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1
Chen, Lei, Zeng Zhou, Fan Xu, Mirian Jimenez, Jianfeng Tao et Changkuan Zhang. « Simulating the impacts of land reclamation and de-reclamation on the morphodynamics of tidal networks ». Anthropocene Coasts 3, no 1 (1 janvier 2020) : 30–42. http://dx.doi.org/10.1139/anc-2019-0010.
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The morphodynamic responses of tidal networks to anthropogenic reclamation and de-reclamation projects are investigated through a three-stage numerical simulation. In the first stage, the natural development of tidal networks is modelled in an open coast without any anthropogenic interventions. At the beginning of the second stage, parts of the computational domain are enclosed by sea dikes, which represents the implementation of the reclamation project. These sea dikes are removed or opened in the third stage to simulate the recovery of the tidal networks after de-reclamation. Each stage was set to last 100 years. The model results indicate that land reclamation can lead to three effects on tidal network morphology: (i) completely terminating the development of channels inside the projected area, (ii) hindering the development of the channel network in front of the dikes, and (iii) turning the channel direction near the corners of the dikes. When removing all the sea dikes, the previously reclaimed areas are quickly occupied by tidal networks. However, the morphology cannot be fully restored to its original natural state, although the entire reclaimed areas are returned. The effects of opening breaches are relatively slow, and tree-like network structures are formed inside the reclaimed areas.
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Zhao, Xin, et Qun Sun. « Influence of Reclamation on Hydrodynamic Environment in Bohai Bay ». Advanced Materials Research 726-731 (août 2013) : 3262–65. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.3262.
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The SWAN model was used to simulate the effect of the coastline change caused by the reclamations on the wave fields in Bohai Bay. The numerical results in the year of 2000 had been compared with that of 2010 to study the influence of the sea reclamations on the wind waves in Caofeidian area. The results show that the significant wave height has a declining trend due to the reclamation and decreased in value of 0.1 to 0.4m in 2010. The magnitude of the decrease of the significant wave height in winter is larger than that in summer. The significant variations of wave fields are occurred in the harbor basin and tide channel.
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Zhao, Xiaodong, Jinrong Ma et Xiangming Wang. « PHYSICAL MODEL EXPERIMENTS ON RECLAMATION PROJECT OF FANGCHENG PORT ». Coastal Engineering Proceedings 1, no 32 (6 février 2011) : 80. http://dx.doi.org/10.9753/icce.v32.sediment.80.
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Tidal flat reclamation works is an effective way to relieve the contradiction between supply and demand of land in the coastal region. The reclamation project in the bay will decrease tidal current velocities, change tidal currents field, then slowdown the water exchange in the bay ,which will influence water quality in the bay and increase sediment deposit at navigation channels. To study impacts of hydrodynamic environmental and sediment movement due to reclamation projects in Fangcheng Port, the physical model for tide-current and sediment was constructed in NHRI. The horizontal scale and vertical scale of the Fangcheng Port model is 1/660 and 1/100 respectively. The siltation in the bay and channels mainly caused by suspended load transport under the action of tidal currents and waves.The ability of water exchange in the bay is discussed by simulating sewage diffusion characteristics before and after reclamation projects in the bay. The physical model test results are shown the total tidal volume is decreased by 20% after the reclamation plan, of which 17.5% reduction in the East Bay, 2.5% in West Bay. The tidal currents field in the channel are discussed. The sedimentation rate increases 3-10cm/a in navigation channels and basins of Fangcheng Port.
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Sánchez-Donoso, Ramón, Nicholas Bugosh et José F. Martín-Duque. « Use of Remote Sensing Tools to Measure a Fluvial Geomorphic Design-Input Parameter for Land Reclamation ». Water 12, no 9 (25 août 2020) : 2378. http://dx.doi.org/10.3390/w12092378.
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Fluvial geomorphic approaches for reclamation landform design have been applied since 2000, mostly in mined lands, as an alternative to conventional landform design methods. Those approaches aim to reconstruct mature landforms and drainage networks that would develop within a natural catchment, after thousands of years of work performed by geomorphic processes. Some fluvial geomorphic design methods take specific measurements from natural and stable reference areas for initial input values for reclamation design. Valid reference areas can be difficult to find, can be in highly anthropized environments, or may be difficult to access. This paper evaluates the use of remote sensing tools to measure morphometric parameters in upper sections of agricultural land catchments considered for use as reference areas. The ridge to head of channel distance (Xrh) was the parameter of interest. We used land surface profiles developed from LiDAR (Laser Imaging Detection and Ranging) data and planimetric measurements from orthoimages to estimate Xrh. The results obtained by the two methods were encouraging but showed a significant difference. Ground truthing showed that ploughing obliterated between 19.5 and 22.4 m (on average) of the headwater section of first-order channels, reducing the channel length by 15.1 to 32.4%. Using a greater Xrh value than appropriate for near steady-state conditions as a design input for a geomorphic reclamation project would be expected to result in active erosion processes in the constructed reclamation to regain their missing channel length. We recognize the advantages and limitations of remote sensing methods for measuring the morphometric parameters of the landform relief design inputs. We show how these tools may be used to help select and prioritize reference areas, and warn about the use of disturbed landscapes as reference areas to assure the geomorphic stability of the constructed reclamation designs.
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Riduan, Rony, Riza Miftahul Khair, Lovina Gianina et M. Istiqlal Hasibuan. « One-Way Flow System Water Quality Modelling of Terantang Reclamation Channel ». IOP Conference Series : Earth and Environmental Science 999, no 1 (1 mars 2022) : 012019. http://dx.doi.org/10.1088/1755-1315/999/1/012019.
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Abstract The implementation of reclamation process in wetland has encountered some obstacles, such as the occurrence of pyrite oxidation, sedimentation, and accumulation of toxic materials, especially the concentration of Fe (iron) in the channel. The condition of the reclamation channel which is influenced by tidal events and environmental factors causes the dynamics of Fe concentration to be strongly influenced by hydrodynamic aspects and its interaction with dissolved and suspended particulates. An accurate model will be useful as a tool to evaluate alternative management of water systems to overcome the problem of Fe concentration accumulation in the tidal wetland reclamation channel. Fe fate and transport were modeled using a numerical model of hydrodynamics and water quality EFDC (Environmental Fluid Dynamic Code). The partition process separates the metal fraction into two phases (dissolved and solid), which is related to the value of the partition coefficient (Kp). The application of the partition process is considered to have a significant influence on the accuracy of the estimated Fe concentration. The simulation results of the model with the partition coefficient approach have better accuracy than the conventional model which tends to be over-predicted compared to the observation data. Simulation of one-way flow system shows a decrease of Fe concentration in the channel by an average of 52.9% compared to two-ways flow system. The application of one-way flow system is possible through the placement of flap gates that will direct the flow to the drainage channels.
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Liu, Chin-I., et Ruey-Shyong Shang. « CLOSURE OF TIDAL CHANNEL IN LAND RECLAMATION ». Coastal Engineering Proceedings 1, no 20 (29 janvier 1986) : 99. http://dx.doi.org/10.9753/icce.v20.99.
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The land reclamation of Lunwei subdistrict A in the development of Changhua Industrial Estate Project was commenced in May 1980. Fill sand was dredged by suction dredgers from borrow area and placed in the south and central parts of this subdistrict. Bamboo fence was used as sand retaining structure. In November, a new tidal channel occurred between two fill sand islands and across the head of seawall, it caused the increase of materials and the difficulty of construction of the seawall. Closure of the tidal channel was completed by constructed a sand embankment dike with low cost materials such as; bamboo piles, bamboo mattress and sand bags.
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R. Newlin, Dev, et C. Seldev Christopher. « Novel Random Valued Impulse Denoising Technique ». International Journal of Engineering & ; Technology 7, no 4.36 (9 décembre 2018) : 744. http://dx.doi.org/10.14419/ijet.v7i4.36.24233.
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The pictures in the advanced arrangement are generally corrupted by drive commotion which is because of the unexpected blunders in correspondence channels or electronic sensors. Most existing strategies fall flat at high clamor thickness. Here another versatile insertion procedure is foreseen for reclamation of exceptionally corrupted pictures by arbitrary esteemed drive clamor. This new method gives a more corrected preferred picture quality over the standard Versatile Middle Channel, Standard Middle Channel, Choice Based Calculation, Dynamic Exchanged middle Channel, Choice Based Un-symmetric Trimmed Middle Channel and altered Choice Based Un-symmetric Trimmed Middle Channel. The strategy anticipated is confirmed for its proficiency against various pictures and is found to give enhanced Pinnacle Motion to-Commotion Proportion.
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Lama, Giuseppe Francesco Cesare, Alessandro Errico, Simona Francalanci, Luca Solari, Federico Preti et Giovanni Battista Chirico. « Evaluation of Flow Resistance Models Based on Field Experiments in a Partly Vegetated Reclamation Channel ». Geosciences 10, no 2 (25 janvier 2020) : 47. http://dx.doi.org/10.3390/geosciences10020047.
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This study presents a methodology for improving the efficiency of Baptist and Stone and Shen models in predicting the global water flow resistance of a reclamation channel partly vegetated by rigid and emergent riparian plants. The results of the two resistance models are compared with the measurements collected during an experimental campaign conducted in a reclamation channel colonized by Common reed (Phragmites australis (Cav.) Trin. ex Steud.). Experimental vegetative Chézy’s flow resistance coefficients have been retrieved from the analysis of instantaneous flow velocity measurements, acquired by means of a downlooking 3-component acoustic Doppler velocimeter (ADV) located at the channel upstream cross section, and by water level measurements obtained through four piezometers distributed along the reclamation channel. The main morphometrical vegetation features (i.e., stem diameters and heights, and bed surface density) have been measured at six cross sections of the vegetated reclamation channel. Following the theoretical assumptions of the divided channel method (DCM), three sub-sections have been delineated in the reference cross section to represent the impact of the partial vegetation cover on the cross sectional variability of the flow field, as observed with the ADV measurements. The global vegetative Chézy’s flow resistance coefficients have been then computed by combining each resistance model with four different composite cross section methods, respectively suggested by Colebatch, Horton, Pavlovskii, and Yen. The comparative analysis between the modeled and the experimental vegetative Chézy’s coefficients has been performed by computing the relative prediction error (εr, expressed in %) under two flow rate regimes. Stone and Shen model combined with the Horton composite cross section method provides vegetative Chézy’s coefficients with the lowest εr.
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Moldamuratov, Zh N., A. A. Iglikov, E. B. Madaliyeva, S. Zh Daurbekova et A. Sh Asylbekov. « CROSS-SECTION CHANNELS OF HYDRAULICALLY AND STATICALLY STABLE SHAPE ». Bulletin of Kazakh Leading Academy of Architecture and Construction 86, no 4 (15 décembre 2022) : 199–209. http://dx.doi.org/10.51488/1680-080x/2022.4-20.
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The article presents the results of research on the substantiation of giving a stable shape of cross-section to the channels of hydro-reclamation systems of southern Kazakhstan. The calculations on the stability of irrigation channel slopes were made, as well as their design features and practical substantiation of stable profiles were presented. The shapes of stable slope were determined using of actual values of geotechnical parameters of slope soils. The results showed that the slope profile takes a stable shape during the channel operation, close to the parabolic.
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Xing, C. H., X. H. Wen, Y. Qian, D. Sun, P. S. Klose et X. Q. Zhang. « Fouling and cleaning of microfiltration membrane in municipal wastewater reclamation ». Water Science and Technology 47, no 1 (1 janvier 2003) : 263–70. http://dx.doi.org/10.2166/wst.2003.0065.
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This paper presents an investigation on fouling and cleaning of a tubular microfiltration membrane for municipal wastewater reclamation. A bi-level complex model, namely channel clogging and pore plugging, was introduced to elucidate the fouling mechanism. Based on 135 days of microfiltration of activated sludge, a preventive method for channel clogging was reasonably proposed and proven to be effective. Without channel clogging, the operation period was observed a five-fold increase on average, reaching 3-4 weeks. To remove pore plugging, a multi-step chemical cleaning was employed and further optimized in terms of temperature and alkaline concentration. Generally, the chemical cleaning could restore the membrane permeability to higher than 90%.
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Nirtha NNPS, Rd Indah, et Dwi Puspita Sari. « ANALISIS NILAI PH DAN KONSENTRASI LOGAM BESI (Fe) PADA MEDIA LAHAN BASAH BUATAN ALIRAN HORIZONTAL BAWAH PERMUKAAN YANG MENGOLAH AIR SALURAN REKLAMASI ». EnviroScienteae 14, no 3 (31 décembre 2018) : 200. http://dx.doi.org/10.20527/es.v14i3.5692.
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One of the impacts of reclamation of swamps is poison substances in the water channels, which can cause to pyrite oxidation, sedimentation and accumulation of toxic substances in secondary channels. The reclamation channel unit in Semangat Karya Village has a water pH of ± 3 and has the iron level of 4.95 mg / l. Based on South Kalimantan Provincial Governor Regulation Year 2007, pH grade and iron concentration are over the quality standard, while the water is consumed by the residents for everyday intentions. One of the technologies that are applied to increase the pH and to minimize the concentration of iron (Fe) is constructed wetland with the horizontal sub-surface flow (CW-HSSF). The objectives of this research were to study the dynamics of pH and Fe in the media acid sulfate soils mixed with organic fertilizer (bokashi) 10% at CW-HSSF system using Purun Tikus (Eleocharis dulcis) and Kalakai (Stenochlaena palustris). The conclusion of this research indicated that pH value and absorption of Fe in CW-HSSF using Purun Tikus (Eleocharis dulcis) was better than Kalakai (Stenochlaena palustris).
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Setiawan, A., B. S. Wignyosukarto et A. P. Rahardjo. « One-way flow system for improvement of the acid sulfate soil reclamation process in the Belanti II tidal swamp irrigation network, Central Kalimantan, Indonesia. » IOP Conference Series : Earth and Environmental Science 1091, no 1 (1 novembre 2022) : 012053. http://dx.doi.org/10.1088/1755-1315/1091/1/012053.
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Belanti II tidal irrigation network was developed in 1980 on acid sulphate soil with an area of approximately 3976 ha. Belanti II has one primary channel and several secondary channels, without any water structures that regulate the direction of flow. Two-way flow occurs in the channel, supplying fresh water from the river at high tide and flowing back into the river at low tide. This two-way flow system inhibits the leaching process of acid sulphate soil. Up to now, acid sulfate soils are still found at a depth of 50-75 cm with a pH of 2.5 ~ 3.5. A one-way flow system is expected to improve water circulation, assisted by channel rehabilitation, collector channels and water control structures. The spillway structure at the secondary channel regulates the freshwater supply at high tide and the flap gate at the end regulates the flow of water to the collector channel at low tide. Hydraulic analysis was carried out using HEC-RAS modelling. The results showed the ability of the system to supply fresh water, flushing/leaching acid sulfate water and drainage the toxic water. The effectiveness of the system is evaluated regarding the direction and the volume of freshwater flowing into the secondary channel.
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Xu, Ting. « Study of Morphological Changes Induced by Man-Made Coastal Project ». Advanced Materials Research 989-994 (juillet 2014) : 1240–43. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.1240.
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With rapid development of economy, the crisis of land resources is faced. Land expansion by enclosing sea in estuaries has become an important carrier for city space extension. In this paper,the large-scale marine reclamation project in the Oujiang River Estuary (ORE) of Wenzhou shoal was taken as an example.Based on the intoduction of the study area,the 3D marine numerical model (EFDC) was setup and used for simulation of sediment enviroment and morphological changes induced by the reclamation. The results indicated that the project doesn’t have obvious adverse effects on its nearby sediment environment and seabed. On the contrary, it settles the problem of mouth bar of the ORE and provides some advantages to maintain and steady the deep water channel and improve the sail condition from the north mouth of Oujiang River to Huangda’ao channel.
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Klemens, Christine A., Michael W. Brands et Alexander Staruschenko. « Postprandial effects on electrolyte homeostasis in the kidney ». American Journal of Physiology-Renal Physiology 317, no 6 (1 décembre 2019) : F1405—F1408. http://dx.doi.org/10.1152/ajprenal.00350.2019.
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Insulin is known to be an important regulator of a number of different channels and transporters in the kidney, but its role in the kidney to prevent Na+ and volume loss during the osmotic load after a meal has only recently been validated. With increasing numbers of people suffering from diabetes and hypertension, furthering our understanding of insulin signaling and renal Na+ handling in both normal and diseased states is essential for improving patient treatments and outcomes. The present review is focused on postprandial effects on Na+ reabsorption in the kidney and the role of the epithelial Na+ channels as an important channel contributing to insulin-mediated Na+ reclamation.
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Ilinskij, A. V. « ECOLOGICAL AND MELIORATIVE ASSESSMENT OF HEAVY METALS CONTENT IN WATER OF THE MAIN CHANNEL OF THE RYAZAN MESHCHERA DRAINAGE SYSTEM ». EurasianUnionScientists 10, no 5(74) (14 juin 2020) : 17–20. http://dx.doi.org/10.31618/esu.2413-9335.2020.10.74.800.
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The article presents the results of environmental monitoring of the content of heavy metals (copper, zinc, lead and cadmium) in the water of the main channel of the tinki-2 reclamation facility. It was found that the concentration of elements at the exit from the object is less than at the entrance of the reclamation system, copper-by 41%, zinc-by 46%, lead-by 86% and cadmium-by 37%. Based on the ecological and meliorative assessment of the content of heavy metals in water, recommendations are given for their use for on-farm purposes and the use of water circulation systems in agriculture
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Zhang, Haifeng, Lin Zhao, Wen Du, Qing Liu, Yifei Zhao et Min Xu. « Research on the Limit Values of Reclamation Based on Ecological Security : A Case Study of Tongzhou Bay in Rudong, Jiangsu Province ». International Journal of Environmental Research and Public Health 19, no 14 (7 juillet 2022) : 8301. http://dx.doi.org/10.3390/ijerph19148301.
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Due to the growing demand for land resources, many coastal reclamation projects have been implemented around the world in recent decades. Although coastal zone reclamation provides economic benefits, it produces a series of threats to coastal environments and ecosystems. Hence, the ecological costs and economic benefits of reclamation projects must be balanced. In this study, we select Tongzhou Bay, a key development area of the marine industry in the Jiangsu Province, as the research region to study the limits of reclamation control of the port operation area based on regional ecological security. First, we determine the standard limit values of the tidal catchment water line and the water dividing line, the change rate of the tidal flux ±5%, and water area of sandbars above the 0 m line based on key factors and evaluation indices for the ecological impact of reclamation in this region. Then, eight reclamation cases are investigated in Tongzhou Bay, which include the undeveloped natural state, development status, construction projects to be built, and possible construction scale based on the results of tidal current numerical simulation calculations. Although case 3 has impacts on Section 2 (DM2) tidal flux of less than 5% and on Section 1 (DM1) tidal flux of less than 10%, it causes a northward shift of the flood catchment water line in the middle of Yaosha. Finally, case 8 meets the requirements of the standard limit values of evaluation indicators, e.g., 1455 hectares of reclamation is the limit value to maintain the natural state of the Sanshahong channel and the stability of the tidal creek system and Yaosha. Therefore, the results suggest optimizing the structure and layout of breakwaters, controlling the restriction of reclamation, and further maintaining and protecting the ecological function of Tongzhou Bay.
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Li, Jing, Yong Ning An et Hai Chen Sui. « Hydrodynamic and Sediment Transport in the Headland of Caofeidian after Reclamation of the Industrial Zone ». Applied Mechanics and Materials 405-408 (septembre 2013) : 1437–40. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1437.
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Caofeidian sand island unique shoal-channel system provides construction conditions for deep-water port.By comparing the underwater topography changes before and after Caofeidian industrial construction to understand the sediment transport and erosion-deposition evolution. Bathymetry results in 2006 and 2012 showed that the deep channel is in good stability. 2 to 3 years later after construction, excepting artificial dredging area, erosion occurs in front of the headland. The sediment is transported to the west of harbor 1 entrance. Seabed sediment controlled by wave comes from the front of the southeast seawall inflection point is transported to the deep channel, some deposits in the east slope and the most is taken away by the deep channel water. All processes above become more weakly now, in the future the sea area in front of the headland will erode weakly, the sea area in the west slope will deposit weakly while in the east slope will erode weakly, and the sea area near the harbor entrance will erode.
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Shimalov, Vladimir Vasilievich. « Findings of Fluke Prosolecithus Danubica (Trematoda, Dicrocoeliidae) in Shrews in South-West Belarus ». International Journal of Zoology and Animal Biology 5, no 4 (2022) : 1–3. http://dx.doi.org/10.23880/izab-16000389.
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The helminthological examination of one hundred sixty-three specimens of shrews of four species (2 bicoloured white-toothed shrews, 139 common shrews, 14 lesser shrews, 8 water shrews) captured on drainage channel banks of eight reclamation systems in Brest Polesie (Brest, Zhabinka and Malorita districts of Brest region; South-West Belarus) during 2015–2020 were carried out. 5.1 % examined common shrews were infected with fluke Prosolecithus danubica Tkach et Bray, 1995. Number of helminth specimens varied from 1 to 32. The result of previous studies in this region was also taken into account. A total of fluke P. danubica found in eight specimens of common shrews lives on drainage channel banks in four reclamation systems of Brest Polesie (2 systems were located in Brest district and 2 systems were located in Malorita district, South-West Belarus). All helminths were found in gall-bladder and/or bile-ducts of the liver. The information about shrews infected this fluke are presented. This investigation expands the areal of fluke P. danubica in Europe.
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Pengfei, Huang, Liu Pei et Xu Wei. « Study on Water Exchange and Water Quality Simulation of Macao Airport Expansion Project ». E3S Web of Conferences 261 (2021) : 03019. http://dx.doi.org/10.1051/e3sconf/202126103019.
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In this paper, we analyzed the current situation of water pollution sources near Macao airport, established a two-dimensional water exchange and water quality mathematical model near the project, and compared and simulated the reclamation schemes of Macao airport. According to the results of water exchange and COD calculation of water quality, the 80 m channel scheme was remarkably better than the 40 m one in terms of water exchange capacity and the possibility of achieving the water quality target. However, with the increase of channel width, the variation of water exchange rate and half exchange period would slow down. There was no significant difference in water exchange rate, water exchange period and water quality distribution between 80m channel and 120 m channel. The final scheme was to adopt the 80 m channel.
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Xu, Shaochun, Shuai Xu, Yi Zhou, Shidong Yue, Xiaomei Zhang, Ruiting Gu, Yu Zhang, Yongliang Qiao et Mingjie Liu. « Long-Term Changes in the Unique and Largest Seagrass Meadows in the Bohai Sea (China) Using Satellite (1974–2019) and Sonar Data : Implication for Conservation and Restoration ». Remote Sensing 13, no 5 (25 février 2021) : 856. http://dx.doi.org/10.3390/rs13050856.
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Seagrass meadows play critical roles in supporting a high level of biodiversity but are continuously threatened by human activities, such as sea reclamation. In this study, we reported on a large seagrass (Zostera marina L.) meadow in Caofeidian shoal harbor in the Bohai Sea of northern China. We evaluated the environmental impact of sea reclamation activities using Landsat imagery (1974–2019) by mapping seagrass meadow distribution changes. ISODATA was adopted for the unsupervised classification and mapping of seagrass beds. The error matrix developed using the in situ data obtained from acoustic surveys for Landsat 8OLI image classification was 87.20% accurate. The maps showed rapidly increasing changes in seagrass meadows as the amount of reclaimed land increased. Some seagrass meadows experienced large-scale changes, and sea reclamation has been suggested as the main factor responsible for habitat loss, which results from physical damage, excessive sedimentation, and increased turbidity caused by reclamation. In addition, habitat degradation may have resulted from three storm surges induced by typhoons in 1992–1998. Fortunately, land reclamation, forming an artificial “longshore bar”, buffers seagrass meadows from wave actions, providing relatively sheltered conditions, which has allowed a large habitat increase since 2012. These were the largest eelgrass meadows (3,217.32 ha), with a peripheral area of ~100 km2, in the Bohai Sea of northern China in 2019. However, the existing largest eelgrass beds in China are threatened by trawling, clam harvesting (especially clam sucking), channel dredging, and culture pond construction. Our work will help coastal managers monitor the environmental impacts of reclamation activities on seagrass meadows on a large spatio-temporal scale and will also provide information for seagrass restoration using artificial “longshore bars”.
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LEE, JONG KOO, OK-SIK CHUNG, JIN-YOUNG PARK, HWA-JUNG KIM, WEE-HAENG HUR, SUNG-HYUN KIM et JIN-HAN KIM. « Effects of the Saemangeum Reclamation Project on migratory shorebird staging in the Saemangeum and Geum Estuaries, South Korea ». Bird Conservation International 28, no 2 (13 février 2017) : 238–50. http://dx.doi.org/10.1017/s0959270916000605.
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SummaryThe Saemangeum tidal flat, an important staging site for migratory shorebirds that travel the East Asian-Australasian (EAA) Flyway, was isolated from the eastern Yellow Sea in 2006 as part of a large-scale reclamation project. To gain a better understanding of the impacts that this reclamation has had on the long-distance migratory shorebirds that use the EAA Flyway, we examined the number of shorebirds visiting Saemangeum and three adjacent sites in the Geum Estuary (Yubu Island, the Janghang coastline, and the Geum River Channel) during the spring and fall prior to, and after, completion of the reclamation (2004–2013). A total of 48 shorebird species, including one Critically Endangered, three Endangered, and nine Near Threatened species, were observed over this period. Peak numbers of shorebirds recorded at sites in Saemangeum and the Geum Estuary following completion of the project were 74% below those recorded in 2004 and 2005, the years prior to reclamation activity. In Saemangeum, shorebird abundance declined by approximately 95% and 97.3% during the northward and southward migrations, respectively, as a result of reclamation. Although shorebird populations in the Geum Estuary increased by 5% and 20% during the northwards and southward migrations, respectively, these increases failed to offset the reduction in shorebird abundance in Saemangeum; overall, shorebird abundance at Saemangeum and the three adjacent sites in the Geum Estuary markedly declined over the reclamation period. Given the more favourable conditions of adjacent areas, sites in Saemangeum and the Geum Estuary no longer provide the habitat conditions necessary for long-distance migratory shorebirds. In order to improve habitat for staging migratory birds, we suggest that measures such as the conversion of an abandoned salt farm for use as roosting sites, the construction of artificial barriers to prevent human disturbance, and re-opening of the river-banks to facilitate water flow be implemented.
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Corbet, S. P., et A. R. Toms. « Reclamation at Bathside Bay, Harwich : Planning and evaluation for roads and port ». Geological Society, London, Engineering Geology Special Publications 4, no 1 (1987) : 533–39. http://dx.doi.org/10.1144/gsl.eng.1987.004.01.66.
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AbstractBathside Bay, situated between Harwich and Parkeston Quay, has been the subject for many plans for reclamation and development. Following a period of inactivity by developers Essex County Council commissioned an independent study into alternative routes for a road between Parkeston and Harwich to relieve traffic congestion in Dovercourt.The comprehensive geological, geotechnical, engineering and environmental studies carried out by G. Maunsell and Partners had been completed when a large volume of spoil from a channel dredging contract to be carried out in Harwich Harbour became available at short notice. There were benefits to both Essex County Council and owners of Bathside Bay, Sealink British Ferries Ltd., if this spoil could be used to reclaim part of Bathside Bay. Negotiations with the various statutory bodies, authorities and affected groups were started while further geotechnical and engineering work was competed.The reclamation of approximately 40 hectares of Bathside Bay was completed using 1.2 million cubic metres of material. Observations of settlement show that about 0.2 m settlement took place immediately with a further 0.4 m taking place during the following year. Several minor slips occurred during the filling operation partly attributable to geological features.Having completed the reclamation work Essex County Council are now proceeding with plans for the new road. Sealink are preparing for port development, including reclamation of the remaining area in Bathside Bay.
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Xiao, Xianbiao, Yunhai Li, Junjian Tang, Fusheng Luo, Fangfang Shu, Liang Wang, Jia He et al. « Coupling Relationship of Geomorphic Evolution and Marine Hydrodynamics in the Stage-Specific Development of Urban Bays : A Modelling Case Study in Quanzhou Bay (1954–2017), China ». Journal of Marine Science and Engineering 10, no 11 (7 novembre 2022) : 1677. http://dx.doi.org/10.3390/jmse10111677.
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With the development of social economy and human activities, the geomorphology and hydrodynamic conditions of coasts have been dramatically changed, causing serious environmental pollution and resource depletion. Taking Quanzhou Bay as an example, this study combined geomorphologic change with a hydrodynamic model to simulate the change in tidal currents in different periods. The results show a change in the coastline was the main cause of hydrodynamic change during the industrialization reform. During the past 70 years, the tidal prism decreased year by year, and the average velocity of the tidal current in the channel decreased by 33.7% and 30.8% at flood and ebb tide, respectively. In the early stages of industrialization, reclamation land was used in a single way. The tidal prism decreased by 22.2% and 29.8% in the spring and neap tide, respectively. In the middle and later stages, the tidal current velocity increased, and reclamation land was used in a variety of ways. In modern society, the reclamation land-use type was unitary. Based on this research, we show the influence of human activities on the evolution of the bay’s geomorphology and provide suggestions for the management of the bay.
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Anoshkin, Andrey V., et Vitaliy A. Zubarev. « Land reclamation and transformation of floodplain-channel complexes at the Middle Amur Lowland ». Regional Problems 21, no 3 (1) (2018) : 70–74. http://dx.doi.org/10.31433/1605-220x-2018-21-3(1)-70-74.
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Liang, Huidi, Cuiping Kuang, Maitane Olabarrieta, Honglin Song, Yue Ma, Zhichao Dong, Xuejian Han, Liming Zuo et Youcai Liu. « Morphodynamic responses of Caofeidian channel-shoal system to sequential large-scale land reclamation ». Continental Shelf Research 165 (août 2018) : 12–25. http://dx.doi.org/10.1016/j.csr.2018.06.004.
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Firstyadi, A. D. F., B. S. Wignyosukarto, Istiarto et S. Purboseno. « Post reclamation of acid sulphate soil due to extended tidal irrigation area in Palingkau, Central Kalimantan, Indonesia ». IOP Conference Series : Earth and Environmental Science 930, no 1 (1 décembre 2021) : 012017. http://dx.doi.org/10.1088/1755-1315/930/1/012017.
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Abstract The Palingkau Swamp Irrigation Scheme SP1 SP2 SP3 extends tidal irrigation between Kapuas Murung River and Kapuas River, which local peoples developed. The development of the new agricultural land behind the old tidal irrigation system creates oxidation of potential acid sulphate (FeS2) soil. The result of the leaching process polluted local’s agricultural area causes the decrease land productivity. The field observation recorded the water pH ranges between 3.9 - 5.3; 3.7 - 4.31 at the handil; 2.5 - 4 at the collector channels; and 2.8 - 3.6 at the primary channels. Good water management is needed to overcome these problems, both at the new irrigation system and handil. The HECRAS mathematical model is used to evaluate water circulation in the system and its reliability. The Efforts to normalize the handil impact increasing the amount of water entering the handil although it is not significant. Moreover, it still cannot meet the water demand for the leaching process in the network system by 2.06 million m3/day. It is necessary to increase the capacity of the channel to allow freshwater flow from the river for the leaching process in the network system.
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TALYZOV, A. A. « NUMERICAL COMPUTER SIMULATION OF THE OPERATION OF CULVERTS OF A HYDRO-RECLAMATION SYSTEM ». Prirodoobustrojstvo, no 5 (2021) : 105–10. http://dx.doi.org/10.26897/1997-6011-2021-5-105-110.
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The aim of this research was to study the operating modes of water-passing structures that are part of the irrigation and drainage system using numerical computer modeling in the HEC-RAS environment. The paper describes the main stages of processing the source data, preparing a model, performing modeling and analyzing the results. The problem of the program description of the rules for managing a water-passing structure – a controlled gate located on a trapezoidal channel and performing the function of regulating water levels is investigated. The created rules for the operation of the structure imply a change in the position of the gate depending on the water levels in the upper and lower reaches, which ensures regulation. For the resulting model of a channel with a controlled gate, calculations were carried out for a non-steady fl ow of water, the response of the structure to a change in the fl ow rate of water was investigated, and the obtained values of water levels in the upper and lower reaches was analyzed. Based on the simulation results, conclusions were drawn about the applicability of this research method for solving problems related to the optimization of operating modes of irrigation and drainage systems.
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Krafft, Douglas R., Richard Styles et Mitchell E. Brown. « Feedback between Basin Morphology and Sediment Transport at Tidal Inlets : Implications for Channel Shoaling ». Journal of Marine Science and Engineering 10, no 3 (18 mars 2022) : 442. http://dx.doi.org/10.3390/jmse10030442.
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Increasing societal pressures (e.g., population growth and urbanization) are driving land use change practices in coastal areas that could potentially alter the hydrodynamics and sediment transport patterns near coastal inlets in ways that might exacerbate existing shoaling conditions. To investigate the potential impact of coastal development, a numerical model is used to predict the long-term evolution of an idealized lagoonal-type barrier island inlet under five different morphological conditions that transitioned from net sediment import to net sediment export. The simulations were designed to address the potential effect of inter-tidal placement and land reclamation on sediment transport and the resulting deposition/erosion patterns. Estuaries that were deeper and devoid of extensive tidal flats tended to promote sediment import and had a greater propensity to exacerbate channel shoaling. Simulations that were characteristic of inter-tidal placement showed net export, yet the likelihood of channel shoaling was increased because some of the material eroded from the tidal flats was deposited in the deeper channels as opposed to being carried out the inlet throat. Alternatively, it was found that regions in which the intertidal area was restricted to elevations higher in the tidal frame, which also showed a net export, produced greater sediment loss in the inter-tidal zone that tended to bypass the deeper sections, reducing the likelihood of channel shoaling.
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Kosichenko, Yurij M., et Oleg A. Baev. « Hydraulic efficiency of irrigation channels in the course of operation ». Vestnik MGSU, no 8 (août 2020) : 1147–62. http://dx.doi.org/10.22227/1997-0935.2020.8.1147-1162.
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Introduction. The co-authors have analyzed different reasons for the reduction of the hydraulic efficiency of irrigation channels comprising hydro-technical reclamation systems. The main factors include plant invasion, siltation and deformation of beds. The co-authors provide data describing changes in the values of bed roughness ratios and efficiency of main and distributary channels in the process of operation in the south of Russia.
Materials and methods. The hydraulic efficiency of irrigation and drainage systems will be called the pro-vision of their high throughput, close to the design, with minimal losses. They are based on throughput capacity and efficiency values, acceptable flow rates and water losses due to the process of filtration. The criteria have been developed in furtherance of the analysis of operation of irrigation channels and previous studies.
Results. Factors reducing throughput capacity and channel efficiency have been identified for normal operating conditions; dependences needed to identify other hydraulic efficiency factors are also provided. Based on the analysis of actual data, the efficiency of main canals in the earthen bed is 0,790, and for canals in the cladding — 0,870, which is significantly lower than the re-quirements of the norms. Computer assisted processing of the field data on roughness and channel efficiency ratios, obtained under normal conditions, was performed to obtain empirical dependences n = f(Q) and η = f(Q). The field data describing changes in the throughput capacity of linings and earth beds of irrigation channels exposed to significant plant invasions (vegetation and algae) are provided for comparison purposes. The influence of these factors is demonstrated in the photos and proven by the values of roughness ratios that are two to four times different from the design ones.
Conclusions. Comparison of the roughness coefficients for 15 canals and sections with strong overgrowth with the design data indicates that for canals in the earthen channel their roughness increases by 2.5...4.0 times, and for canals in the lining — 1.7...2.5 times. Weedy bed roughness ratios were obtained by applying theoretical formulas and the field data, their comparison has demonstrated close convergence in respect of three channels, including Nizhne-Donskoy and Azovsky main channels, as well as distributary channel Bg-R-7.
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Євсейчик, Юрій, et Костянтин Медведєв. « ВИЗНАЧЕННЯ КОЕФІЦІЄНТУ ШОРСТКОСТІ ДЛЯ РОЗРАХУНКУ ПОТОКУ НЕУСТАЛЕНОГО РУХУ РІДИНИ ». Automobile Roads and Road Construction, no 112 (30 novembre 2022) : 163–69. http://dx.doi.org/10.33744/0365-8171-2022-112-163-169.
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The analysis of the literature devoted to calculation of hydrotechnical structures showed that there are recommendations that take into account the influence roughness of the channel on magnitude transformation transit flow of liquid along the length of the channel. But these recommendations are difficult to apply to reclamation systems, which include complexes of hydraulic engineering and transport facilities, because they do not take into account the characteristic features of unsteady fluid movement in such systems. Unfortunately, as of today, this issue has not been adequately addressed in modern scientific literature. The article considers the issue of determining the roughness coefficient based on the materials of field experiments on irrigation systems of Ukraine for its further use in the Saint-Venant equations for unsteady water movement in open prismatic channels. At one time, professor V.O. Bolshakov applied the method of running according to the implicit difference scheme, provided that the roughness coefficients are known, to solve the Saint-Venant equations. The authors conducted an analysis errors of field measurements of maximum depths, calculation area of live sections, etc. The absolute error of finding the drop in water levels in individual sections of the channel was determined. The results. Among the issues that were covered in the discussed publication, the main attention was paid to the issue of studying the influence of the roughness coefficient on flow elements during unsteady motion in meliorational (irrigation) systems. Also, the characteristics conducted field measurements are given, a detailed overview field data is provided, and the measured parameters at different sections research channel are listed. Conclusions. An indicative evaluation and analysis errors of the performed measurements was carried out, and recommendations were given for determining the average values of roughness coefficients for irrigation channels (channels) with a well-planned bottom and slopes, as well as for banks not covered with vegetation. The results of data processing of field observations are summarized in a table, which presents a comparison calculated values of the roughness coefficients.
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Setiawan, A., B. S. Wignyosukarto, A. P. Rahardjo et Yakubson. « A Proposed Improvement of Belanti II Tidal Irrigation Scheme, Kalimantan, to Support Leaching of Acid Sulphate Soil Reclamation ». IOP Conference Series : Earth and Environmental Science 930, no 1 (1 décembre 2021) : 012011. http://dx.doi.org/10.1088/1755-1315/930/1/012011.
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Abstract The reclamation process of acid sulphate soil of the Belanti II tidal irrigation scheme remains unfinished. During ebb tide, the upstream acidic drainage water retains and settles in the irrigation canals. During high tide, the acidic water flows back into some parts of the agricultural land and reduces rice productivity. The measured pH is about 2.5 ~ 3.5 and the measured electric conductivity is about 0,25 ~ 0,35 mS/cm. Sedimentation in the middle to the end of the primary, secondary, and collector canals and tidal pond at the upstream end of the primary canal, preventing the leaching process of sulfuric acid soil. Primary canal normalization as an alternative solution to increase the capability of acidity leaching is proposed. Leaching the acidic soil of Belanti II irrigated area of 3.976 ha requires 500 m3/ha/day of freshwater, equivalent to 1.998.000 m3/day. The one-dimensional HEC RAS mathematical model is used to evaluate the hydraulics performance to support the leaching process. The hydraulic analysis was carried out using two tidal cycles on the existing channel and the normalized channel. Channel normalization has succeeded in reducing the water supply deficit to support the leaching process from 39% to 9%.
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Imanudin, Momon Sodik, Bakri Bakri, Muhammad Edi Armanto, Budi Indra Setiawan et Ratmini S. NP. « Land And Water Management Option of Tidal Lowland Reclamation Area to Support Rice Production (A Case Study in Delta Sugihan Kanan of South Sumatra Indonesia) ». Journal of Wetlands Environmental Management 6, no 2 (13 février 2019) : 93. http://dx.doi.org/10.20527/jwem.v6i2.165.
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<p>The main problem for agriculture at tidal lowland swamp is low soil quality and high acidity of soil and high water. The research objective was to investigate how far the effort in increasing tertiary canal network to improve water quality (increasing pH and reducinf iron) in channel and tertiary plot. Field study was conducted at Bandarjaya Village of Jalur 25, Delta Sugihan Kanan, South Sumatra. Field activities were consisted of network investigation land use and farm enterprise system which located at Primr 13 of Sugihan Kiri and Primer 25 of Sugihan Kanan. The network improvement perfomance was conducted by constructing micro water management (installed the tertiary gate and developen quartey canal) at tertiary plot which consisted of collector channel, sub tertiary channel and control plot which was outfall at quarterly channel downstream end. Water gate having goose neck pipe system was constructed to control water table in tertiary channel. Results of field study showed that land use at the study area was still dominated by rice crop with magnitude of 83% and the rest of 17% was used for rubber plantation, orange planation and mix plantation. The depth of phyrite layer was in the range of 60 to 100 cm below soil surface. Water table surface in October was in the range of 10 to 35 cm. Field adaptation showed that water gate was operated in closed condition (water retention) during vegetative phase. Water retention showed significant to improve rice yield in which water table since November had increased from -10 cm to flooding condition of 15 cm in January. This condition provide sufficient water for rice crop which was similar as the result found at irrigation area. The addition of ameliorant substances such as coconut fiber, and sand semen block at outfall of tertiary and kuartely channels also increase water quality in which water pH was increased from 2.95 to 3.7 and iron concentration was decreased from 4.01 to 0.32 mg/liter. Rice yield was increased from average production of 2 ton/ha to 3 ton/ha. This low production was due to land flushing process which need longer time process for at least 2 to 3 years from current condition as well as other production inputs such as fertilization and ameliorant substances.</p>
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Leuven, Jasper R. F. W., Sanja Selaković et Maarten G. Kleinhans. « Morphology of bar-built estuaries : empirical relation between planform shape and depth distribution ». Earth Surface Dynamics 6, no 3 (11 septembre 2018) : 763–78. http://dx.doi.org/10.5194/esurf-6-763-2018.
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Abstract. Fluvial–tidal transitions in estuaries are used as major shipping fairways and are characterised by complex bar and channel patterns with a large biodiversity. Habitat suitability assessment and the study of interactions between morphology and ecology therefore require bathymetric data. While imagery offers data of planform estuary dimensions, only for a few natural estuaries are bathymetries available. Here we study the empirical relation between along-channel planform geometry, obtained as the outline from imagery, and hypsometry, which characterises the distribution of along-channel and cross-channel bed levels. We fitted the original function of Strahler (1952) to bathymetric data along four natural estuaries. Comparison to planform estuary shape shows that hypsometry is concave at narrow sections with large channels, while complex bar morphology results in more convex hypsometry. We found an empirical relation between the hypsometric function shape and the degree to which the estuary width deviates from an ideal convergent estuary, which is calculated from river width and mouth width. This implies that the occurring bed-level distributions depend on inherited Holocene topography and lithology. Our new empirical function predicts hypsometry and along-channel variation in intertidal and subtidal width. A combination with the tidal amplitude allows for an estimate of inundation duration. The validation of the results on available bathymetry shows that predictions of intertidal and subtidal area are accurate within a factor of 2 for estuaries of different size and character. Locations with major human influence deviate from the general trends because dredging, dumping, land reclamation and other engineering measures cause local deviations from the expected bed-level distributions. The bathymetry predictor can be used to characterise and predict estuarine subtidal and intertidal morphology in data-poor environments.
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Zhang, Chi, Jinhai Zheng, Xiaowei Dong, Kai Cao et Jisheng Zhang. « Morphodynamic response of Xiaomiaohong tidal channel to a coastal reclamation project in Jiangsu Coast, China ». Journal of Coastal Research 65 (2 janvier 2013) : 630–35. http://dx.doi.org/10.2112/si65-107.1.
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Amano, Atsuko, Naoya Iwamoto, Takahiko Inoue et Yoshio Inouchi. « Seafloor environmental changes resulting from nineteenth century reclamation in Mishou Bay, Bungo Channel, Southwest Japan ». Environmental Geology 50, no 7 (13 avril 2006) : 989–99. http://dx.doi.org/10.1007/s00254-006-0268-3.
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Raslan, Ahmed M., Peter H. Riad et Mona A. Hagras. « 1D hydraulic modelling of Bahr El-Baqar new channel for northwest Sinai reclamation project, Egypt ». Ain Shams Engineering Journal 11, no 4 (décembre 2020) : 971–82. http://dx.doi.org/10.1016/j.asej.2020.02.005.
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Xie, Chengjie, Baoshan Cui, Tian Xie, Shuling Yu, Zezheng Liu, Qing Wang et Zhonghua Ning. « Reclamation shifts the evolutionary paradigms of tidal channel networks in the Yellow River Delta, China ». Science of The Total Environment 742 (novembre 2020) : 140585. http://dx.doi.org/10.1016/j.scitotenv.2020.140585.
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Si, Wei Bin, Yong Tao Lv et Xiao Jun Liu. « On Cause Analysis and Treatment Strategy of River Water Pollution in Northern China ». Advanced Materials Research 356-360 (octobre 2011) : 2097–101. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.2097.
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Taking the Weihe River in Baoji area as an example, the paper discusses the contaminants’ (counted with COD) production, treatment capacity, pollutant amount into the river, river water quality and relationship between annual water inflow distribution and river water quality in river channel. It is argued that it is impossible by relying solely on the sewage treatment to control the pollutant amount into the river and solve the river water pollution. The paper also presents that sewage reclamation is a new method to treat the river water pollution in Northern China.
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Athali, Nadia, et Aris Munandar. « N-words in Black Stand-Up Comedy : A Linguistic Reclamation ». Lexicon 9, no 1 (1 avril 2022) : 33. http://dx.doi.org/10.22146/lexicon.v9i1.72804.
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In the United States of America, the stand-up comedy community consists of comics from a diverse range of ethnicities/races, one of them being African American (black people). Among this particular group, the use of the N-word has been prominent throughout the years. Although commonly used as a slur, the N-word becomes an interesting discussion, as its function within stand-up comedy is not solely derogatory when uttered by black comics. In this research, the functions of the N-word used by black comics in stand-up comedy are investigated. Moreover, its relation to linguistic reclamation is also examined. The data were obtained from a YouTube channel named Laugh Factory in the form of videos by black comics aired in 2020. The analysis of the functions was conducted by categorizing the functions of the N-word. In order to relate the functions of the N-word with linguistic reclamation, a qualitative analysis was conducted by using Illocutionary Force Indicator Account to see whether the N-word succeeds or fails to function as a slur. Despite some of the occurrences of the N-word having derogatory functions, the ends of uttering them are not actually regarded as a slur. Moreover, it is discovered that the N-word used by black comics in stand-up comedy fails to function as a slur, proving that there is a process of linguistic reclamation with the N-word being non-derogatory.
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Abdulmazhidov, Kh A. « Dependence of the performance of the reclaiming sewer cleaner with rigid guides from interchangeable bucket tools capabilities ». Vegetable crops of Russia, no 6 (10 décembre 2022) : 125–29. http://dx.doi.org/10.18619/2072-9146-2022-6-125-129.
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Relevance. Cleaning of reclamation channels is a very relevant event. The need to clean the canals and maintain them in working condition becomes obvious during the flood period, when it is necessary to remove excess water. The paper presents mathematical models for determining the performance of the PP-303 canal cleaner, a feature of which is the rectilinear movement of the bucket on rigid guides along the bottom along the axis of the canal to be cleaned.Methods. The article is formed on the basis of experimental research methods. The research was carried out based on experimental and calculated data. A network of drainage canals of the drainage system was taken as the research object, and the working equipment of the canal cleaner was taken as the research subject. Performance, which is the amount of products produced by the machine per unit of time, can be of three types (theoretical, technical, and operational) and can be determined with consideration of the design parameters of the working equipment. During the operation of trench cutting machines, their performance directly depends on the main parameter, namely, the depth of the canal being built; in the case of canal cleaning with canal cleaners, this parameter cannot be considered as the main one. This is due to the fact that siltation and sediments accumulating on the bottom and slopes of the canals during the operation of the reclamation system are extremely unevenly distributed along the length of the canal. The highest concentration and amount of sediments and siltation is observed mainly at the mouth of the canals, the junctions of canals of different levels, and the junctions of the drainage with the drainage canal. In this case, the most significant parameter is the thickness of the chips removed from the bottom and slopes of the canal by the bucket.Results. The results of the research showed that the performance of the channel cleaner, as a batch machine, is influenced by the very design of the working equipment, the main element of which is a bucket capable of moving in a straight line along rigid guides at different speeds. With obvious high values of the performance of continuous channel cleaning machines, it can be concluded that the channel cleaner RR-303 showed high values of technical and operational characteristics, mainly due to the use of a trapezoidal profile bucket.
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Mohammed, Alauddin, Rokshana Pervin et Md Zakir Hasan. « Effect of Various Groins in a Series on Channel Bed Morphology : an Experimental Investigation ». Stavební obzor - Civil Engineering Journal 31, no 1 (30 avril 2022) : 211–21. http://dx.doi.org/10.14311/cej.2022.01.0016.
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Alluvial rivers in Bangladesh are unstable keep changing their main channel, banklines, and so on. Groins are extensively used worldwide for shore protection from erosion, river navigation, beach reclamation among many other services. Improving the performance of groins is a crucial issue around the glove. Experimental investigations under clear water scour conditions have been conducted in this research to compare the performance of different groins in order to find out the suitable design of a groin. From the experimental runs, it is revealed that the groin models of different configurations behave in different ways. In the case of a solid I-shaped groin, a huge scour near the groin head and irregular bed pattern develop in the channel bed. While L-head and hockey-shaped groins improve the channel response a bit leading to decreased scour. Moreover, the hockey-shaped groin attracts the flow, and thus requires groin installation closely. The scour hole for a combined groin is relatively very small. As the scour endangers the stability of the groin structure, this turns out to be the most suitable one.
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CHERNYKH, O. N., et A. V. RBURLACHENKO. « RECLAMATION AND CULVERT CROSSINGS MADE OF CORRUGATED PIPES ON SPAWNING STREAMS ». Prirodoobustrojstvo, no 5 (2020) : 68–77. http://dx.doi.org/10.26897/1997-6011-2020-5-68-77.
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Recommendations are presented for solving issues that arise in the design and operation of tubular transport crossings of corrugated metal structures through spawning streams while ensuring the safety and natural reproduction of fish stocks. There are discussed the results of experimental studies of culverts made of metal corrugated pipes with a normal and spiral shape of corrugation the bottom of which is buried and filled with suitable granular material to the level of the natural channel of a small watercourse. It is established that when 10% of the area of the corrugated pipe is occupied by stone filling, its throughput is reduced by about 10-12%. Based on the review of the existing literature and the results of laboratory experiments, data is provided to estimate the values of the roughness coefficients of the composite cross-section of a single-point junction and directions for future research on culvert reclamation are outlined. Studying of the structure of the velocity distribution in culverts can lead to the improved conditions for fish passage without installing special structural elements in the transit path of the fish passage structure.
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SEMENOVA, K. S., et O. V. KABLUKOV. « THE METHODOLOGY OF MONITORING THE TWO-WAY REGULATION OF SOIL MOISTURE DURING THE OPERATION OF ENGINEERING RECLAMATION SYSTEMS ». Prirodoobustrojstvo, no 4 (2021) : 23–30. http://dx.doi.org/10.26897/1997-6011-2021-4-23-30.
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The purpose of the performed research is, based on the analysis of field studies, to select a well (point) for the selection of averaged moisture in the inter-drainage space for monitoring reclamation systems, to justify the construction of drainage-humidification systems to regulate moisture in a fire-hazardous peat bog. To solve the problem, a scheme has been developed for organizing monitoring on engineering reclamation systems that provide a two-way regulation of the water regime in the root layer of the soil in the zone of unstable moisture, as well as for monitoring and ensuring fire safety of the entire peat profile. The article discusses measuring equipment for determining the dynamics of soil moisture which must be used to monitor reclamation systems. There are given the results of field studies on peat bogs of the floodplain of the Dubna River, Moscow region, namely: meteorological data and data on soil moisture. On the basis of the research carried out, a representative point of moisture sampling for monitoring of reclamation systems has been substantiated. The sampling point should be located on a typical plot with the same relief, the soil profile should be uniform with the properties and soil morphology characteristic of the entire field. Wells for sampling checks the value of the distance in ¼E (E is the distance between drains), in this case the measured value is close to the average value in relation to the entire section of the drainage-humidified system. For the soil conditions of the experimental site, the humidity in the selected well during the locking of the canal in the dry period of summer increased by 1.5 times reaching the fireproof one. It is noted that when supplying and maintaining a propped water level in a channel up to 85 cm deep for 5 or more hours, the humidity in the interdrains space rises to the value of the fire safety norm in the dry period.
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Larin, Dmitry, Evgeny Mikhaylov et Elena Staseva. « Restoration of the disturbed natural hydrological regime of the fish-breeding channel Kazachy Yerik within the framework of fishery reclamation ». E3S Web of Conferences 273 (2021) : 03007. http://dx.doi.org/10.1051/e3sconf/202127303007.
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Intensive economic use of small rivers and channel water bodies leads to their pollution and siltation. The anthropogenic impact on aquatic ecosystems negatively affects the state of the fish industry, which leads to a reduction in the spawning fund, deterioration of the conditions for reproduction and survival of juveniles. Violation of the existing conditions for the habitat and reproduction of aquatic organisms leads to a decrease in the productivity of water bodies and the loss of their fishery value. The inflow from the catchment area of solid and liquid runoff containing organic matter, oil products and other impurities of anthropogenic and technogenic origin leads to irreversible entry, siltation and shallowing of small rivers and channel water bodies. The restoration of the disturbed hydrological regime of water bodies by means of reclamation works contributes to the restoration of natural spawning grounds for commercial fish species, an increase in yield and productivity.
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MacDonald, Graham K., Paula E. Noel, Danika van Proosdij et Gail L. Chmura. « The Legacy of Agricultural Reclamation on Channel and Pool Networks of Bay of Fundy Salt Marshes ». Estuaries and Coasts 33, no 1 (28 octobre 2009) : 151–60. http://dx.doi.org/10.1007/s12237-009-9222-4.
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Pan, Xicai, Stefan Jaumann, Jiabao Zhang et Kurt Roth. « Efficient estimation of effective hydraulic properties of stratal undulating surface layer using time-lapse multi-channel GPR ». Hydrology and Earth System Sciences 23, no 9 (10 septembre 2019) : 3653–63. http://dx.doi.org/10.5194/hess-23-3653-2019.
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Abstract. Multi-scale soil architectures in shallow subsurface are widespread in natural and anthropogenic depositional environments, and acquisition of the surface stratal structure and hydrological properties are essential in quantifying water cycling. Geophysical methods like ground-penetrating radar (GPR) can provide quantitative information like soil architecture and spatiotemporal soil water content distribution for the shallow layer. Concerning the informative multi-dimensional water flow in the surface layer with an undulating bottom at the plot scale, this study assesses the feasibility of efficiently estimating soil hydraulic properties using a few time-lapse multi-channel GPR observations, namely soil water storage and layer thickness of the surface layer, at reclamation land near an old river channel. We show that effective hydraulic properties of the surface layer can be obtained with a small number of time-lapse GPR measurements during a rainfall event. Additionally, we analyze the effect of some key factors controlling the informative lateral water redistribution on the results of the proposed approach using synthetic simulations.
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SNEZHKO, V. L., D. M. BENIN et D. D. KOBOZEV. « INFLUENCE OF DESIGN FEATURES ON THE REGULATING CAPACITY OF INJECTION WATER OUTLETS ». Prirodoobustrojstvo, no 5 (2021) : 91–97. http://dx.doi.org/10.26897/1997-6011-2021-5-91-97.
Texte intégralRésumé :
The high degree of deterioration of hydraulic structures of reclamation systems and a decrease in the efficiency of using reclaimed land required the adoption at the state level of a number of programs The high degree of deterioration of hydraulic structures of reclamation systems and a decrease in the efficiency of using reclaimed land required the adoption at the state level of a number of programs aimed at the development and modernization of the reclamation complex of Russia. Ensuring the water regime on irrigated lands requires the introduction of technological innovations that can ensure the regulation of the water supply of hydraulic structures without involving non-renewable energy sources with maximum savings in water resources. The injection flow controllers considered in the work are able to use the hydraulic energy of the flow and carry out the control process with feedback.With a decrease in water consumption downstream, the regulator changes its capacity, providing the circulation of excess incoming water at the end of the structure. The operation of water outlets is based on the injection process, in which the regulator is a kind of jet pump located under the structure blocking the channel or under the dam of a small pond. The energy of the flow passing through the pipe from the upper stream is used to inject excess water coming from the reverse wave current through the diverting channel. The results of theoretical studies, physical and numerical modeling of injection water outlets with various forms of execution of the flow part are presented. Particular attention is paid to the execution of the output section of the structure – the diffuser and the prismatic section in front of it – the mixing chamber. The values of the hydraulic resistance coefficients of pyramidal diffusers with a high degree of expansion were studied and obtained for the first time. To prevent flow failure, the diffusers are equipped with shortened separate walls. The processing of the experiment data is carried out in accordance with international standards. When numerically modeling the flow in the regulator, the data of the physical experiment are used as the initial and boundary conditions. There is given a comparison of the fl ow rate of the studied regulators, the values of the parameters necessary for performing the hydraulic calculation are determined.
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Rijal, G., C. Petropoulou, J. K. Tolson, M. DeFlaun, C. Gerba, R. Gore, T. Glymph et al. « Dry and wet weather microbial characterization of the Chicago area waterway system ». Water Science and Technology 60, no 7 (1 octobre 2009) : 1847–55. http://dx.doi.org/10.2166/wst.2009.598.
Texte intégralRésumé :
The Chicago Area Waterway System (CAWS) is a man-made channel, which serves the Chicago area for the drainage of urban storm water and the conveyance of secondary treated effluent from the Metropolitan Water Reclamation District of Greater Chicago's (District) North Side, Stickney and Calumet water reclamation plants (WRPs). A microbial characterization of the CAWS upstream and downstream of the WRPs and from the WRP outfall was initiated by collecting dry and wet weather samples and analyzing for indicators and pathogens. During dry weather, indicator bacteria (fecal coliform [FC], E. coli [EC], enterococci [EN]) were the most abundant microbial species detected in the CAWS compared to pathogens (Salmonella spp [SA], enteric viruses [EV], adenovirus [AV], norovirus [NV] and Giardia and Cryptosporidium). Pseudomonas aeruginosa [PA] levels in the outfall samples were either lower or equivalent to the CAWS. The wet weather samples had a higher frequency of detection of indicator bacteria and pathogens compared to dry weather samples. Overall, the concentrations of pathogens in the CAWS, representing the weather conditions experienced in a recreational year, were relatively low. The study concluded that the presence of pathogens in the CAWS downstream of the WRPs were due to secondary loading of the waterway under wet weather conditions from combined sewer overflows (CSOs) and other discharges.
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Fang, Jin-Qi. « Lake Evolution during the Last 3000 Years in China and Its Implications for Environmental Change ». Quaternary Research 39, no 2 (mars 1993) : 175–85. http://dx.doi.org/10.1006/qres.1993.1021.
Texte intégralRésumé :
AbstractTaking China as a whole, lake expansion occurred 500 B.C. (?)-0 A.D., 650-950 A.D., and 1250-1650 A.D. over the past 3000 yr. The expansions were mainly due to climatic fluctuations and correspond to frequent flood reports. Three regional characteristics of lake development have been recognized. (1) Fluctuations of near-coastal lakes, and those in other regions as well, were out of phase during 500 B.C.-500 A.D., which possibly resulted from out-of-phase fluctuations of climate and sea level on 10- to 100-yr time scale. (2) As the lower Yellow River channel migrated southward, the lakes in the south of the North China Plain formed and reached their largest sizes much later than those in the north. (3) For the lakes in the middle and lower Yangtze River valley, the higher a lake basin lies above a neighboring river and the further the lake is from the river's mouth, in general, the younger the lake is. Through land reclamation, the ancient Chinese have changed most of the lakes greatly. However, human activities were also constrained in certain ways by the natural changes of the lakes. Reclamation usually was banned and farmland was abandoned to repair reservoirs while lakes were expanding.
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Zhang, Bohu, Zhiyong Zhang, Fuyuan Chen et Kun He. « Study on the Morphological Evolution of the Oujiang Estuary, China, in the 21st Century ». Journal of Marine Science and Engineering 11, no 2 (8 février 2023) : 378. http://dx.doi.org/10.3390/jmse11020378.
Texte intégralRésumé :
Based on four years of spatially synchronous topographic data of the Oujiang Estuary from 2002 to 2019, the variations and physical mechanisms of estuarine evolution driven by natural conditions and human activities since the beginning of this century were analyzed. The results show that the evolution of the Oujiang Estuary has changed dramatically in the past 20 years. From 2002 to 2019, the net sediment erosion of the estuary was 163.44 million m3, and the average bed elevation of the river-dominated section (RDS), transition section (TS) and tide-dominated section (TDS) decreased by 4.61 m, 1.30 m and 2.14 m, respectively. In addition, the pattern of the shoal channel had changed, and the river facies coefficient (width–depth ratio) decreased by 16–64%. The evolution of the Oujiang Estuary is mainly caused by human activities (such as sand mining, reclamation). Sand mining is the direct cause of riverbed undercutting, and the large undercutting of riverbed terrain causes the increase in tidal power in the estuary and further causes river channel scouring. In the last 20 years, the average annual tidal range of the estuary increased by 0.19–1.14 m, and the flood discharge increased by about 17–80%, with an average value of 58%. The impact of tidal power on the evolution and development of the estuary has increased significantly. Apart from sand mining, reclamation projects such as the Wenzhou shoal outside the mouth also cause the local velocity of the tidal current section to increase, which aggravates the scouring trend of local river sections downstream. The scouring and silting changes in the Oujiang Estuary since the beginning of this century are the result of the adjustment of the estuarine system in response to the strong intervention of human activities.