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1.
Haiqing Liu Kaczkowski Timothy W. Kana Steven B. Traynum Ruben Visser 《Ocean Dynamics》2018,68(9):1191-1206
Natural dune growth after nourishment is often observed, and such growth plays an important role in beach management for coastal communities. Nourishment sand equilibration after construction is another important topic for project planning and design. Large-scale nourishment projects at Nags Head (NC, USA) (completed in 2011) and Bridgehampton–Sagaponack (NY, USA) (completed in 2014) are under comparatively high-wave energy conditions and offer new insight regarding these topics. After nourishment, a natural beach and inshore morphology were produced with high rates of dune growth by eolian transport. At Nags Head, volumetric dune growth averaged 8 m3/m/yr over the first 5 years following project completion, while Bridgehampton–Sagaponack averaged 9 m3/m/yr over the first 3 post-project years. Results are compared with the Bagnold (1941) analytical model predictions of dune growth and are shown to correlate and decay closely with dry-sand beach width as the nourished profile equilibrates. The extra volume and elevation in the dunes have provided a higher level of storm protection and have helped the sites avoid any major damage to oceanfront properties during hurricanes or numerous severe winter storms. 相似文献
2.
INAGAKI Hidehiro UNNO Nahoko SAKAKIBARA Takumi KUBOTA Sakiko HASEGAWA Kana 《资源与生态学报(英文版)》2021,12(2):254-259
禾本科物种(例如银草、芦苇)在日本传统的地膜覆盖农业中普遍使用,西阿瓦地区是全球重要的农业遗产系统(GIAHS)所在地。传统上,这里的农民使用银草覆盖农业土壤。但当地农民从长期的经验中了解到,日本虎杖覆盖更适合该地区茄科作物的种植。目前尚不清楚日本虎杖覆盖物为何对茄科作物的种植有益。在本项研究中,我们假设日本虎杖覆盖物可能会有效避免连续种植马铃薯的危害。因为过去每年都会种植两次本地马铃薯,因此,我们调查了日本虎杖覆盖对连续种植马铃薯以及番茄种植后对马铃薯产量的影响。在2018年进行的田间试验中,我们首先在连续马铃薯栽培的土壤和未耕种的土壤中比较了日本虎杖覆盖、银草覆盖和无草覆盖(对照)对马铃薯产量的影响,结果表明日本虎杖覆盖减少了马铃薯产量的降低程度。其次,我们比较了番茄种植后的土壤和未耕种的土壤中的虎杖覆盖和无草覆盖对马铃薯产量的影响,结果再次表明了日本虎杖覆盖减少了马铃薯生长和产量下降的程度。这些发现表明用日本虎杖覆盖有助于避免连续种植马铃薯的风险。 相似文献
3.
Kana NAGASHIMA Masayuki NARA Jun‐ichi MATSUDA 《Meteoritics & planetary science》2012,47(11):1728-1737
Abstract– We performed micro‐Raman spectroscopic analyses of the carbon vein in five ureilites: Allan Hills (ALH) A77257, Northwest Africa (NWA) 3140, Shi?r 007, Yamato 790981 (Y‐790981), and Yamato 791538 (Y‐791538). The graphite peaks showed that the graphite structure in ureilite is well developed, especially compared with the carbonaceous material in carbonaceous chondrite. The domain sizes of the graphite were 45–110 Å. We observed shifts in the diamond peak positions to higher wave numbers with a large full width at half maximum (FWHM), especially for NWA 3140. Although the FWHM of a diamond peak is not a crucial diagnostic test for a chemical vapor deposition (CVD) origin of diamond, the shift of the diamond peaks to higher wave numbers could be a strong indicator that supports the CVD origin as these shifts have only been observed in CVD diamonds. We discuss the origin of diamond from various aspects, and confirm that the CVD model is the most plausible. We conclude that all carbon material (graphite, amorphous carbon, diamond, etc.) condensed on the early condensates in the primitive solar nebula. 相似文献
4.
Mitigation works are very essential for mitigation of debris-flow hazards in mountainous areas. Usually, it is difficult to assess the effectiveness of existing mitigation works in a catchment. This paper presented a method for quantitative assessment of debris flow mitigation measures by using Kanako system, a user-friendly GUI-equipped debris flow simulator that allows good visualization and easy interpretation. Kanako 2D (Ver. 2.04) was applied to a case study at Caijia Gully, Sichuan Province, China. Mitigation works including check dams, drainage channel, and deposition basin were constructed in the gully in 2001 and 2006. Kanako 2D can simulate debris flow from steep area to alluvial fan. 1D simulation was applied for assessing the effect of the check dams at the lower part of the gully, and 2D simulation was applied for the effect of the drainage channel and deposition basin on the alluvial fan. The simulation results indicate that debris flow will cause great damage to residential area on the alluvial fan if mitigation measures were not implemented in the gully. For old dams which have been filled up with deposits of previous debris flows, the results show that they still have the function for controlling debris flow due to the gradient reduction of the channel bed in front of the dams by the trapped debris flow deposition. After the comprehensive control of debris flow including trapping, drainage, and deposition in the gully, the simulation results indicate that the risk on the alluvial fan can be reduced to an acceptable level. 相似文献
5.
INAGAKI Hidehiro KUBOTA Sakiko HASEGAWA Kana UNNO Nahoko USUI Yukiko TAKIKAWA Yuichi 《资源与生态学报(英文版)》2021,12(6):869-875
Poaceae plant species, such as silver grass, are commonly used in mulching activities Japan. In contrast, local farmers have traditionally used Japanese knotweed (Fallopia japonica) mulch in the cultivation of solanaceous crops in the Nishi-Awa area of Japan, which is a Globally Important Agricultural Heritage Systems site. We have previously evaluated the positive effects of Japanese knotweed mulching on solanaceous crops, such as eggplants, tomato, and potato. In the present study, we observed that the naturally occurring diseases in the solanaceous crops tended to decrease when the knotweed mulching system was adopted, in comparison to when Poaceae mulch was adopted. In eggplants, leaf mold and powdery mildew decreased under Japanese knotweed mulching. We further evaluated the effects of Japanese knotweed mulching by inoculating test plants with Pseudomonas cichorii. We observed suppression of bacterial disease and tomato mosaic virus under Japanese knotweed mulching and following spraying with Japanese knotweed extracts. In addition, disease-resistance genes were expressed at high levels in Arabidopsis thaliana, a model plant, following treatment with Japanese knotweed extracts. The results suggest that Japanese knotweed has potential applications in future sustainable agriculture activities. 相似文献
6.
Kana?NakataniEmail author Satoshi?Hayami Yoshifumi?Satofuka Takahisa?Mizuyama 《山地科学学报》2016,13(2):193-202
This paper presents debris-flow numerical simulations using the Hyper KANAKO system, developed by the authors. The system uses the debris flow simulator KANAKO 2D equipped with a graphical user interface (GUI); hence, a user can easily produce appropriate landform data for simulations using standard laser profiler data, and visualize the results using a GIS. Hyper KANAKO was applied to the streams around Kiyomizu-dera in Kyoto, Japan. Kiyomizu-dera is a famous temple in Japan which is visited by numerous tourists throughout the year. We simulated a disaster scenario of debris flow caused by torrential rain. We set the hydrograph using rainfall intensity data, and set the landform data using information from the Geospatial Information Authority of Japan (GSI) and a digital elevation model (DEM). We evaluated different mesh sizes and also used a digital surface model (DSM) to consider the building heights. The simulation results showed that with small mesh size, the debris flow moved through the roads, which seems realistic for a disaster situation. When buildings were considered, the flow direction changed, and a 1-m flow depth, which was deeper than in other cases, appeared in the flow path. This may pose a dangerous situation for evacuations. 相似文献
7.
Kana NAKATANI Yuki OKUYAMA Yuji HASEGAWA Yoshifumi SATOFUKA Takahisa MIZUYAMA 《山地科学学报》2013,10(2):273-280
Debris flows form deposits when they reach an alluvial fan until they eventually stop.However,houses located in the alluvial fan might affect the debris flow flooding and deposition processes.Few previous studies have considered the effects of houses on debris flow flooding and deposition.This study conducted model experiments and numerical simulations using the Kanako2D debris flow simulator to determine the influence of houses on debris flow flooding and deposition.The model experiments showed that when houses are present,the debris flow spreads widely in the cross direction immediately upstream of the houses,especially when the flow discharge is large or the grain size is small.Houses located in the alluvial fan also influence the deposition area.The presence of houses led to flooding and deposition damage in some places and reduced the damage in others.The simulation also demonstrated the influence of houses.Both the model experiment and the simulation showed that houses change the flooding and deposition areas. 相似文献
8.
Gouet Daniel Herv&#; Kana Janvier Domra Oya Valentin Ewembe Fontama Yuka 《Hydrogeology Journal》2022,30(4):1055-1069
Hydrogeology Journal - Lom River basin, associated with outflow from the Lom River system, is located in the East Region of Cameroon. The geology of the basin comprises Precambrian crystalline and... 相似文献
9.
Debris flow often causes enormous loss to life and property,especially on alluvial fans.Engineering structures such as retention check dams are essential to reduce the damage.In hazard mitigation evaluation and planning it is of significance to determine the location,size and type of dam and the effects of damage mitigation.We present a numerical simulation method using Kanako simulator for hazard mitigation planning of debris flow disaster in Tanjutani Gully,Kyoto City,Japan.The simulations were carried out for three situations:1) the simulations of erosion,deposition,hydrograph changing and inundation when there were no mitigation measures;2) the simulations of check dams in four locations(470 m,810 m,1,210 m and 1,610 m from the upstream end) to identify the best location;3) the simulations of check dams of three types(closed,slit and grid) to analyze their effects on sediment trapping and discharge reduction.Based on the simulations,it was concluded that two closed check dams(located at 470 m and 1,610 m from the upstream end) in the channel and a drainage channel on the alluvial fan can reduce the risk on the alluvial fan to an acceptable level. 相似文献
10.
Millennial-scale oscillations of the westerly jet path during the last glacial period 总被引：1，自引：0，他引：1
Kana Nagashima Ryuji Tada Atsushi Tani Youbin Sun Yuko Isozaki Shin Toyoda Hitoshi Hasegawa 《Journal of Asian Earth Sciences》2011,40(6):239-1220
It has been established that East Asian summer monsoon intensity varies with Dansgaard–Oeschger cycles, suggesting a connection between the climates of East Asia and the North Atlantic on a millennial timescale. However, the dynamics of such a connection are still unsolved. Here we demonstrate that temporal changes in the provenance of aeolian dust in Japan Sea sediments, which we interpret to reflect changes in the westerly jet path over East Asia, exhibit variations in harmony with Dansgaard–Oeschger cycles. The dominance of dust with a Mongolian Gobi provenance during stadials suggests a westerly jet axis located to the south of the Himalaya–Tibetan Plateau throughout most of the year, whereas the co-dominance of dust from both the Taklimakan Desert and the Mongolian Gobi during interstadials suggests that the westerly jet axis jumped to the north of the Tibetan Plateau at latest in summer. As the shift of the westerly jet axis to the north of the Tibetan Plateau is closely related to the onset of the East Asian summer monsoon, changes of the westerly jet path apparently critically affect the teleconnection between the climates of Asia and North Atlantic on a millennial timescale. 相似文献