约旦的地震危险性

<正> 1 地震危险性评定历史约旦位于阿拉伯板块,它与长达1000km的死海地震活动带相邻,死海裂谷带为左旋走滑断层系。死海裂谷带为左旋滑动板块边界,起自亚喀巴湾东北,沿死海—约旦裂谷进入黎巴嫩中部直到叙利亚西北。过去曾发生过大地震(图1),图2表示1903～1983年仪器震中分布,1983～1992年由约旦地震台(JSO)记录到的地震如图3所示。自1983年以来,约旦建立了由26个地震台组成的台网,1990年又建了一个强震台网。1990年约旦出版了一部建筑规范,其中有一章为抗震设计规范。     

前苏联的地震危险性

<正> 1 地震危险性评定历史Gorshkov(1937)所汇编的前苏联大陆最早的地震区划图.是世界上最早的这类图之一。这是最早的地震危险性预测图,因为它标识出了潜在地震危险地区:不仅已知历史地震的地区,而且还根据较早地震地区推断“地质相似区”。1957、1968和1978年的正式建筑规范采用了一些成功的地震区划图。许多年以来,苏联领土的所有地震区划工作均是在E.F.Savarenskiy,S.L.Solviev和M.A.Sadovskiy指导下,地震与地震工程部门委员会指挥和协调下进行的。该机构出版了一部有关震源、方法、结果和参考文献方面的完整的说明书(ICSEE,1980)。Bune等(1974)和Reisner(1985)阐述了影响地震区划实践的思想史。通过对地震危险性预测结果与10年或20年后观测的进行比较,使得地震区划的定性控制理论得到了发展(Mokrushina和Shebalin,1982,1991)。分析了各个地区和整个区域的预报错误、     

厄瓜多尔的地震危险性

<正> 1 地震危险性评定历史在厄瓜多尔460年的历史上,地震扮演了一个很重要的角色,大约有8万人在地震灾害中丧生,其中包括1797年的Riobamba地震中死亡的4万人和1868年Ibarra地震中死亡的2.5万余人。在20世纪前,全国的总人口还不到100万,由此可知,地震死亡人数比例之大。随着仪器地震学的问世,本世纪在厄瓜多尔的俯冲带至少监测到六个Ms>7.5级的地震。其中最大的一次是1906年的震级Ms=8.8地震(Kanamori,McNally,1982),最近的一次大地震(1987年3月5日,Ms=6.9)发生在安第斯山脉的东部,这次地震严重地影响了厄瓜多尔唯一的输油管线,使其关闭六个月之久。由于整个国家收入的60％靠原油出口,为此这次破坏性地震对厄瓜多尔的经济产生了严重的副作用。尽管地震灾害的历史悠久,但直到本世     

Modeling the spatial dynamics of regional land use: the CLUE-S model

Land-use change models are important tools for integrated environmental management. Through scenario analysis they can help to identify near-future critical locations in the face of environmental change. A dynamic, spatially explicit, land-use change model is presented for the regional scale: CLUE-S. The model is specifically developed for the analysis of land use in small regions (e.g., a watershed or province) at a fine spatial resolution. The model structure is based on systems theory to allow the integrated analysis of land-use change in relation to socio-economic and biophysical driving factors. The model explicitly addresses the hierarchical organization of land use systems, spatial connectivity between locations and stability. Stability is incorporated by a set of variables that define the relative elasticity of the actual land-use type to conversion. The user can specify these settings based on expert knowledge or survey data. Two applications of the model in the Philippines and Malaysia are used to illustrate the functioning of the model and its validation.     

Speciation of arsenic in plants by HPLC-HG-AFS: extraction optimisation on CRM materials and application to cultivated samples

A recently developed method for the determination of arsenic species (arsenite, arsenate, monomethylarsonate, MMAA, and dimethylarsinate, DMAA) has been applied to the study of arsenic speciation in plants. This method uses ion-exchange liquid chromatography coupled on-line to atomic fluorescence spectrometry through continuous hydride generation. Various extraction procedures have been studied in detail using three plant certified reference materials. None of the procedures tested revealed fully satisfying results with all kinds of plant samples; microwave assisted extraction with 0.3 mol dm-3 orthophosphoric acid was found to be the most convenient for dealing with terrestrial plants. Species stability appears good. This method was applied to real world cultivated plant parts. Arsenate appears to predominate in soils, roots and leaves; unidentified species (probably arsenosugars) play an important role (60%) in rice fruits. Carrot was found to be the most contaminated edible plant part, containing 1 mg kg-1 essentially as arsenate species. MMAA was detected in all soils and some plant parts especially shallots at low levels, whereas DMAA was found only in one soil sample and in hot pepper leaves. Arsenite is a minor component of all soils; it is also present in some plant parts at low levels. However, no evident relationships were found between As speciation in the various plant parts and much more detailed studies will be necessary to elucidate As behaviour in plants.     

Comparison of emissions estimates derived from atmospheric measurements with national estimates of HFCs,PFCs and SF6

This paper assesses the feasibility of using atmospheric measurement of fluorinated greenhouse gases (HFCs, PFCs and SF6) for the review and verification of greenhouse gas inventories provided by national governments. For this purpose, available data were compiled. It was found that atmospheric measurements of these gases are available and provide an indication of global annual emissions with sufficient certainty to reach the following conclusions: Within the uncertainty of the method, it was found that emissions of HFC-23, a by-product of HCFC-22 production, as obtained from atmospheric measurements did not decrease as fast, as the countries have reported. In contrast, SF6 concentrations in the atmosphere suggest higher emissions than reported by countries. Regional emission estimates from atmospheric measurements are still in a more pioneering state and cannot be compared to national estimates. Intensified efforts to measure HFCs, PFCs and SF6 in the atmosphere are recommended.     

Cypress tree (Cupressus semervirens L.) bark as an indicator for heavy metal pollution in the atmosphere of Amman City,Jordan

Bio-monitoring of air quality in Amman City was investigated by analyzing 36 cypress tree (Cupressus semervirens L.) bark samples from three sites of different anthropogenic activities at the end of summer season 2001. Cypress barks were found to be a good bio-indicator for air pollution in arid regions. Variation in Pb, Zn, Mn, Cr, Ni, Cd, and Cu contents between sites was observed due to different types of activities. Traffic emissions were found to be the main source of heavy metal pollution in the atmosphere of Amman. Lead content was found to be the highest in highly traffic density areas. The industrial part of the city was characterized by high Zn, Mn, Cr, Ni, and Co contents. No significance variations were found in pH values of the bark between the sites. This was attributed to buffering effect of carbonate in the atmosphere originated from soil of the area.     

COUNTERMEASURES AGAINST LANDSLIDE GEOLOGICAL DISASTERS IN TIBET

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90年代世界近海铁矿石的贸易状况

从过去数十年全世界近海铁矿石的贸易增长状况,可反映出世界对钢材的需求量。而90年代全世界的钢材生产发生了什么变化?铁矿石生产国能否满足全世界对铁矿石的需求增长量?本文在回顾和分析过去40年全世界对钢材需求量和近海铁矿石贸易状况的基础上,对以上问题进行了讨论。