scholarly journals Technical Note: Water flow routing on irregular meshes

2006 ◽  
Vol 3 (6) ◽  
pp. 3675-3689 ◽  
Author(s):  
D. Bänninger
Keyword(s):  
Water Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Technical Note ◽  
Hill Slope ◽  
Digital Elevation ◽  
Irregular Meshes ◽  
Elevation Model ◽  
Local Gradient ◽  
Flow Cross

Abstract. For spatial explicit hydrological modelling an algorithm was needed which works as cellular automata on irregular meshes. From literature it was found that usual algorithms applied for this purpose do not route the water flow correctly to its adjacent cells. In this study the hydraulic linking between mesh cells is done by calculating the flow cross section between the mesh cells. The flow cross sections are positioned in the centre of the mesh edges and are perpendicular to the local gradient of the digital elevation model. The presented algorithm is simple in its implementation and efficient in computation. It is shown that the proposed algorithm works correctly for different synthesised hill slope shapes.

scholarly journals Technical Note: Water flow routing on irregular meshes

2007 ◽  
Vol 11 (4) ◽  
pp. 1243-1247 ◽  
Author(s):  
D. Bänninger
Keyword(s):  
Water Flow ◽  
Cross Sections ◽  
Technical Note ◽  
Spatially Explicit ◽  
Hill Slope ◽  
Digital Elevation ◽  
Irregular Meshes ◽  
Elevation Model ◽  
Local Gradient ◽  
Flow Cross

Abstract. For spatially explicit hydrological modelling an algorithm was required that works as a cellular automata on irregular meshes. From literature it was found that the usual algorithms applied for this purpose do not route the water flow correctly between adjacent cells. In this study the hydraulic linking between mesh cells is done by calculating the flow cross section between the mesh cells. The flow cross sections are positioned in the centre of the mesh edges and are perpendicular to the local gradient of the digital elevation model. The presented algorithm is simple in its implementation and efficient in computation. It is shown that the proposed algorithm works correctly for different synthesised hill slope shapes.

scholarly journals Reconstructing Pre-Industrial Long Distance Roads in a Hilly Region in Germany, Based on Historical and Archaeological Data

2017 ◽  
Vol 1 (2) ◽  
pp. 642-660 ◽  
Author(s):  
Irmela Herzog
Keyword(s):  
Cross Sections ◽  
Lidar Data ◽  
Long Distance ◽  
Early 19Th Century ◽  
Digital Elevation ◽  
Hilly Region ◽  
Local Accuracy ◽  
Cost Paths ◽  
Elevation Model ◽  
The One

The aim of this contribution is on the one hand to map pre-industrial long distance roads located in a hilly region east of Cologne, Germany, as exactly as possible and on the other hand to assess the accuracy of least-cost approaches that are increasingly applied by archaeologists for prehistoric road reconstruction. Probably the earliest map covering the study area east of Cologne dates back to 1575. The map is distorted so that rectification is difficult. But it is possible to assess the local accuracy of the map and to transfer the approximate routes to a modern map manually. Most of the area covered by the 1575 map is also depicted on a set of more accurate maps created in the early 19th century and a somewhat later historical map set (ca. 1842 AD). The historical roads on these rectified historical maps close to the approximate roads were digitized and compared to the outcomes of least-cost analysis, specifically least-cost paths and accessibility maps. Based on these route reconstructions with limited accuracy, Lidar data is checked to identify remains of these roads. Several approaches for visualizing Lidar data are tested to identify appropriate methods for detecting sunken roads. Possible sunken roads detected on the Lidar images were validated by checking cross sections in the digital elevation model and in the field.

Experimental study on improvement effect of guide wall to water flow in bend of spillway chute

2015 ◽  
Vol 73 (3) ◽  
pp. 669-678 ◽  
Author(s):  
Qinghua Zhang ◽  
Yanfang Diao ◽  
Xingtao Zhai ◽  
Shuning Li
Keyword(s):  
Water Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Water Surface ◽  
Great Influence ◽  
Flow Rates ◽  
Improvement Effect ◽  
Guide Wall ◽  
The Cross ◽  
Surface Improvement

In order to improve water flow in a bend of a spillway chute using a guide wall, modeling experiments with or without a guide wall under conditions of three different bend axial radii, three chute bottom slopes and three flow rates were carried out in this study. Two indexes were calculated, which are the improved water surface uniformity and the reduced rate of water surface difference in concave and convex banks of the cross-section. The results show that: (1) setting a guide wall in a bend can improve water flow in the bend because it increased the water surface uniformity of the cross-section and reduced the water surface difference in the concave and convex banks; (2) the smaller the bend axial radius, the better the water surface improvement effect will be using a guide wall; (3) the steeper the bottom slope, the more cross-sections with less water surface difference; and (4) flow rates have a great influence on water surface improvement in the bend, and the guide wall can improve water flow obviously when the water depth in the starting section of the bend is lower than the height of the guide wall. This study has important implications in engineering design of guide walls.

scholarly journals INTEGRASI SIG-INFOWORKS RIVER SIMULATION UNTUK PEMODELAN HIDRODINAMIK SUNGAI SADDANG DAN SUNGAI MATA ALLO

2020 ◽  
Vol 2 (2) ◽  
pp. 178
Author(s):  
Srie Wulandarie
Keyword(s):  
Water Level ◽  
Water Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Hydrodynamic Model ◽  
Simulation Models ◽  
Water Levels ◽  
Average Increase ◽  
Hydrodynamic Models ◽  
Gis Data

AbstractThe purpose of this study was to determine the hydrodynamic model of the river so that can know the capacity of the river to accommodate the incoming water flow. The simulation models can be used in structural mitigation plan as an attempt to prevent flooding in the future. The application program used to create hydrodynamic models that Infoworks River Simulation integrated with GIS. Data cross-section of the river as much as 39 points inputted into Infoworks River Simulation program. Furthermore, the discharge input the Saddang River and the Mata Allo River to determine variations in water level at each cross-section. The results of this study showed an average increase in water level of the Saddang  and Mata Allo River in the event of the maximum discharge of 2.59 meters. Sectional increased water levels are all cross sections along the Saddang and Mata Allo River Saddang used in modeling the variation of the rise in water level of 0.8 to 5.39 meters.

scholarly journals Managing the Flood Waves from Hemrin Dam

2021 ◽  
Vol 27 (7) ◽  
pp. 42-52
Author(s):  
Hajir Majid Ghali ◽  
Riyadh Z. Azzubaidi
Keyword(s):  
Cross Sections ◽  
Design Flood ◽  
Digital Elevation ◽  
Full Capacity ◽  
High Flood ◽  
Diyala River ◽  
Elevation Model ◽  
Strategic Study ◽  
Drop Structure ◽  
Flood Waves

Diyala Governorate was exposed recently to high flood waves discharged from Hemrin Dam to Diyala River when the dam reached its full capacity. The recently recorded discharge capacity of Diyala River was reduced to just 750m3/s. This exposes cities and villages along the Diyala River to flood risk when discharging the flood waves, which may reach 3000 m3/s. It is important to manage, suggest, and design flood escapes to discharge the flood waves from Hemrin Dam away from Diyala River. This escape branches from Hemrin Lake towards Ashweicha Marsh. One dimensional hydraulic model was developed to simulate the flow within the escape by using HEC-RAS software. Eighty-two cross-sections were extracted from the digital elevation model for the escape and used as geometric data. Moreover, thirty cross-sections for the Diyala River were utilized from the Strategic Study for Water and Land Resources in Iraq. Since the escape passes through two regions of different geological formations, two roughness coefficients of 0.035and0.028were used. Two discharge cases were applied3000m3/s, which is the 500 years return period extreme hydrograph of Hemrin Dam, and 4000 m3/s, which is the design discharge of Hemrin Dam spillway. A spillway was proposed at the escape entrance with crest level 105m.a.m.s.l., followed by a drop structure with eighteen rectangular steps

scholarly journals Influence of different sources of topographic data on flood mapping: urban area São Vendelino municipality, southern Brazil

RBRH ◽  
2020 ◽  
Vol 25 ◽  
Author(s):  
Fernando Campo Zambrano ◽  
Masato Kobiyama ◽  
Marco Alésio Figueiredo Pereira ◽  
Gean Paulo Michel ◽  
Fernando Mainardi Fan
Keyword(s):  
Cross Sections ◽  
Field Survey ◽  
Flood Mapping ◽  
Mean Velocity ◽  
Topographic Data ◽  
Digital Elevation ◽  
Wetted Area ◽  
Elevation Model ◽  
Best Fit ◽  
Different Sources

ABSTRACT Generally, the base for any flood mapping is the topography information whose resolution determines the map accuracy. Furthermore, river bathymetry in detail and the type of used model are also relevant. Therefore, the objective of the present study was to evaluate the influence of different sources of topographic data on the flood mapping by using the CAESAR-Lisflood model and three Digital Elevation Model (DEM) configurations, among which two were freely available, and the other was generated with field survey (topography and bathymetry). First, the resolution and precision of each DEM were evaluated, from the comparison of different cross-sections, besides the variation of the wetted area and absolute value of the relative error in mean velocity as a function of depth. Subsequently, after elaborating flood maps with each DEM, the results were compared in terms of flood area, mean flood width and flow depth. It is observed that the more accurate resolution, the smaller the flood area becomes. The flood map elaborated with the DEM through field survey had the best fit to the observed area. However the relation between the topographic resolutions and flow-depths was not clear in obtained results.

Impacts of peatland drainage on the properties of typical water flow paths determined from a digital elevation model

2008 ◽  
Vol 39 (5-6) ◽  
pp. 359-368 ◽  
Author(s):  
Timo Korkalainen ◽  
Ari Laurén ◽  
Harri Koivusalo ◽  
Teemu Kokkonen
Keyword(s):  
Digital Elevation Model ◽  
Water Flow ◽  
Water Body ◽  
Water Bodies ◽  
Flow Paths ◽  
Digital Elevation ◽  
The Mean ◽  
Growth Changes ◽  
Elevation Model ◽  
Water Flow Paths

Peatland drainage enhances tree growth, changes catchment hydrology and increases export of nutrients and suspended solids to water bodies. In this study, impacts of peatland drainage on the properties of water flow paths in terrestrial parts of catchments were assessed in terms of slope, elevation, length and soil type. Three study catchments (area 31.8–153.5 km2) were delineated using a 25 m × 25 m digital elevation model (DEM). Typical water flow paths were calculated for each catchment to characterize the mean elevation above the receiving water body as a function of distance along water flow paths. The resulting two-dimensional (2D) profile also allowed calculations of horizontally distributed properties of catchments as a function of distance to the water body. Peatland drainage decreased the length and elevation of the typical water flow path, and increased the area near water bodies. Increasing drainage from 10.7% to 55.4% of the total catchment area increased the area residing close to a water body (no farther than 25 m) from 17.1% to 60.7%. This area estimate is useful for assessing the costs of water protection, arising from restricting forestry operations in the vicinity of water bodies.

Relationships between inherited crustal structures and seismicity in the western Alps inferred from 3D structural modeling

2010 ◽  
Vol 181 (6) ◽  
pp. 583-590 ◽  
Author(s):  
Christian Sue ◽  
Philippe Calcagno ◽  
Gabriel Courrioux ◽  
Pierre Tricart ◽  
Julien Frechet ◽  
...  
Keyword(s):  
Cross Sections ◽  
Seismic Activity ◽  
Structural Model ◽  
Sedimentary Cover ◽  
Field Method ◽  
Western Alps ◽  
Geological Body ◽  
Digital Elevation ◽  
Crustal Structures ◽  
Elevation Model

Abstract We developed a 3-D structural model of a key area in the southwestern Alps, at the boundary between the external and internal zones. Six geological bodies are analyzed: internal and external basements, Briançonnais and Piemontais zones (internal sedimentary cover nappes), exotic flyschs, and external sedimentary cover. 3D volumes of each geological body are modeled using the structural map of the area projected on the Digital Elevation Model (DEM) and 5 cross-sections. The global model is interpolated from the map, DEM, and cross sections, using the potential field method, and represented by a Voronoï diagram. The final 3D-model is used as a structural frame to plot the earthquakes of the GéoFrance3D database, allowing to precisely and quantitatively investigate the relationships between crustal structures and current seismic activity of the belt. The boundary between external and internal zones corresponds to the so-called Crustal Penninic Thrust (CPT), which is a former Oligocene major thrust. Our model establishes that this former thrust represents the western limit of the seismic activity along the Briançonnais seismic arc, currently undergoing extensional tectonics.

Vertical Velocity Profile on the Noncircular Flow Cross-Section of Water Intake Pipeline with Deposition on Bottom

2013 ◽  
Vol 864-867 ◽  
pp. 2050-2055
Author(s):  
Xiao Xiao Li ◽  
Xiao Dong Zhao ◽  
Xiao Feng Luo
Keyword(s):  
Cross Section ◽  
Water Intake ◽  
Cross Sections ◽  
Vertical Velocity ◽  
Maximum Velocity ◽  
Mean Velocity ◽  
Flow Cross Section ◽  
Fine Sediments ◽  
Deposition Thickness ◽  
Flow Cross

Under small water-intake flow or overhaul periods, sediments deposit in the water intake pipeline with noncircular flow cross-section formed. According to the hydrostatic settling test results of fine sediments in circular pipeline, the sectional features of the deposition on pipe bottom is provided. And the vertical velocity profiles on perpendicular bisectors of noncircular flow cross-sections are measured under three kinds of typical deposition thickness. The relative positions of the maximum velocity point and the center of flow cross-section should be determined with an overall consideration to the two factors of wall roughness and wall restraint which is controlled by the transverse width of flow cross-section. When the mean velocity of flow cross-section keeps a constant value, the larger the deposition thickness is, the larger the velocity near the deposition surface, which is more favorable for sediment incipient motion.

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