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Kandari, Ester Ria Dwi - One of the best experts on this subject based on the ideXlab platform.
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UJI STABILITAS CHECK DAM KEDUNGREJO 15 DI KALI KONTO KECAMATAN PUJON KABUpATEN MALANG
'Unitri Press', 2017Co-Authors: Suhudi Suhudi, Kandari, Ester Ria DwiAbstract:Cactment area Kali Konto is the part of Up stream Brantas which is located in Pujon Malang It’s 233 km2. The main building water that’s located at DAS Brantas Hulu is Selorejo reservoir. It’s ethnic age reach 100 years but will be reduced because the Silting Up of reservoir. It’s caused of the big erotion and sedimentation in the water arrest area. The erotion happened more than the limit of tolerance from the land erotion whichs is permitted. Kali Konto is the biggest sedimentation contributor for Selorejo Reservoir. One of the action in case erotion and sedimentation in the river is by building Sediment Controller Building or generally mentioned by Check Dam. From the calculation stated that the dimension of check dam will be made of river stone like the elevation of top spillway peak dam main in 862 m with effectife height amount of 4 m and foundation depth amount of 2 m, the width of mercu pelimpah main dam amount of 3 m with discharge in the repeatance periode is 50 years amount of 1186,79 m3/sec, the controlling height amount of 1 m. The analytic of building stability check dam is in the safe condition, it is 1,27 1,2 (required)
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UJI STABILITAS CHECK DAM KEDUNGREJO 15 DI KALI KONTO KECAMATAN PUJON KABUpATEN MALANG
Reka Buana: Jurnal Ilmiah Teknik Sipil dan Teknik Kimia, 2016Co-Authors: Suhudi Suhudi, Kandari, Ester Ria DwiAbstract:Cactment area Kali Konto is the part of Up stream Brantas which is located in Pujon Malang It’s 233 km2. The main building water that’s located at DAS Brantas Hulu is Selorejo reservoir. It’s ethnic age reach 100 years but will be reduced because the Silting Up of reservoir. It’s caused of the big erotion and sedimentation in the water arrest area. The erotion happened more than the limit of tolerance from the land erotion whichs is permitted. Kali Konto is the biggest sedimentation contributor for Selorejo Reservoir. One of the action in case erotion and sedimentation in the river is by building Sediment Controller Building or generally mentioned by Check Dam. From the calculation stated that the dimension of check dam will be made of river stone like the elevation of top spillway peak dam main in 862 m with effectife height amount of 4 m and foundation depth amount of 2 m, the width of mercu pelimpah main dam amount of 3 m with discharge in the repeatance periode is 50 years amount of 1186,79 m 3 /sec, the controlling height amount of 1 m. The analytic of building stability check dam is in the safe condition, it is 1,27 > 1,2 (required). Key words: flood discharge, check dam, stabilit
Robresco Sebastien - One of the best experts on this subject based on the ideXlab platform.
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Enregistrements d'événements extrêmes et évolution des paysages dans les basses vallées luviales du Taravo et du Sagone (Corse occidentale, France) au cours de l'âge du Bronze moyen à inal : une perspective géoarchéologique
'OpenEdition', 2017Co-Authors: Ghilardi Matthieu, Delanghe Doriane, Demory Francois, Leandri Franck, Peche-quilichini Kewin, Vacchi Matteo, Vella Marc-antoine, Rossi Veronica, Robresco SebastienAbstract:The west coast of Corsica includes a series of freshwater ponds and coastal marshes which are located in the lower river valleys, at a short distance from the river mouths. he origin and the morphodynamic evolution of these wetlands have seen little investigation from both geomorphological and palaeoenvironmental perspectives while the archaeological context is well documented, in particular for the periods ranging from the Early to the Late Bronze Age. Archaeological research indicates that probable changes in landscape coniguration occurred during the second half of the 2nd millennium BC, leaving the river valleys unsuitable places for human occUpation: only megaliths with humanlike faces are found, while the habitats are mainly situated on the Upper slopes of the valleys. Until now, this question has never been evaluated by geomorphologists and palaeoenvironmentalists. Here, geoarchaeological research aims to evaluate the dynamics of human settlement around the wetlands within the lower river valleys. he objective is therefore founded on the need to better understand their morpho-sedimentary evolution during Mid-Holocene via correlation with hydroclimatic oscillations and an assessment of their impact on the dynamics of human occUpation and resilience. With these issues in mind, two major Corsican river valleys, comprising Bronze Age archaeological evidence, have been investigated: the Sagone and the Taravo rivers. Palaeoenvironmental methods comprise the coring of four boreholes drilled in three diferent ponds. Palaeontological identiications (ostracods and foraminifera) combined with mollusc analyses helped identify the diferent environments. he sedimentological analyses are based on a granulometric study (LASER method) and the measurements of the magnetic parameters (magnetic susceptibility and thermomagnetism) of both, the sediments derived from the cores and the whole Taravo river drainage basin. Finally, a series of twenty-seven radiocarbon dates were taken, and these facilitated the creation of a robust chronostratigraphy for each site. he most relevant results reveal that an increase of marine incursions (storm events notably) is recorded between 1650 and 1100 cal. BC for both lower valleys. In parallel, an important luvial and torrential detritism is observed from 1300 to 1000 cal. BC, this created an induced Silting Up of some ponds. Both extreme events (that were initiated during Mid Bronze Age and that continued during the irst phase of Late Bronze Age) can be explained by regional climate variability observed at around the 3.2 ka BP: a cold and arid RCC event in the Mediterranean within a context of high anthropisation of the slopes from the southwest river valleys of Corsica
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Enregistrements d'\uc3\ua9v\uc3\ua9nements extr\uc3\uaames et \uc3\ua9volution des paysages dans les basses vall\uc3\ua9es luviales du Taravo et du Sagone (Corse occidentale, France) au cours de l'\uc3\ua2ge du Bronze moyen \uc3\ua0 inal : une perspective g\uc3\ua9oarch\uc3\ua9ologique
'OpenEdition', 2017Co-Authors: Ghilardi Matthieu, Delanghe Doriane, Demory Francois, Leandri Franck, Peche-quilichini Kewin, Vacchi Matteo, Vella Marc-antoine, Rossi Veronica, Robresco SebastienAbstract:The west coast of Corsica includes a series of freshwater ponds and coastal marshes which are located in the lower river valleys, at a short distance from the river mouths. he origin and the morphodynamic evolution of these wetlands have seen little investigation from both geomorphological and palaeoenvironmental perspectives while the archaeological context is well documented, in particular for the periods ranging from the Early to the Late Bronze Age. Archaeological research indicates that probable changes in landscape coniguration occurred during the second half of the 2nd millennium BC, leaving the river valleys unsuitable places for human occUpation: only megaliths with humanlike faces are found, while the habitats are mainly situated on the Upper slopes of the valleys. Until now, this question has never been evaluated by geomorphologists and palaeoenvironmentalists. Here, geoarchaeological research aims to evaluate the dynamics of human settlement around the wetlands within the lower river valleys. The objective is therefore founded on the need to better understand their morpho-sedimentary evolution during Mid-Holocene via correlation with hydroclimatic oscillations and an assessment of their impact on the dynamics of human occUpation and resilience. With these issues in mind, two major Corsican river valleys, comprising Bronze Age archaeological evidence, have been investigated: the Sagone and the Taravo rivers. Palaeoenvironmental methods comprise the coring of four boreholes drilled in three diferent ponds. Palaeontological identiications (ostracods and foraminifera) combined with mollusc analyses helped identify the diferent environments. he sedimentological analyses are based on a granulometric study (LASER method) and the measurements of the magnetic parameters (magnetic susceptibility and thermomagnetism) of both, the sediments derived from the cores and the whole Taravo river drainage basin. Finally, a series of twenty-seven radiocarbon dates were taken, and these facilitated the creation of a robust chronostratigraphy for each site. he most relevant results reveal that an increase of marine incursions (storm events notably) is recorded between 1650 and 1100 cal. BC for both lower valleys. In parallel, an important luvial and torrential detritism is observed from 1300 to 1000 cal. BC, this created an induced Silting Up of some ponds. Both extreme events (that were initiated during Mid Bronze Age and that continued during the irst phase of Late Bronze Age) can be explained by regional climate variability observed at around the 3.2 ka BP: a cold and arid RCC event in the Mediterranean within a context of high anthropisation of the slopes from the southwest river valleys of Corsica
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Recording extreme events and reconstructing past landscapes within the Taravo and Sagone lower fluvial valleys (Western Corsica, France) during the Mid-to Late Bronze Age: a geoarchaeological perspective
'OpenEdition', 2017Co-Authors: Ghilardi Matthieu, Delanghe Doriane, Demory Francois, Leandri Franck, Peche-quilichini Kewin, Vacchi Matteo, Vella Marc-antoine, Rossi Veronica, Robresco SebastienAbstract:International audienceThe west coast of Corsica includes a series of freshwater ponds and coastal marshes which are located in the lower river valleys, at a short distance from the river mouths. The origin and the morphodynamic evolution of these wetlands have seen little investigation from both geomorphological and palaeoenvironmental perspectives while the archaeological context is well documented, in particular for the periods ranging from the Early to the Late Bronze Age. Archaeological research indicates that probable changes in landscape configuration occurred during the second half of the 2nd millennium BC, leaving the river valleys unsuitable places for human occUpation: only megaliths with humanlike faces are found, while the habitats are mainly situated on the Upper slopes of the valleys. Until now, this question has never been evaluated by geomorphologists and palaeoenvironmentalists. Here, geoarchaeological research aims to evaluate the dynamics of human settlement around the wetlands within the lower river valleys. The objective is therefore founded on the need to better understand their morpho-sedimentary evolution during Mid-Holocene via correlation with hydroclimatic oscillations and an assessment of their impact on the dynamics of human occUpation and resilience. With these issues in mind, two major Corsican river valleys, comprising Bronze Age archaeological evidence, have been investigated: the Sagone and the Taravo rivers. Palaeoenvironmental methods comprise the coring of four boreholes drilled in three different ponds. Palaeontological identifications (ostracods and foraminifera) combined with mollusc analyses helped identify the different environments. The sedimentological analyses are based on a granulometric study (LASER method) and the measurements of the magnetic parameters (magnetic susceptibility and thermomagnetism) of both, the sediments derived from the cores and the whole Taravo river drainage basin. Finally, a series of twenty-seven radiocarbon dates were taken, and these facilitated the creation of a robust chronostratigraphy for each site. The most relevant results reveal that an increase of marine incursions (storm events notably) is recorded between 1650 and 1100 cal. BC for both lower valleys. In parallel, an important fluvial and torrential detritism is observed from 1300 to 1000 cal. BC, this created an induced Silting Up of some ponds. Both extreme events (that were initiated during Mid Bronze Age and that continued during the first phase of Late Bronze Age) can be explained by regional climate variability observed at around the 3.2 ka BP: a cold and arid RCC event in the Mediterranean within a context of high anthropisation of the slopes from the southwest river valleys of Corsica
K. Beryouni - One of the best experts on this subject based on the ideXlab platform.
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Silting Up and development of anoxic conditions enhanced by high abundance of the geoengineer species Ophiothrix fragilis
Continental Shelf Research, 2016Co-Authors: A. Murat, Y. Méar, E. Poizot, Jean-claude Dauvin, K. BeryouniAbstract:In the English Channel, the brittle-star Ophiothrix fragilis is a common epifaunal species typically found on pebbles in habitats with strong tidal currents. This species forms dense aggregations on the seafloor, sUpporting populations that can reach Up to 7500 ind m−2 in the eastern part of the Baie de Seine, offshore from Antifer harbour. Here, O. fragilis occurs in an area with unexpected amounts of fine-grained sediment. Some of these mud deposits are made Up of unusually compact black muds, an indication of the development of anoxic conditions in surficial sediments. To highlight a potential link between Silting Up and dense O. fragilis populations, and identify the interactions between environmental conditions and the population dynamics of this species, we analyse the data from three surveys corresponding to exceptional situations: (1) just after a Seine flood; (2) just after a storm and (3) after a period of ten months without any flood or storm. Four parameters are taken into account: number of brittle stars per 0.25 m2, Fine Fraction percentage, Total Organic Carbon and Total Sulphur. The main environmental forcings appear to be Seine river inflow, regional circulation dependent on tidal currents and the occurrence of storms. O. fragilis is able to geoengineer its environment in various ways and at different rates. Silting Up is enhanced by increasing abundance of O. fragilis and takes place at a very fast rate. As a result, floods and storms reflecting instantaneous events give rise to a steady-state situation established between the abundance of this species and the fine fraction percentage. Anoxic conditions are dependent on the degradation of organic matter and require more time to be established. After many months in the absence of any disturbing events, anoxic conditions are developed in non-compacted muddy sediments (stability situation) and represent the normal surficial situation when the sediment becomes compacted (compact black muds). The development of anoxic conditions is dependent on the abundance of the O. fragilis population and occurs at a very slow rate.
Jean-claude Dauvin - One of the best experts on this subject based on the ideXlab platform.
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Silting Up and development of anoxic conditions enhanced by high abundance of the geoengineer species Ophiothrix fragilis
Continental Shelf Research, 2016Co-Authors: A. Murat, Y. Méar, E. Poizot, Jean-claude Dauvin, K. BeryouniAbstract:In the English Channel, the brittle-star Ophiothrix fragilis is a common epifaunal species typically found on pebbles in habitats with strong tidal currents. This species forms dense aggregations on the seafloor, sUpporting populations that can reach Up to 7500 ind m−2 in the eastern part of the Baie de Seine, offshore from Antifer harbour. Here, O. fragilis occurs in an area with unexpected amounts of fine-grained sediment. Some of these mud deposits are made Up of unusually compact black muds, an indication of the development of anoxic conditions in surficial sediments. To highlight a potential link between Silting Up and dense O. fragilis populations, and identify the interactions between environmental conditions and the population dynamics of this species, we analyse the data from three surveys corresponding to exceptional situations: (1) just after a Seine flood; (2) just after a storm and (3) after a period of ten months without any flood or storm. Four parameters are taken into account: number of brittle stars per 0.25 m2, Fine Fraction percentage, Total Organic Carbon and Total Sulphur. The main environmental forcings appear to be Seine river inflow, regional circulation dependent on tidal currents and the occurrence of storms. O. fragilis is able to geoengineer its environment in various ways and at different rates. Silting Up is enhanced by increasing abundance of O. fragilis and takes place at a very fast rate. As a result, floods and storms reflecting instantaneous events give rise to a steady-state situation established between the abundance of this species and the fine fraction percentage. Anoxic conditions are dependent on the degradation of organic matter and require more time to be established. After many months in the absence of any disturbing events, anoxic conditions are developed in non-compacted muddy sediments (stability situation) and represent the normal surficial situation when the sediment becomes compacted (compact black muds). The development of anoxic conditions is dependent on the abundance of the O. fragilis population and occurs at a very slow rate.
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the intra annual variability of soft bottom macrobenthos abundance patterns in the north channel of the seine estuary
Hydrobiologia, 2007Co-Authors: Nicolas Desroy, Annelaure Janson, Lionel Denis, Gregory Charrier, Sandric Lesourd, Jean-claude DauvinAbstract:Temporal and spatial variability of the Abra alba–Pectinaria koreni and Macoma balthica communities was examined in the northern part of the Seine estuary (North Channel) over different space and time scales in order to assess the role that the hydrologic regime and/or anthropogenic influences play in defining benthic communities over time. Sediment in the North Channel displayed strong spatial and temporal variability, sustained by intense sediment transport episodes. Total macrobenthic abundances ranged widely on the course of the year and there was no evidence of a seasonal signal for the density fluctuations, whatever the spatial scale considered. The bio-sedimentary dynamics can be divided into two periods: the first corresponds to the high flow rate period (January–May) during which fauna is influenced by fine silt/clay deposition, and the second to the low flow rate period (June–December) during which sandy deposits prevail. Despite the absence of significant correlations between sediment composition and abundance, episodes of sediment transport seem to be an important structuring mechanism in the Seine estuary. As a consequence, the faunal composition varied throughout the year. The winter and spring fauna, characterised by species living on muddy fine-sands or muds, were enriched during the summer and autumn by species living in clean fine sand, such as Donax vittatus, Nephtys cirrosa or Spio decoratus, mainly represented by adult individuals. Secondary settlement of drifters may explain the rapid structuration of assemblages a few days after the sandy deposits. Our results suggest the importance of the bentho-pelagic coUpling, primarily induced by the sedimentary instability, on the macrobenthic fauna dynamics. The intra-annual variability of assemblages at the mouth of the Seine river and the silted situation of the North Channel might simply be the result of the Silting Up and alteration of the inner estuary, generated by several decades of man-made modifications and natural processes.
Yuhong Liu - One of the best experts on this subject based on the ideXlab platform.
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evolution process and related driving mechanisms of yellow river delta since the diversion of yellow river
Journal of Applied Ecology, 2011Co-Authors: Guangxuan Han, Guangmei Wang, Zhidong Zhang, Peili Mao, Yuhong LiuAbstract:Based on the 23 sheets of remote sensing images from 1976 to 2009, in combining with the water and sediment data from Lijin station and the annual precipitation data of Yellow River Basin from 1976 to 2008, this paper quantitatively analyzed the features of water and sediment discharge from Yellow River, and the evolution process of Yellow River Delta and related driving mechanisms. In 1976-2008, the annual runoff and the annual sediment discharge into sea changed largely and frequently, but overall, presented a decreasing trend. Since the course of the Yellow River changed its direction to Qingshui channel in 1976, the Delta coastline and area were generally in a Silting-Up state. The evolution process of the Delta could be approximately divided into three stages, i.e., 1976-1985, 1986-1995, and 1996-2009, and the increasing rate of the Delta decreased with the stages. The coastline and area of the Delta were significantly exponentially correlated to the sediment accumulated at Lijin station, and the inter-annual variation of the precipitation of the Yellow River Basin had a strong correlation with that of the sediment at Lijin station, suggesting that the annual variation of the precipitation in Yellow River Basin was the main factor affecting the runoff and sediment discharge into sea.