scholarly journals Method of restorating water level of small rivers

2021 ◽  
Vol 273 ◽  
pp. 05007
Author(s):  
Evgeny Kuznetsov ◽  
Anna Khadzhidi ◽  
Larisa Motornaya ◽  
Kharlampiy Kilidi ◽  
Maxim Filimonov ◽  
...  

The article presents method for restoring the water level of small rivers that are subjected to degradation on the example of section of the Meklet River. To assess the degradation of rivers, there is proposed method based on maintaining balance between bottom sediments removed from the riverbed and the water volume in the prism of coastal landscape flooding during high water. The methodology for calculating the amount of silt shifting can be used to monitor the state of river beds. When forming coastline on inconvenient coastal landscapes as enclosing structures, the method allows the use of flexible tanker shells filled with excavated bottom sediments.

2007 ◽  
Vol 158 (1-2) ◽  
pp. 14-21
Author(s):  
Vasyl Sabadosh ◽  
Oleg Suprunenko

The upper Theresian Valley lies along the southwest-facing ridge of the Ukrainian Carpathians. Despite expansive forestation high water levels are frequent. The forest belongs to the state and is centrally administrated. Felling is sometimes outsourced to private companies and private companies have also been founded to process the timber. Job opportunities have become fewer and illegal work is increasing. A new democratic awareness has emerged since the «Orange Revolution» in 2004. With foreign investors, however, new risks emerge. The authors recommend giving monies from forest management to the communities, the founding of new wood processing enterprises and more transparent information.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1269
Author(s):  
George Alexandrakis ◽  
Stelios Petrakis ◽  
Nikolaos A. Kampanis

Understanding the processes that govern the transformation of the landscape through time is essential for exploring the evolution of a coastal area. Coastal landscapes are dynamic sites, with their evolution strongly linked with waves and sea level variations. Geomorphological features in the coastal area, such as beachrock formations and dune fields, can function as indicators of the coastal landscape evolution through time. However, our knowledge of the chronological framework of coastal deposits in the Aegean coasts is limited. Optically Stimulated Luminescence dating techniques are deemed to be very promising in direct dating of the coastal sediments, especially when they are linked with archaeological evidence. The dating of the sediments from different sediment core depths, determined by the method of luminosity, allowed us to calculate the rate of sediment deposition over time. More recent coastal evolution and stability were examined from 1945 to 2020 with the use of aerial photographs and satellite images. This paper presents the 6000 ka evolution of a coastal landscape based on geomorphological, archaeological, and radio-chronological data. Based on the results, the early stages of the Ammoudara beach dune field appears to have been formed ~9.0–9.6 ka BP, while the OSL ages from 6 m depth represented the timing of its stabilization (OSL ages ~5–6 ka). This indicates that the dune field appears to already have been formed long before the Bronze Age (5–10 ka BP). It became stabilized with only localized episodes of dune reactivation occurring. In contrast, while high coastal erosion rates were calculated for modern times.


The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.


2021 ◽  
Author(s):  
Musab Mbideen ◽  
Balázs Székely

<p>Remote Sensing (RS) and Geographic Information System (GIS) instruments have spread rapidly in recent years to manage natural resources and monitor environmental changes. Remote sensing has a vast range of applications; one of them is lakes monitoring. The Dead Sea (DS) is subjected to very strong evaporation processes, leading to a remarkable shrinkage of its water level. The DS is being dried out due to a negative balance in its hydrological cycle during the last five decades. This research aims to study the spatial changes in the DS throughout the previous 48 years. Change detection technique has been performed to detect this change over the research period (1972-2020). 73 Landsat imageries have been used from four digital sensors; Landsat 1-5 MSS C1 Level-1, Landsat 4-5 TM C1 Level-1, Land sat 7 ETM+ C1  Level-1, and Landsat 8 OLI-TIRS C1 Level. After following certain selection criteria , the number of studied images decreased. Furthermore, the Digital Surface Model of the Space Shuttle Radar Topography Mission and a bathymetric map of the Dead Sea were used. The collected satellite imageries were pre-processed and normalized using ENVI 5.3 software by converting the Digital Number (DN) to spectral radiance, the spectral radiance was converted to apparent reflectance, atmospheric effects were removed, and finally, the black gaps were removed. It was important to distinguish between the DS lake and the surrounding area in order to have accurate results, this was done by performing classification techniques. The digital terrain model of the DS was used in ArcGIS (3D) to reconstruct the elevation of the shore lines. This model generated equations to detect the water level, surface area, and water volume of the DS. The results were compared to the bathymetric data as well. The research shows that the DS water level declined 65 m (1.35 m/a) in the studied period. The surface area and the water volume declined by 363.56 km<sup>2 </sup>(7.57 km<sup>2</sup>/a) and 53.56 km<sup>3</sup> (1.11 km<sup>3</sup>/a), respectively. The research also concluded that due to the bathymetry of the DS, the direction of this shrinkage is from the south to the north. We hypothesize that anthropogenic effects have contributed in the shrinkage of the DS more than the climate. The use of the DS water by both Israel and Jordan for industrial purposes is the main factor impacting the DS, another factor is the diversion of the Jordan and Yarmouk rivers. Our results also allow to give a prediction for the near future of the DS: the water level is expected to reach –445 m in 2050, while the surface area and the water volume is expected to be 455 km<sup>2</sup> and 142 km<sup>3</sup>, respectively. </p>


2011 ◽  
Vol 4 (1) ◽  
pp. 71-97 ◽  
Author(s):  
A. K. Rennermalm ◽  
L. C. Smith ◽  
V. W. Chu ◽  
R. R. Forster ◽  
J. E. Box ◽  
...  

Abstract. Pressing scientific questions concerning the Greenland ice sheet's climatic sensitivity, hydrology, and contributions to current and future sea level rise require hydrological datasets to resolve. While direct observations of ice sheet meltwater losses can be obtained in terrestrial rivers draining the ice sheet and from lake levels, few such datasets exist. We present a new dataset of meltwater river discharge for the vicinity of Kangerlussuaq, Southwest Greenland. The dataset contains measurements of river water level and discharge for three sites along the Akuliarusiarsuup Kuua (Watson) River's northern tributary, with 30 min temporal resolution between June 2008 and August 2010. Additional data of water temperature, air pressure, and lake water level and temperature are also provided. Discharge data were measured at sites with near-ideal properties for such data collection. Regardless, high water bedload and turbulent flow introduce considerable uncertainty. These were constrained and quantified using statistical techniques, which revealed that the greatest discharge data uncertainties are associated with streambed elevation change and measurements. Large portions of stream channels deepened according to statistical tests, but poor precision of streambed depth measurements also added uncertainty. Data will periodically be extended, and are available in Open Access at doi:10.1594/PANGAEA.762818.


2019 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Yuono Mugi Kuncoro ◽  
Djoko Trijanto ◽  
Medi Efendi

In dry season Tarokan Sub-district of Kediri, often suffers from drought, so a small dam (embung) was required. The objectives of the study are to determine the dimension of the dam, its spillway and to analyze its stability. The required data were of rainfall, topographic maps, soil, and population.The initial design was hydrologic analysis by finding out the planned discharge Q50 and determining the water volume of inflow. To determine the effective catchment ponds, capacity analysis using topographical data and comparing the volume of water available. And analysis of spillway to determine the flood water level.The analyses result, the amount of the water needs of a population of 258.854.400m3, and the magnitude of the draft Q50 discharge of in 4.027 m3/sec (The  room  for  sediment  is  29,234.9 m3  at  elevation  1 m from the bottom of the pool); 390,000m3 effective capacity at +131.75 elevation, and flood water level at +132.75 elevation. The dimension of embung main dam is 6 m deep; embung crest at +133.00 elevation ; 3m wide embung crest ; 1:3 upstream slope; 1 : 2.25 downstream slope ; 10 m wide spillway channel 1 : 1 slope of wall of spillway channel ; and crest of spillway at +131.75. Geostudio software was used to calculate the figures safety against sliding. Keywords: embung, spillway, embung dimensions, slope stabilty


1978 ◽  
Vol 1 (16) ◽  
pp. 148
Author(s):  
G.R. Mogridge ◽  
W.W. Jamieson

Cooling water from a power generating station in Eastern Canada is pumped to an outfall and distributed into the ocean through discharge ports in the sidewalls of a diffuser cap. The cap is essentially a shell-type structure consisting of a submerged circular cylinder 26.5 ft in diameter and 14 ft high. It is located in 25 ft of water at low water level and 54 ft at high water level. Horizontal forces, vertical forces and overturning moments exerted by waves on a 1:36 scale model of the diffuser cap were measured with and without cooling water discharging from the outfall. Tests were run with regular and irregular waves producing both non-breaking and breaking wave loads on the diffuser cap. The overturning moments measured on the diffuser cap were up to 150 percent greater than those on a solid submerged cylinder sealed to the seabed. Unlike sealed cylinders, all of the wave loads measured on the relatively open structure reached maximum values at approximately the same time. The largest wave loads were measured on the diffuser structure when it was subjected to spilling breakers at low water level. For a given wave height, the spilling breakers caused wave loads up to 100 percent greater than those due to non-breaking waves.


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