General and local estimation of local average and their application in geotechnical parameter estimations

Two kinds of estimation variance functions for estimating a local average (LA) of a stationary (homogeneous) random field (RF) are derived. One is local estimation (LE) and the other is general estimation (GE) of LA. The former is for estimating LA at the observation location, and the latter is for obtaining LA at any arbitrary location within the RF. The geotechnical implications of these two estimations are that LE is for estimating LA of geotechnical parameters at the spot where the investigations are made, whereas GE is for estimating LA at any arbitrary location within the same layer. The behavior of the two estimation variance functions differs greatly, controlled by the number of observations (i.e. sample size) and the normalized layer thickness (layer thickness divided by autocorrelation distance of RF). Based on the derived estimation variance functions, methods for determining reliable characteristic values of geotechnical parameters and necessary sample size are proposed. The methods are based on the same framework as that of the traditional statistical theory, i.e. confidence interval of estimated parameters. However, the assumption of independently and identically distributed (i.i.d.) samples in the traditional statistical theory is replaced by the assumption of correlated samples from a stationary RF. The results obtained from the proposed methods for LE and GE differ from each other as well as from the traditional results, which has significant implications for geotechnical parameter estimation in geotechnical engineering practice.     

Promoting local management in groundwater

There is a strong case for making greater effort to promote local groundwater management—in addition to other measures that regulate groundwater use. Though scattered, there are several examples—from India, Pakistan, Yemen and Egypt—where groundwater users effectively self-imposed restrictions on the use of groundwater. There are a number of recurrent themes in such spontaneously-developed examples of local regulation: the importance of not excluding potential users; the importance of simple, low transaction cost rules; the power of correct and accessible hydrogeological information; the possibility of making more use of demand and supply management strategies; and the important supportive role of local governments. The case is made, using examples, for actively promoting local groundwater management as an important element in balancing groundwater uses. Two programmes for promoting local groundwater management in South India are described—one focussing on participatory hydrological monitoring, and one focussing on micro-resource planning and training. In both cases the response was very positive and the conclusion is that promoting local groundwater regulation is not difficult, costly or sensitive and can reach the necessary scale quickly.     

区域地下水动态数值模拟

在系统综述区域地下水数值模拟的基础上,运用有限差分和有限体积法,结合济南泉域裂隙岩溶地下水含水介质系统,采用二维非稳定流数学模型进行了数值模拟,对泉域地下水动态变化进行了评价,为泉域地下水资源评价与管理提供了一种有效的分析手段,为区域地下水资源的科学管理提供了有意义的参考。     

Ecological entrepreneurship: sustainable development in local communities through quality food production and local branding

The paper explores the importance of specialised networks in shaping local/regional responses to the deepening crisis of conventional agriculture in the EU, as well as potentially creating a more sustainable platform for rural development. The emphasis will be on the problem-solving aspects of network creation and maintenance within a broader and not necessarily supportive competitive and regulatory environment. This involves examining, both over time and space, how networks function to shape knowledge and create a competitive willingness to innovate to achieve mutually beneficial goals. Through a process which we call ecological entrepreneurship, key actors facilitate sustainable development in the countryside by a combination of fragmentation, specialisation and quality building strategies. We empirically explore these evolutionary and spatial factors through two farming-centred networks—an organic farming network in the UK: the Graig Farm Producer Group; and a regional quality brand in the Netherlands: the Waddengroup Foundation.The analysis of these two networks is used to examine in-depth the significance and construction of the social and spatial milieu for providing the individual and collective capabilities to establish viable problem-solving responses. This raises questions of: (i) how such networks are and can be sustained over time; (ii) the extent to which there are common evolutionary pathways which reproduce and embed problem-solving network building; (iii) how different spatial relations are engendered and (iv) whether such ‘local’ projects can advance to wider counter-movements in the context of the prevailing political economy.     

Measurement of small strain behavior of a local soil by fiber Bragg grating-based local displacement transducers

The small strain stiffness of soils has a significant role in geotechnical design and analysis. In laboratory, the small strain behavior is examined by different techniques including the bender element method for measuring the maximum shear modulus and local displacement transducer (LDT) for measuring Young’s modulus at small strains. However, most commonly used LDTs are based on electrical components and have limitations, such as electromagnetic interference and possibility of short circuit in the presence of water. To overcome these limitations, in the present study, a conventional triaxial apparatus has been modified to measure and study the stress–strain behavior of soils at small strains. The major modifications include addition of piezoceramic sensors (bender elements) for measuring the maximum shear modulus and fiber Bragg grating (FBG) sensor-based local displacement transducers (FBG–LDTs) for measuring the stress–strain behavior at small strains. The modified triaxial apparatus has been used to conduct several tests on a completely decomposed granite soil from a site in Hong Kong. The stress–strain behaviors measured by the newly developed FBG–LDTs and an external displacement transducer are compared and discussed. In particular, the shear modulus values obtained using the bender elements, FBG–LTDs, and the external displacement transducer are also compared, discussed, and evaluated. The comparison and assessment show that the FBG–LTDs are more suitable for measuring the small strain behavior of soils.     

Geochemical patterns from local to global

The historical development of geochemical exploration is, in a sense, a process of progressive enlargement of areal coverage by exploration projects and progressive widening of sampling space. Along with this process, a hierarchy of geochemical patterns from small to large is gradually discovered and understood. In this paper, we try to summarize systematically the whole hierarchy of geochemical patterns from local, regional, provincial, megaprovincial to global, using examples obtained in China.Local anomalies (various types of dispersion halos, trains and fans) within areas not exceeding a few km², can be delineated when sampling is done with very close intervals in limited areas. Regional anomalies within areas of tens to hundreds km² and threshold values lower than local anomalies can be identified only when large areas of more than thousands of km² are mapped with wider space sampling. Geochemical provinces with areas of thousands or tens of thousands of km² can be discovered if even larger areas, of more than tens or hundreds of thousands of km², are covered with very low density sampling. More than millions of km² should be covered in order to discover geochemical megaprovinces somewhere in the world. Such megaprovinces are often associated with extraordinarily large mineral resources. If ultra-low density geochemical mapping can be carried out across national boundaries on a continental or global scale, we could find even broader geochemical patterns which will reflect the global tectonic features.The classification of geochemical patterns according to their sizes is necessary because it will be extremely useful in planning sampling layout in order to hit targets of certain size ranges. This in turn is arranged in different geochemical projects for achieving specific aims.     

Spectral analysis of local climatic fluctuations

This paper employs spectral analysis to detect regular cyclical patterns or periodicities of local climate parameters of five major cities of Pakistan. Our calculations show that the temperature of all major climate stations may be affected by ENSO or QBO or Sunspot Cycles. As for the rainfall, what we find is that Pakistan summer monsoon exhibits a fairly similar bienniality with that of the Indian monsoon.     

Efficiency of local polynomials in contour mapping

On the basis of samples taken from a known topographic surface, the parameters of two types of linear models are estimated. The first category is defined by polynomials or trigonometric functions, whose parameters are simultaneously computed from available data. In the second category a set of local centers is defined, and in the neighborhood of each center a fixed-degree polynomial is developed. An approximative resemblance index is calculated, and contour maps corresponding to various models are compared with the topographic map. It is found that with an increasing number of grid points, maps of local polynomials are converging both in continuity and in resemblance. For a sufficient number of grid points, this resemblance is always higher than those produced by models of the first category.     

The financial entanglements of local energy projects

There is currently an expansion of local energy initiatives, underpinned by the desire to reduce energy-related carbon emissions and in recognition of the importance of the local arena to achieving such change. Much of the research on these initiatives has been framed by a conventional economic approach, identifying barriers, drivers and incentives to explain their emergence (or not). Here a new economic sociological approach is taken which sees markets as socio-materially constructed and points to the importance of tracing exchange flows and determining modalities of valuation for such exchanges. Artefacts or market devices are seen to play a particular role in connecting actors and technologies within coordinating institutional arrangements and offer the potential for making innovative projects conventional. These aspects are explored in four international case-studies from Wales, Sweden, Germany and USA, mapping relations, identifying exchange flows, pinpointing how artefacts coordinate and showing the multiple modalities of valuation involved in each case. Conclusions concerning the importance of negotiation against a market backdrop and rendering exchange flows more certain are drawn.     

Low-cost local road materials in southern Africa

Summary Southern African natural gravel and soil road materials are mostly residual soils, residual weathered rocks or pedocretes which are inferior in quality to materials found in northern Europe and North America. Although they can be used to effect substantial savings in costs, the conditions under which marginal and nonstandard materials can be successfully used are not yet well-understood, and further research is necessary. Greater political and engineering acceptance of appropriate standards and risk would probably enable more unpaved roads to be surfaced.     

局部地震属性识别火山岩体

中国的火山岩储层具有很大的生油潜力,尤其在东北地区的松辽盆地,火山岩广泛发育,如何有效识别火山岩储层具有重要意义。地震属性是一种有效的储层特征分析工具,是研究火山岩空间分布的参数。频率、地震倾角和曲率等属性是利用地震数据识别火山岩的敏感特征。笔者提出利用局部地震属性方法,通过计算地震剖面的局部频率,在局部频率数据体上画出低频的区域范围,对同一剖面计算曲率,在曲率数据体上将高曲率值区域圈出,在地震剖面上将这两个区域进行叠置显示,能够自动识别出火山岩体的可能分布区域,为进一步识别火山岩储层提供指导。     

The university as a local source of expertise

The relationship between the university and the city is expressed, amongst others, by the transfer of knowledge from the university to local actors. The universitys role as a local source of knowledge is studied by analyzing the outflow of the two main knowledge assets to the local area: graduates and research results. By comparing the results from universities in the Netherlands and the United Kingdom comparative evidence is discussed.     

Approximate local confidence intervals under change of support

Approximate local confidence intervals are constructed from uncertainty models in the form of the conditional distribution of the random variable Z given values of variables [Z_i, i=1,...,n]. When the support of the variable Z is any support other than that of the data, the conditional distributions require a change of support correction. This paper investigates the effect of change of support on the approximate local confidence intervals constructed by cumulative indicator kriging, class indicator kriging, and probability kriging under a variety of conditions. The conditions are generated by three simulated deposits with grade distributions of successively higher degree of skewness; a point support and two different block supports are considered. The paper also compares the confidence intervals obtained from these methods using the most used measures of confidence interval effectiveness.     

Uncertainties attached to global or local climate changes

The successive reports of the Intergovernmental Panel on Climate Change (IPCC) illustrate an apparent contradiction. On the one hand, the large scale climatic change in response to the increase of greenhouse gases is structured following patterns which have remained surprisingly stable throughout the development of climate models. Already in the 1980s model simulations of climate change were characterized by a larger warming in polar areas and over the continents, and a tendency for precipitations to accentuate existing contrasts, with a drier climate in semiarid regions and more precipitations at mid-latitudes or near the Equator. On the other hand, models have made little progress in predicting more unanimously and more reliably the global amplitude of climate changes and their geographical distributions. This lack of progress is certainly linked with the role of the atmospheric dynamics in shaping up certain aspects of climate response, either small scales which affect atmospheric stratification, or synoptic scales, whose inherent complexity and nonlinear interactions also limit the possibility of more accurate regional predictions.