Stream Power determination along of a basin: First trial in the Chancay-Lambayeque basin.

2021 ◽  
Author(s):  
Joshua Er Addi Iparraguirre Ayala ◽  
Estibene Pool Vásquez Choque ◽  
Carlos Lenin Benavente Escobar ◽  
Flor de María Zanini Maldonado ◽  
Hugo Dulio Gómez Velásquez
Keyword(s):  
Power Relationship ◽  
Stream Power ◽  
Process Data ◽  
Rock Falls ◽  
Alos Palsar ◽  
Flow Rates ◽  
Digital Elevation ◽  
Peruvian Coast ◽  
Critical Zones ◽  
Gravitational Processes

<p>The Peruvian coast is one of the driest in the world, but it is continuously affected by extraordinary rains associated with El Niño and/or La Niña phenomenon. During these periods of intense rainfall, high flow rates are registered and gravitational processes are reported along the valleys, such as: landslides, debris flow, rock falls, avalanches, among others.</p><p>This work presents the first estimation of the Stream Power, relationship between the energy, the flow, the slope of the channel and the density of the flow of the Chancay - Lambayeque basin, with the objective of determining the energy of the main rivers in the basin and relating with gravitational processes and damage to infrastructures.</p><p>We use two softwares: LSDTopoTools and ArcSWAT (version for ArcGIS 10.6). Using high resolution Digital Elevation Models (Alos Palsar, 12.5 m) we delimit the basin, its drainage area, water network and slope using LSDTopoTools. Subsequently, we use the SWAT program.</p><p>First, the sub-basins were delimited. Second, the Hydrological Response Units (HRU) were obtained, applying the Land Use data and the FAO base guide on soil types updated by the Ministry of Agriculture and Irrigation of Peru (MINAGRI). Third, we process data on temperature, wind speed, humidity, solar radiation and rainfall from 1970 - 2018 from five meteorological stations distributed in the study basin, whose data were provided by the National Meteorology and Hydrology Service of Peru (SENAMHI). Next, we include in the analyzes the flow data from the Tinajones reservoir (6° 38´S, 79° 29´W). Finally, the annual flow rates (Hm<sup>3</sup>/s) were simulated and adjusted using SWATCup.</p><p>The results show an average flow for the year 2018 that varies from 13 Hm<sup>3</sup>/s - 49 Hm<sup>3</sup>/s. This means that the Stream Power varies from 1.3x10<sup>12</sup>Kw-4.8x10<sup>12</sup>Kw, the maximum power coinciding with the location of the Tinajones reservoir in the middle basin.</p><p>These results have allowed us to identify that 73% of the critical zones (zones with presence of gravitational processes) are in the sections where the rivers register high Stream Power; and in the same way in these sections geological dangers predominate such as flows and rock falls. In addition, infrastructures were located that may be susceptible to being damaged (e.g. three bridges, where flows range between ~22-35 Hm<sup>3</sup>/s) and/or may compromise the health of the inhabitants (e.g. five mining deposits located along the basin, considered high risk).</p><p>And to conclude, because the Tinajones reservoir is reaching its maximum capacity, a possible area was identified where a new reservoir can be housed (complying with all technical conditions), whose location would be 20 km to the east, in the province of Chumbil Alto (Cajamarca - Peru).</p>

scholarly journals Digital elevation models (DEM) used to assess soil erosion risks: a case study in Boyaca, Colombia

2016 ◽  
Vol 34 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Jeiner Yobany Buitrago E. ◽  
Luis Joel Martínez M.
Keyword(s):  
Slope Aspect ◽  
Mountainous Area ◽  
Stream Power ◽  
Topographic Wetness Index ◽  
Alos Palsar ◽  
Erosion Risk ◽  
Digital Elevation ◽  
Stream Power Index ◽  
Logic Functions ◽  
Soil Surveys

The objective of this research was to develop a model for assessing the risk of erosion, exploring the potential of DEMs from SRTM, ASTER, ALOS PALSAR and one made with interpolation of a 1:25,000 contour map to calculate the variables of the relief that have greater impact on erosion. Several geomorphometric parameters, such as slope, aspect, profile and plan curvature, topographic wetness index, stream power index, and sediment transport capacity were computed from the DEM's elevation, some fuzzy logic functions proposed to evaluate the incidence of each parameter on erosion risk in a mountainous area of Colombia. The results showed that the use of DEM data is a relatively easy, uncostly method to identify, in a qualitative way, the risk of erosion and contribute to the enhancement of erosion information that is obtained with conventional general soil surveys.

Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

2003 ◽  
Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Air Flow ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Process Data ◽  
Cfb Boiler ◽  
Flow Rates ◽  
Load Change ◽  
Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

scholarly journals Influência de lineamentos estruturais no desencadeamento dos movimentos de massa no maciço de Uruburetama, Ceará

2020 ◽  
Vol 13 (3) ◽  
pp. 1294
Author(s):  
Eduardo Viana Freires ◽  
Cláudio Ângelo da Silva Neto ◽  
Cynthia Romariz Duarte ◽  
César Ulisses Vieira Veríssimo ◽  
Daniel Dantas Moreira Gomes ◽  
...  
Keyword(s):  
High Energy ◽  
Automatic Extraction ◽  
Mass Movements ◽  
Alos Palsar ◽  
Geological Structures ◽  
Physical Conditions ◽  
Directional Filters ◽  
Digital Elevation ◽  
Predominant Orientation ◽  
Elevation Model

A disposição de estruturas geológicas em áreas planálticas é elemento importante na compreensão da dinâmica que ocorre na superfície de suas encostas e que é responsável pela esculturação do relevo. Neste contexto destacam-se os movimentos gravitacionais, que podem gerar perdas econômicas, ambientais e humanas em eventos de alta energia e/ou com grande extensão. Esta pesquisa analisou a influência de lineamentos estruturais no desencadeamento dos movimentos gravitacionais no maciço de Uruburetama, localizado no estado do Ceará. A metodologia consistiu na extração automática de lineamentos a partir do Modelo Digital de Elevação (MDE) fornecido pelo sensor orbital ALOS PALSAR. A partir da média de filtros direcionais aplicados a 0°, 45°, 90° e 135° de iluminação foi possível realçar as feições lineares da imagem original, facilitando sua extração. Posteriormente, foram elaborados mapas de distribuição espacial e densidade de lineamentos, além de diagrama de roseta. Tais produtos subsidiaram a análise da disposição dos principais trends estruturais da área, destacando que a maior densidade e a orientação predominante de lineamentos podem ser indicativas do grau de susceptibilidade à ocorrência de movimentos de massa no maciço de Uruburetama, desde que também sejam consideradas as características físicas dominantes e o grau de intervenção humana nas encostas. Os resultados demonstraram que os lineamentos estruturais obtidos de forma automática, quando analisados em conjunto com as características ambientais podem ser aplicados na análise de susceptibilidade à ocorrência de movimentos de massa.  Influence of structural lineaments as a trigger of mass movements in the Uruburetama massif, Ceará state, Brazil A B S T R A C TThe geological structures arrangement in plateau areas is an important element in understanding the dynamics that occur on the surface of their slopes and which is responsible for relief sculpting. In this context, gravitational movements stand out, which can generate economic, environmental and human losses in high energy events and / or with large extension. This research analyzed the influence of structural lineaments in the gravitational movements triggering in the Uruburetama massif, located in the state of Ceará. The methodology consisted of automatic extraction of lineaments from the Digital Elevation Model (DEM) provided by the ALOS PALSAR orbital sensor. From the average of directional filters applied at 0°, 45°, 90° and 135° of illumination it was possible to enhance the linear features of the original image, facilitating their extraction. Subsequently, maps of spatial distribution and lineaments density were developed, as well as a rosette diagram. Such products subsidized the analysis of the disposition of the main structural trends of the area, emphasizing that the higher density and the predominant orientation of lineaments may be indicative of the degree of susceptibility to the occurrence of mass movements in the Uruburetama massif, if the dominant physical conditions and the degree of human intervention on the slopes are also considered. The results showed that the structural lineaments obtained automatically, when analyzed together with the environmental characteristics can be applied in the susceptibility analysis to the occurrence of mass movements.Keywords: ALOS PALSAR, directional filters, image fusion, lineaments extraction

scholarly journals Stream Power Determination in GIS: An Index to Evaluate the Most ’Sensitive’Points of a River

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1145 ◽  
Author(s):  
Pierluigi De Rosa ◽  
Andrea Fredduzzi ◽  
Corrado Cencetti
Keyword(s):  
Methodological Approach ◽  
Main Stream ◽  
Stream Power ◽  
Digital Elevation ◽  
Original Definition ◽  
Study Support ◽  
Solid Transport ◽  
Gis Environment ◽  
Standardized Screening ◽  
Hydrographic Network

This paper focuses on the problem of measuring stream power in a hydrographic network using the original definition provided by Bagnold in 1996. Recent digital elevation models have enabled the calculation of channel gradients and, consequently, stream power with a finer spatial resolution, and this has created promising and novel opportunities to investigate river geomorphological processes and forms. The work carried out in this study includes defining and implementing a methodological approach that could be automated within a geographic information system and that meets two requirements: (1) it uses a DEM as input data at a suitable resolution; (2) it estimates the stream power Ω , as well as its variability along the considered stream, in the best possible way using available data. In particular, the methodological approach was implemented in a GIS environment (GRASS GIS) and applied to a sample basin to highlight the variability in Ω along the main stream and its most important tributaries. The sudden and more substantial variations in stream power were then related to the processes acting in the fluvial system. This approach made it possible to highlight how erosion, solid transport, and sedimentation phenomena occurring along the fluvial reaches are related to abrupt variations (increase/decrease) in the “power” available. The results of this study support the idea that the automated and standardized screening of stream power variability along a stream can be used as a preliminary diagnostic element to identify the most “sensitive” points of the stream on which to concentrate subsequent investigations (field checks to verify the causes), with the aim of mitigating risks due to the dynamics of the riverbed.

scholarly journals DEM Construction using DInSAR

2014 ◽  
Vol XL-8 ◽  
pp. 817-820 ◽  
Author(s):  
R. Mangla ◽  
S. Kumar
Keyword(s):  
Flash Flood ◽  
3D Visualization ◽  
Sar Interferometry ◽  
Atmospheric Effects ◽  
Alos Palsar ◽  
Digital Elevation ◽  
Temporal Decorrelation ◽  
Elevation Model ◽  
Differential Sar Interferometry ◽  
Differential Interferogram

A digital elevation model (DEM) is a 3D visualization of a terrain surface. It can be used in various analytical studies such as topographic feature extraction, hydrology, geomorphology and landslides analysis etc. Uttrakhand region is affected with landslides, earthquake and flash flood phenomenon. Hence this study was focused on DEM generation using Differential SAR Interferometry (DINSAR) on ALOS PALSAR dataset. Two Pass DINSAR technique involves one interferometric pair in addition with an external DEM. The external DEM was used as a reference to reduce topographic errors. The data processing steps were image co-registration, interferogram generation, interferogram flattening (Differential Interferogram), interferogram filtering, coherence map, phase unwrapping, orbital refinement and re-flattening and DEM generation. Interferogram fringes observed in forest areas were due to temporal decorrelation and the fringes in mountain regions were obtained due to topography changes (may be due to landslides in rainy season). The range of elevation in generated DEM were 132 m to 2823 m and Root Mean Square Error (RMSE) error was 36.765159 m. The generated DEM was compared with ASTER DEM and variation in height was analyzed. Atmospheric effects were not removed due to geometrical and temporal decorrelation which affect the accuracy.

scholarly journals The stream power variation in a GIS environment as an index to evaluate the most 'sensitive' points of a river

2018 ◽  
Author(s):  
Pierluigi De Rosa ◽  
Corrado Cencetti ◽  
Andrea Fredduzzi
Keyword(s):  
Methodological Approach ◽  
Specific Weight ◽  
Main Stream ◽  
Stream Power ◽  
Time Rate ◽  
Liquid Discharge ◽  
Digital Elevation ◽  
Original Definition ◽  
Solid Transport ◽  
Gis Environment

The note deals with the problem of measurement and variability, along the fluvial reaches of a hydrographic network, of the stream power, according to the original definition provided by Bagnold (1966) “The available power supply, or time rate of energy supply, to unit lenght of a stream is clearly the time rate of liberation in kinetic form of the liquid’s potential energy as it descends the gravity slope S”. In formula: Ω = ρ g Q S where: Ω = stream power per unit of flow length (W/m) ρ g = density x gravity acceleration = specific weight of the fluid (kg/m3) Q = liquid discharge (m3/s) S = slope of the considered reach (m/m). Recent digital elevation models allow the calculation of channel gradient and consequently stream power with a finer spatial resolution, opening promising and novel opportunities to investigate river geomorphical processes and forms. The work carried out consisted in defining and implementing a methodological approach that could be automated within a geographic information system and that meets two requirements: 1) use input data that is easy to find as DEM at a low resolution; 2) estimate, in the best possible way and on the basis of the available data, the stream power and its variability along the considered stream. In particular, the methodological approach has been implemented in GIS environment (GRASS Gis, Qgis), and it has been applied to a sample basin, highlighting the variability of Ω along the streams of a higher order (in practice the main stream and its most important tributaries). The sudden and more substantial variations of stream power were then related to the processes acting in the fluvial system. This approach has made it possible to highlight how the erosion, solid transport and sedimentation phenomena occurring along the fluvial reaches (and the geomorphological and geologicalapplicative problems that these involve, especially in anthropized areas), are correlated precisely to abrupt variations (increase/decrease) of the ”power” available. Hence the idea that automated and standardized screening of stream power variability along a stream can be used as a preliminary diagnostic element to identify the most ”sensitive” points of the same, on which to concentrate subsequent investigations (field checks, to verify the causes), aimed at mitigating the risk due to the dynamics of the riverbed.

scholarly journals The stream power variation in a GIS environment as an index to evaluate the most 'sensitive' points of a river

2018 ◽  
Author(s):  
Pierluigi De Rosa ◽  
Corrado Cencetti ◽  
Andrea Fredduzzi
Keyword(s):  
Methodological Approach ◽  
Specific Weight ◽  
Main Stream ◽  
Stream Power ◽  
Time Rate ◽  
Liquid Discharge ◽  
Digital Elevation ◽  
Original Definition ◽  
Solid Transport ◽  
Gis Environment

The note deals with the problem of measurement and variability, along the fluvial reaches of a hydrographic network, of the stream power, according to the original definition provided by Bagnold (1966) “The available power supply, or time rate of energy supply, to unit lenght of a stream is clearly the time rate of liberation in kinetic form of the liquid’s potential energy as it descends the gravity slope S”. In formula: Ω = ρ g Q S where: Ω = stream power per unit of flow length (W/m) ρ g = density x gravity acceleration = specific weight of the fluid (kg/m3) Q = liquid discharge (m3/s) S = slope of the considered reach (m/m). Recent digital elevation models allow the calculation of channel gradient and consequently stream power with a finer spatial resolution, opening promising and novel opportunities to investigate river geomorphical processes and forms. The work carried out consisted in defining and implementing a methodological approach that could be automated within a geographic information system and that meets two requirements: 1) use input data that is easy to find as DEM at a low resolution; 2) estimate, in the best possible way and on the basis of the available data, the stream power and its variability along the considered stream. In particular, the methodological approach has been implemented in GIS environment (GRASS Gis, Qgis), and it has been applied to a sample basin, highlighting the variability of Ω along the streams of a higher order (in practice the main stream and its most important tributaries). The sudden and more substantial variations of stream power were then related to the processes acting in the fluvial system. This approach has made it possible to highlight how the erosion, solid transport and sedimentation phenomena occurring along the fluvial reaches (and the geomorphological and geologicalapplicative problems that these involve, especially in anthropized areas), are correlated precisely to abrupt variations (increase/decrease) of the ”power” available. Hence the idea that automated and standardized screening of stream power variability along a stream can be used as a preliminary diagnostic element to identify the most ”sensitive” points of the same, on which to concentrate subsequent investigations (field checks, to verify the causes), aimed at mitigating the risk due to the dynamics of the riverbed.

scholarly journals Free Global DEMs and Flood Modelling—A Comparison Analysis for the January 2015 Flooding Event in Mocuba City (Mozambique)

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 176
Author(s):  
Julio Garrote
Keyword(s):  
Developing Countries ◽  
Data Acquisition ◽  
Field Data ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Control Point ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Flooding Event

Flood hazard and risk analysis in developing countries is a difficult task due to the absence or scarce availability of flow data and digital elevation models (DEMs) with the necessary quality. Up to eight DEMs (ALOS Palsar, Aster GDEM, Bare Earth DEM, SRTM DEM, Merit DEM, TanDEM-X DEM, NASA DEM, and Copernicus DEM) of different data acquisition, spatial resolution, and data processing were used to reconstruct the January 2015 flood event. The systematic flow rate record from the Mocuba city gauge station as well as international aid organisms and field data were used to define both the return period peak flows in years for different flood frequencies (Tyear) and the January 2015 flooding event peak flow. Both visual and statistical analysis of flow depth values at control point locations give us a measure of the different hydraulic modelling performance. The results related to the Copernicus DEM, both in visual and statistical approach, show a clear improvement over the results of the other free global DEMs. Under the assumption that Copernicus DEM provides the best results, a flood hazard analysis was carried out, its results being in agreement with previous data of the effects of the January 2015 flooding event in the Mocuba District. All these results highlight the step forward that Copernicus DEM represents for flood hazard analysis in developing countries, along with the use of so-called “citizen science” in the form of flooding evidence field data acquisition.

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