Climatic risk zoning for potential occurrence of cacao moniliasis disease in Northeastern Brazil under the influence of ENSO phases

Theoretical and Applied Climatology - Air temperature and relative humidity are the main drivers of many fungal diseases, such as moniliasis (Moniliophthora roreri), which affects cocoa production...     

New method for estimating reference evapotranspiration and comparison with alternative methods in a fruit-producing hub in the semi-arid region of Brazil

Theoretical and Applied Climatology - Analysing alternative methods for estimating reference evapotranspiration (ET0) is essential for improving the management of water resources, especially where...     

Investigation of the 20 August 2005 fatal landslide at Fu Yung Shan Tsuen, Hong Kong

On 20 August 2005, a landslide with a volume of about 400  m³ occurred at Fu Yung Shan Tsuen, Tsuen Wan in Hong Kong during a severe rainstorm with a return period of about 100  years on a hillside that has been disturbed locally by past human activities. The incident resulted in one fatality and permanent evacuation of residents of four squatter structures in the vicinity. A forensic investigation into the landslide was carried out to review the mechanism and probable causes of the landslide. The key contributory factors in the landslide were diagnosed. The investigation concluded that the landslide was probably caused by the loss of soil suction and transient build-up of groundwater pressure in the near-surface soil materials following prolonged and intense rainfall. The paper presents the methodology adopted for the landslide study, findings of the investigation and the lessons learnt from this fatal landslide.     

Radiological and geochemical characteristics of an ultramafic massif (NE Portugal) regarding the site aptness to host a near surface repository for low and intermediate level radwaste

The search for suitable sites to install near-surface repositories for low to intermediate level radioactive wastes has increased in the recent years, reflecting both the continuous rise in radioactive materials applications by the society and the increasing awareness of public perception regarding radwaste management. International recommendations towards the application of higher safety standards to low and intermediate level waste disposal sites being developed by the International Atomic Energy Agency (IAEA), and the European Commission decision that each Member State must safely dispose its own radwaste in its territory, according to national radwaste management plans, has leading to new soundly scientific studies. In Portugal, possible locations for that purpose are under study since 2006, following the pre-requisites indicated by IAEA. One of these sites overlaps a significant portion of an ultramafic massif, corresponding to an allochthonous and metamorphosed ophiolite complex. In the surveyed area of this massif, the prevailing rock type consists of (serpentinised) peridotites, occasionally containing irregular bodies of (amphibolitised) gabbros, over which an irregular/ill-developed regolith exists. The activities of ⁴⁰K, ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra and ²³²Th measured in samples representing three consecutive levels of the regolith upper portion in 13 stations confirm the heterogeneity put in evidence through in situ γ-ray surveys previously performed. The available dataset also demonstrates that radionuclide contents decrease prominently with depth, becoming closer to the bedrock values (up to ca. 41 Bq kg^?1 for ⁴⁰K in flaser-gabbros and near zero for all the remaining cases) but never reaching them. Therefore, the low/moderate radionuclide activity in the regolith upper portion reflect the contribution of sources that are independent of the lithological background; i.e. they indicate external and miscellaneous contributions to the “soil”-forming components, most of them coming from (dry or wet) atmospheric deposition. The chemical composition of the (serpentinised) peridotites and (amphibolitised) gabbros in the surveyed area, as well as their alteration products included in regolith, is homogeneous enough to be used as a faithful reference in monitoring studies of any kind. In addition, the significant ¹³⁷Cs activities measured in some top “soil” samples (up to 92 Bq kg^?1) strongly suggest that there are mineralogical specificities of the peridotite-derived regolith able to fix that radionuclide. This particular feature reinforces the existing criteria that favour the peridotites of Morais as a suitable host for a near surface repository of low to intermediate level radwaste.     

Definition of areas of probable risk to human health posed by As and Pb in soils and ground-level dusts of the surrounding area of an abandoned As-sulfide mine in the north of Portugal: part 1

The aim of this study is to assess the potential health risk posed by As and Pb in the soils of the Pintor mine area. The site was never remediated but a residential area is being constructed in the mine land, next to the smelters, a fact that raised some concern about the probable risk posed by potentially harmful elements in the soil to the health of the residents. 132 samples were collected and analyzed by ICP-MS to determine total metal concentrations. The soluble fraction of As in the soil was obtained using 1 M NH₄ Acetate, pH 4.5. To assess the probable risk, total concentrations are compared with the soil guideline value established for the UK. Exposure through soil ingestion is probable in and around the residential area that has higher As and Pb concentrations, and therefore is classified as area with a potential health risk.     

中国西部生态环境变化与对策建议

中国西部地区生态环境的历史演变过程与未来可能变化趋势是科学界面对的一大难题,正确认识西部地区生态环境的演变过程与变化趋势,是西部地区社会经济可持续发展必须面对的课题,是正确制定西部大开发战略方针的重要科学基础。依托中国科学院牵头完成的《中国西部环境演变评估》研究成果,介绍了中国西部地区生态环境演变的主要特征与基本事实,主要强调近50年来全球变暖与人类活动在西部生态环境演变中的重要作用;指出未来的气候与环境变化对西部地区的经济社会发展将产生重要影响;提出了西部地区生态保护与可持续发展的对策与建议,指出西部地区的生态建设必须综合治理、突出重点,特别强调要强化对西部地区的科学研究,为西部大开发服务。     

Technical guidelines for the assessment of earthquake induced liquefaction hazard at urban scale

Bulletin of Earthquake Engineering - Microzonation for earthquake-induced liquefaction hazard is the subdivision of a territory at a municipal or submunicipal scale in areas characterized by the...     

Site classification using equivalent soil profiles for building-liquefaction interaction

The seismic behaviour of a building on a liquefiable deposit is a complex interaction which involves quantifying both shaking induced damage and permanent ground deformation-related damage. In this paper the key parameters that influence both surface shaking and foundation settlements have been identified as the depth, thickness and liquefaction resistance of an equivalent liquefiable layer. These parameters can be used to develop an ‘equivalent soil profile’ that is analogous to the equivalent single degree-of-freedom that reduces the complexity of the dynamic response of a building into comparable and easily understood quantities. The equivalent soil profile is quantified independent of the seismic hazard, making it compatible with performance based design and assessment frameworks such that the building and soil profile can be directly assessed at different levels of seismic hazard. Several numerical studies are presented that demonstrate the influence of these key parameters on the ground surface shaking and foundation settlement. A set of criteria are proposed for classifying soil profiles into 22 different soil classes for regional loss assessment. An algorithm was developed for automatically fitting the equivalent soil profile to a cone penetration test trace and issues with the fitting are discussed. Field reconnaissance was undertaken to collect additional data to support existing datasets on the performance of buildings in Adapazari, during the 1999 Kocaeli, Turkey, earthquake (Mw = 7.4). The field case history data was used to investigate the correlation between the depth, thickness and liquefaction resistance of an equivalent liquefiable layer, on the extent of foundation permanent deformation. The case history data showed that in general a shallow, thick and weak liquefiable layer near the surface results in significant settlement but a lack of data for buildings on non-liquefiable deposits and the additional complexities involved with real buildings and soil deposits, meant that the trends observed in the idealised numerical models could not identified in the field case history data set.

     

Can the Intermediate Western Boundary Current recirculation trigger the Vitória Eddy formation?

Ocean Dynamics - South of the Vitória-Trindade Ridge, a seamount chain off East Brazil, the Brazil Current (BC) meanders cyclonically within Tubarão Bight, occasionally forming the...