K. Onitsuka, J. Akiyama, Akiyoshi Yamamoto, T. Waki
Schooling behavior of fish and interaction between a few individual fish in schooling have been investigated. However, swimming behavior of isolated fish has not been investigated. In this study, the swimming behavior of isolated ayu in the circular pools with changing the radius was recorded with a digital video camera. It was found that the swimming trajectory of ayu can be described by nodes and branches. The frequencies of the swimming distance and angle between each branch are modeled by the gamma distribution. The mean swimming distance of each branch divided by the body length is 2.51 and the mean angle between each branch is 72.5. The directions of angle between each branch do not depend on the swimming distance and also the angle just before the swimming.
{"title":"SWIMMING BEHAVIOR OF ISOLATED AYU IN STATISTIC WATER","authors":"K. Onitsuka, J. Akiyama, Akiyoshi Yamamoto, T. Waki","doi":"10.2208/PROHE.52.1195","DOIUrl":"https://doi.org/10.2208/PROHE.52.1195","url":null,"abstract":"Schooling behavior of fish and interaction between a few individual fish in schooling have been investigated. However, swimming behavior of isolated fish has not been investigated. In this study, the swimming behavior of isolated ayu in the circular pools with changing the radius was recorded with a digital video camera. It was found that the swimming trajectory of ayu can be described by nodes and branches. The frequencies of the swimming distance and angle between each branch are modeled by the gamma distribution. The mean swimming distance of each branch divided by the body length is 2.51 and the mean angle between each branch is 72.5. The directions of angle between each branch do not depend on the swimming distance and also the angle just before the swimming.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"1998 1","pages":"1195-1200"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88222139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extreme environmental events such as rainstorms give severe consequences to human society. Magnitude evaluation of an extreme event for a given return period is an important step in planning of flood prevention facilities. The estimation of the spatial distribution of magnitude is difficult because extreme events are rare and the data record is often short. Regionalization resolves this problem by “trading space for time”; data from several sites are used in estimating event frequencies at any one site. Applying regional frequency analysis, regression analysis and kriging method to Miyagi prefecture, we have obtained the estimates and the accuracy for probable rainfall and discussed incorporation of orographic effects.
{"title":"ESTIMATION OF SPATIAL DISTRIBUTION OF PROBABLE RAINFALL BY REGIONALIZATION","authors":"A. Mano, Ryoji Nakayama","doi":"10.2208/PROHE.52.217","DOIUrl":"https://doi.org/10.2208/PROHE.52.217","url":null,"abstract":"Extreme environmental events such as rainstorms give severe consequences to human society. Magnitude evaluation of an extreme event for a given return period is an important step in planning of flood prevention facilities. The estimation of the spatial distribution of magnitude is difficult because extreme events are rare and the data record is often short. Regionalization resolves this problem by “trading space for time”; data from several sites are used in estimating event frequencies at any one site. Applying regional frequency analysis, regression analysis and kriging method to Miyagi prefecture, we have obtained the estimates and the accuracy for probable rainfall and discussed incorporation of orographic effects.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"71 1","pages":"217-222"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86414341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yoichi Takahashi, T. Fujino, Hnin Wityi, T. Asaeda
This topic presents the effect of water temperature on benthic invertebrate growth and assemblages at downstream site of the Dam in winter, in Japan. The surface layer water of dam was released, and the temperature was always 3-5 degrees higher than the upstream. This was because of tentative manipulation of dam. Life cycles of dominated species were faster and their body size were all larger in the downstream than the upstream. Kamimuria tibialis (Perlidae) as a predator grew faster. Also, its body weight was much heavier than in the upstream, even its body length is the same in the upstream. Periphyton biomass was also much higher, especially, filamentous species were dominated at slow current site in the downstream. Regardless of abundance of periphyton, Heptageniidae as a grazer were not increased compared with the upstream. Besides discharge control, water temperature changes invertebrate assemblages quickly. This result implies that restrict of the movement of species is need to consideration.
{"title":"COMPARISON OF BENTHIC INVERTEBRATE ASSEMBLAGES BETWEEN PRE AND AFTER IMPOUNDMENT AT UP- AND DOWNSTREAM OF DAM","authors":"Yoichi Takahashi, T. Fujino, Hnin Wityi, T. Asaeda","doi":"10.2208/PROHE.52.1165","DOIUrl":"https://doi.org/10.2208/PROHE.52.1165","url":null,"abstract":"This topic presents the effect of water temperature on benthic invertebrate growth and assemblages at downstream site of the Dam in winter, in Japan. The surface layer water of dam was released, and the temperature was always 3-5 degrees higher than the upstream. This was because of tentative manipulation of dam. Life cycles of dominated species were faster and their body size were all larger in the downstream than the upstream. Kamimuria tibialis (Perlidae) as a predator grew faster. Also, its body weight was much heavier than in the upstream, even its body length is the same in the upstream. Periphyton biomass was also much higher, especially, filamentous species were dominated at slow current site in the downstream. Regardless of abundance of periphyton, Heptageniidae as a grazer were not increased compared with the upstream. Besides discharge control, water temperature changes invertebrate assemblages quickly. This result implies that restrict of the movement of species is need to consideration.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"21 1","pages":"1165-1170"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86188453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The erosion rate of naturally deposited cohesive sediment on river beds was investigated experimentally. In this study, we tried to establish reasonably the preparation procedure of a test sample which has almost same property of deposited cohesive sediment in an actual field of each river. After some detailed investigations about the preparation of test sample, a series of experiments were conducted in a laboratory flume in a same manner as that of our previous work. As a result of this erosion experiments, it was found that the measured data has the same tendency as that obtained by previous work.
{"title":"EXPERIMENTAL STUDY ON THE EROSION RATE OF NATURALLY DEPOSITED COHESIVE SEDIMENT ON RIVER BEDS","authors":"K. Nishimori, M. Sekine, T. Higuchi, Toshio Akagi","doi":"10.2208/PROHE.52.541","DOIUrl":"https://doi.org/10.2208/PROHE.52.541","url":null,"abstract":"The erosion rate of naturally deposited cohesive sediment on river beds was investigated experimentally. In this study, we tried to establish reasonably the preparation procedure of a test sample which has almost same property of deposited cohesive sediment in an actual field of each river. After some detailed investigations about the preparation of test sample, a series of experiments were conducted in a laboratory flume in a same manner as that of our previous work. As a result of this erosion experiments, it was found that the measured data has the same tendency as that obtained by previous work.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"76 1","pages":"541-546"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86313480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nakashita, T. Hibino, S. Fukuoka, M. Okada, Masamitsu Mizuno
Water environment at tidal flat is maintained by the provision of groundwater in Ota River Floodway during a flood. In this paper, variation characteristics of groundwater quality in the tidal flat, located in 5.4 km upstream from Ota River mouth were investigated by river discharge and groundwater level in Ota Rive Delta. It is considered that salinity of the groundwater in the tidal flat was decreased by outflow of the groundwater in Ota River Delta. The high gradient of water level was formed by high ground water level in the rainy season and small amplitude of the tide under the ground of the delta. As a result, ground water in the delta is easy to flow into the tidal flat.
{"title":"VARIATION CHARACTERISTICS OF GROUNDWATER QUALITY IN TIDAL FLAT DURING FLOOD PERIOD","authors":"S. Nakashita, T. Hibino, S. Fukuoka, M. Okada, Masamitsu Mizuno","doi":"10.2208/PROHE.52.1081","DOIUrl":"https://doi.org/10.2208/PROHE.52.1081","url":null,"abstract":"Water environment at tidal flat is maintained by the provision of groundwater in Ota River Floodway during a flood. In this paper, variation characteristics of groundwater quality in the tidal flat, located in 5.4 km upstream from Ota River mouth were investigated by river discharge and groundwater level in Ota Rive Delta. It is considered that salinity of the groundwater in the tidal flat was decreased by outflow of the groundwater in Ota River Delta. The high gradient of water level was formed by high ground water level in the rainy season and small amplitude of the tide under the ground of the delta. As a result, ground water in the delta is easy to flow into the tidal flat.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"48 11 1","pages":"1081-1086"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82794304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the applications of the Large eddy simulation (LES) to open-channel flows with roughness, water surface is usually treated as a fixed boundary by neglecting the effects of surface fluctuation generated by boil vortices or relatively large surface variations caused by the drag force at each roughness element. In the present study, in order to expand the applicability of LES to such general conditions, the bottom topography is treated by introducing the immersed boundary method and the free surface variation is simulated by introducing a density function. It was made clear that the developed model is capable to represent relatively large surface variations in the strip-roughness flows with various roughness spacings. The numerical results agreed fairly well with those obtained by PIV.
{"title":"ANALYSIS OF TURBULENT FLOW OVER ROUGHNESS BY LES AND PIV WITH WATER SURFACE FLUCTUATION","authors":"H. Yoshimura, I. Fujita","doi":"10.2208/PROHE.52.1015","DOIUrl":"https://doi.org/10.2208/PROHE.52.1015","url":null,"abstract":"In the applications of the Large eddy simulation (LES) to open-channel flows with roughness, water surface is usually treated as a fixed boundary by neglecting the effects of surface fluctuation generated by boil vortices or relatively large surface variations caused by the drag force at each roughness element. In the present study, in order to expand the applicability of LES to such general conditions, the bottom topography is treated by introducing the immersed boundary method and the free surface variation is simulated by introducing a density function. It was made clear that the developed model is capable to represent relatively large surface variations in the strip-roughness flows with various roughness spacings. The numerical results agreed fairly well with those obtained by PIV.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"18 1","pages":"1015-1020"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80771959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, river flow measurement equipment such as ADCP (Acoustic Doppler Current Profilers) has come down in cost and instrumentation technology has improved. As a result, developments of new flow measurement techniques and data correction methods are actively advancing. We measured the flood flow of Typhoon No. 5 in the Shimanto River at Gudo point in 2007 using an unmanned boat equipped with ADCP. From the measurement results, we report on boat operation in high velocity currents, methods of correcting measured data, and accuracy evaluation methods concerning moving observation using ADCP.
近年来，ADCP (Acoustic Doppler Current profiler)等河流流量测量设备的成本下降了，仪器技术也得到了提高。因此，新的流量测量技术和数据校正方法的发展正在积极推进。我们利用配备ADCP的无人船测量了2007年台风5号在岛渡河古岛点的洪水流量。从测量结果出发，介绍了高速海流中船舶的运行情况、测量数据的校正方法以及ADCP移动观测的精度评价方法。
{"title":"FLOOD FLOW OBSERVATION IN SHIMANTO RIVER GUDO POINT USING UNMANNED BOAT EQUIPPED WITH ADCP","authors":"S. Okada, T. Kitsuda, Seiro Morimoto, M. Masuda","doi":"10.2208/PROHE.52.919","DOIUrl":"https://doi.org/10.2208/PROHE.52.919","url":null,"abstract":"In recent years, river flow measurement equipment such as ADCP (Acoustic Doppler Current Profilers) has come down in cost and instrumentation technology has improved. As a result, developments of new flow measurement techniques and data correction methods are actively advancing. We measured the flood flow of Typhoon No. 5 in the Shimanto River at Gudo point in 2007 using an unmanned boat equipped with ADCP. From the measurement results, we report on boat operation in high velocity currents, methods of correcting measured data, and accuracy evaluation methods concerning moving observation using ADCP.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"16 1","pages":"919-924"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83791778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Field surveys, experiments and numerical calculations were conducted to examine driftwood accumulation in a river channel, with respect to the existence of sandbars. We investigated the areas where driftwood accumulated and captured from river channel is observed in two rivers. It seemed that factors such as the existence of riparian woods, sandbar configurations, and sandbar locations relative to the river flow determined the points of driftwood accumulation. Based on the field survey results, hydraulic model experiments investigated the flow path of driftwood in model river with alternate sandbars. The analysis related to flood flow indicates that when the flow velocity and the water depth of the main current differ greatly from the flow velocity and the water depth of the flow that is away from the main current, the force of the main current acting on driftwood pushes the driftwood outward. And we clarified the relationship between discharge and the locations of driftwood capture, traps were built at different points on a sandbar.
{"title":"ANALYSIS OF DRIFTWOOD BEHAVIOR AND ACCUMULATIONS ON SANDBAR CONSIDERING FLOOD FLOW AND DISCHARGE","authors":"H. Yabe, Yasuharu Watanabe","doi":"10.2208/PROHE.52.661","DOIUrl":"https://doi.org/10.2208/PROHE.52.661","url":null,"abstract":"Field surveys, experiments and numerical calculations were conducted to examine driftwood accumulation in a river channel, with respect to the existence of sandbars. We investigated the areas where driftwood accumulated and captured from river channel is observed in two rivers. It seemed that factors such as the existence of riparian woods, sandbar configurations, and sandbar locations relative to the river flow determined the points of driftwood accumulation. Based on the field survey results, hydraulic model experiments investigated the flow path of driftwood in model river with alternate sandbars. The analysis related to flood flow indicates that when the flow velocity and the water depth of the main current differ greatly from the flow velocity and the water depth of the flow that is away from the main current, the force of the main current acting on driftwood pushes the driftwood outward. And we clarified the relationship between discharge and the locations of driftwood capture, traps were built at different points on a sandbar.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"13 1","pages":"661-666"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84693955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A computational method has been developed to predict the movements of driftwoods transported by three-dimensional free-surface flows. A T-type solid model is introduced into the prediction method, MICS, which deals with a free-surface flow including floating objects as a multiphase flow field. In the T-type model, a driftwood is represented by multiple tetrahedron elements and its volume, mass and inertial tensors are accurately represented. The contact forces are evaluated with the contact-spheres distributed near the surfaces. The MICS with the T-type model was applied to experimental results and it was shown that the movements and accumulation of driftwoods are reasonably predicted by the present method.
{"title":"3D NUMERICAL PREDICTION FOR TRANSPORTATION AND ACCUMULATION OF DRIFT-WOODS WITH T-TYPE SOLID MODELS","authors":"O. Makino, S. Ushijima, N. Yoshikawa, I. Nezu","doi":"10.2208/PROHE.52.991","DOIUrl":"https://doi.org/10.2208/PROHE.52.991","url":null,"abstract":"A computational method has been developed to predict the movements of driftwoods transported by three-dimensional free-surface flows. A T-type solid model is introduced into the prediction method, MICS, which deals with a free-surface flow including floating objects as a multiphase flow field. In the T-type model, a driftwood is represented by multiple tetrahedron elements and its volume, mass and inertial tensors are accurately represented. The contact forces are evaluated with the contact-spheres distributed near the surfaces. The MICS with the T-type model was applied to experimental results and it was shown that the movements and accumulation of driftwoods are reasonably predicted by the present method.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"44 1","pages":"991-996"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84809901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to clarify the runoff mechanism in urban catchment area, field observation of discharge and application of runoff analysis to the urban catchments are reported in this paper. Land-use in urban area has become more complicated by urbanization during the last several decades. As a result of urbanization, the peak discharge increases and the concentration time of flood decreases. It makes flood disasters in urban area more serious problem. On the other hand, discharge data in urban catchments are very few. In this paper, field observation of discharge are carried out and runoff analysis method for land surface area based on morphological and geological properties is applied several urban catchments to evaluate the effects of urbanization on runoff characteristics in urban area.
{"title":"FIELD OBSERVATION OF DISCHARGE IN URBAN CATCHMENTS AND EFFECTS OF URBANIZATION ON RUNOFF CHARACTERISTICS","authors":"Y. Akabane, S. Kure, Tadashi Yamada","doi":"10.2208/PROHE.52.481","DOIUrl":"https://doi.org/10.2208/PROHE.52.481","url":null,"abstract":"In order to clarify the runoff mechanism in urban catchment area, field observation of discharge and application of runoff analysis to the urban catchments are reported in this paper. Land-use in urban area has become more complicated by urbanization during the last several decades. As a result of urbanization, the peak discharge increases and the concentration time of flood decreases. It makes flood disasters in urban area more serious problem. On the other hand, discharge data in urban catchments are very few. In this paper, field observation of discharge are carried out and runoff analysis method for land surface area based on morphological and geological properties is applied several urban catchments to evaluate the effects of urbanization on runoff characteristics in urban area.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"6 1","pages":"481-486"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86987731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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