The Development of Closure Dike as Countermeasure of Sedimentation in the Wonogiri Reservoir, Indonesia

Abstract The problem of reservoir sedimentation occurs worldwide, including in the Wonogiri reservoir, Indonesia. The reservoir was built from 1977 to 1980, but the dam faces a severe problem of sedimentation. Sediment inflow in the Wonogiri Reservoir comes from several sources, especially from Keduang River, a tributary from Mount Lawu. The sediment management problems are generally complicated and different in every place. In some conditions, it will be possible to prevent sediment from entering the reservoir by adding an internal barrier as applied in the Wonogiri Reservoir. The reservoir is divided into two reservoirs by a closure dike equipped with an overflow dike and a new spillway. This paper will describe the development of closure dike based on field observation and data obtained from the Ministry of Public Works and Housing. Moreover, this paper will also describe the sedimentation status of the Wonogiri reservoir based on the recent bathymetric data. The development of closure dike already completed, which consists of Closure Dike A (700 m), B (700 m), C (302 m), and Overflow Dike (298 m). The recent bathymetric survey revealed that the capacity of effective storage of the main reservoir is 322.84 MCM.

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3D hydro-morphodynamic models as support tools for obtaining sustainable sediment management strategies of reservoirs

10.5194/egusphere-egu2020-10548 ◽

2020 ◽

Author(s):

Kilian Mouris ◽

Leon Saam ◽

Felix Beckers ◽

Silke Wieprecht ◽

Stefan Haun

Keyword(s):

Sediment Transport ◽

Water Level ◽

Management Strategies ◽

Sediment Management ◽

Transport Processes ◽

Water Levels ◽

Hydraulic Structures ◽

Suspended Sediment Transport ◽

Reservoir Sedimentation ◽

Bottom Outlets

Reservoir sedimentation reduces not only the available storage volume of reservoirs, but may also create other serious problems, such as an increase of bed levels or accumulations of nutrients and contaminants, which affect the environment. An increase in bed levels at the head of the reservoir can reduce flood safety and increase the risk for the surrounding areas. Deposited sediments close to the dam may block hydraulic structures, such as the bottom outlets, or, in case they enter the intake, lead to possible abrasion of plant components (e.g. wear of turbines and pipes).Prior to reservoir construction, a pre-evaluation of the sediment yield from the catchment is usually performed by using soil erosion and sediment delivery models. However, the trapping efficiency is often only obtained by empirical approaches, such as Brune&#8217;s or Churchill&#8217;s curve, which are based on the capacity of the reservoir and the mean annual inflow. This is still common practice, although 3D hydro-morphodynamic models became powerful tools to numerically study sediment transport and reservoir sedimentation prior to the construction of reservoirs as well as during its operation.Within this study, a fully 3D hydro-morphodynamic numerical model, based on the Reynolds-averaged Navier-Stokes equations, is applied to a case study to simulate, on the one hand suspended sediment transport within a hydropower reservoir and on the other hand a reservoir flushing operation as potential management scenario, with the goal to remobilize already deposited sediments and to release these sediments from the reservoir. The modeled reservoir has a total storage capacity of around 14 million m&#179;, whereby the water level can fluctuate due to pumped-storage operation by 40.5&#160;m (difference between the maximum operation level and the operational outlet). At the head is the natural inflow of two creeks into the reservoir and a lateral transition tunnel is located on the orographic right side, which collects several headwater streams from adjacent catchments.Simulations are performed for different operation modes of the reservoir. The results clearly show that through active reservoir management (variation of water levels as well as using the momentum of the discharge from the transition tunnel) the sediment motion in the reservoir can be affected to a certain extent. It is for instance possible to almost completely avoid reservoir sedimentation in front of the dam and the hydraulic structures (water intake and bottom outlets) during sediment-laden flows when simultaneously high discharges are provided from the laterally located transition tunnel. The conducted simulation results of reservoir flushing also show that the success of the flushing operation is strongly dependent on the water level. As expected, flushing with full drawdown of the water level is the most efficient method to release sediments.Through the detailed results of the 3D hydro-morphodynamic model, it is feasible to receive a deeper knowledge of the ongoing sediment transport processes within the studied reservoir. The gained knowledge can further be used to derive sustainable and efficient management strategies for the sediment management of the reservoir.

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ICESat-2 Marine Bathymetry: Extraction, Refraction Adjustment and Vertical Accuracy as a Function of Depth in Mid-Latitude Temperate Contexts

Remote Sensing ◽

10.3390/rs13214352 ◽

2021 ◽

Vol 13 (21) ◽

pp. 4352

Author(s):

Seamus Coveney ◽

Xavier Monteys ◽

John D. Hedley ◽

Yeray Castillo-Campo ◽

Brian Kelleher

Keyword(s):

Satellite System ◽

Coastal Monitoring ◽

Temperate Latitude ◽

Bathymetric Survey ◽

Bathymetric Data ◽

Monitoring Applications ◽

Vertical Accuracy ◽

Global Navigation Satellite ◽

Maximum Photon ◽

Manual Extraction

Nearshore bathymetric data are used in many coastal monitoring applications, but acquisition conditions can be challenging. Shipborne surveys are prone to the risk of grounding in shallow waters, and scheduled airborne surveys often fail to coincide with optimal atmospheric and water conditions. As an alternative, since its launch in 2018, ICESat-2 satellite laser profile altimetry data provide free and readily available data on a 91-day repeat cycle, which may contain incidental bathymetric returns when suitable environmental conditions prevail. In this paper, the vertical accuracy of extracted, refraction-adjusted ICESat-2 nearshore marine bathymetric data is evaluated at four test sites in a Northern hemisphere, temperate latitude location. Multiple ICEsat-2 bathymetric values that occurred in close horizontal proximity to one another were averaged at a spatial scale of 1 m and compared with Multibeam Echosounder bathymetric survey data and Global Navigation Satellite System reference data. Mean absolute errors of less than 0.15 m were observed up to depths of 5 m, with errors of less than 0.24 m (to 6 m), 0.39 m (to 7 m) and 0.52 m (to 10 m). The occurrence of larger bathymetric errors with depth, which increase to 0.54 m at maximum photon depths of 11 m, appears to be primarily related to reduced numbers of geolocated photons with depth. The accuracies achieved up to 6 m suggest that the manual extraction, refraction adjustment and bathymetric filtering steps were effective. Overall, the results suggest that ICESat-2 bathymetric data accuracy may be sufficient to be considered for use in nearshore coastal monitoring applications where shipborne and airborne bathymetric data might otherwise be applied.

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A Field Comparison of Methods and Data Results Between a Manual And Robotic Remote Sensed Survey of a Storm Water Management Pond in Kitchener, Ontario

GEOMATICA ◽

10.5623/cig2014-408 ◽

2014 ◽

Vol 68 (4) ◽

pp. 345-354

Author(s):

Andrew Blakey ◽

Eugenia Acosta ◽

Ryan Gariepy

Keyword(s):

Data Collection ◽

Human Error ◽

Survey Methods ◽

Sediment Surface ◽

Measurement Unit ◽

Bathymetric Survey ◽

Single Beam ◽

Bathymetric Data ◽

Unmanned Surface Vessel ◽

Accuracy Data

Conventional shallow water bathymetric survey methods are time consuming, expensive, susceptible to human error, and often hazardous. An innovative end-to-end solution that improves water surveying by reduc ing these risks through the use of an unmanned bathymetric data collection system has been designed and built. This system combines a collection of pre- and post-processing routines with the capabilities of a purposebuilt unmanned surface vessel to measure and build accurate bathymetric datasets that are easy to integrate into any CAD or GIS database. Data collection involves the fusion of high-accuracy data from a single beam echosounder, GPS, and iner tial measurement unit (IMU) to generate sediment surface points at centimetre-level accuracy. Through use of an unmanned vessel, these surveys are repeatable without requiring any persons to be on or in the waterbody. This paper presents the results of a focused validation study conducted to illustrate that this platform gen er ates comparable data to a manual survey while greatly reducing survey time and improving safety. Results show a volumetric difference of 2.8% between the Kingfisher USV and manual survey data. Surveying duration was shorter at 42 minutes compared to 140 minutes. This survey was also reliably completed despite challenging environmental conditions.

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Current State of Deep Ocean Bathymetric Exploration

Annual of Navigation ◽

10.1515/aon-2017-0019 ◽

2017 ◽

Vol 24 (1) ◽

pp. 257-267 ◽

Cited By ~ 2

Author(s):

Karolina Zwolak ◽

Andrzej Felski

Keyword(s):

New Technology ◽

Deep Ocean ◽

Bathymetric Survey ◽

Bathymetric Data ◽

Current State ◽

Starting Point

AbstractThe paper presents current state of bathymetric survey concerning deep ocean rather than shallow areas, which are better surveyed due to safety of navigation concerns. Rules and requirements of the new challenge, called the Shell Ocean Discovery XPRIZE, became a starting point for a discussion about the possibilities of mapping large areas of the ocean using up-to-date and new technology. The amount of bathymetric data available nowadays and the current state of ocean map compilations are also discussed in the paper as a motivation to inspire the new initiatives in the deep ocean.

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Evaluation of spatial resolution and estimation error of seafloor displacement observation from vessel-based bathymetric survey by use of AUV-based bathymetric data

Marine Geophysical Research ◽

10.1007/s11001-014-9242-8 ◽

2014 ◽

Vol 36 (1) ◽

pp. 45-60 ◽

Cited By ~ 5

Author(s):

Toshiya Fujiwara ◽

Yuka Masaki ◽

Fujio Yamamoto

Keyword(s):

Spatial Resolution ◽

Estimation Error ◽

Bathymetric Survey ◽

Bathymetric Data

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Bathymetric and Volumetric Analysis of Jebba (Hydropower) Dam Harnessing its Capability for Multipurpose Use

Nigerian Journal of Environmental Sciences and Technology - March 2018 ◽

10.36263/nijest.2017.01.0028 ◽

2017 ◽

Vol 1 (1) ◽

pp. 111-122

Author(s):

S. O. Olushola ◽

R. Ehigiator–Irughe R.

Keyword(s):

Power Plants ◽

Volumetric Analysis ◽

Base Station ◽

Dual Frequency ◽

Bathymetric Survey ◽

Bathymetric Data ◽

Actual Volume ◽

Data Collections ◽

Water Uses ◽

Hydropower Reservoirs

The need to carry out routine bathymetric survey on dam in order to analyse the quantity of water in the dam’s reservoir cannot be underrated. “multipurpose water uses of hydropower reservoirs” has been the world water council advocacy. Multipurpose water use include categories, such as domestic purposes, cooling of power plants, irrigation, mining, recreation, navigation, fisheries, etc., This research uses topographic and bathymetric data obtained from field operations to compute the volume of water present in the dam. Midas Surveyor dual frequency GPS echo sounder, Trimble 5700 Dual Frequency GPS ‘Base Station’ receiver and Trimble 5800 Dual Frequency GPS ‘Rover’ receiver, were employed for data collections. Data processing and presentation were done with Surfer 10 software. The volume computed from data analysis gives 3880 x 106 MCM. The volume of water needed to run the six turbines per day added up to 1,735200 litres and that of per capita use was 0.006 litre per day for minimum and 0.025 litres per day for maximum. The volume left after removing other withdrawer was 62% of the actual volume computed for the dam.

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Seafloor Geodesy From Repeated Multibeam Bathymetric Surveys: Application to Seafloor Displacement Caused by the 2011 Tohoku-Oki Earthquake

Frontiers in Earth Science ◽

10.3389/feart.2021.667666 ◽

2021 ◽

Vol 9 ◽

Author(s):

Toshiya Fujiwara

Keyword(s):

Horizontal Displacement ◽

Relative Difference ◽

Japan Trench ◽

Bathymetric Survey ◽

Seafloor Geodesy ◽

Bathymetric Data ◽

Rupture Area ◽

Trench Axis ◽

The Difference ◽

Northern Japan

Repeated multibeam bathymetric surveys played an important role for understanding the distribution of coseismic seafloor displacement caused by the March 11, 2011 Mw 9.0 Tohoku-oki earthquake. After the earthquake, we collected bathymetric data along the same tracks obtained before the earthquake. The selected tracks were crossing the trench and extending from the landward to seaward trench slopes. We examined the seafloor displacement on the landward relative to the seaward by means of the difference in bathymetry before and after the earthquake. The multibeam bathymetric survey has the advantage of areal coverage. The repeated surveys clarified the areal distribution of the coseismic seafloor displacement. In the main rupture area, very large seafloor displacement was observed. Sharp bathymetric change at the trench axis provided solid evidence that the fault slip on the shallowest part of the megathrust reached the trench axis and peaked at the trench axis. The very large displacement is limited to the particular area. Smaller seafloor displacements were observed in the area tens of kilometers away from the main rupture area. We present methods and results of the repeated multibeam bathymetric surveys and an application to the seafloor displacement caused by the 2011 Tohoku-oki earthquake in the northern Japan Trench. Less than several meters in seafloor vertical displacements and less than 20 m in seafloor horizontal displacement were estimated in the northern Japan Trench. The estimated smaller displacements are comparable in magnitude to error of the seafloor displacement observation from our bathymetric survey. Nevertheless, three adjacent survey tracks showed coherent relative differences in seafloor elevation, which suggests the relative difference enables us to discuss the along-track variation in seafloor displacement in the area. However, our survey was affected by uncertainties of roll and pitch biases and sound velocity errors. Well-prepared repeated multibeam bathymetric survey for the purpose of seafloor geodesy could lead to a higher resolution and more accurate result. Repeated acquisition of high resolution and accuracy bathymetric data using state-of-the-art technology will be important to quantitative discussion of the seafloor displacements caused by even smaller magnitude earthquakes and tsunamis.

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OWA operators with different Orness levels for sediment management alternative selection problem

Water Science & Technology Water Supply ◽

10.2166/ws.2019.149 ◽

2019 ◽

Vol 20 (1) ◽

pp. 173-185 ◽

Cited By ~ 1

Author(s):

Hamid Khakzad

Keyword(s):

Sediment Management ◽

Decision Makers ◽

Weighted Averaging ◽

Reservoir Sedimentation ◽

Owa Operators ◽

Multiple Decision Makers ◽

Dam Reservoirs ◽

Management Alternative ◽

The Cost ◽

Hydropower Reservoir

Abstract The importance of reservoir sedimentation management as a multi criteria problem in practice with multiple decision makers is evident when one considers that the cost of replacing storage lost annually due to sediment deposition throughout the world is in the order of US$13 billion. If sedimentation can be managed successfully, as it has been in some reservoirs, the loss in reservoir storage space due to this phenomenon can be lowered significantly. The purpose of this research is to develop the ordered weighted averaging (OWA) algorithm and apply it and to select the most preferred alternative with different Orness levels for sediment management in dam reservoirs to satisfy the technical and executive requirements, economic factors, social welfare, and environmental impacts. In this way, we present analytic forms of OWA operator weighting functions, each of which has properties of rank-based weights and a constant level of Orness, irrespective of the number of objectives considered. The model are successfully applied to the Dez hydropower reservoir, which has faced serious sedimentation problems. Results of this study provide a general class of parameterized aggregation operators that include the min, max, and average and have shown themselves to be useful for modeling many different kinds of aggregation problems.

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Unbiased estimation of particle number and sizes using the new stereological tools: the disector, the fractionator, the selector, and the nucleator — or just point-sampled intercepts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104200 ◽

1988 ◽

Vol 46 ◽

pp. 428-429

Author(s):

H.J.G. Gundersen

Keyword(s):

Particle Number ◽

Small Distance ◽

Parallel Plane ◽

Unbiased Estimation ◽

Severe Problem ◽

New Era ◽

Size And Shape ◽

Distinct Property ◽

Sectioned Tissue

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.

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