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Currently, many studies have reported that many landslides occur in tea or rubber plantation areas. In these areas, it is important to make a landslide susceptibility map and to take necessary measures to mitigate landslide damage. However, since historical landslide distribution data and land use data are not available, quantitative landslide assessment measurements have not been made in many countries. Therefore, in this study, landslide distribution maps and land use maps are created with worldwide available satellite imagery and Google Earth imagery, and the relationship between landslides and land use is analyzed in Rize, Turkey. The results show that landslides are 1.75 to 5 times more likely to occur in tea gardens than in forests. It was also found that land use has the highest contribution to landslides among the landslide conditioning factors. The landslide assessment, using a simple landslide detection method and land use classification method with worldwide available data, enabled us to quantitatively reveal the characteristics of landslides. The results of this study reveal that quantitative landslide assessments can be applied in any location, where relatively high resolution satellite imagery and Google Earth imagery, or its alternatives, are available.

DOI： 10.3390/w14111811

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

Lava flows from the 2018 Kı¯lauea eruption caused a volcanic disaster on the island of Hawaii. This study summarizes lava flow characteristics, and reviews past volcanic disasters and countermeasures. Based on an interview survey on the 2018 Kı¯lauea Volcano eruption, we discuss the direction of future countermeasures to be used against possible similar lava flows in Japan. Considering the high viscosity and low flow velocity, no significant damage to humans occurred or is expected, except for special cases. However, economic damage to buildings and other structures was significant. A large amount of basaltic lava erupted during the 2018 Kı¯lauea event, causing damage to homes, infrastructure, and farmland. The main eruptive activity began with the fissure eruption on the Lower East Rift Zone, followed by the summit explosion and collapse of the Halema‘uma‘u crater in the K¯ılauea Caldera. Although no structural measures against lava flows such as flow direction control or cooling to reduce the flow velocity were taken, warning information was issued two days before the eruption and a lava-flow hazard map was updated almost every day. To provide effective lava-flow hazard maps, it is important to obtain updated data continuously, including the information on the volcano effusion rate and the latest topographical data during the eruption. These can be utilized in developing and maintaining a lava flow simulation model. The 2018 Kı¯lauea eruption was the largest in the Hawaiian Islands in the last 200 years. Similarly, in Japan the possibility for volcanic eruptions with lava flow exists, even though no event has occurred in hundreds of years. Due to the steep and narrow topography in Japan, it would be difficult to implement structural measures effectively. Furthermore, an eruption involving a large amount of lava may isolate areas, cutting them off by slope failure associated with strong volcanic earthquakes. Therefore, risk management for volcanic lava flow events also necessitates formulating an evacuation plan that considers the occurrence of multiple hazard chains.

DOI： 10.11475/sabo.73.6_27

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© 2019, Fuji Technology Press. All rights reserved. After a volcanic eruption, in situations where pyroclastic material generates thick ground cover, even small amounts of rainfall can trigger lahars; this effect sometimes continues for many years. For hazard mitigation against lahar disasters after an eruption, it is essential to evaluate the current risk of occurrence and estimate any possible temporal changes for the future. Putih River is one of the rivers where lahars occurred frequently after the 1984 eruption of Mt. Merapi. In this study, the characteristics of lahars and floods in the Putih River after the 1984 eruption and their change over the years were analyzed, focusing on the runoff characteristics of lahars. Irrelevant rainfall and discharge data for analyzing runoff characteristics of lahars were excluded in preprocessing. The magnitude and occurrences of lahars decreased annually during the four years following the eruption. The maximum runoff rate of lahars was approximately 12 during the 1984-1985 rainy season and decreased yearly after this. A judgement graph was employed to track the temporal changes of lahartriggering rainfall characteristics. For the 1984-1985 and 1985-1986 rainy seasons discriminant lines, which discriminate between rainfall events triggering lahar flow with peak discharge > 900 m3/s and other rainfall events, were drawn on the judgement graph.

DOI： 10.20965/JDR.2019.P0061

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

<p>A heavy rainfall event in July 2018, attributable to the influence of the baiu front activated by Typhoon Prapiroon, which was named the "Heavy Rain Event of July 2018" by the Japan Meteorological Agency, caused numerous disasters. Therefore, we conducted a field survey of sediment-related disasters around Uwajima City and Seiyo City in Ehime Prefecture and Otoyo-cho in Kochi Prefecture. The total rainfall amounts from July 5-9 observed at the Uwa AMeDAS (Seiyo City) and Uwajima AMeDAS stations were 539.5 mm and 381.5 mm, respectively. In the vicinity of Uwajima City and Seiyo City, many slope failures and debris flows occurred at dawn on July 7, 2018. Many of these slope failures/debris flows occurred on the south side of the mountain range forming the boundary area between Uwajima City and Seiyo City. This boundary area roughly overlaps the Butsuzo tectonic line, which geologically separates the Chichibu zone and Shimanto zone. Although many of the slope failures were shallow landslides with failure depths of about 1-5 m, relatively large slope failures also occurred in the area where the record for cumulative rainfall was updated by a large amount. In Otoyo-cho in Kochi Prefecture, a deep-seated landslide occurred at dawn on July 7, 2018. The total rainfall from July 5-8 observed in the proximity of the Tachikawa rain gauge station was about 1200 mm, and the maximum hourly rainfall, which occurred at 19 : 00 on July 6, was 111 mm/h. This deep-seated landslide in Otoyo-cho was topographically located in a landslide area, and scars of previous landslide movements were confirmed from a topographical survey performed using airborne LiDAR.</p>

DOI： 10.11475/sabo.71.5_43

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© Proceeding of the 21st LAHR-APD Congress 2018. All rights reserved. After an eruption of the volcanic mountain, in case the pyroclastic material covers the ground thickly, the situation that even small amount of rainfalls trigger lahars, continues for the long period. For the hazard mitigation against lahar disasters after the eruption, it is essential to determine the danger of occurrence of them and estimate its temporal change. Putih River is one of the rivers where lahars occurred frequently after the 1984 eruption of Mt. Merapi. In this study, the characteristics of lahar in the Putih River after the 1984 eruption and their change over the years were analyzed, focusing on runoff characteristics of lahar. Exclusion of inappropriate rainfall data and discharge data for runoff characteristics analysis was conducted as preprocessing. Magnitude and occurrence number of lahar decrease with years during four years after the eruption. Maximum runoff rate was approximately 12 during 1984-1985 rainy season and decreased with years. A few hypotheses that describe the mechanism that runoff rate became much greater than 1 were introduced. However, high spatial resolution and high accuracy rainfall data are necessary in order to Figure out its mechanism. In case of 1984-1985 and 1985-1986 rainy season, rainfall, which triggered lahar flow with peak discharge &gt; 900m3/s were discriminated on the judgement graph wherein maximum 10 minutes&#039; rainfall within a rainfall event is an abscissa axis and antecedent rainfall with half-life 24 hour at maximum 10 minutes&#039; rainfall is an ordinate axis.

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© Proceeding of the 21st LAHR-APD Congress 2018. All rights reserved. Debris flow simulation is an effective method for understanding the behavior and influence of debris flows. This simulation allows for effective countermeasures such as sabo facilities and evacuation planning. This study focuses on the Mt. Sinabung volcanic region of North Sumatra, which has recently experienced increased eruptive activity. Given that a landslide dam was formed upstream of the main torrent at Mt. Sinabung, debris flow scenarios arising from the outburst need to be considered to predict and prevent damage in downstream regions. For the simulation, we applied KANAKO system with a 2 m resolution DEM for landform setting. To set the supplied discharge, we applied a rational formula using recorded rainfall data. We observed that the constituent material of the riverbed was relatively small-sized with regard to the field surveys. The larger portion of the sediment constituting approximately 35% of the riverbed ranged in particles sized from 0.05 to 0.3 m. The other 65% of the sediment was fine-grained smaller than 0.1 mm. Recent studies have indicated that the debris flows that contained a high concentration of fine particles had a higher flow-ability and larger fluid phase density than stony debris flows. Therefore, we considered scenarios involving fine materials that contributed toward a larger fluid phase density. We also considered scenarios without considering the effect of fine materials. Based on the results, the debris flow scenario considering the fine material effect appeared to flow down for a long distance and exhibited a higher risk at the downstream side.

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In many cases of disaster risk mitigation program, the community preparedness often becomes the important aspect to support the success of the program. There are two modalities where the community is considered having sufficient preparedness, namely the availability of reliable prediction of the disaster characteristics and the familiarization of the real time process of the related trigger. The reliable prediction of disaster characteristics may be obtained through study on the previous disaster records or occurrences. One way to predict the disaster characteristics is carried out through hydraulics-related simulation or modeling. For cases where disaster characteristics are uncertain, the presentation of such predictions in the form of alternative scenarios is advisable. Less number of alternatives would be better, however, it may not accommodate full possibilities in mitigating the risk. In line with the rapid progress on the information and communication technology, real time monitoring of factors triggering the hazards occurrences has become valuable supports in mitigating the disaster risk. Such real time monitoring results may be easily and accurately identified by community with relatively affordable cost. This paper illustrates how the integration of the real time monitoring system with the disaster warning criteria may play an important role in the disaster risk mitigation. The snake line behavior obtained from the real time monitoring system of rainfall and its integration with the warning criteria at a certain scheme of debris flow disaster has shown a promising contribution to the community to make self-rescue. Advantages and disadvantages regarding such integration program are discussed and recommendation for further application is presented.

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo.70.5_34

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Erosion Control Engineering  

<p>On 19 May 2017, slope failure occurred and a landslide dam formed at Idegawa watershed, Iiyama city, Nagano prefecture. After three days interval, debris flow occurred several times at Degawa River then partially reached Chikumagawa River. Although there were no loss of lives or property damage, an evacuation advisory has been issued on 20 May, then changed evacuation order on 22 May. After 23 June, this area is under evacuation advisory again. After the disaster, research team was immediately organized by The Shin-etsu Branch of Japan Society of Erosion Control Engineering. In this report, we described the magnitude and the generation processes of landslide and subsequent debris flow occurrence based on a field survey, weather observation data and the airborne laser scanning and videos. Furthermore, we evaluated the effect of the sabo-related facilities and overviewed the monitoring system and emergency measures.</p>

DOI： 10.11475/sabo.70.3_41

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo.68.4_37

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo.67.5_55

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Other Link： https://agriknowledge.affrc.go.jp/RN/2010873427

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11475/sabo.66.6_60

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After the 2010 eruption of Mt. Merapi in Indonesia, many instances of debris flows and flash floods occurred in the Putih River basin. The characteristics of debris flows and flash floods were analyzed using images of these events captured by an internet protocol (IP) camera installed near the PU-C11 sabo dam and rainfall records collected at the Gunung Maron observation station. The magnitude of debris flows and flash floods during the 2011–2012 rainy season was smaller than during the 2010–2011 rainy season. Additionally, the rainfall intensity that caused no debris flows or flash floods during the 2011–2012 rainy season was smaller than that observed during the early 1990s, when few debris flows and flash floods occurred. These results suggest that the hydrological regime of the catchment area was radically altered after the eruption.

DOI： 10.13101/ijece.7.63

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Language：Japanese   Publisher：The Japanese Society of Irrigation, Drainage and Rural Engineering  

We developed resistivity fish counter unit, which is a resistivity fish counter with rectangle frame type electrodes installed inside a polyvinyl chloride tube. In this study four resistivity fish counter units were assembled in the fish way at the Tone-ozeki weir at upstream period for small fish. We counted the number of small fish passing through each fish counter units. The each fish counter units was captured by a video camera from directly above, for 100 minutes. The number of fish was counted from the video analysis. The accuracy of the number of fish counted by using the fish counter was evaluated by comparing the result obtained from the fish counter with that obtained from the video analysis. The accuracy of the number of passing fish counted by using the fish counter was about 90% when number of fish, which pass through a fish counter unit, was less than 50/min. However the accuracy of the number of fish was about 60% when number of fish was more than 50/min because a number of fish pass through a fish counter unit together. The correction method using a correction formula was proposed to improve the counting accuracy by the resistivity fish counter in case number of fish is more than 50/min. It was shown that number of fish per 10 minutes can be counted with an accuracy of nearly 100% using the correction method.

DOI： 10.11408/jsidre.81.301

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学教育・学生支援機構  

本研究では, カリキュラムマップを用いた成績評価に基づく学習成果の可視化において, 既に整備されている人材育成の枠組みを活用する力法と, その課題を明らかにするととを目的とする．既存のJABEE学習教育目標と主専攻プログラムの到達目標を整理する手法を用いた可視化を提案すると共に, 到達目標毎の配点のばらつきによる可視化された学習成果の見え方について議論した．

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Other Link： http://hdl.handle.net/10191/24045

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

To examine the effects of thinning intensity on wind vulnerability and regeneration in a coastal pine (Pinus thunbergii) forest, thinning with intensities of 20%, 30% and 50% was conducted in December 1997; there was an unthinned treatment as the control (total 8 stands). We re-measured the permanent sites to assess the regeneration characteristics 11 years after thinning. In the 50% thinned stand, seedlings aged from 2 to 10 years exhibited the highest pine seedling density and growth. The age composition ranged from 1-3 years with densities of 9.9 and 5.1 seedlings m(-2) in 30% and 20% thinned stands; only 1-year-old seedlings with a density of 6.1 seedlings m(-2) in the unthinned stand. Similar trends were found for the regeneration of broadleaved species such as Robinia pseudoacacia and Prunus serrulata. We speculate that the canopy openness and moss coverage contributed to the regeneration success in the 50% thinned stand, while the higher litter depth and lack of soil moisture induced the regeneration failure in the unthinned stand. The stands thinned at 20% or 30% were less favourable for pine regeneration than the stands thinned at 50%. Therefore, thinning with less than 30% canopy openness (20% and 30% thinned stands) should be avoided, and thinning at higher than 30% canopy openness (50% thinned stand, approximately 1500 stems ha(-1) at ages 40-50 years) is suggested for increasing regeneration in the coastal pine forest. The implications of thinning-based silviculture in the coastal pine forest management are also discussed. The ongoing development of the broadleaved seedlings calls for further observations.

DOI： 10.1371/journal.pone.0047593

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japanese Society of Irrigation, Drainage and Rural Engineering  

The objective of this study is to develop a system that can automatically count the number of loaches ascending corrugated-pipe paddy field fishways by adopting the counting principle of resistivity fish counter originally designed for salmon. As the results of laboratory and in situ experiments, the counting mechanism of the resistivity fish counter could be applied to counting loaches by modifying the sensor allocation and adjusting voltage level. Counting precision was evaluated to be 86% with video monitoring analyses. In addition, long-term automatic operation in situ without permanent power sources was successful using rechargeable batteries (capacity 115Ah) and high-resolution and large-capacity data logger (memory capacity 2GB). The system could operate as long as 79 hours with two batteries connected in parallel.

DOI： 10.11408/jsidre.80.277

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

DOI： 10.11475/sabo.64.5_43

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Language：Japanese   Publisher：Japan Society of Civil Engineers  

&nbsp;The resistivity fish counter is widely used in Europe to count Atlantic salmon that pass through in-river structures (e. g., a Crump weir). The use of the counter is known to be an accurate and economical way of counting fish. However, the counter is rarely used in Japan. This study aims to establish a method for counting fish that pass through a fish way in Japan by using the resistivity fish counter.<br>&nbsp;A platform equipped with the sensor component of the resistivity counter was assembled in the fishway at the headwork of the Tone-ozeki. We designed the platform in accordance with the requirements of a fish way for Atlantic salmon (i. e., with appropriate velocity and height of water flow). We counted the number of salmon passing through the fish way during the spawning season by using the resistivity fish counter on the platform.<br>&nbsp;The sensor component of the fish counter was captured by a video camera from directly above, for a total of 19 h. The number of fish was counted from the video analysis. The accuracy of the number of salmon determined by using the fish counter was evaluated by comparing the result obtained from the fish counter with that obtained from the video analysis.<br>&nbsp;The accuracy of the number of salmon counted by using the fish counter was found to be 96%. The factors that might decrease the accuracy of the counter, the method of designing the platform in accordance with the requirements of a fish way, and cost for this study were considered. Methods for improving the accuracy of the counter are discussed.

DOI： 10.2208/jscejer.68.1

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：京都大学防災研究所  

Eruptions of Mt. Merapi, Yogyakarta, Indonesia produced a lot of pyroclastic flows in 2010. The pyroclastic flows directly killed more than three hundred people in south slope area and the topographical change due to the pyroclastic flows caused some severe floods in Opak River where little flood had occurred before the eruption. The widely deposited volcanic ash on south-west slope caused several large floods up to the end of rainy season in 2011. Particularly, the change in rainfall runoff process due to the deposition of volcanic ash seems to be one of the reasons why the large floods occurred frequently after the eruptions. As a result a lot of infrastructures such as roads, bridges and sabo structures were severely damaged in the tributaries of Progo River and Opak River.

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Other Link： http://hdl.handle.net/2433/161810

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 砂防学会  

The deluge on July 21 2009 in Yamaguchi, with the area&#039;s exceptionally heavy rainfall of 297 mm, maximum intensity 72.5 mm/hr and countless traces of debris flow, resulted in tremendous damage and high number of causalities in the area. Hence, urgent field investigation and reconnaissance were conducted by the society to overview this sediment related disaster. Here, the various results and the information obtained through this investigation were reported, mentioning the damages, the meteorological condition featuring precipitation, geologic-geomorphologic features and hydraulic characteristics of the debris flows, vegetation effects, and the efficiency of Sabo facilities against the sediment runoff in this disaster.

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学農学部  

本研究では、新潟大学農学部附属佐渡演習林内を流れる大倉川源流部に位置する林地流域と草地流域の水源涵養機能の評価を目的に、Cl（－）イオンをトレーサーとして用いた時系列解析を行い、流域内に分布する流路の通過時間を評価した。解析の結果、草地流域の流出には通過時間の比較的短い流出が寄与し、また、林地流域の流出には通過時間の比較的長い流出が寄与していることが示唆された。今回の結果から、林地流域と草地流域の渓流水は、それぞれ異なる流出過程を経て渓流へと流出していることがわかった。

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 砂防学会  

A debris-flow brake is an erosion control facility designed to stop debris flows. However, the mechanism of the debris-flow brake has not been explained. This study discusses the change in pore-water pressure near the deck of a debris flow brake which controls solid friction between the debris flow and the deck. A dynamic model that describes the behavior of debris flows at the debris-flow brake was built It incorporates not only the change in sediment concentration of the debris flow due to water draining through the debris-flow brake but also the resulting change in pore-water pressure. Numerical simulations and experiments examined the behavior of debris flows at a debris-flow brake. The simulation and experimental results agreed. The simulation results show that the change in pore-water pressure plays an important role in how a debris-flow brake stops debris flows.

DOI： 10.13101/ijece.2.15

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学農学部  

本研究では、山地河川が本来有している特性を明らかにすることを目的に、河川環境の重要な構成要素であるStep-Pool構造に焦点をあて、流域特性・降雨特性の異なる, 新潟県および三重県の8つの山地河川、合計35調査プロットにおいて、Step-Poolの形状と河床勾配や流路幅といった河道条件の計測結果を行った。調査結果を用いて、実河川におけるStep-Pool構造の形状及び分布特性やStepの成因、形成流量について考察した。その結果、河床勾配、低水路幅、Step 構成礫の礫径の3つは、Step-Poolの形状や分布特性を特徴付ける重要なパラメータであることがわかった。今回の調査結果を基に、地形図などから容易に調べることが可能な流域面積や勾配を用いて、山地河川に存在するStep-Pool構造のスケールを表す関係式を構築した。In this study, the relationship between channel geometry and step-pool morphology are discussed. The channel geometry, i.e., the channel gradient, channel width, the step-pool dimensions, size and number of step particle, etc., were surveyed at 35 study reaches of eight small basins in Japan. The results show that the channel gradient, channel width, and particle size have various implications for the step-pool geometry. With regard to the longitudinal profile of a step, the relationship between the channel geometry, step wavelength and step-step drop differs from that reported by previous studies at high-gradient reaches (&gt; 0.15 gradientA). The channel width and particle size are important variables aff ecting the step wavelength and step-step drop. Step width, which is the transverse profile of a step, is about 6 times the mean size of the rocks that form the step, and it is probably controlled by the particle size and channel width. The pool geometry is likely to be related to the channel gradient, discharge, and particle size. The characteristics of the distribution and the geomAetry of the step-pool can be explained by three parameters (particle size, discharge, and channel gradient). Estimation formulae were developed, which estimate local average geometry of the step-pool with catchment area and channel gradient.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER TOKYO  

Our objective was to detect environmental and disturbance factors that determine plant species composition in a downstream riverside floodplain of the Shinano River, where both natural flooding and artificial fire disturbances predominate. We classified the natural vegetation into five types by physiognomy, i.e., burnt field, intact (unburnt) field, early-successional forest, later-successional forest, and margin of channel. We deployed 14 transect belts containing 713 plots of 1 m x 1 m at these sites. In the plots, we determined plant occurrences and values of five environmental (soil moisture, soil texture, relative elevation above the river, horizontal distance from the river, and light conditions) and two disturbance factors (scouring of plants by flooding and fire). Plant species compositions and environmental and disturbance factors were different among the sites. Logistic regression analysis showed that burning stimulated the occurrences of herbaceous annuals and conversely constrained those of woody and fern species, suggesting that fire disturbance resets the succession. Scouring of plants by flooding also affected the occurrences of many species, and had a positive influence on that of herbaceous winter annuals in particular. Canonical correspondence analysis indicated that the distributional characteristics of the plant species in the riverside floodplain were influenced primarily by distance from the river, reflecting the magnitude of flood disturbance. We conclude that (1) magnitude of flood disturbance is the primary factor determining plant species composition, and (2) burning maintains early successional vegetation and simultaneously creates a unique plant species composition by stimulating the germination of buried viable seeds transported by flood.

DOI： 10.1007/s11284-007-0434-4

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学大学教育開発研究センター  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学  

The Mid Niigata Prefecture Earthquake on October 23, 2004 caused much landslides and slope failures in the Chuetsu region of Niigata prefecture, particularly in the river basin of the Imo river, a tributary of the Uono river, which is itself a part of Shinano river system. Characteristics of landslides and slope failure caused by the earthquake were analyzed using GIS. Rate of slope failure or landslide by area in the Imo river basin is as high as that by 1923 Kanto earthquake and 1999 Taiwan Chi-Chi earthquake. Number and total area of slope failures are greater than those of landslides. However, average area size of landslide is greater than that of slope failure. Slope failures were most common at slope inclinations in the range 30°-.Landslides were most common at slope inclinations in the range 20°- 30°. Rate of slope failure and landslide was higher in sandstone region and alternation of sandstone and mudstone region. Rate of slope failure and landslide inside landslide configuration was greater that outside landslide configuration. Especially, difference of landslide rate between inside and outside landslide configuration was great.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Soil Science Society of China  

To estimate the mean value of surface soil water content rapidly, accurately, and nonintrusively, field investigations on soil electrical resistivity (SER) with the Yokogawa 324400 earth resistivity meter and the surface (0-150 cm) soil water content (SWC) with time domain reflectometry (TDR), together with the abiotic factors including soil texture, structure, and salinity concentrations were conducted in the Mongolian pine (Pinus sylvestris var. mongolica) plantations on a sandy land. The measurement of SER was based on the 4-probe Wenner configuration method. Relationships between the values of SWC and SER were obtained based on analysis of the abiotic factors of the research site, which play a key role in affecting the soil electrical resistivity. Results indicate that the SER meter could be used to estimate the mean value of SWC in the Mongolian pine plantations on the sandy land during the growing seasons. The bulky nature of the equipment simplified the cumbersome measurements of soil water content with the general methods. It must be noted that the Wenner configuration method could only provide the mean values of the SWC, and the soil texture, structure, temperature, and solute concentrations influenced the SER and further affected the estimation of the SWC by the SER meter. Therefore, the results of this study could be applied on a sandy land during the growing seasons only. However, the SWC of other soil types also may be obtained according to the individual soil types using the procedures of this study. © 2007 Soil Science Society of China.

DOI： 10.1016/S1002-0160(07)60096-4

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：FINNISH SOC FOREST SCIENCE-NATURAL RESOURCES INST FINLAND  

In order to understand the processes of snow and wind induced damage in a natural montane, secondary forest in northeastern China, we examined the impacts of site conditions on the snow and wind damage; analyzed if the dominant tree species differed in their susceptibilities to the damage; and established the relationships between the characteristics of tree and stand and the damage. The results indicated that in regard to the topography factors, slope steepness and soil depth played a relatively important role for the damage. Damage ratios of all types combined were positively related with the composition of dominant tree species. The stand density was also important in determining resistance to the damage, i.e., the densely populated stand exhibited less overall damage ratios; however, the dominant tree species were commonly damaged easily by the snow and wind. Four damage modes found (uprooting, stem breakage, canopy damage and bending) were closely related to the stem taper (p &lt; 0.05), and they could be ranked in following order: bending (92.0) &gt; uprooting (85.3) &gt; stem breakage (80. 1) &gt; canopy damage (65.0). In regard to differences in tree species' susceptibilities to the damage, Betula costata exhibited the most uprooting, bending and overall damage ratios; while Quercus mongolica showed the highest breakage (both stem breakage and canopy damage) ratio, and Fraxinus mandshurica exhibited the least damage ratio (overall). The major six tree species could also be divided into two groups according to the overall damage ratios, i.e., more susceptible ones (B. costata, Ulmus laciniata and Q. mongolica), and less susceptible ones (F mandshurica, Acer mono and Juglans mandshurica) to the snow and wind damage.

DOI： 10.14214/sf.351

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

DOI： 10.11475/sabo1973.58.3_44

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The purposes and methods of soil resistivity measurement were introduced in this paper. Particularly, the theoretical background, field operating steps and data processing method of soil resistivity measurement using specific earth resistance tester (Yokogawa Type3244 Japan) were explained with the example measurement in sandy woodland. The results showed that 'method using the 3244 specific earth resistance tester, based on Wenner principle, to measure the sandy woodland soil resistivity was feasible. The measured results of soil resistivity have a certain application prospect in sandy soil delamination, soil water content prediction and the underground water table determination.

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Language：Japanese   Publisher：砂防学会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会誌  

Two strong typhoons in July and August 2004 caused the record heavy rainfall in Taiwan. Several floods and sediment disasters occurred in middle Taiwan, and 71 deaths and missings were recorded. Total damage was less than the former damage by the typhoons in 2001, however, the cumulative rainfall marked the maximum record at 2, 115mm, was bigger than typhoon Herb in 1996.

DOI： 10.11475/sabo1973.57.5_32

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：砂防学会  

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Language：Japanese   Publisher：農業情報学会  

It is important to eliminate the delay of the computerization in the agricultural field.&lt;br&gt;In this research, the agricultural information support by the group &quot;Gaccomi&quot; was proposed paying attention to human ware. &quot;Gaccomi&quot; is a group which works for two purposes; 1.information support in the agricultural field, 2.information education and personnel training for university students. It is run by university students and staff. This name is the coined word which combined the student (school: Gakkou) and the community (communication).&lt;br&gt;In &quot;Gaccomi&quot;, university students study the information technology (how to operate a personal computer (PC), how to dispatch on the internet, etc.) by construction of a student portal site. This is useful website for university students, and it is mainly targeted at the students and the community around a university. After training the students, The &quot;Gaccomi&quot; group supports farmers and agricultural corporations that wish to construct their website, or to study the use of a PC, etc. In this paper, establishment and the activities of this group were performed. The following were evaluated: 1.the activity situation of group, 2. the result of a student portal site construction, 3.the support result for farmers and agricultural corporations, 4.award and mass media coverage achievements. The information support technique of the agricultural field used by this group is proven to be effective and serves also as information education and personnel training.

DOI： 10.3173/air.13.213

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

It is desirable and necessary to preserve the continuity of a coastal forest through reasonable management because it can provide many shelter benefits through altering the wind behavior along the shore. Thinning is an undoubtedly important measure for the continuity of forests as it provides suitable conditions for natural regeneration; however, thinning increases the risk of wind damage immediately after thinning in the coastal areas. Therefore, few thinning study related to regeneration in a coastal forest has been made. In order to test whether coastal forest of Japanese black pine (Pinus thunbergii Parl.) requires a specific gap size created by thinning for regeneration and to compare seedling establishment among four thinning treatments, observations of emergence, survival and establishment of P. thunbergii seedlings, together with soil water content, litter, wind and light regime were made. The observations were conducted over four growing seasons in three sizes of circular gaps (the gap diameter to stand height ratios for the four gap sizes were 0.5, 1.0, 1.5 and 0.0, the control) corresponding to the four thinning treatments in Niigata shore, Japan. Results indicated that density of seedlings older than 1 year increased with gap size or canopy openness (OP). Seedling establishment was greater in 1.5 gap sizes than in any other gap sizes, while seedlings peaked near the west and north edges of the gaps but not in the gap centers exposed to direct solar radiation. Seedling growth in 1.5 gap sizes was also significantly higher than that in any others. A tendency of seedling height increasing from east to west edge and from south to north edge across the gap was observed. Only 1- or 2-year-old seedlings occurred in gap sizes of 0.0 and 0.5, therefore establishment in both gap sizes was considered as failing. The results imply that although P. thunbergii seeds can germinate in small gaps, even in under canopy, the seedlings are unable to survive. The seedlings apparently require a minimum gap size greater than or equal to 1.0, or OP &gt;30% in order to survive, and may require at least gap size greater than or equal to 1.5, or OP &gt;40% for further development into sapling. These results can be explained by the changes of microclimates, i.e. increase of light, soil water and airflow exchange, decrease of litter and canopy cover, and alleviation of the competitions for water in gaps created by thinning. Therefore, thinning strategy, especially patch-pattern thinning is potentially a viable silvicultural measure in management for the coastal pine forest. These results provide references for establishment and management of coastal P. thunbergii forests. (C) 2003 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0378-1127(03)00094-X

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Porosity of a forest stand is an important descriptor of vertical forest structure, although it is a difficult variable to define and measure because of its three-dimensional nature. Fortunately, studies on the effects of obstruction on irradiation in forest stands provide us with a method which uses a hemispherical photographic silhouette to estimate an alternative measure of porosity, here defined as optical stratification porosity (OSP). The differences between OSP and canopy closure, canopy cover and canopy gap, which are frequently used by ecologists and foresters, are discussed. The estimation of OSP of a forest stand using hemispherical photographic silhouettes is evaluated based on an analysis of stratification patterns in vertical forest structure. The OSP measured in a coastal pine forest having different thinning ratios is presented as an example to demonstrate the method. The results indicate that when the strata can be visually identified, the OSP can be obtained using hemispherical photographic silhouettes. Alternatively, if OSP is measured at various canopy heights in a forest stand continuously, the stratified vertical structure patterns of the forest stand can be determined. The predicted stratification of vertical forest structure based on the measurement of OSP can indicate the vertical strata more accurately than visual identification alone. Therefore, the estimation of OSP may be helpful in modeling wind profile, leaf area index, crown ratio and light inside a forest stand and may prove useful to those applications in which fine-scale vertical stratification is desirable. (C) 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0378-1127(01)00813-1

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Erosion Control Engineering  

The 15th typhoon named Rusa hit Korea during in August 31 to September 1. It caused serious damages particularly in the eastern region where the heavy rainfall concentrated, triggered debris flows, slope collapses and flood water inundations in major rivers. Many surface failures and debris flows occurred especially on the burned slope by forest fire, in addition, tremendous volume of sediment flowed into rivers and caused dangerous aggradations. Accordingly, it is imperative to control the discharged sediment by installing sabo dams.

DOI： 10.11475/sabo1973.55.6_59

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：FINNISH SOC FOREST SCIENCE-NATURAL RESOURCES INST FINLAND  

Wind speed and optical stratification porosity (OSP) were measured at various heights inside a coastal protective forest thinned to different stem densities to assess whether any characteristics of the wind profile in the coastal protective forest could be predicted from OSP. OSP was defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, and was determined for various heights using hemispherical photographic silhouettes on a computer processing system. The distribution of OSP in the coastal forest follows the Lambert-Beer s law with an extinction coefficient (nu). The relative wind speed within the canopy can be described using an exponential form with an attenuation coefficient (alpha). Variation in relative wind speed was very closely correlated with the distribution of OSP within the canopy. While below the canopy, i.e., in the trunk space, relative wind speed was little correlated with the distribution of OSP because the distribution of OSP was relatively constant there. Therefore, the linear relationships between relative wind speed and OSP and between the two coefficients nu and alpha were established within the canopy. The results suggest that OSP can be used to predict the wind profile in case of the application within the canopy of the coastal forest.

DOI： 10.14214/sf.501

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Language：Chinese   Publishing type：Research paper (scientific journal)  

A coastal forest planted nearby the sea can provide many shelter benefits for the coastal regions. It is ideally if the continuity of the shelter benefits could be preserved through reasonable management. Thinning and regeneration as the most important management techniques for plantations can help the continuity of the shelter benefits of the coastal forest. However, because of the peculiarities of coastal forest, i.e., the coastal plantation nearby the sea is vulnerable to disturbances (thinning as one kind of disturbance), the study on thinning and regeneration within a coastal forest is poorly understood. The purpose of this paper is to give a primary understanding in natural regeneration for the coastal Pinus thunbergii forest with different thinning rates after four growing seasons since thinning. The experiment was carried out at the middle of the shoreline along the Japan Sea, and the investigated sites consisted of four thinning treatments (control, 0% thinned, 20% thinned, 30% thinned and 50% thinned) in a coastal P. thunbergii forest. After thinning, the regenerated seedlings, soil water content, light condition (canopy openness or canopy density), wind regime, and litter depth and quantity were investigated for four growing seasons. The relationships between the regenerated seedlings and light condition, litter, wind profile and soil water content were examined. The results showed that thinning could improved the light condition on the forest floor, increase the exchange of airflow (wind speed) in the coastal forest stand, and ameliorate the water content of the forest soil. These factors accelerated the decomposition of litters, and provided necessary conditions for natural regeneration. The results of regeneration observation indicated that the most intensively thinned treatment (50% thinned with density of about 1500 stems'hm-2) could provide a better condition for regeneration during the four growing seasons. The density and growth of seedling (greater than 1 year) increased significantly with increasing thinning intensities, and the establishment of seedlings was obviously succeeded in the most intensively thinned treatment, but failed in less thinned treatments and understory. The thinned intensity of 50% did not induce wind damage to the coastal forest in the four years after thinning, and did not cause the loss of shelter functions of the coastal forest such as sand blocking, wind breaking and salt preventing etc.. On the contrary, it could provide the suitable conditions for natural regeneration of the pine coastal forest, or for the immigration of other species. Therefore, thinning as the silviculturally created openness is very important for the establishment of seedlings in the coastal forests, which provides a mechanism for the coastal forest from even aged stands dominated by P. thunbergii to stands containing multiple size classes and canopy layers.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KLUWER ACADEMIC PUBL  

Wind velocity, vertical stand structure and sea-salt distribution were measured at various heights inside a plantation of coastal pine forest, with thinning and unthinning, to assess whether any relationships exist between the wind profile, stand structure and sea-salt distribution in the coastal pine forest. The vertical stand structure, i.e., optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was determined for each height by computer analysis of digital images taken with a hemispherical lens. The distribution of OSP in the coastal forest follows the Lambert-Beer's law with absorbency coefficient (v). The relative windspeed within canopy can be described using the exponential form with the attenuation coefficient (alpha). The sea-salt was collected using salt gauze (a surgical dressing of loosely woven cotton) both inside and outside the coastal forest, and the distribution of sea-salt within canopy was also in accordance with an exponential function. The relationships among windspeed, OSP and sea-salt indicate that the distributions of both sea-salt and windspeed within canopy were very closely correlated with the distribution of OSP. A linear relationship between OSP and sea-salt has been found. Additionally, linear regression between coefficients v and alpha has been obtained as well. Based on these relationships between OSP, wind and sea-salt in the coastal forest, the sea-salt distribution and wind profile within the canopy of the coastal forest can be predicted according to OSP. These results may therefore be useful in analyzing the effects of sea-salt on vegetation and evaluating the filter functions of coastal forests.

DOI： 10.1023/A:1021174324616

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：Niigata University  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Forestry Society  

Simultaneous measurements of windspeed were made outside and inside a pine (Pinus thunbergii Parl.) coastal forest with different thinning intensities. Synchronously, optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was estimated using hemispherical silhouettes in each treatment area. Based on the observations, the frequency distribution of velocity, turbulence intensity, wind profile, and the corresponding relationships of these respective parameters with the vertical forest structure (OSP) were examined and compared among the treatment areas. A normal distribution of wind velocity was observed at the lower zone of the forest stand in all treatment areas. The turbulence intensity, the highest value of which was found near the canopy, changed greatly with height, wind velocity, and treatment, and decreased with windspeed and increased with the thinning intensity. It was found that the exponential relationship between wind-speed and height could be used to describe the wind profiles within the canopy of the coastal forest. The results demonstrate that the attenuation coefficient of the wind profile corresponds to the grade of thinning intensities. The wind patterns in a coastal forest with different thinning intensities are related to the vertical forest structure, particularly, wind profiles within the canopy are closely correlated with the distribution of OSP. The results indicate that wind profiles can be estimated simply based on the measurement of OSP with a very high coefficient of determination. Reciprocally, the estimation of OSP can also be obtained from the measurement of wind profile.

DOI： 10.1007/BF02762470

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学  

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DOI： 10.11475/sabo1973.54.12

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学  

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Language：English   Publishing type：Research paper (bulletin of university, research institution)   Publisher：新潟大学農学部  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Erosion Control Engineering  

There are many studies of the mechanics of suspended load laden flow, and many theoretical formula to estimate the concentration of suspended load have been proposed so far. But all has common problems;<br>(1) The relation between the characteristics of the turbulence of flow and the behaviour of suspended load is not so much reflected on the formula.<br>(2) It's necessary to know a reference concentration at a reference level to evaluate the formula. The reference level has not been set up theoretically.<br>And there are few studies of the suspended load on the torrential bed condition, in comparison with that on the alluvial bed condition.<br>This study was made by using a steep channel with large roughness on its bed. The results were analyzed using the diffusion model in order to check the suitability. The results are;<br>(1) The similarity between the dispersion of suspended load and the momentum transfer of flow was not always shown.<br>(2) The concentration distribution below roughness height decrease with decreasing height in some cases.<br>(3) It's more reasonable that the reference level is set up at the point with the roughness height from the theoretical bed.<br>In order to figure out mechanics of suspended load laden flow, especially on the torrential bed condition, the structure of the turbulence of the flow, the behaviour of suspended load near the bed and the behaviour of suspended load there should be studied.

DOI： 10.11475/sabo1973.46.3

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Language：Japanese   Publisher：京都大学防災研究所  

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo.69.6_97

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Language：Japanese   Publisher：公益社団法人 砂防学会  

DOI： 10.11475/sabo.69.6_01

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Language：Japanese   Publisher：砂防学会  

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Language：Japanese   Publisher：新潟大学災害復興科学センター  

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Language：Japanese   Publisher：新潟大学災害復興科学センター  

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Language：Japanese   Publisher：新潟大学災害復興科学センター  

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo1973.56.5_87

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Language：Japanese   Publisher：Japan Society of Erosion Control Engineering  

DOI： 10.11475/sabo1973.49.3_43

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Event date： 2005

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