scholarly journals PRECISÃO DO MODELO DIGITAL DE ELEVAÇÃO (SRTM-Topodata) COM BASE EM DADOS DE PROJETOS DE APROVEITAMENTOS HIDRELÉTRICOS

Nativa ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 184
Author(s):  
Marcel Medinas de Campos ◽  
Rafael Pedrollo Paes ◽  
Ana Rubia De Carvalho Bonilha Silva ◽  
Ibraim Fantin-Cruz
Keyword(s):  
Digital Elevation Model ◽  
Cross Section ◽  
Power Plants ◽  
Coefficient Of Determination ◽  
Hydroelectric Power ◽  
Hydropower Plants ◽  
Digital Elevation ◽  
The Subject ◽  
Elevation Model ◽  
River Cross Section

A precisão altimétrica do Modelo Digital de Elevação – MDE tem sido tema de diversos estudos. Essa precisão exerce forte influência sobre as informações extraídas desses dados. Nesse contexto, o presente estudo compara dados observados em projetos de aproveitamentos hidrelétricos com dados extraídos do MDE. A comparação de dados altimétricos de informações extraídas pelo MDE com as contidas no Projeto Básico Ambiental – PBA desses empreendimentos, assumido como informação verdadeira, foi feita com o intuito de analisar o erro das informações extraídas do MDE em relação aos dados contidos no PBA e assim verificar a confiança nesse tipo de estimativa. Foram calculados o erro e o coeficiente de determinação de Pearson entre a altura da barragem (determinada com base no MDE) em relação à altura apresentada no PBA. Também foi comparada uma seção topobatimétrica do PBA com a mesma seção extraída pelo MDE. O erro relativo médio e o coeficiente de determinação entre as cinco alturas (estimadas e de projeto) foi de 11% e 0,874, respectivamente. O coeficiente de determinação, o erro médio quadrático e o erro médio entre as seções foram de 0,98, 1,56 e -0,02, respectivamente. A análise evidenciou que há erros em relação às informações extraídas do MDE. Entretanto, considerando a escala utilizada nesse estudo, os erros foram menores que os observados na literatura.Palavras-chave: MDE validação, Altura de barragem, Seção topobatimétrica. ALTIMETRY ACCURACY OF THE DIGITAL ELEVATION MODEL (SRTM-Topodata) BASED ON DESIGNS OF HYDROPOWER PLANTS DATA ABSTRACT: The altimetry accuracy measurements of the Digital Elevation Model - DEM have been the subject of several studies. This accuracy plays an important role on information extracted from these data. In this context, this study compares data observed in designs of hydroelectric power plants with data extracted from the DEM. The comparison between the altimetry of data extracted from the DEM with those contained in the Basic Environmental Project - BEP of these facilities, assumed as the true information, was done with the purpose of analyzing the error of the information extracted from the DEM in relation to the data contained in the BEP and thus verifying the confidence in this type of estimate. The error and the coefficient of determination between the dam height (determined based on the DEM) and the dam height presented in the BEP were calculated. Moreover, a river cross section published in the BEP was contrasted with the same cross section extracted from the DEM. The mean relative error and the coefficient of determination between the five heights (estimated and projected) was 11% and 0.874, respectively. The coefficient of determination, mean square error and mean error between sections were 0.98, 1.56 and -0,02, respectively. The analysis evidenced that there are errors in relation to the information extracted from the DEM. However, considering the scale used in this study, the errors were smaller than those observed in the literature.Keywords: DEM validation, dam height, cross section.

Assessment of Hydropower Potential Using Geospatial Technology in a Case Study of Guna-Tana Landscape Upper Abay Basin, Ethiopia

2020 ◽  
Author(s):  
Asirat Teshome ◽  
Yonas Tibebu ◽  
Endalkachew Addis
Keyword(s):  
Digital Elevation Model ◽  
Hydroelectric Power ◽  
Stream Network ◽  
Geospatial Technology ◽  
Gis Tools ◽  
Digital Elevation ◽  
Hydropower Potential ◽  
Elevation Model ◽  
Planning And Construction

Abstract Background: In this study, geospatial technology was used to assess potential sites for hydroelectric potential in the Ribb and Gumara Rivers of the Guna-Tana landscape of the upper Abay basin in Ethiopia. The important parameters used in this study were the Digital Elevation Model, the stream network, the stream elevation; the stream slope, the height difference, and the stream flow were analysed. In addition, the results obtained from the geospatial model, satellite data and GIS tools were used to identify the hydroelectric potential in the landscape. Results: Twenty sites with hydroelectric potential were identified within the 3528.16 km2 of the Guna-Tana landscape. The maximum power in the Ribb River was 48,389.98 kW, while in the Gumara River it was 41,984.01 kW. Therefore, the development of strategies to improve the decision-making process for hydroelectric power planning and construction is of utmost importance to support renewable energy production with minimal negative environmental social impacts. Conclusion: Therefore, this study revealed that the hydroelectric potential of a river basin could be correctly assessed using a digital elevation model, stream network data, within a GIS framework.

scholarly journals Fire on the Water Towers: Mapping Burn Scars on Mount Kenya Using Satellite Data to Reconstruct Recent Fire History

2019 ◽  
Vol 11 (2) ◽  
pp. 104
Author(s):  
Mary C. Henry ◽  
John K. Maingi ◽  
Jessica McCarty
Keyword(s):  
Digital Elevation Model ◽  
Fire History ◽  
Slope Aspect ◽  
Burned Area ◽  
Semiarid Region ◽  
Landsat 8 ◽  
Hydroelectric Power ◽  
Active Fire ◽  
Digital Elevation ◽  
Elevation Model

Mount Kenya is one of Kenya’s ‘water towers’, the headwaters for the country’s major rivers including the Tana River and Ewaso Nyiro River, which provide water and hydroelectric power to the semiarid region. Fires affect water downstream, but are difficult to monitor given limited resources of local land management agencies. Satellite-based remote sensing has the potential to provide long term coverage of large remote areas on Mount Kenya, especially using the free Landsat data archive and moderate resolution imaging spectroradiometer (MODIS) fire products. In this study, we mapped burn scars on Mount Kenya using 30 m Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI) derived dNBR (change in normalized burn ratio) and MODIS active fire detection and burned area data for fires occurring from 2004 to 2015. We also analyzed topographic position (elevation, slope, aspect) of these fires using an ASTER global digital elevation model (GDEM v2) satellite-derived 30 m digital elevation model (DEM). Results indicate that dNBR images calculated from data acquired about one year apart were able to identify large fires on Mount Kenya that match locations (and timing) of MODIS active fire points and burned areas from the same time period, but we were unable to detect smaller and/or older fires.

STUDY OF THE LANDSLIDE MORPHOLOGY BASED ON GNSS DATA AND AIRBORNE SOUNDING (ON THE EXAMPLE OF A SECTION OF THE PROTVA RIVER VALLEY)

2018 ◽  
Vol 12 (5-6) ◽  
pp. 50-57 ◽  
Author(s):  
I. S. Voskresensky ◽  
A. A. Suchilin ◽  
L. A. Ushakova ◽  
V. M. Shaforostov ◽  
A. L. Entin ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Geodetic Network ◽  
Aerial Survey ◽  
River Valley ◽  
Ease Of Use ◽  
Digital Elevation ◽  
Loose Deposits ◽  
Positioning Method ◽  
Landslide Body ◽  
Elevation Model

To use unmanned aerial vehicles (UAVs) for obtaining digital elevation models (DEM) and digital terrain models (DTM) is currently actively practiced in scientific and practical purposes. This technology has many advantages: efficiency, ease of use, and the possibility of application on relatively small area. This allows us to perform qualitative and quantitative studies of the progress of dangerous relief-forming processes and to assess their consequences quickly. In this paper, we describe the process of obtaining a digital elevation model (DEM) of the relief of the slope located on the bank of the Protva River (Satino training site of the Faculty of Geography, Lomonosov Moscow State University). To obtain the digital elevation model, we created a temporary geodetic network. The coordinates of the points were measured by the satellite positioning method using a highprecision mobile complex. The aerial survey was carried out using an unmanned aerial vehicle from a low altitude (about 40–45 m). The processing of survey materials was performed via automatic photogrammetry (Structure-from-Motion method), and the digital elevation model of the landslide surface on the Protva River valley section was created. Remote sensing was supplemented by studying archival materials of aerial photography, as well as field survey conducted immediately after the landslide. The total amount of research results made it possible to establish the causes and character of the landslide process on the study site. According to the geomorphological conditions of formation, the landslide refers to a variety of landslideslides, which are formed when water is saturated with loose deposits. The landslide body was formed with the "collapse" of the blocks of turf and deluvial loams and their "destruction" as they shifted and accumulated at the foot of the slope.

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