T. Horiguchi, S. Katsuki, N. Ishikawa, T. Mizuyama
this issue should be applied to investigate the trapping mechanism. Many studies of open Sabo dams have been carried out [ Ishikawa et al ., 1988 ; , 2008, 2010 ; Silva et 2015]. In particular, Shima et Seventy percent of Japan is mountainous, and there are a number of residential areas near piedmonts and/or downstream alluvial flows. Debris flows, including driftwood, have occurred recently. Hence, it is necessary to take measures against such occurrences. Over the past 30 years, open Sabo dams with steel pipes that are a countermeasure against woody debris and debris flows have been constructed. However, it is difficult for designers to select the optimum spacing between pipes. Therefore, the concept of general entrapment tends to employ smaller spacing intervals between pipes to protect downstream areas, which have a high expectation of security, although open Sabo dams gradually lose their function of routine sediment transport to pass through. Furthermore, in current design methods, the maximum grain size ( ) is applied to determine the optimum spacing interval for entrapment, which does not take into account driftwood and roots. Thus, an effective method to evaluate the effects of woody debris is required to analyze the problems that arise due to trapping effects. We propose a novel method for evaluating the optimum spacing interval of open Sabo dams using a distinct element method. Moreover, the trapping mechanism of woody debris was investigated for open Sabo dams.
这个问题应该应用于调查陷阱机制。对开放式Sabo水坝进行了许多研究[Ishikawa等人，1988;， 2008, 2010;Silva et 2015]。日本70%的国土是山区，山麓和/或下游冲积流附近有许多居民区。最近发生了包括浮木在内的泥石流。因此，有必要采取措施防止这种情况的发生。在过去的30年里，作为防止木屑和泥石流的对策，建设了钢管开坝。然而，设计人员很难选择最佳的管道间距。因此，一般截流的概念倾向于采用较小的管道间距来保护下游地区，尽管开放式Sabo水坝逐渐失去了常规输沙通过的功能，但下游地区的安全性期望很高。此外，在现有的设计方法中，采用最大粒径()来确定最佳截留间距，没有考虑浮木和树根。因此，需要一种有效的评估木屑效应的方法来分析由于捕获效应而产生的问题。本文提出了一种用离散元法评价开放式沙坝最佳坝距的新方法。此外，还研究了开放式沙坝木屑的捕集机理。
{"title":"Method for Evaluating the Trapping Effects of Woody Debris Using a Distinct Element Method","authors":"T. Horiguchi, S. Katsuki, N. Ishikawa, T. Mizuyama","doi":"10.13101/ijece.12.1","DOIUrl":"https://doi.org/10.13101/ijece.12.1","url":null,"abstract":"this issue should be applied to investigate the trapping mechanism. Many studies of open Sabo dams have been carried out [ Ishikawa et al ., 1988 ; , 2008, 2010 ; Silva et 2015]. In particular, Shima et Seventy percent of Japan is mountainous, and there are a number of residential areas near piedmonts and/or downstream alluvial flows. Debris flows, including driftwood, have occurred recently. Hence, it is necessary to take measures against such occurrences. Over the past 30 years, open Sabo dams with steel pipes that are a countermeasure against woody debris and debris flows have been constructed. However, it is difficult for designers to select the optimum spacing between pipes. Therefore, the concept of general entrapment tends to employ smaller spacing intervals between pipes to protect downstream areas, which have a high expectation of security, although open Sabo dams gradually lose their function of routine sediment transport to pass through. Furthermore, in current design methods, the maximum grain size ( ) is applied to determine the optimum spacing interval for entrapment, which does not take into account driftwood and roots. Thus, an effective method to evaluate the effects of woody debris is required to analyze the problems that arise due to trapping effects. We propose a novel method for evaluating the optimum spacing interval of open Sabo dams using a distinct element method. Moreover, the trapping mechanism of woody debris was investigated for open Sabo dams.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115526257","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 environmental and socio-economic impact of erosion in Nigeria is huge and well-known to international organizations including the United Nations. Although gully erosion is a serious problem in south eastern Nigeria, it does not affect all the states in the region equally. While Abia, Anambra Enugu and Imo states are severely affected, Ebonyi state is mildly affected. It is shown in this paper that geology and nature of soils underlying the areas, rather than the level of human activity, are the main reasons for the difference in severity. It is emphasized that even the smectite-rich soils covering major parts of Ebonyi state are less prone to gully erosion than the loosely consolidated coastal sands covering the other states. Multiple potholes are a constant distinguishing feature on the smectite-rich roads but not gullies. Most adults do not have proper understanding of sediment disaster nor do they want a career in geo-disaster related discipline. This paper theorizes that apathy and ignorance will hinder any effort at erosion control; and perpetuate the negative impacts of erosion in the area for a long time to come.
{"title":"Environmental and Socio-Economic Impact of Erosion in Nigeria, West Africa","authors":"O. Igwe, H. Fukuoka","doi":"10.13101/IJECE.3.102","DOIUrl":"https://doi.org/10.13101/IJECE.3.102","url":null,"abstract":"The environmental and socio-economic impact of erosion in Nigeria is huge and well-known to international organizations including the United Nations. Although gully erosion is a serious problem in south eastern Nigeria, it does not affect all the states in the region equally. While Abia, Anambra Enugu and Imo states are severely affected, Ebonyi state is mildly affected. It is shown in this paper that geology and nature of soils underlying the areas, rather than the level of human activity, are the main reasons for the difference in severity. It is emphasized that even the smectite-rich soils covering major parts of Ebonyi state are less prone to gully erosion than the loosely consolidated coastal sands covering the other states. Multiple potholes are a constant distinguishing feature on the smectite-rich roads but not gullies. Most adults do not have proper understanding of sediment disaster nor do they want a career in geo-disaster related discipline. This paper theorizes that apathy and ignorance will hinder any effort at erosion control; and perpetuate the negative impacts of erosion in the area for a long time to come.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116226585","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}
Nobuaki Kawata, Mitsuyasu Yada, H. Yoshino, M. Kaneko, M. Fujita, H. Takebayashi
Many of the dams and reservoirs in Japan have been operated for more than thirty years and some of them face sedimentation problems. In addition research and investigation of climate change is ongoing and its impact has been clarified recently. Therefore the authors try to predict future reservoir sedimentation considering impact of climate change by use of a sediment runoff model developed by Egashira and Matsuki. The authors consider that their sediment runoff model is convenient because a topographic model of the dam’s basin for numerical analysis is relatively easy to provide. However, the model does not have a sediment supply process from mountain slopes to river channels. This is an issue and applicability of the model is considered to be limited. In this paper the authors carry out correlation analysis between water inflow to reservoirs and reservoir sedimentation for several dams and analyze applicability of the model from the viewpoint of relationship between correlation coefficient and characteristics of the dam’s basin. As a result, the authors reach a conclusion that large specific sedimentation rate and gentle river bed slope near the reservoir entrance are important characteristics for applicability of the model. In the end the authors carry out simulation analysis of reservoir sedimentation against one of the dams and confirm acceleration of future reservoir sedimentation due to the impacts of climate change.
{"title":"Analysis of the Future Reservoir Sedimentation at Several Watersheds Considering the Geologic and Topographic Characteristics of the Basins","authors":"Nobuaki Kawata, Mitsuyasu Yada, H. Yoshino, M. Kaneko, M. Fujita, H. Takebayashi","doi":"10.13101/IJECE.5.93","DOIUrl":"https://doi.org/10.13101/IJECE.5.93","url":null,"abstract":"Many of the dams and reservoirs in Japan have been operated for more than thirty years and some of them face sedimentation problems. In addition research and investigation of climate change is ongoing and its impact has been clarified recently. Therefore the authors try to predict future reservoir sedimentation considering impact of climate change by use of a sediment runoff model developed by Egashira and Matsuki. The authors consider that their sediment runoff model is convenient because a topographic model of the dam’s basin for numerical analysis is relatively easy to provide. However, the model does not have a sediment supply process from mountain slopes to river channels. This is an issue and applicability of the model is considered to be limited. In this paper the authors carry out correlation analysis between water inflow to reservoirs and reservoir sedimentation for several dams and analyze applicability of the model from the viewpoint of relationship between correlation coefficient and characteristics of the dam’s basin. As a result, the authors reach a conclusion that large specific sedimentation rate and gentle river bed slope near the reservoir entrance are important characteristics for applicability of the model. In the end the authors carry out simulation analysis of reservoir sedimentation against one of the dams and confirm acceleration of future reservoir sedimentation due to the impacts of climate change.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117272611","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}
. Nakamura H., Tsuchiya T., Inoue K. & Ishikawa Y. (2000): Earthquake Sabo, Kokon Shoin, p. 190 (in Japanese). Otsuka T. and Nemoto J. (2003): The landslide dam at Tobata (1757) along the Azusa River, Azumi Village, Nagano Prefecture, central Japan, The Annals of Environmental Science, Shinshu University, 25, pp. 81–89 (in Japanese). Schuster, R., L. (1986): Landslide Dams: Risk and Mitigation, Geotechnical Special Publication No.3, American Society of Civil Engineers, p. 163. Tabata S., Mizuyama T. and Inoue K. (2002): Landslide Dams and Disasters, Kokon Shoin, p. 205 (in Japanese). Zenkoji Earthquake Disaster Study Group (1994): Zenkoji Earthquake and landslide disaster, p. 130 (in Japanese). Received: 14 July, 2009 Accepted: 16 August, 2012
{"title":"Three Large Historical Landslide Dams and Outburst Disasters in the North Fossa Magna Area, Central Japan","authors":"Kimio Inoue, Toshio Mori, T. Mizuyama","doi":"10.13101/IJECE.5.145","DOIUrl":"https://doi.org/10.13101/IJECE.5.145","url":null,"abstract":". Nakamura H., Tsuchiya T., Inoue K. & Ishikawa Y. (2000): Earthquake Sabo, Kokon Shoin, p. 190 (in Japanese). Otsuka T. and Nemoto J. (2003): The landslide dam at Tobata (1757) along the Azusa River, Azumi Village, Nagano Prefecture, central Japan, The Annals of Environmental Science, Shinshu University, 25, pp. 81–89 (in Japanese). Schuster, R., L. (1986): Landslide Dams: Risk and Mitigation, Geotechnical Special Publication No.3, American Society of Civil Engineers, p. 163. Tabata S., Mizuyama T. and Inoue K. (2002): Landslide Dams and Disasters, Kokon Shoin, p. 205 (in Japanese). Zenkoji Earthquake Disaster Study Group (1994): Zenkoji Earthquake and landslide disaster, p. 130 (in Japanese). Received: 14 July, 2009 Accepted: 16 August, 2012","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"69 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115820803","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}
Throughout Japan, almost all areas near hillsides or mountain slopes are threatened by landslides caused by heavy rainfall during the rainy and typhoon seasons. To mitigate potential disasters, many researchers have investigated landslides caused by heavy rainfall and have developed simulation models to predict landslide occurrence. However, because landslide mechanisms are complicated and involve many factors such as rainfall, surface and subsurface geomorphology, and soil physical properties, accurate prediction of landslides remains difficult by conventional simulation methods. Over the last several decades, many researchers have reported the existence of numerous preferential flow pathways for subsurface runoff, such as soil pipes or macro-pores in the soil layer. Simple infiltration analysis ignores those preferential flow pathways and therefore does not accurately simulate actual soil water flow, making it difficult to predict landslide occurrence accurately. For the last five years, we have investigated several landslide sites and have used experimental and modeling approaches to examine landslide occurrence. The results confirm that to improve precision of landslide prediction, simulation models should incorporate some important factors that affect landslide occurrence. This paper reports these issu es as well as the results of the landslide investigations, and discusses the methods required to predict and mitigate landslide disasters.
{"title":"Relative importance of slope material properties and timing of rainfall for the occurrence of landslides","authors":"D. Tsutsumi, M. Fujita","doi":"10.13101/IJECE.1.79","DOIUrl":"https://doi.org/10.13101/IJECE.1.79","url":null,"abstract":"Throughout Japan, almost all areas near hillsides or mountain slopes are threatened by landslides caused by heavy rainfall during the rainy and typhoon seasons. To mitigate potential disasters, many researchers have investigated landslides caused by heavy rainfall and have developed simulation models to predict landslide occurrence. However, because landslide mechanisms are complicated and involve many factors such as rainfall, surface and subsurface geomorphology, and soil physical properties, accurate prediction of landslides remains difficult by conventional simulation methods. Over the last several decades, many researchers have reported the existence of numerous preferential flow pathways for subsurface runoff, such as soil pipes or macro-pores in the soil layer. Simple infiltration analysis ignores those preferential flow pathways and therefore does not accurately simulate actual soil water flow, making it difficult to predict landslide occurrence accurately. For the last five years, we have investigated several landslide sites and have used experimental and modeling approaches to examine landslide occurrence. The results confirm that to improve precision of landslide prediction, simulation models should incorporate some important factors that affect landslide occurrence. This paper reports these issu es as well as the results of the landslide investigations, and discusses the methods required to predict and mitigate landslide disasters.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"104 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132498099","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}
Debris flows and floods caused by outburst of glacial lakes have frequently occurred in the Himalaya of South Asia. The frequency of these disasters has been increasing tremendously due to global climate change. It is thus necessary to investigate debris-flow and flood characteristics due to outburst of glacial lakes in order to manage the hazards and risk in the areas. In this study, the characteristics of debris flows and floods caused by potential outburst flood from the Imja glacial lake in Nepal due to moraine dam failure by water overtopping were analyzed using developed numerical model. The numerical model was validated with the flume experimental cases. The relationship between peak outburst discharges with the volumes of lake water for experimental conditions was also analyzed. The erosion and deposition processes along the river valley were also considered in the analyses of potential outburst floods from the Imja glacial lake. Sensitivity analyses of the parameters of river bed sediment were also conducted. The predicted results of debris-flow and flood characteristics such as outburst discharge, flood arrival time, sediment concentrations, peak flow velocity and maximum flow depth can be useful for effective preventive measures, river basin management and infrastructure planning in the river basin.
{"title":"Prediction of Debris-Flow and Flood Characteristics Caused by Potential Outburst of the Imja Glacial Lake in Nepal","authors":"B. Shrestha, H. Nakagawa","doi":"10.13101/IJECE.9.7","DOIUrl":"https://doi.org/10.13101/IJECE.9.7","url":null,"abstract":"Debris flows and floods caused by outburst of glacial lakes have frequently occurred in the Himalaya of South Asia. The frequency of these disasters has been increasing tremendously due to global climate change. It is thus necessary to investigate debris-flow and flood characteristics due to outburst of glacial lakes in order to manage the hazards and risk in the areas. In this study, the characteristics of debris flows and floods caused by potential outburst flood from the Imja glacial lake in Nepal due to moraine dam failure by water overtopping were analyzed using developed numerical model. The numerical model was validated with the flume experimental cases. The relationship between peak outburst discharges with the volumes of lake water for experimental conditions was also analyzed. The erosion and deposition processes along the river valley were also considered in the analyses of potential outburst floods from the Imja glacial lake. Sensitivity analyses of the parameters of river bed sediment were also conducted. The predicted results of debris-flow and flood characteristics such as outburst discharge, flood arrival time, sediment concentrations, peak flow velocity and maximum flow depth can be useful for effective preventive measures, river basin management and infrastructure planning in the river basin.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131551329","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}
There are many experimental approaches, field investigations and numerical calculations for movements of woods in a clear water and debris flow. However, treatments and evaluations for accumulated logs and interactions between a main flow and logs are not fully developed. In mountainous torrents, the logs yielding from slopes and stream beds depend on the condition of previous and present forest stands. Mitigations for woods need to be conducted taking into account tree species such as conifer and broad-leaf trees and shapes such as root swells and crown. In the present study, we focus on the differences in specific weight of conifer and broad-leaf trees with some moisture in a sediment-water mixture flow with narrow flow width. Conifer and broad-leaf tree are considered as floating and submerged solid phase, respectively. Flume tests are conducted in steady flow of clear and debris flow over a rigid bed in order to evaluate flow characteristics of clear and debris flow with woods. Debris flow is specified as flow with clear water and sediment mixture layers on a rigid bed, whose slope is 0.045. Preliminary experimental data, which suggest that influences of specific weight on logs movements are significant, has been obtained to evaluate those experimental results such as movements of floating and submerged woods and multi-layer consisted of woods and debris flow. However, detail considerations and collections of flume data are needed based on flow characteristics such as spatial eddies structures in depth-scale, diffusion/dispersion of woods, momentum transfer induced interactions between logs and mixture flow and bed conditions.
{"title":"Preliminary Experimental Studies on Debris Flow with Woods focusing on Difference of Specific Weight of Tree Species","authors":"T. Itoh, K. Ogawa, Nishimura Shigeki, S. Kuraoka","doi":"10.13101/IJECE.3.9","DOIUrl":"https://doi.org/10.13101/IJECE.3.9","url":null,"abstract":"There are many experimental approaches, field investigations and numerical calculations for movements of woods in a clear water and debris flow. However, treatments and evaluations for accumulated logs and interactions between a main flow and logs are not fully developed. In mountainous torrents, the logs yielding from slopes and stream beds depend on the condition of previous and present forest stands. Mitigations for woods need to be conducted taking into account tree species such as conifer and broad-leaf trees and shapes such as root swells and crown. In the present study, we focus on the differences in specific weight of conifer and broad-leaf trees with some moisture in a sediment-water mixture flow with narrow flow width. Conifer and broad-leaf tree are considered as floating and submerged solid phase, respectively. Flume tests are conducted in steady flow of clear and debris flow over a rigid bed in order to evaluate flow characteristics of clear and debris flow with woods. Debris flow is specified as flow with clear water and sediment mixture layers on a rigid bed, whose slope is 0.045. Preliminary experimental data, which suggest that influences of specific weight on logs movements are significant, has been obtained to evaluate those experimental results such as movements of floating and submerged woods and multi-layer consisted of woods and debris flow. However, detail considerations and collections of flume data are needed based on flow characteristics such as spatial eddies structures in depth-scale, diffusion/dispersion of woods, momentum transfer induced interactions between logs and mixture flow and bed conditions.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129444076","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}
Hisashi Sasaki, Masayuki Sakagami, S. Fujiwara, Takumi Sato, K. Honda, Masamichi Haraguchi, A. Kasuga, Hirokazu Muraki, K. Iribe, Tetsuo Kobayashi
In January 2011, a magmatic eruption occurred in Shinmoedake Volcano, which is part of the Kirishima volcanic group and is located in Kyushu, southwestern Japan. We employed C-band synthetic aperture radar (SAR) data acquired by RADARSAT-2 to examine ground surface changes caused by the volcanic activities (ash fall and volcanic bombs) for the prediction of sediment-related disaster. Change detection images recorded by the before-eruption and after-eruption SAR data revealed regional and local changes, especially around the craters and distribution area of volcanic ejecta. The Pauli color-coded image was classified into bare ground, forest area, and built-up area on the basis of the differences in the reflecting features, enabling us to detect a distribution of volcanic ejecta. Although our method cannot yield quantitative features, it is suitable for mapping widely distributed volcanic ejecta. Because SAR is an all-weather sensor, we found that our method of using SAR data was more efficient for investigating the volcanic eruption than image comparison using optical sensor data.
{"title":"Investigation of the 2011 Eruption of Shinmoedake Volcano, Kirishima Volcanic Group, Japan, Using RADARSAT-2 SAR Data","authors":"Hisashi Sasaki, Masayuki Sakagami, S. Fujiwara, Takumi Sato, K. Honda, Masamichi Haraguchi, A. Kasuga, Hirokazu Muraki, K. Iribe, Tetsuo Kobayashi","doi":"10.13101/IJECE.5.80","DOIUrl":"https://doi.org/10.13101/IJECE.5.80","url":null,"abstract":"In January 2011, a magmatic eruption occurred in Shinmoedake Volcano, which is part of the Kirishima volcanic group and is located in Kyushu, southwestern Japan. We employed C-band synthetic aperture radar (SAR) data acquired by RADARSAT-2 to examine ground surface changes caused by the volcanic activities (ash fall and volcanic bombs) for the prediction of sediment-related disaster. Change detection images recorded by the before-eruption and after-eruption SAR data revealed regional and local changes, especially around the craters and distribution area of volcanic ejecta. The Pauli color-coded image was classified into bare ground, forest area, and built-up area on the basis of the differences in the reflecting features, enabling us to detect a distribution of volcanic ejecta. Although our method cannot yield quantitative features, it is suitable for mapping widely distributed volcanic ejecta. Because SAR is an all-weather sensor, we found that our method of using SAR data was more efficient for investigating the volcanic eruption than image comparison using optical sensor data.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128375323","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}
Y. Yamakawa, K. Kosugi, N. Masaoka, Jun Sumida, M. Tani, T. Mizuyama
), Butsuri-Tansa, Vol. 47, No. 4, pp. 161-172. Nishimaki, H., Sekine, I., Ishigaki, K., Hara, T., and Saito, A. (1999): Electrical resistivity of rock and its correlation to engineering properties. (in Japanese, with English abstract.), Butsuri-Tansa, Vol. 52, No. 2, pp. 161-171.), Butsuri-Tansa, Vol. 52, No. 2, pp. 161-171. Katsura, S., Kosugi, K., Mizutani, T., and Mizuyama, T. (2009): Hydraulic properties of variously weathered granitic bedrock in headwater catchments, Vadose Zone Journal, Vol. 8, No. 3, pp. 557-573. Sekine, I., Nishimaki, H., Ishigaki, K., Hara, T., and Saito, A. (1996): Rock resistivity and its correlation to mechanical properties. (in Japanese, with English abstract.), Proceedings of Japan society civil engineers, Vol. 541, pp.
{"title":"Estimation of Soil Thickness Distribution on a Granitic Hillslope using Electrical Resistivity Method","authors":"Y. Yamakawa, K. Kosugi, N. Masaoka, Jun Sumida, M. Tani, T. Mizuyama","doi":"10.13101/IJECE.3.20","DOIUrl":"https://doi.org/10.13101/IJECE.3.20","url":null,"abstract":"), Butsuri-Tansa, Vol. 47, No. 4, pp. 161-172. Nishimaki, H., Sekine, I., Ishigaki, K., Hara, T., and Saito, A. (1999): Electrical resistivity of rock and its correlation to engineering properties. (in Japanese, with English abstract.), Butsuri-Tansa, Vol. 52, No. 2, pp. 161-171.), Butsuri-Tansa, Vol. 52, No. 2, pp. 161-171. Katsura, S., Kosugi, K., Mizutani, T., and Mizuyama, T. (2009): Hydraulic properties of variously weathered granitic bedrock in headwater catchments, Vadose Zone Journal, Vol. 8, No. 3, pp. 557-573. Sekine, I., Nishimaki, H., Ishigaki, K., Hara, T., and Saito, A. (1996): Rock resistivity and its correlation to mechanical properties. (in Japanese, with English abstract.), Proceedings of Japan society civil engineers, Vol. 541, pp.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122385022","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}
Hua-yong Chen, P. Cui, Xiao-qing Chen, Jin-bo Tang
In this article, experimental tests were conducted to study the characteristics of the surge wave and its effects on the failure process of a glacier dam. The results indicated that two obvious surges were monitored by pore pressure transducers (PPTs) when the blockage slid into water. The surge wave attenuated exponentially near the plunging location and then attenuated slowly when it propagated downstream. When the surge wave reached the glacier dam it climbed up along the dam and flew over. Sequential propagating surges exerting on the dam were one of the main factors causing the failure of the glacier dam. The failure mechanism of glacier dam triggered by the surge waves under different initial water supply conditions was primarily analyzed in this article.
{"title":"Study on the Surge Wave Induced by Glacier Avalanches and its Effects on Dam Failure Process","authors":"Hua-yong Chen, P. Cui, Xiao-qing Chen, Jin-bo Tang","doi":"10.13101/IJECE.10.9","DOIUrl":"https://doi.org/10.13101/IJECE.10.9","url":null,"abstract":"In this article, experimental tests were conducted to study the characteristics of the surge wave and its effects on the failure process of a glacier dam. The results indicated that two obvious surges were monitored by pore pressure transducers (PPTs) when the blockage slid into water. The surge wave attenuated exponentially near the plunging location and then attenuated slowly when it propagated downstream. When the surge wave reached the glacier dam it climbed up along the dam and flew over. Sequential propagating surges exerting on the dam were one of the main factors causing the failure of the glacier dam. The failure mechanism of glacier dam triggered by the surge waves under different initial water supply conditions was primarily analyzed in this article.","PeriodicalId":378771,"journal":{"name":"International Journal of Erosion Control Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130613429","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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