城市化对石家庄站近地面风速趋势的影响

利用1972—2012年石家庄城市站和4个乡村站地面风速资料,采用城乡对比方法,对石家庄城市站地面风速序列中的城市化影响进行分析,结果表明,石家庄站年和季节平均地面风速和平均10 min最大风速的长期下降趋势,主要是由城市化因素引起。具体结论如下：(1)石家庄站年和四季平均风速、平均10 min最大风速和大风日数均呈极显著的减少趋势,年平均减少速率分别为-0.15 (m/s)/10a、-1.05 (m/s)/10a和-2.90 d/10a;乡村站年平均风速呈微弱下降趋势,年平均10 min最大风速减少较为明显,年大风日数减少趋势非常显著,减少速率分别为-0.02 (m/s)/10a、-0.21 (m/s)/10a和-2.19 d/10a。(2)石家庄站年平均风速下降趋势中的城市化影响为-0.13 (m/s)/10a,城市化影响非常显著,城市化贡献率达到86.0%。该站春、夏、秋、冬季平均风速变化的城市化影响分别为-0.16 (m/s)/10a、-0.10 (m/s)/10a、-0.13 (m/s)/10a和-0.15 (m/s)/10a,城市化贡献率分别为82.8%、87.6%、88.6%和85.4%。(3)石家庄站年平均10 min最大风速变化趋势中的城市化影响为-0.84 (m/s)/10a,城市化贡献率为79.7%;春、夏、秋、冬季平均10 min最大风速变化趋势中的城市化影响分别为-0.94 (m/s)/10a、-0.80 (m/s)/10a、-0.60 (m/s)/10a和-1.01 (m/s)/10a,城市化贡献率分别达到90.4%、78.6%、64.9%和79.1%。(4)城市化对石家庄站年大风日数减少的影响不显著,但冬季大风日数减少仍明显与城市化过程有关。     

祁连山西段诸盆地水文地质条件

祁连山西段诸盆地地下水的形成与分布不仅取决于第四系厚度、孔隙、冻土等条件，更重要的还取决于山前平原与基岩的接触关系及其地质结构。盆地内地表水与地下水的相互转化，不仅使地下水的水质、水量具明显的水平分带性，而且也影响着主干河流流量的大小。在海拔３８００ｍ以上多年冻土区，地下水以冻结层上水和冻结层下水形式存在；在海拔３８００ｍ以下非多年冻土区，地下水主要以潜水形式存在，富水性中等或强。诸盆地地下水主要以ＨＣＯ３－Ｃａ－Ｍｇ型水为主，水质优良     

Pesticide Pollution in Surface‐ and Groundwater by Paddy Rice Cultivation: A Case Study from Northern Vietnam

This study was designed to examine the environmental exposure of surface‐ and groundwater pollution in remote mountainous regions of northern Vietnam. In 2008, we monitored the loss of four commonly applied pesticides (imidacloprid, fenitrothion, fenobucarb, dichlorvos) from paddy rice farming systems to a receiving stream on the watershed scale and quantified groundwater pollution. For the entire monitoring period, runoff loss of pesticides from the watershed was estimated to range between 0.4% (dichlorvos) and 16% (fenitrothion) of the total applied mass. These losses were correlated well with the octanol–water partition coefficient and water solubility of pesticides (r² = 0.78–0.99). In the groundwater collected from eight wells, all target pesticides were frequently detected. Maximum measured concentrations were 0.47, 0.22, 0.17, and 0.07 µg L^?1 for fenitrothion, imidacloprid, fenobucarb, and dichlorvos, respectively. Our results strongly indicate that under the current management practice pesticide use in paddy fields poses a serious environmental problem in mountainous regions of northern Vietnam.     

Leaching evaluation of cement stabilisation / solidification treated kaolin clay

Sustainable land management often requires redevelopment of existing and often contaminated Brownfield sites over use of Greenfield or agricultural land. Stabilisation / solidification (S/S) offer a viable remediation option with particular suitability in treating heavy metal contaminants. However, uncertainties over long-term durability and previously cheap landfill disposal costs resulted in limited use in many countries. There is a need to characterise treated material and assess components containment and release, to improve S/S confidence and inform remedial design, using the evaluation of the leaching controlling mechanisms. To improve understanding of key features that will enable improvements to such designs, this paper presents an evaluation of leaching for CEM II stabilised kaolin, using the leaching behaviour of 4 main components—aluminium, silicon, calcium and sulphur. Results show no detrimental implications on chemical durability due to kaolin degradation with hydration under induced alkalinity, with increased formation of stable cementitious minerals. Availabilities for components show that aluminium and silicon had minimal leachability compared to total content, whilst calcium and sulphur show almost total leaching availability. Decreasing calcium and silicon leachability under natural chemical conditions with increased hydration duration supports the increased formation of stable cementitious products with time, using the products of kaolin dissociation.     

Numerical analysis of overburden soil subjected to strike-slip fault: Distinct element analysis of Nojima fault

A distinct element method analysis is carried out to examine the development of shear bands in overburden soil subjected to a strike-slip fault. About 2.3 million spherical particles are used in the analysis and the results are compared with the shears observed at the Nojima earthquake fault during the 1995 Hyogoken Nanbu earthquake. En echelon shears and secondary shears which strike at lower angles to the basement fault – typical in strike-slip faults – are observed in the numerical analysis. Simple shear in the horizontal plane and drag due to the dependence of velocity on depth are confirmed to control the helicoidal shape of Riedel shears. Rotation of the compressional direction toward the fault strike as a result of slip along Riedel shears is also verified. It is found that the compressional direction is more horizontal within the area enclosed by Riedel shears than in outside areas and that these compressional directions produce secondary lower-angle shears that are less helicoidal. It is shown that the formation of column-like structures of particles and their subsequent buckling play significant micromechanical roles in three-dimensionally wrenched shears. The results of the numerical analysis, such as shear intervals and striking angles, show a resemblance to observational results at sites where sediment contains coarse grains and is subjected to strike slip with a small dip component, although they are not exactly the same as those observed at locations with similar overburden thicknesses.     

Global surface wave inversion with model constraints‡

Practical applications of surface wave inversion demand reliable inverted shear‐wave profiles and a rigorous assessment of the uncertainty associated to the inverted parameters. As a matter of fact, the surface wave inverse problem is severely affected by solution non‐uniqueness: the degree of non‐uniqueness is closely related to the complexity of the observed dispersion pattern and to the experimental inaccuracies in dispersion measurements. Moreover, inversion pitfalls may be connected to specific problems such as inadequate model parametrization and incorrect identification of the surface wave modes. Consequently, it is essential to tune the inversion problem to the specific dataset under examination to avoid unnecessary computations and possible misinterpretations. In the heuristic inversion algorithm presented in this paper, different types of model constraints can be easily introduced to bias constructively the solution towards realistic estimates of the 1D shear‐wave profile. This approach merges the advantages of global inversion, like the extended exploration of the parameter space and a theoretically rigorous assessment of the uncertainties on the inverted parameters, with the practical approach of Lagrange multipliers, which is often used in deterministic inversion, which helps inversion to converge towards models with desired properties (e.g., ‘smooth’ or ‘minimum norm' models). In addition, two different forward kernels can be alternatively selected for direct‐problem computations: either the conventional modal inversion or, instead, the direct minimization of the secular function, which allows the interpreter to avoid mode identification. A rigorous uncertainty assessment of the model parameters is performed by posterior covariance analysis on the accepted solutions and the modal superposition associated to the inverted models is investigated by full‐waveform modelling. This way, the interpreter has several tools to address the more probable sources of inversion pitfalls within the framework of a rigorous and well‐tested global inversion algorithm. The effectiveness and the versatility of this approach, as well as the impact of the interpreter's choices on the final solution and on its posterior uncertainty, are illustrated using both synthetic and real data. In the latter case, the inverted shear velocity profiles are blind compared with borehole data.     

中国东部地区城市化对气温影响的观测分析

现有场地观测表明,城市化对于气温的影响在静风、无云条件下的晚上最明显,而在大风、多云条件下的晚上最小.本文采用一套经过均一化处理的中国地区逐日平均、最高以及最低气温序列资料集,分析了中国东部地区在不同风速、云量条件下地面气温变化的趋势.结果表明,从1960-2008年,中国东部地区(20～45° N,110～125° ...     

地面气象观测数据文件存在问题浅析

天气学原理的角度对2009至2010年全区上报的地面气象数据文件在人工观测和人工器测之记录方面存在的问题分析了云的生消演变过程和产生降水的物理机制、天气现象“飑”的成因和特征;进一步阐述了云与降水的关系：同时对影响蒸发量的气象要素作了相关分析,提出了疑误记录的处理方法。对提高云状和天气现象记录水平,正确处理异常观测记录...     

成都平原土壤中Cd的空间分布与成因探讨

通过样品采集和室内分析,研究了成都平原区土壤中Cd高含量区的区域分布特征和形成原因。在绵远河、石亭江流域冲积物中存在Cd含量高值区。Cd高含量区域分布Ⅰ、Ⅱ级阶地-Ⅲ级-Ⅳ级或Ⅴ级阶地冲击物中Cd含量逐渐降低。发育与龙门山的河流(绵远河、石亭江)沉积物Cd含量显著高于其他水系沉积物。Cd高含量分布区与不同级次的阶地相吻合的特征表明其控制因素显著,属于地质作用的产物。这一结论与多数研究者认为的人为因素引起的具有根本区别。     

浅谈山东省枣庄市某露天开采石灰岩矿山地质环境治理与恢复

针对枣庄市某水泥用灰岩矿开采导致了土地挖损和压占、地形地貌景观破坏和崩塌地质灾害隐患等地质环境问题,提出了:生产过程中发现的危岩,及时予以清理,或对其进行加固;采矿结束后,开采平台外缘用浆砌毛石砌筑挡土坝,平台上部30cm覆土,下部20cm用强风化页岩做铺垫,种植侧柏,平台的内侧,按照2m的间距种植爬山虎、葛藤等攀缘类植被,绿化边坡面;露天采坑治理成人工湖等治理办法。经过恢复治理,不仅能适时地保护和恢复自然生态环境,也能有效消除矿业活动带来的地质灾害隐患;另可恢复林地及人工湖面积33.48hm2(502.2亩),具有显著的社会效益。