addition to having a great scientific interest, can provide essential tools for upper Maira Valley Administrations, being the main available support for an appropriate urban planning.</p>

scholarly journals Simple Model for Simulating Characteristics of River Flow Velocity in Large Scale

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Husin Alatas ◽  
Dyo D. Prayuda ◽  
Achmad Syafiuddin ◽  
May Parlindungan ◽  
Nurjaman O. Suhendra ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Large Scale ◽  
Inelastic Collision ◽  
River Flow ◽  
Equation Of Motion ◽  
Momentum Conservation ◽  
Digital Elevation ◽  
Computer Based ◽  
Elevation Model ◽  
Modified Equation

We propose a simple computer based phenomenological model to simulate the characteristics of river flow velocity in large scale. We use shuttle radar tomography mission based digital elevation model in grid form to define the terrain of catchment area. The model relies on mass-momentum conservation law and modified equation of motion of falling body in inclined plane. We assume inelastic collision occurs at every junction of two river branches to describe the dynamics of merged flow velocity.

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 Development and Assessment of the Monthly Grid Precipitation Datasets in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiadong Peng ◽  
Lijie Duan ◽  
Wenhui Xu ◽  
Qingxiang Li
Keyword(s):  
Climate Models ◽  
Absolute Error ◽  
Four Seasons ◽  
Interpolation Accuracy ◽  
Digital Elevation ◽  
Weather And Climate ◽  
The Mean ◽  
Weather Stations ◽  
Elevation Model ◽  
Inverse Distance

Based on the high-quality homogenized precipitation data from all 2,419 national weather stations in China, the climatology and anomaly percentage fields are derived, and then the digital elevation model (DEM) is employed to reduce the influence of elevation on the spatial interpolation accuracy of precipitation due to the unique topography in China. Then, the gradient plus inverse distance squared (GIDS) method and the inverse distance squared (IDS) method are used to grid the climatology field and the anomaly percentage field, respectively, and the 0.5 × 0.5° gridded datasets during 1961–2018 in China are obtained by combining them together. The evaluation shows that the mean absolute error (MAE) between the analysis value and the observation is 15.8 mm/month. The MAE in South China is generally higher than that in North China, and the MAE is obviously larger in summer than in other seasons. Specifically, 94.6, 54.4, 4.6, and 53.8% of the MAE are below 10 mm/month in winter (DJF), spring (MAM), summer (JJA), and autumn (SON), respectively, and 99.5, 79.9, 22.8, and 82.1% of them are less than 20 mm/month. The MAE over China in four seasons is 3.8, 13.2, 33.5, and 12.7 mm/month, respectively. This dataset has the potential of broad application prospects in the evaluations of weather and climate models and satellite products.

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.

Sign in / Sign up

Export Citation Format

Share Document