The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
Sungkee Yang - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of day and night time video accuracy to calculate the Flood Runoff using surface image velocimeter siv
Journal of Environmental Sciences-china, 2015Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract This study analyzed the velocimetry of Runoff and measured the Flood discharge by applying the SIV (Surface Image Velocimetrer) to the daytime and nighttime flow image data with special reference to Seong-eup Bridge at Cheonmi stream of Jeju during the flow by the severe rainstorm on May 27, 2013. A 1000W lighting apparatus with more than 150 lux was installed in order to collect proper nighttime flow image applied to the SIV. Its value was compared and analyzed with the velocity value of the fixed electromagnetic wave surface velocimetry (Kalesto) at the same point to check the accuracy and applicability of the measured velocity of flow. As a result, determination coefficient values were 0.891 and 0.848 respectively in line with the velocity distribution of the daytime and nighttime image and the flow volume measured with Kalesto was approximately 18.2% larger than the value measured with the SIV. Key words : Surface Image Velocimetry, CCTV, Kalesto, Doppler radar, Surface velocity
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Flood Runoff calculation using disaster monitoring cctv system
Journal of Environmental Sciences-china, 2014Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:【The present study aims to apply a surface image velocimetry(SIV) system to video images captured with CCTV and estimate the Flood discharge. The CCTV was installed at the Hancheon Bridge of the Han Cheon in Jeju Island for disaster surveillance, and seven Flood events occurred in 2012 were used. During the image analyses, input parameters, interrogation areas and searching areas were determined with proper calibration procedures. To check for accuracy and applicability of SIV, the velocities and Flood discharges estimated by SIV were compared with the measured ones by an electromagnetic surface velocimeter, Kalisto. The comparison results showed fairly good agreements. The RMSE(Root Mean Square Error) values between two instruments showed a range of 4.13 and 14.2, and the determination coefficients reached 0.75 through 0.85. It means that the SIV could be used as a good alternative method for other traditional velocity measuring instruments in measuring Flood discharges.】
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calculation of the Flood Runoff of the river with imaging equipments
Journal of Environmental Sciences-china, 2014Co-Authors: Boseong Kang, Sungkee Yang, Wooyeol Jung, Yongseok KimAbstract:Abstract This study Analyzed four of seven Runoffs which had happened in 2012 in comparison with the Runoffs shown in Kalesto data, using the fixed surface image velocimetry (FSIV) installed at Oedo stream, Jeju Island. As a result of identifying a Runoff curve graph, it was analyzed that the Flood Runoffs calculated with two observation devices were almost equivalent. As the differences in peak flows were 10 m 3 /s, 0.7 m 3 /s and 3 m 3 /s, the very similar result values were calculated. Even though there were errors in RMSE(Root Mean Square Error) made by two observation devices according to the degree of the peak flow, the values of R² by Flood event were 0.89, 0.87, 0.86 and 0.82, showing the result values almost close to 1. Therefore, there was a very high correlation in Flood Runoffs calculated with two observation devices. This research method was considered to be a very suitable method to measure unexpected Flood Runoffs which could happen in the island area such as Jeju island during bad weather.
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Flood Runoff measurements using surface image velocimetry
Journal of Environmental Sciences-china, 2013Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract Surface Image Velocimetry(SIV) is an instrument to measure water surface velocity by using image processing techniques. Since SIV is a non-contact type measurement method, it is very effective and useful to measure water surface velocity for steep mountainous streams, such as streams in Jeju island. In the present study, a surface imaging velocimetry system was used to calculate the flow rate for Flood event due to a typhoon. At the same time, two types of electromagnetic surface velocimetries (electromagnetic surface current meter and Kalesto) were used to observe flow velocities and compare the accuracies of each instrument. The comparison showed that for velocity distributions root mean square error(RMSE) was 0.33 and R-squared was 0.72. For discharge measurements, root mean square error(RMSE) reached 6.04 and R-squared did 0.92. It means that surface image velocimetry could be used as an alternative method for electromagnetic surface velocimetries in measuring Flood discharge.Key words: SIV, Kalesto, electromagnetic surface current meter, Doppler radar, Surface velocity
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stream flow analysis of dry stream on Flood Runoff in islands
Journal of Environmental Sciences-china, 2013Co-Authors: Wonseok Yang, Sungkee YangAbstract:In this study, compared with the result of water surface elevation and water velocity on the establishment of river maintenance basic plan and result of HEC-GeoRAS based GIS, and after use the result of water surface elevation and velocity were observed in the Han stream on Jeju island, analysis 2 dimensional stream flow. the lateral hydraulic characteristics and curved channel of the stream were analyzed by applying SMS-RMA2 a 2 dimensional model. The results of the analysis using HEC-RAS model and HEC-GeoRAS model indicated that the distribution ranges of water surface elevation and water velocity were similar, but the water surface elevation by section showed a difference of 0.7~2.18 EL.m and 0.63~1.16 EL.m respectively, and water velocity also showed differences of maximum 1.58m/sec and 2.67m/sec. SMS-RMA2 analysis was done with the sphere of Muifa the typhoon as a boundary condition, and as a result, water velocity distribution was found to be 1.19 through 3.91 m/sec, and the difference of lateral water velocity in No. 97 through 99 the curved channel of the stream was analyzed to be 1.59 through 2.36 m/sec. In conclusion it is anticipated that the flow analysis of 2 dimension model of stream can reflect the hydraulic characteristics of the stream curved channel or width and shape, and can be applied effectively in the establishment of river maintenance basic plan or management and designing of stream.
Yongseok Kim - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of day and night time video accuracy to calculate the Flood Runoff using surface image velocimeter siv
Journal of Environmental Sciences-china, 2015Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract This study analyzed the velocimetry of Runoff and measured the Flood discharge by applying the SIV (Surface Image Velocimetrer) to the daytime and nighttime flow image data with special reference to Seong-eup Bridge at Cheonmi stream of Jeju during the flow by the severe rainstorm on May 27, 2013. A 1000W lighting apparatus with more than 150 lux was installed in order to collect proper nighttime flow image applied to the SIV. Its value was compared and analyzed with the velocity value of the fixed electromagnetic wave surface velocimetry (Kalesto) at the same point to check the accuracy and applicability of the measured velocity of flow. As a result, determination coefficient values were 0.891 and 0.848 respectively in line with the velocity distribution of the daytime and nighttime image and the flow volume measured with Kalesto was approximately 18.2% larger than the value measured with the SIV. Key words : Surface Image Velocimetry, CCTV, Kalesto, Doppler radar, Surface velocity
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calculation of the Flood Runoff of the river with imaging equipments
Journal of Environmental Sciences-china, 2014Co-Authors: Boseong Kang, Sungkee Yang, Wooyeol Jung, Yongseok KimAbstract:Abstract This study Analyzed four of seven Runoffs which had happened in 2012 in comparison with the Runoffs shown in Kalesto data, using the fixed surface image velocimetry (FSIV) installed at Oedo stream, Jeju Island. As a result of identifying a Runoff curve graph, it was analyzed that the Flood Runoffs calculated with two observation devices were almost equivalent. As the differences in peak flows were 10 m 3 /s, 0.7 m 3 /s and 3 m 3 /s, the very similar result values were calculated. Even though there were errors in RMSE(Root Mean Square Error) made by two observation devices according to the degree of the peak flow, the values of R² by Flood event were 0.89, 0.87, 0.86 and 0.82, showing the result values almost close to 1. Therefore, there was a very high correlation in Flood Runoffs calculated with two observation devices. This research method was considered to be a very suitable method to measure unexpected Flood Runoffs which could happen in the island area such as Jeju island during bad weather.
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Flood Runoff calculation using disaster monitoring cctv system
Journal of Environmental Sciences-china, 2014Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:【The present study aims to apply a surface image velocimetry(SIV) system to video images captured with CCTV and estimate the Flood discharge. The CCTV was installed at the Hancheon Bridge of the Han Cheon in Jeju Island for disaster surveillance, and seven Flood events occurred in 2012 were used. During the image analyses, input parameters, interrogation areas and searching areas were determined with proper calibration procedures. To check for accuracy and applicability of SIV, the velocities and Flood discharges estimated by SIV were compared with the measured ones by an electromagnetic surface velocimeter, Kalisto. The comparison results showed fairly good agreements. The RMSE(Root Mean Square Error) values between two instruments showed a range of 4.13 and 14.2, and the determination coefficients reached 0.75 through 0.85. It means that the SIV could be used as a good alternative method for other traditional velocity measuring instruments in measuring Flood discharges.】
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Flood Runoff measurements using surface image velocimetry
Journal of Environmental Sciences-china, 2013Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract Surface Image Velocimetry(SIV) is an instrument to measure water surface velocity by using image processing techniques. Since SIV is a non-contact type measurement method, it is very effective and useful to measure water surface velocity for steep mountainous streams, such as streams in Jeju island. In the present study, a surface imaging velocimetry system was used to calculate the flow rate for Flood event due to a typhoon. At the same time, two types of electromagnetic surface velocimetries (electromagnetic surface current meter and Kalesto) were used to observe flow velocities and compare the accuracies of each instrument. The comparison showed that for velocity distributions root mean square error(RMSE) was 0.33 and R-squared was 0.72. For discharge measurements, root mean square error(RMSE) reached 6.04 and R-squared did 0.92. It means that surface image velocimetry could be used as an alternative method for electromagnetic surface velocimetries in measuring Flood discharge.Key words: SIV, Kalesto, electromagnetic surface current meter, Doppler radar, Surface velocity
Dongsu Kim - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of day and night time video accuracy to calculate the Flood Runoff using surface image velocimeter siv
Journal of Environmental Sciences-china, 2015Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract This study analyzed the velocimetry of Runoff and measured the Flood discharge by applying the SIV (Surface Image Velocimetrer) to the daytime and nighttime flow image data with special reference to Seong-eup Bridge at Cheonmi stream of Jeju during the flow by the severe rainstorm on May 27, 2013. A 1000W lighting apparatus with more than 150 lux was installed in order to collect proper nighttime flow image applied to the SIV. Its value was compared and analyzed with the velocity value of the fixed electromagnetic wave surface velocimetry (Kalesto) at the same point to check the accuracy and applicability of the measured velocity of flow. As a result, determination coefficient values were 0.891 and 0.848 respectively in line with the velocity distribution of the daytime and nighttime image and the flow volume measured with Kalesto was approximately 18.2% larger than the value measured with the SIV. Key words : Surface Image Velocimetry, CCTV, Kalesto, Doppler radar, Surface velocity
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Flood Runoff calculation using disaster monitoring cctv system
Journal of Environmental Sciences-china, 2014Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:【The present study aims to apply a surface image velocimetry(SIV) system to video images captured with CCTV and estimate the Flood discharge. The CCTV was installed at the Hancheon Bridge of the Han Cheon in Jeju Island for disaster surveillance, and seven Flood events occurred in 2012 were used. During the image analyses, input parameters, interrogation areas and searching areas were determined with proper calibration procedures. To check for accuracy and applicability of SIV, the velocities and Flood discharges estimated by SIV were compared with the measured ones by an electromagnetic surface velocimeter, Kalisto. The comparison results showed fairly good agreements. The RMSE(Root Mean Square Error) values between two instruments showed a range of 4.13 and 14.2, and the determination coefficients reached 0.75 through 0.85. It means that the SIV could be used as a good alternative method for other traditional velocity measuring instruments in measuring Flood discharges.】
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Flood Runoff measurements using surface image velocimetry
Journal of Environmental Sciences-china, 2013Co-Authors: Yongseok Kim, Sungkee Yang, Dongsu KimAbstract:Abstract Surface Image Velocimetry(SIV) is an instrument to measure water surface velocity by using image processing techniques. Since SIV is a non-contact type measurement method, it is very effective and useful to measure water surface velocity for steep mountainous streams, such as streams in Jeju island. In the present study, a surface imaging velocimetry system was used to calculate the flow rate for Flood event due to a typhoon. At the same time, two types of electromagnetic surface velocimetries (electromagnetic surface current meter and Kalesto) were used to observe flow velocities and compare the accuracies of each instrument. The comparison showed that for velocity distributions root mean square error(RMSE) was 0.33 and R-squared was 0.72. For discharge measurements, root mean square error(RMSE) reached 6.04 and R-squared did 0.92. It means that surface image velocimetry could be used as an alternative method for electromagnetic surface velocimetries in measuring Flood discharge.Key words: SIV, Kalesto, electromagnetic surface current meter, Doppler radar, Surface velocity
Weijian Zhou - One of the best experts on this subject based on the ideXlab platform.
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natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the loess plateau of china
Science of The Total Environment, 2014Co-Authors: Zhao Jin, Yunshe Dong, Yunqiang Wang, Xiaorong Wei, Yafeng Wang, Buli Cui, Weijian ZhouAbstract:Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC δ(13)C values were investigated in the two ecosystems in the upper 1m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the δ(13)CSOC value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The δ(13)CSIC values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through Flood Runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink.
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natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the loess plateau of china
Science of The Total Environment, 2014Co-Authors: Yunshe Dong, Yunqiang Wang, Yafeng Wang, Weijian ZhouAbstract:Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC delta C-13 values were investigated in the two ecosystems in the upper 1 m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the delta C-13(SOC) value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The delta C-13(SIC) values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through Flood Runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink. (C) 2014 The Authors. Published by Elsevier B.V.
Yunshe Dong - One of the best experts on this subject based on the ideXlab platform.
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natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the loess plateau of china
Science of The Total Environment, 2014Co-Authors: Zhao Jin, Yunshe Dong, Yunqiang Wang, Xiaorong Wei, Yafeng Wang, Buli Cui, Weijian ZhouAbstract:Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC δ(13)C values were investigated in the two ecosystems in the upper 1m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the δ(13)CSOC value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The δ(13)CSIC values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through Flood Runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink.
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natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the loess plateau of china
Science of The Total Environment, 2014Co-Authors: Yunshe Dong, Yunqiang Wang, Yafeng Wang, Weijian ZhouAbstract:Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC delta C-13 values were investigated in the two ecosystems in the upper 1 m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the delta C-13(SOC) value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The delta C-13(SIC) values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through Flood Runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink. (C) 2014 The Authors. Published by Elsevier B.V.