scholarly journals Development of a screening method to assess flood risk on Danish national roads and highway systems

2011 ◽  
Vol 63 (12) ◽  
pp. 2957-2966 ◽  
Author(s):  
N. H. Nielsen ◽  
M. R. A. Larsen ◽  
S. F. Rasmussen
Keyword(s):  
Flood Risk ◽  
Preferential Flow ◽  
Screening Method ◽  
Great Influence ◽  
Drainage System ◽  
Accurate Estimation ◽  
Volume Data ◽  
Large Area ◽  
Terrain Model ◽  
Upstream Catchment

A method to assess flood risk on Danish national roads in a large area in the middle and southern part of Jutland, Denmark, was developed for the Danish Road Directorate. Flood risk has gained renewed focus due to the climate changes in recent years and extreme rain events are expected to become more frequent in the future. The assessment was primarily based on a digital terrain model (DTM) covering 7,500 km2 in a 1.6 × 1.6 m grid. The high-resolution terrain model was chosen in order to get an accurate estimation of the potential flooding in the road area and in the immediate vicinity, but also put a high requirement on the methods, hardware and software applied. The outcome of the analysis was detailed maps (as GIS layers) illustrating the location of depressions with depths, surface area and volume data for each depression. Furthermore, preferential flow paths, catchment boundaries and ranking of each depression were calculated. The ranking was based on volume of depressions compared with upstream catchment and a sensitivity analysis of the runoff coefficient. Finally, a method for assessing flood risk at a more advanced level (hydrodynamic simulation of surface and drainage) was developed and used on a specific blue spot as an example. The case study shows that upstream catchment, depressions, drainage system, and use of hydrodynamic calculations have a great influence on the result. Upstream catchments can contribute greatly to the flooding.

scholarly journals Flood risk assessment and cultural heritage impact in the Instituto Superior de Arte (ISA) in Habana.

2020 ◽  
Author(s):  
Daniele Fabrizio Bignami ◽  
Leonardo Stucchi ◽  
Daniele Bocchiola ◽  
Christian Zecchin ◽  
Davide Del Curto ◽  
...  
Keyword(s):  
Flood Risk ◽  
Laser Scanner ◽  
Drainage System ◽  
Digital Terrain Model ◽  
Field Measurements ◽  
Point Of View ◽  
Discharge Data ◽  
Terrain Model ◽  
Critical Discharge ◽  
The Status

<p>Keeping ISA Modern is a project of Fondazione Politecnico di Milano and other partners aimed at planning the conservation of some of the buildings (Schools) of the University of Arts (ISA) of Cuba, built over a former country club, designed by eminent architects of the time (Vittorio Garatti, Roberto Gottardi and Ricardo Porro), and bestowed with the status of UNESCO World Heritage in 2003.</p><p>Most of the Schools are currently unusable, also due to damages caused by frequent floods from the surrounding Rio Quibù river, and they need urgent restoration if they are to be used. Personnel of Politecnico di Milano carried out a field survey on the Rio Quibù during 2019, and also based upon information from the Cuban National Institute of Hydraulic Resources (INRH) they studied established flood risk for ISA.</p><p>Here, we built a high-resolution digital terrain model (DTM) of the park where Schools are located, using laser scanner data, and previously georeferenced points. Using field measurements taken in June 2019 we were able to assess geometry (included bridges), slope and roughness coefficients of the main channel of the Quibù river, influence of the sea level. Then using as input critical discharge data provided by INRH we evaluated flood area and flood volume for 4 representative return periods (5, 20, 50, 100 years).</p><p>The most impacted building is the School of Ballet, located within a narrow meander of Rio Quibù, immediately upstream of a narrow bridge, clogging largely during floods, only 1 km far from the sea, and with drainage system unable to discharge storm water.</p><p>Given the high required cost, a partially collapsed wall originally partially protecting the School of Ballet was not rebuilt, and we are now exploring flood mitigation strategy which are cheaper, and feasible from the point of view of compatibility with the historical and architectural value of the building.</p>

Synchronization Design for Multi-Channel Data Acquisition System

2013 ◽  
Vol 333-335 ◽  
pp. 472-479
Author(s):  
Jian Fei An ◽  
Ke Zhu Song ◽  
Lin Feng Shang ◽  
Jun Feng Yang
Keyword(s):  
Data Acquisition ◽  
Clock Synchronization ◽  
Great Influence ◽  
Channel Structure ◽  
Seismic Exploration ◽  
Large Area ◽  
Clock Data Recovery ◽  
System Clock ◽  
Recovery Technique ◽  
Synchronization Scheme

In land seismic data acquisition systems, as seismic exploration goes towards to cover large area, a multi-channel structure is needed. In such systems, synchronization is very important, which has great influence on data acquisition and transmission. In this paper, a clock synchronization scheme for seismic exploration is proposed. In the scheme, LVDS serial transmission is used so that the whole system clocks can be made to have the same frequency through clock data recovery technique. Moreover, to compensate the effect caused by transmission delay, an effective algorithm based on PLL phase locked and FPGA logic is proposed in this scheme. The test results show that this scheme meets the system clock synchronization requirements well with the error precision less than 1ns, which fully demonstrates the feasibility and reliability of the scheme. The scheme proposed here can be used in related systems which require clock synchronization.

scholarly journals Mapping of slopes for the operation of agricultural harvesters in Bandeirantes Municipality (PR)

2017 ◽  
Vol 38 (1) ◽  
pp. 97
Author(s):  
Gustavo Rodrigues Gimenes ◽  
Rone Batista Oliveira ◽  
Alessandra Fagioli da Silva ◽  
Luiz Carlos Reis ◽  
Teresinha Esteves da Silveira Reis
Keyword(s):  
Ground Surface ◽  
Digital Terrain Model ◽  
Large Area ◽  
Terrain Model ◽  
Spatial Point ◽  
Aster Gdem ◽  
Digital Terrain ◽  
Contour Lines ◽  
High Resolution Images ◽  
Point Data

The slope of terrain represents a risk factor for mechanized harvesting, leading to impediments or restrictions on agricultural operations, or even to machines toppling over in the field. Recently, the Digital Terrain Model (DTM) has become widely adopted as one of the most viable techniques for obtaining slope and elevation. Therefore, this study aims to assess methods of acquiring DTMs to calculate the slope, and to determine the areas that are suitable and unsuitable for the operation of harvesters in the municipality of Bandeirantes (PR). Four methods were selected to produce DTMs for the construction of slope zoning maps applicable for harvester operations. The image sources included SRTM, ASTER GDEM, digitizing contour lines and kriging of spatial point data. After generating DTMs by the four different methods, the area suitable for the operation of harvesters was obtained based on the limits of operational slopes for harvesters in the literature. The high-resolution images, such as those obtained by scanning the contour lines and ASTER GDEM gave the best representation of the ground surface. Regardless of the method used to obtain the operational slopes, the municipality has a large area that is suitable for mechanized harvesting.

scholarly journals The contribution of remote sensing in hydraulics and hydrology, analysis and evaluation of digital terrain model for flood risk mapping

2018 ◽  
Vol 39 (1) ◽  
pp. 17-26
Author(s):  
Faiza hassainia Bouzahar ◽  
Lahbaci Ouerdachi ◽  
Mahdi Keblouti ◽  
Akram Seddiki
Keyword(s):  
Remote Sensing ◽  
Spatial Analysis ◽  
Flood Risk ◽  
Digital Terrain Model ◽  
Risk Map ◽  
Terrain Model ◽  
Digital Terrain ◽  
Wetland Biodiversity ◽  
Adopted Model ◽  
Flood Risk Map

AbstractThe study of flood risk involves the knowledge of the spatial variability in the characteristics of the vegetation cover, terrain, climate and changes induced by the intervention of humans in watersheds. The increased needs of the actors in land management mean that static maps no longer meet the requirements of scientists and decision-makers. Access is needed to the data, methods and tools to produce complex maps in response to the different stages of risk evaluation and response. The availability of very high spatial resolution remote sensing data (VHSR) and digital terrain model (DTM) make it possible to detect objects close to human size and, therefore, is of interest for studying anthropogenic activities. The development of new methods and knowledge using detailed spatial data, coupled with the use of GIS, naturally becomes beneficial to the risks analysis. Indeed, the extraction of information from specific processes, such as vegetation indices, can be used as variables such as water heights, flow velocities, flow rates and submersion to predict the potential consequences of a flood. The functionalities of GIS for cartographic overlay and multi-criteria spatial analysis make it possible to identify the flood zones according to the level of risk from the flood, thus making it a useful decision-making tool.This study was carried out on the territory of watersheds in the Annaba region, East of Algeria. The choice was guided by the availability of data (satellites images, maps, hydrology, etc.) and hydrological specificities (proximity to an urban area). The adopted model is divided into two parts. The first part is to establish a methodology for the preservation of wetland biodiversity and the protection of urban areas against floods. Thanks to the multi-criteria spatial analysis and the functionalities of the GIS, we established a flood risk map for the watershed defined above. The result was satisfactory compared with the field reality. The second part of the model consisted of the integration of cadastral information with the flood risk map obtained in the first part of our research.The primary objective of this mapping is to contribute to the development of flood risk management plans (in the sense of risk reduction). The mapping stage also provides quantitative elements to more accurately assess the vulnerability of a territory.

scholarly journals Digital Terrain Characterization of Nilona Micro Watershed of Darwha Block of Maharastra

2021 ◽  
pp. 42-50
Author(s):  
R. Rakesh ◽  
Ashay D Souza ◽  
Sudipta Chattaraj
Keyword(s):  
Quantitative Description ◽  
Drainage System ◽  
Digital Terrain Model ◽  
Mean Value ◽  
Terrain Analysis ◽  
Terrain Model ◽  
Terrain Attributes ◽  
Digital Terrain ◽  
Grid Points

Watershed characterization is the first step in the sustainable management of    watershed resources. Morphometric analysis of a watershed using Digital Elevation Model (DEM) provides a quantitative description of the drainage system which is an important aspect   of the characterization of watersheds. The study was conducted in Nilona micro-watershed covering an area of 1297.35 ha in Darwha tehsil of Yavatmal district, Maharashtra. The terrain attributes and drainage configuration were derived from the Cartosat-1 data, 10m resolution Digital Terrain Model (DTM) using ArcGIS. Surface soil samples of 118 locations were collected from grid points located at regular interval of 325 m. The digital terrain analysis  showed that slope varies from 0 to 45.9 percent, with a mean value of 4.5%. Most of the area of Nilona micro-watershed was classified as gentle sloping. Profile curvature   varies from -5.1 to 4.6 m m-1, respectively indicating the coexistence of erosive as well  as depositional landforms. Overall, the study documents the utility of   site-specific modeling and geo-statistical interpolation based predictive mapping for watershed planning.

scholarly journals Chemical and U–Sr isotopic variations in stream and source waters of the Strengbach watershed (Vosges mountains, France)

2014 ◽  
Vol 18 (10) ◽  
pp. 3969-3985 ◽  
Author(s):  
M. C. Pierret ◽  
P. Stille ◽  
J. Prunier ◽  
D. Viville ◽  
F. Chabaux
Keyword(s):  
Preferential Flow ◽  
Great Influence ◽  
Chemical Compositions ◽  
Northern Slope ◽  
Soil System ◽  
Hydrological Conditions ◽  
Vosges Mountains ◽  
Isotopic Variations ◽  
Strengbach Catchment ◽  
Source Waters

Abstract. This is the first comprehensive study dealing with major and trace element data as well as 87Sr/86Sr isotope and (234U/238U) activity ratios (AR) determined on the totality of springs and brooks of the Strengbach catchment. It shows that the small and more or less monolithic catchment drains different sources and streamlets with very different isotopic and geochemical signatures. Different parameters control the diversity of the source characteristics. Of importance is especially the hydrothermal overprint of the granitic bedrock, which was stronger for the granite from the northern slope; also significant are the different meteoric alteration processes of the bedrock causing the formation of 0.5 to 9 m thick saprolite and above the formation of an up to 1m thick soil system. These processes mainly account for springs and brooks from the northern slope having higher Ca / Na, Mg / Na, and Sr / Na ratios, but lower 87Sr/86Sr isotopic ratios than those from the southern slope. The chemical compositions of the source waters in the Strengbach catchment are only to a small extent the result of alteration of primary bedrock minerals, and rather reflect dissolution/precipitation processes of secondary mineral phases like clay minerals. The (234U/238U) AR, however, are decoupled from the 87Sr/86Sr isotope system, and reflect to some extent the level of altitude of the source and, thus, the degree of alteration of the bedrock. The sources emerging at high altitudes have circulated through already weathered materials (saprolite and fractured bedrock depleted in 234U), implying (234U/238U) AR below 1, which is uncommon for surface waters. Preferential flow paths along constant fractures in the bedrocks might explain the – over time – homogeneous U AR of the different spring waters. However, the geochemical and isotopic variations of stream waters at the outlet of the catchment are controlled by variable contributions of different springs, depending on the hydrological conditions. It appears that the (234U/238U) AR are a very appropriate, important tracer for studying and deciphering the contribution of the different source fluxes at the catchment scale, because this unique geochemical parameter is different for each individual spring and at the same time remains unchanged for each of the springs with changing discharge and fluctuating hydrological conditions. This study further highlights the important impact of different and independent water pathways on fractured granite controlling the different geochemical and isotopic signatures of the waters. Despite the fact that soils and vegetation cover have a great influence on the water cycle balance (evapotranspiration, drainage, runoff), the chemical compositions of waters are strongly modified by processes occurring in deep saprolite and bedrock rather than in soils along the specific water pathways.

scholarly journals Link between Land Use and Flood Risk Assessment in Urban Areas

Proceedings ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 62
Author(s):  
Zahra Kalantari ◽  
Johanna Sörensen
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Green Infrastructure ◽  
Flood Risk ◽  
Urban Areas ◽  
Land Use Changes ◽  
Drainage System ◽  
Property Owners ◽  
Pluvial Flooding ◽  
The Impact

The densification of urban areas has raised concerns over increased pluvial flooding. Flood risk in urban areas might increase under the impact of land use changes. Urbanisation involves the conversion of natural areas to impermeable areas, causing lower infiltration rates and increased runoff. When high-intensity rainfall exceeds the capacity of an urban drainage system, the runoff causes pluvial flooding in low-laying areas. In the present study, a long time series (i.e., 20 years) of geo-referenced flood claims from property owners has been collected and analysed in detail to assess flood risk as it relates to land use changes in urban areas. The flood claim data come from property owners with flood insurance that covers property loss from overland flooding, groundwater intrusion through basement walls, as well as flooding from drainage systems; these data serve as a proxy of flood severity. The spatial relationships between land use change and flood occurrences in different urban areas were analysed. Special emphasis was placed on examining how nature-based solutions and blue-green infrastructure relate to flood risk. The relationships are defined by a statistical method explaining the tendencies whereby land use change affects flood risk.

scholarly journals Limitations of Emergent Constraints on Multi-Model Projections: Case Study of Constraining Vegetation Productivity With Observed Greening Sensitivity

2018 ◽  
Author(s):  
Alexander J. Winkler ◽  
Ranga B. Myneni ◽  
Victor Brovkin
Keyword(s):  
Co2 Concentration ◽  
Accurate Estimation ◽  
Spatial And Temporal Variability ◽  
Large Area ◽  
Area Index ◽  
Emergent Constraints ◽  
Data Source ◽  
Fertilization Effects ◽  
Historical Past ◽  
Co2 Forcing

Abstract. Recent research on Emergent Constraints (EC) has delivered promising results. The method utilizes a measurable variable (predictor) from the recent historical past to obtain a constrained estimate of change in a difficult-to-measure variable (predictand) at a potential future CO2 concentration (forcing) from multi-model projections. This procedure critically depends on, first, accurate estimation of the predictor from observations and models, and second, on a robust relationship between inter-model variations in the predictor-predictand space. We investigate issues related to these two themes in this article, using vegetation greening sensitivity to CO2 forcing during the satellite era as a predictor of change in Gross Primary Productivity (GPP) of the Northern High Latitudes region (60° N–90° N, NHL) for a doubling of pre-industrial CO2 concentration in the atmosphere. Greening sensitivity is defined as changes in annual maximum of green leaf area index (LAImax) per unit CO2 forcing realized through its radiative and fertilization effects. We first address the question of how to realistically characterize the greening sensitivity of a large area, the NHL, from pixel-level LAImax data. This requires an investigation into uncertainties in LAImax data source and an evaluation of the spatial and temporal variability in greening sensitivity to forcing in both the data and model simulations. Second, the relationship between greening sensitivity and ΔGPP across the model ensemble depends on a strong coupling among simultaneous changes in GPP and LAImax. This coupling depends in a complex manner on the magnitude (level), time-rate of application (scenarios) and effects (radiative and/or fertilization) of CO2 forcing. We investigate how each one of these three aspects of forcing can impair the EC estimate of the predictand (ΔGPP). Accounting for uncertainties in greening sensitivity and stability of the relation between inter-model variations results in a quantitative estimate of the uncertainty (±0.2 Pg C yr−1) on constrained GPP enhancement (ΔGPP = +3.4 Pg C yr−1) for a doubling of pre-industrial atmospheric CO2 concentration in NHL. This ΔGPP is 60 % larger than the conventionally used average of model projections. The illustrated sources of uncertainty and limitations of the EC method go beyond carbon cycle research and are generally relevant for Earth system sciences.

Automated-Horn Warning System for Highway-Railroad Grade Crossings: Evaluation at Three Crossings in Ames, Iowa

2000 ◽  
Vol 1708 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Steve J. Gent ◽  
Scott Logan ◽  
David Evans
Keyword(s):  
Quality Of Life ◽  
Urban Areas ◽  
Warning System ◽  
Volume Data ◽  
Land Area ◽  
Large Area ◽  
Strobe Light ◽  
Locomotive Engineer ◽  
Horn Systems

Traditionally, locomotive engineers begin sounding the train horn approximately one-quarter mile from the crossing to warn motorists and pedestrians approaching the intersection. To be heard over this distance, the train horn must be very loud. This combination of loud horns and the length along the tracks that the horn is sounded creates a large area adversely impacted by the horn noise. In urban areas, this area likely includes many nearby residents. The automated-horn system provides a similar audible warning to motorists and pedestrians by using two stationary horns mounted at the crossing. Each horn directs its sound toward the approaching roadway. The horn system is activated using the same track–signal circuitry as the gate arms and bells located at the crossing. Once the horn is activated, a strobe light begins flashing to inform the locomotive engineer that the horn is working. Horn volume data collected near the crossings clearly demonstrate the significant reduction of land area negatively impacted by using the automated horns. Residents overwhelmingly accepted the automated-horn systems and noted a significant improvement in their quality of life. Motorists preferred the automated-horn systems, and locomotive engineers rated these crossings slightly safer compared with the same crossings in the before (train horn) condition.

scholarly journals Estimating the Probability of Compound Floods in Estuarine Regions

2020 ◽  
Author(s):  
Wenyan Wu ◽  
Seth Westra ◽  
Michael Leonard
Keyword(s):  
Frequency Analysis ◽  
Flood Risk ◽  
Data Availability ◽  
Flood Frequency Analysis ◽  
Accurate Estimation ◽  
Flood Events ◽  
Advantages And Disadvantages ◽  
Comparative Review ◽  
Flood Probability

Abstract. The quantification of flood risk in estuarine regions relies on accurate estimation of flood probability, which is often challenging due to the rareness of flood events and their multi-causal (or compound) nature. Failure to consider the compounding nature of estuarine floods can lead to significant underestimation of flood risk in these regions. This study provides a comparative review of alternative approaches for estuarine flood estimation; namely, traditional univariate flood frequency analysis applied to both observed historical data and simulated data, and multivariate frequency analysis applied to flood events. Three specific implementations of the above approaches are evaluated on a case study – the estuarine portion of Swan River in Western Australia, highlighting the advantages and disadvantages of each approach. The theoretical understanding of the three approaches, combined with findings from the case study, enable generation of guidance on method selection for estuarine flood probability estimation, recognising issues such as data availability, complexity of the application/analysis process, location of interest within the estuarine region, computational demands and whether or not future conditions need to be assessed.

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