Fourier-domain modeling of gravity effects caused by a vertical polyhedral prism, with application to a water reservoir storage process

We have developed a new Fourier-domain algorithm for the modeling of gravity effects caused by a vertical polyhedral prism. Simplified and more compact Fourier-domain expressions are derived for the vertical gravity anomaly on a 2D plane either above, in the middle of, or below the vertical polyhedral prism. A new Fourier-domain algorithm, which combines a low-order Gauss fast Fourier transform (FFT) algorithm and a low-order nonuniform FFT algorithm, to permit polar sampling near the zero wave vector, is introduced. To validate the numerical efficiency of the new algorithm, we carry out a series of synthetic tests. Numerical results show that the new algorithm is superior in numerical accuracy and efficiency compared to a pure Gauss-FFT algorithm, and both Fourier methods run much faster than traditional space-domain analytical solutions. We then apply the Fourier forward algorithms to the prediction of vertical component of gravity at many survey points, as a function of the water level of a reservoir located in Xianlin, Hangzhou, China. The reservoir geometry is approximated by a single vertical polyhedral prism. Water storage corresponds to increased heights of the polyhedral prism. Detailed maps of vertical gravity value changes corresponding to a water level rise of 5 and 10 m, with spatial resolution [Formula: see text], on the local topography covering a study area of approximately [Formula: see text] around the water reservoir, are calculated using the new algorithm. Then, the gravity values are classified according to the accuracy of the gravimeter, providing a reference of optimal site selection for a proposed cold-atom gravimetry survey to be carried out in the near future.

Download Full-text

Fourier-domain modeling of gravity effects caused by polyhedral bodies

Journal of Geodesy ◽

10.1007/s00190-018-1187-2 ◽

2018 ◽

Vol 93 (5) ◽

pp. 635-653 ◽

Cited By ~ 7

Author(s):

Leyuan Wu

Keyword(s):

Fourier Domain ◽

Domain Modeling ◽

Gravity Effects ◽

Polyhedral Bodies

Download Full-text

Eolation dynamics in the shore of artificially impounded bodies (by the example of Bratsk water reservoir, Russia)

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16984 ◽

2018 ◽

Vol 40 (3) ◽

pp. 1449

Author(s):

V. Khak ◽

E. Kozyreva ◽

Yu. B. Trzhcinsky

Keyword(s):

Water Level ◽

Sedimentation Rate ◽

Water Reservoir ◽

Landscape Changes ◽

Dune Sand ◽

Cyclical Pattern ◽

Near Shore ◽

Topography Model

The process of eolation in the near-shore area of the Bratsk water reservoir results in the landscape changes and may lead to abrasion process activation. The eolation dynamics factors are water level and wind conditions. The eolation shows a cyclical pattern that is primarily related to the duration of low stand of level. The eolation processes that differ in sedimentation rate, water level and morphology of eolian relief forms ranging from mere sand blowing to travelling dunes have been phased in studies of the sections of dune sand deposits. The topography model of index plot Rassvet that makes it possible to scale the process of eolation and to know some regular trends and mechanisms of its development has been constructed as result of eolation dynamics research.

Download Full-text

Ground-vehicle INS/GPS vector gravimetry

Geophysics ◽

10.1190/1.2821155 ◽

2008 ◽

Vol 73 (2) ◽

pp. I1-I10 ◽

Cited By ~ 14

Author(s):

Xiaopeng Li ◽

Christopher Jekeli

Keyword(s):

Large Scale ◽

Mineral Exploration ◽

Vertical Component ◽

Mean Value ◽

Estimation Methods ◽

Gps Data ◽

Land Vehicle ◽

Southwestern Montana ◽

Vector Gravimetry ◽

Vertical Gravity

For geophysical purposes, gravity is measured in many ways, from static-point observations, using a gravimeter, to mean-value determinations from gravimeter and gravity gradiometer data collected by airplanes, ships, and satellites. We tested estimates of vertical and horizontal components of the gravity vector by combining Global Positioning System (GPS) data with a Honeywell H764G inertial navigation system (INS) on a land vehicle traversing highways in southwestern Montana. The estimation methods were based on techniques applied successfully to airborne INS/GPS data. In addition, we used wavelet denoising and wavenumber correlation procedures to enhance the estimates. Analyses of multiple traverses along the roads verified levels of repeatability as good as [Formula: see text] (all numerical accuracy values refer to standard deviations) in the vertical gravity-disturbance component. Control data, interpolated onto each road segment from an available database of gravity values, had an accuracy better than [Formula: see text]. Compared with this interpolated control, our vertical gravity estimates compare as well as [Formula: see text]. Resolution of the estimated vertical component is about [Formula: see text], based on [Formula: see text] data smoothing and a vehicle averaging about [Formula: see text]. Large scale-factor errors exist in the horizontal gravity estimates. Removing those on the basis of extensive deflection-of-the-vertical (DOV) control yields repeatability in the horizontal components of [Formula: see text] and agreement with the control at [Formula: see text]. Our tests confirm that a land-vehicle INS/GPS system is capable of along-track gravity mapping with precision and resolution that have used in local geophysical modeling (e.g., continental rifts) as well as in mineral exploration.

Download Full-text

Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir

Water ◽

10.3390/w10030256 ◽

2018 ◽

Vol 10 (3) ◽

pp. 256 ◽

Cited By ~ 4

Author(s):

Yangdong Pan ◽

Shijun Guo ◽

Yuying Li ◽

Wei Yin ◽

Pengcheng Qi ◽

...

Keyword(s):

Drinking Water ◽

Water Level ◽

Water Reservoir ◽

Phytoplankton Assemblages ◽

Drinking Water Reservoir ◽

Level Increase

Download Full-text

Penerapan Water Level Control Tipe Radar dan Omron 61F-G-AP Untuk Proses Pengisian Air Bersih di Komplek Perintis Kota Banjarbaru

JURNAL APLIKASI DAN INOVASI IPTEKS SOLIDITAS (J-SOLID) ◽

10.31328/js.v3i2.1591 ◽

2020 ◽

Vol 3 (2) ◽

pp. 62

Author(s):

Lauhil Mahfudz Hayusman ◽

Muhammad Ali Watoni ◽

Edy Robinson ◽

Rully Rezki Saputra

Keyword(s):

Electric Power ◽

Water Level ◽

Social Service ◽

Water Reservoir ◽

Level Control ◽

Service Activity ◽

Filling Water ◽

Automation Equipment ◽

Water Pumps ◽

Automation Tools

Social service activities have been conducted in the Complex of Perintis of Sungai Ulin sub-district, North Banjarbaru District, Banjarbaru. The purpose of this activity is to install automation tools in the form of water level control (WLC) Radar ST 70 AB type for several reservoirs owned by residents and WLC (Omron 61F-G-AP type) in the Musalla of Perintis complex. It was done based on the team's observations in the field that there were still many reservoirs owned by residents that were not equipped with the automation equipment. In addition, many residents complained about the ineffective and inefficient process of pumping or filling water into the reservoir due to controlling and monitoring manually. As a result, many water pumps owned by the residents remain running or left running even though the water in the reservoir is fully filled. This is very detrimental to the residents, it is not only dissipation of water, but also dissipation of electric power which results in electricity bills that have to be paid every month by residents. The target of this service activity is to install the WLC equipment in several reservoirs owned by residents and reservoirs owned by Musalla in the Complex of Perintis. In addition, residents have additional skills to install WLC so that the residents can do it independently in the future Keywords: Water level control, WLC, Automation, Water reservoir

Download Full-text

Structural interpretation of lineaments using satellite image processing: A case study in the vicinity of the Charvak reservoir

Proceedings of the International conference “InterCarto/InterGIS” ◽

10.35595/2414-9179-2020-2-26-436-442 ◽

2020 ◽

Vol 26 (2) ◽

pp. 436-442

Author(s):

Lola Sichugova ◽

Dilbarkhon Fazilova

Keyword(s):

Water Level ◽

Satellite Images ◽

Satellite Image ◽

Water Reservoir ◽

Water Level Fluctuations ◽

Landsat 8 ◽

Base Line ◽

The North ◽

Automated Method ◽

Density Maps

This work presents the results of lineaments interpretation using the automated method of the satellite images in the territory of the Charvak water reservoir in Uzbekistan. Tectonic and local (water impoundment in Charvak reservoir) features of the region deformation were determined on base LINE algorithm in software PCI Geomatica. The thematic map with the geospatial arrangement of lineaments was constructed on base of satellite images LANDSAT-8 processing. We concluded that water level fluctuations have a greater influence on the appearance of the lineaments structure than periods of water filling and downstream in the reservoir. Lineament density maps showed dominantly increased density towards the north-southern direction is due to tectonic features of the region and the west-eastern direction is due to water level fluctuations in the reservoir. The lineaments density maps for summer-autumn periods showed the faults arising from water level fluctuations only. Winter-spring period affected with high influence of the seasonal (snow pack, rainfall) processes as well.

Download Full-text

Characterization of SWOT Water Level Errors on Seine Reservoirs and La Bassée Gravel Pits: Impacts on Water Surface Energy Budget Modeling

Remote Sensing ◽

10.3390/rs12182911 ◽

2020 ◽

Vol 12 (18) ◽

pp. 2911

Author(s):

Catherine Ottlé ◽

Anthony Bernus ◽

Thomas Verbeke ◽

Karine Pétrus ◽

Zun Yin ◽

...

Keyword(s):

Water Level ◽

Measurement Errors ◽

Water Reservoir ◽

Global Scale ◽

Water Levels ◽

Surface Energy Budget ◽

Water Bodies ◽

Energy Budgets ◽

Gravel Pits ◽

Better Than

The Surface Water and Ocean Topography (SWOT) space mission will map surface area and water level changes in lakes at the global scale. Such new data are of great interest to better understand and model lake dynamics as well as to improve water management. In this study, we used the large-scale SWOT simulator developed at the French Space National Center (CNES) to estimate the expected measurement errors of the water level of different water bodies in France. These water bodies include five large reservoirs of the Seine River and numerous small gravel pits located in the Seine alluvial plain of La Bassée upstream of the city of Paris. The results show that the SWOT mission will allow to observe water levels with a precision of a few tens of centimeters (10 cm for the largest water reservoir (Orient), 23 km2), even for the small gravel pits of size of a few hectares (standard deviation error lower than 0.25 m for water bodies larger than 6 ha). The benefit of the temporal sampling for water level monitoring is also highlighted on time series of pseudo-observations based on real measurements perturbed with the simulated noise errors. Then, the added value of these future data for the simulation of lake energy budgets is shown using the FLake lake model through sensitivity experiments. Results show that the SWOT data will help to model the surface temperature of the studied water bodies with a precision better than 0.5 K and the evaporation with an accuracy better than 0.2 mm/day. These large improvements compared to the errors obtained when a constant water level is prescribed (1.2 K and 0.6 mm/day) demonstrate the potential of SWOT for monitoring the lake energy budgets at global scale in addition to the other foreseen applications in operational reservoir management.

Download Full-text

Static analysis of a high arch dam

Acta hydrotechnica ◽

10.15292/acta.hydro.2019.04 ◽

2019 ◽

pp. 45-57

Author(s):

Yaser Ghafoori ◽

Andrej Kryžanowski ◽

Dejan Zupan

Keyword(s):

Water Level ◽

Static Analysis ◽

Three Dimensional ◽

Water Reservoir ◽

Arch Dam ◽

Three Dimensional Model ◽

High Arch Dam ◽

Reservoir Water ◽

Reservoir Water Level ◽

Arch Dams

The paper presents the design and static analysis of a high arch dam. A feasibility study was conducted on the dam in the 90s and a preliminary layout was designed. However, the dam’s construction phase has been never started. In this paper, the design and layout of the dam under consideration are in accordance with the US manuals for the design of arch dams. The structure’s three-dimensional model was entered into the program SAP2000 and three-dimensional solid finite elements were used to discretize the model. This paper considers the hydrostatic pressure of the water reservoir and concrete self-weight. The analysis was performed for both the maximum and the minimum designed water level and for the case when the reservoir is empty. Special attention is given to the boundary conditions of the dam at its abutments and foundation. The results show that the planned layout is good for the dam’s construction. The arch dam’s curve transfers the loads to the abutments. The significant role of the foundation rigidity and the reservoir water level in the stress distribution and nodal displacements within the arch dam is observed.

Download Full-text

Relationship between water level temporal changes and seismicity in the Mingechevir reservoir (Azerbaijan)

10.5194/egusphere-egu2020-1846 ◽

2020 ◽

Author(s):

Fakhraddin Gadirov (Kadirov) ◽

Luciano Telesca ◽

Gulam Babayev ◽

Gurban Yetirmishli ◽

Rafig Safarov

Keyword(s):

Water Level ◽

Induced Seismicity ◽

Singular Spectrum Analysis ◽

Water Reservoir ◽

Temporal Variations ◽

Average Width ◽

North West ◽

Reservoir Induced Seismicity ◽

The North ◽

Annual Periodicity

Reservoir-induced seismicity has been studied worldwide due to its potential to provoke damage to buildings and constructions, and, more important, human loss. Reservoir-induced seismicity (RIS) is normally related with additional static loading (the weight of the water reservoir and its seasonal variations), tectonic faults, liquefaction and pore pressure variations.The Mingechevir reservoir is located in the north-west of Azerbaijan on the Kurriver. This water reservoir is extended from north-west towards south-east through Kur river valley by 75 km. The area of the dam is 625 km2 with the average width accounting for 6-8 km. The volume of the dam is 16 km3. The dam filling started in 1953. This reservoir is the largest one in the Caucasus and carries a number of geo-hazards interrelated with geodynamics and technogenic factors. The aim of the present study in the Mingechevir reservoir is to investigate relationship between the fluctuations of the water level and the onset of seismicity in the area around the dam more in detail, by using several and independent statistical methods.The temporal variations of the instrumental seismicity (0.5&#8804;ML&#8804;3.5) recorded in the Mingechevir area (Azerbaijan) between January 2010 to April 2018 and its relationship with the level variation of the water reservoir was analysed in this study. Due to the relative high completeness magnitude (MC = 1.6) of the seismic catalogue of the area, only 136 events were selected over a period of more than 8 years. Thus, the monthly number of events was analysed by using the correlogram-based periodogram, the singular spectrum analysis (SSA) and the empirical mode decomposition (EMD), which are robust against the short size of the time series. Our results point out to the following findings: 1) annual periodicity was found in one SSA reconstructed component of the monthly number of events; 2)quasi-annual periodicity was found in one EMD intrinsic mode function of the monthly number of earthquakes. These obtained results could support in a rigorously statistical manner that the seismicity occurring in Minghechevir area could be triggered by the yearly cycle of the water level of the reservoir.&#160;Keywords:water reservoir, induced seismicity, water level change, Mingechevir reservoir, Azerbaijan

Download Full-text

Experiences with relative microgravity surveying

10.5194/egusphere-egu2020-9664 ◽

2020 ◽

Author(s):

Ola Eiken

Keyword(s):

Random Noise ◽

Measurement Techniques ◽

Water Reservoir ◽

Cold Atom ◽

Time Lapse ◽

Geothermal Field ◽

Personnel Cost ◽

Multiple Sensors ◽

Accuracy Measure ◽

Superconducting Gravimeters

Measurement techniquesHigh-precision aerial gravity surveys can be carried out by relative spring meters, with ties to stable reference stations or absolute measurements for time-lapse studies. Instrument drift is controlled by frequent repeat measurement and repeatability of 1-3 &#181;Gal has been common. &#160;Free-fall gravimeters are heavier and costlier but provide absolute values and are immune to drift. Superconducting gravimeters are stationary and provide sub-&#181;Gal resolution over days and weeks, while drift uncertainty can build up to several &#956;Gal over years. Cold atom gravimeters are under development and may provide yet another survey alternative in the future.Multiple sensors and multiple repeats are effective ways of improving survey precision, as much of the noise reduce at random noise (sqrt(N)). This holds also for the sensor drift residuals. An efficient, transparent and reproducible processing software is an integral part of such techniques.Surface stationsStability of measurement platforms over years is required for &#181;Gal time-lapse precision and can be achieved by installing geodetic monuments. For optimal monitoring of targets like a producing oil, gas or geothermal field, a water reservoir or a volcano, a grid of stations with spacing equal to or smaller than the overburden thickness is required. Surface subsidence or uplift requires sub-cm precision which can be obtained by optical leveling, InSAR or GPS.AccuracyStation repeatability is a robust accuracy measure for relative surveys with multiple occupations of each station. Together with multiple sensors they provide abundant statistics. The redundancy also allows for in-situ calibration of parameters for scale factor, tilt and temperature by minimizing residuals. Time-lapse precision can be judged at stations with minimal or known subsurface changes, and will be affected by gravity survey precision, accuracy of measured depth changes and other time-lapse effects such as benchmark stability and time-lapse signals outside interest. Groundwater variations could be one such noise term, unless the purpose is hydrology monitoring.Efficiency and costMost microgravity projects have been carried out in a research or development setting, with one sensor, few stations repeat and implicit capital and personnel cost. In a more industrial setting, efficiency is likely to improve, together with reduced survey cost. More instruments and measurements will likely reduce the personnel and mobilization portion of the cost. Precision/cost tradeoffs and value of data will determine the economics of a project, whether in a scientific or commercial setting.ConclusionCurrently proven survey repeatabilities of 1-2 &#181;Gal may be regarded state-of-the-art and become commonplace for microgravity surveys using relative gravimeters. This can widen the range of applications and reduce monitoring intervals. Further instrument developments may improve this limitation.

Download Full-text