Mapping vertical profile of discontinuous permafrost with ground penetrating radar at Nalaikh depression,Mongolia

Ground-penetrating radar (GPR) has become an important geophysical tool which can provide a wealth of interpretive information about the vertical profile of discontinuous permafrost. A GPR investigation was conducted in October 2006 at the Nalaikh site at the southern boundary of the Siberian discontinuous permafrost region in Mongolia. GPR data were collected along four 100-m-long profiles to identify the location of the permafrost body, which included an in situ drilling borehole and analysis of temperature observations and soil water content measurements from boreholes. The GPR interpretation results indicated that the thickness of discontinuous permafrost at the study site was only 1.9–3.0 m and the permafrost is vulnerable to climate change. The soil temperature and soil water content data demonstrate the precision of GPR image interpretation. This case demonstrated that GPR is well suited for mapping the internal structure of discontinuous permafrost with relatively low soil water content.     

Bioaccumulation of nitroarenes in bivalves at Osaka Bay, Japan

This paper reports for the first time the detection and occurrence of nitroarenes (NPAHs) in marine organisms. Mussels and oysters collected from Osaka Bay, Japan, had total NPAHs concentrations that ranged from 2380 to 24,688 pg/g dry and 2672 to 25,961 pg/g dry, respectively. Relatively higher concentrations were detected in sampling sites located near the central district and suburbs of Osaka City implying that the most probable sources of NPAHs in the two bivalves are exhaust gases and smokes emitted by automobiles and industrial plants. Bivalves had relatively higher residues of 1-nitronaphthalene, 2-nitronaphthalene, 3-nitrophenanthrene, and 9-nitrophenanthrenes. Residues of 2-nitrofluorene, 1-nitropyrene, 4-nitropyrenes, and 6-nitrochrysene were much lower compared to nitronaphthalenes and nitrophenanthrenes. Inter-species differences was only observed for 2-nitronaphthalene with oysters exhibiting significantly higher residues than mussels.     

长江干流主要营养盐含量的变化特征——1998~1999年日中合作调查结果分析

根据1998年和1999年秋季在长江干流从重庆至长江口进行的纵向采样和分析,对长江干流的各态氮、磷含量的沿江变化进行研究。从整体上了解长江干流的水质变化特性,特别是营养盐含量的分布状况。研究结果表明,长江干流的SS浓度很高,介于50~400 mg/l。TN、TP浓度分别在70~110 滋mol/L、2~25 滋mol/L之间,前者以NO3-N为主,后者以PTP为主,PO4-P含量仅占TP的10%~20%。DIN/PO4-P的比值在70~160之间,远高于浮游植物生长P限制值,表明长江口及临近海域中P可能是生物生命活动的主要限制因素。葛洲坝水库对SS、TP、TN、NH4-N、BOD、COD等水质有一定的净化作用。长江水体在通过各大城市以及两大湖泊时,BOD、NH4-N负荷的增加迅速,特别是通过重庆、武汉、南京、上海及洞庭湖和鄱阳湖之后尤为明显。N、P含量的上升与人口增长、生活污水排放量及流域内化肥施用量增加有关。洞庭湖和鄱阳湖水系以及周围的面源负荷,对长江流域的营养盐变动有很大的影响。     

Three-dimensional image of the anisotropic bodies beneath central Honshu, Japan

Shear-wave splitting from local deep earthquakes is investigated to clarify the volume and the location of two anisotropic bodies in the mantle wedge beneath central Honshu, Japan. We observe a spatial variation in splitting parameters depending on the combination of sources and receivers, nearly N–S fast in the northern region, nearly E–W fast in the southern region and small time delays in the eastern region. Using forward modelling, two models with 30 and 10 per cent anisotropy are tested by means of a global search for the locations of anisotropic bodies with various volumes. The optimum model is obtained for 30 per cent anisotropy, which means a 5 per cent velocity difference between fast and slow polarized waves. The northern anisotropic body has a volume of 1.00° (longitude) × 0.5° (latitude) × 75 km (depth), with the orientation of the symmetry axis being N20°E. The southern anisotropic body has a volume of 1.25° × 1.25° × 100 km with the symmetry axis along N95°E. Our results show that the anisotropic bodies are located in low-velocity and low- Q regions of the mantle. This, together with petrological data and the location of volcanoes in the arc, suggests that the possible cause of the anisotropy is the preferred alignment of cracks filled with melt.     

Growth inhibition of a red tide flagellate,Chattonella antiqua by copper

Journal of Oceanography - Copper toxicity inChattonella antiqua (Raphidophyceae) was examined using an artificial seawater medium. The growth rate (Μ) was found to be a unique function of...     

Generation of greenhouse effect gases from different landfill types

Recently much attention is focussed on the problems of global warming due to greenhouse effect gases, notably carbon dioxide and methane. Because these gases cause important problems to the global environment, their generation from landfill sites containing solid wastes has drawn attention and their environmental impact is causing concern.

Generally, the gases associated with a greenhouse effect include carbon dioxide, methane and nitrous oxide. However, there are no general basic data available concerning gases generated from biodegradation of solid wastes in landfill sites. Specifically, no assessment has been made concerning greenhouse effect gases from different landfill types.

This paper proposes a quantitative model for estimating the gasification rate by different landfill types. The model is based on measurement data for a long-term material balance for an aerobic landfill and an anaerobic landfill, obtained with two types of large-scale lysimeters.

This paper will also give an estimate for the amount of greenhouse effect gases by for different types of landfill and propose countermeasures for their reduction.     

Analysis of dust events in 2008 and 2009 using the lidar network, surface observations and the CFORS model

The Asian dust events in 2008 (May 24–June 4 in 2008) and in 2009 (March 12–25, October 13–26, and December 15–28 in 2009) were analyzed with the lidar network observations, surface observations in China, Korea, Japan, and Mongolia, and with the chemical transport model CFORS. Transport of Asian dust and mixing of dust with air pollution aerosols were studied. The event of May 24 to June 4 in 2008 was a significant event unusually late in the spring dust season. The dust event of March 12–25, 2009 was an interesting example of elevated dust layer, and transport of dust from the elevated dust layer to the ground by the boundary layer activity was observed with the lidars and surface observations in Japan. The concentration of air pollution aerosols was relatively high during the dust event, and the results suggest that vertical structure as well as transport path is important for the mixing of dust and air pollution aerosols. The dust events in October and December 2009 were examples of dust events in autumn and winter. The online mode CFORS reproduced the observation data generally well, except for the event of May 24 to June 4 in 2008. The results of the fourdimensional variational assimilation of the lidar network data reproduced the dust concentration in Korea and Japan reasonably in that event.     

Further evaluation of the Sim-ReSET model for ET estimation driven by only satellite inputs

Abstract

A simple remote sensing evapotranspiration (ET) model (Sim-ReSET) has been proposed but only tested using field measurements at a site with a semi-arid climate. Its performance for mapping ET using only satellite data remained unknown. In this study, the Sim-ReSET model was further evaluated for ET estimation driven by only MODIS data products. The estimated ET rates were compared with ground-based observational data from a variety of ecosystems and climates across China. The results show that MODIS-based ET estimates are consistent with both the ET measurements from eddy covariance flux towers and those from the Penman-Monteith method combined with micrometeorological data. Evaporation fraction (EF) is indicative of land surface moisture. The derivative EF maps demonstrate that the proposed ET data set obtained from the Sim-ReSET model and MODIS data is capable of capturing the spatio-temporal pattern of land surface moisture for different land covers with different climates.

Editor Z.W. Kundzewicz

Citation Sun, Z.G., Wang, Q.X., Matsushita, B., Fukushima, T., Ouyang, Z., Watanabe, M., and Gebremichael, M., 2013. Further evaluation of the Sim-ReSET model for ET estimation driven by only satellite inputs. Hydrological Sciences Journal, 58 (5), 994–1012.     

Possibility of a major earthquake in the tokai district, Japan and its pre-estimated seismotectonic effects

Crustal deformations, tsunamis and seismic intensity are pre-estimated for a large hypothetical earthquake, which it is feared may occur in the Tokai district along the Nankai trough. The long-term seismic quiescence since 1854, as well as the high rate of the present crustal movements in the district, form the principal evidence for the risk of the approaching catastrophe. The location and the mode of faulting in this earthquake are hypothesized in reference to the source mechanisms of the recent and historical earthquakes there. The fault parameters thus assumed are as follows: dip direction: N30°W; dip angle: 25°; fault dimension : 100 km × 70 km; dislocation: 4 m (reverse dip-slip: 3.8 m; right-lateral strike-slip: 1.3 m). The following are the principal conclusions: (a) the eastern part of the epicentral region including the Point Omaezaki will rise up about 100 cm, whereas the western part covering Ise and Mikawa bays will subside about 10–30 cm; (b) the coast extending from Omaezaki to the Shima peninsula will receive tsunami waves as high as 3 m in maximum, which may be locally amplified by the factor 2 or more on the rias coast along the Shima peninsula; (c) the Tokai coastal region with thick alluvium layers may suffer seismic damages as severe as those experienced in the 1854 Ansei I earthquake.     

区域最小人均耕地面积与耕地资源调控

耕地资源对农业和国民经济可持续发展起着不可替代的基础性作用。中国人均耕地资源短缺，快速工业化、城市化进程对耕地的占用使耕地资源更趋紧张。目前的市场机制必然驱动耕地资源不断向获利更多的用途转移，最终会危急食物安全。因此，创新耕地资源利用与保护的调控机制已迫切之至。基于中国耕地资源流失原因及态势的分析，提出了最小人均耕地面积和耕地压力指数概念，并以此为基础提出了构建耕地资源利用和管理调控机制的思路。实际数据分析结果表明，以最小人均耕地面积和耕地压力指数作为耕地保护的基本标准，能因地制宜地兼顾食物安全和经济发展对土地的需求，具有显著的科学性和可操作性。