Prediction of the impact of the Aznalcóllar toxic spill on the trace element contamination of agricultural soils

The interaction of several trace elements (Cd, Zn, Cu, Pb, As, Bi, and Tl) was studied by leaching experiments in agricultural soils affected by the Aznalcóllar toxic spill. The spill led to contamination by acid waste waters and sludge deposition. The levels of contamination recorded after the sludge was removed from soils showed that highly contaminated areas remained. A comparison of soils directly affected by sludge deposition and acid waste waters with soils contaminated only by acid waste waters demonstrated that Zn/As and Cd/As ratios were good indicators of the two contributions to the contamination. Soil samples were characterised and grouped according to their texture and carbonate content. The response of elements to single extractions with CaCl2 0.01 mol l-1, CaCl2 1 mol l-1, CH3COOH 0.43 mol l-1, and EDTA 0.05 mol l-1 enabled us to estimate their mobility in the soils. Cd and Zn were found to be the most mobile elements. Cu showed an intermediate mobility, especially in an acidic medium. Pb, As, Bi and Tl were found to be non-mobile elements. A comparison of referent, low and highly contaminated samples showed that the presence of sludge had an effect on desorption yields, in part due to the short-term after the contamination. Calculations of a relative scale of long-term mobility, between soils and trace elements, provided further conclusions derived from the use of single extractions.     

Electromagnetic properties of the ground: Part I – Fine-grained soils at the Liquid Limit

Knowledge of the geotechnical properties of soils when engineering shallow underground spaces is of obvious importance, as it provides information, for instance, on the susceptibility of their strength to water content changes. It also indicates the degree to which they are likely to shrink or swell with variations in water content, and so whether later displacement of buried infrastructure may occur. Trenchless installations, however, are often undertaken without full knowledge of obstructions and ground conditions along their route, and so increasingly rely on electromagnetic geophysical methods to ‘see’ into the ground. Interpretation of such geophysical data requires full knowledge of the electromagnetic properties of materials, particularly for fine-grained soils. It is less widely appreciated, however, that these electromagnetic properties can be directly related to geotechnical properties, and so additional data could be obtained from geophysical surveys in terms of potential ground conditions and their variations over long installation lengths. Therefore, the aim of this paper is to consider links between these two sets of soil properties as a pre-cursor to investigating the properties of individual soils. The Liquid Limit was considered an important water content at which to test the electromagnetic properties of fine-grained soils, as it provides an immediate opportunity to determine whether any related geophysical correlations exist between soils. In the study described herein the apparent permittivity of a number of fine-grained soils was measured at the Liquid Limit and it was found that at higher frequencies, ca. 1 GHz, good correlation exists between the two. However, at lower frequencies this relationship was not apparent due to significant variations in electromagnetic dispersion. By considering the differences between high and low frequency data to be based on differences in inter-sheet and inter-particle water, however, this discrepancy is explained. It is therefore concluded that, under laboratory conditions, the frequency-dependent nature of apparent permittivity in fine-grained soils can be explained, and even predicted, using the Liquid Limit of a soil, its dry density, and the percentage linear shrinkage it exhibits.     

Electromagnetic properties of the ground: Part II – The properties of two selected fine-grained soils

In Part I of this paper it was established that electromagnetic signal velocities, for instance as used in ground penetrating radar use, are related to the geotechnical properties of Liquid Limit, dry density and percentage linear shrinkage. It was thus established that such geophysical techniques potentially provide an insight into the geotechnical properties of fine-grained soils, as well as illustrating the equal potential of informing radar survey planning and data interpretation through prediction of soil geophysical properties from geotechnical data. In order to extend that research, the work described herein aimed to consider how signal velocities relate to the wide variations in water contents that may occur for a soil in the field, from oven dry to more than 90% by volume. Through the use of time-domain and frequency-domain measurement techniques, data were obtained that allow consideration of soil effects on commercial water content measurement systems and radar equipment. Potentially the most important outcome is that the data indicate that the three geotechnical states (friable, plastic and liquid) give rise to three different signal velocity/water content relationships. In the friable state, the relationship shows large increases in apparent permittivity (as a proxy for signal velocity) with water content, together with increasing electromagnetic dispersion (i.e. variations in velocity with frequency). In the more common plastic state, often not fully considered in the literature, apparent permittivity is shown to increase almost linearly with water content at high frequencies, but in fact can decrease at lower frequencies. This anomaly is explained by the reduction in electromagnetic dispersion caused by reducing dry density. For the liquid state, the relationships are shown to be similar to the plastic state, but with a step increase in apparent permittivity potentially related to soil pore sizes exceeding a critical limit. It is also shown that the plastic and liquid state linear relationships are related to similar trends in the apparent permittivity of the water phase. It is concluded that, when considered over very wide water content and signal frequency ranges, the electromagnetic properties of soils are complex but can be related to geotechnical states and properties. It is, therefore, proposed that the research detailed herein provides a useful initial step in the creation of an electromagnetic properties database of relevance to underground space development.     

Exploring the dynamics of the Turkish construction industry using input–output analysis

Construction is commonly regarded as an important industry in economic policy making owing to its strong interactions with other sectors in the economy. Using six national input–output (IO) tables compiled to date and economic data for the period between 1969 and 2006, the behaviour of the Turkish construction sector and its relationships to investment, income and to other sectors in the economy are examined. Analysis reveals that the construction industry is losing its propulsive role and that it tends to exaggerate the fluctuations of the economy. The examination of lead and lag times between changes in GNP, construction activity and investments show that public sector spending cuts, in particular, have significant effects on the amplitude and the timing of slumps of the industry. The analysis of linkage indicators indicates that for the whole period under consideration the construction industry has high linkages with only one other industry. Thus the ‘leading’ role it plays in the economy is questioned.     

Anticipating the “Bilbao effect”: Transformations of the city of Arles before the opening of the Luma Foundation

By analyzing data from the 2006/07 and 2013 French census as well as data extracted from the Yellow Pages, this paper seeks to understand how the French city of Arles is preparing for the arrival of Frank O. Gehry’s Luma Foundation landmark building in 2019, and how a big-scale construction site, still devoid of its future aesthetics and cultural function, impacts the urban core. To do this, we consider three hypotheses: (1) The Rise of New Audiences: a landmark building attracts the new populations to the pre-existing urban cultural core, (2) Residential Pattern: a landmark building induces social transformation of surrounding neighborhoods, (3) Mobility: a landmark building induces the arrival of the “most talented and educated” people. After testing these hypotheses with cartographical and statistical methods, our findings demonstrate strong support for Mobility, and mixed support for The Rise of New Audiences and Residential Pattern. Even though the causal links between the landmark building and new urban dynamics are difficult to prove, our results reveal that Arles is “customizing” itself to the forthcoming cultural and aesthetic dimensions of the Luma Foundation.     

A consideration of the “no-black-hole” condition

The purpose of this paper is to investigate the economic interpretation of the no-black-hole condition (NBHC) described in the Chapt. 4 of the book by Fujita, Krugman and Venables (1999), under the context of a more general model. The main findings are as follows. First, there is the case in which the NBHC does not hold even though the real wage falls at the symmetric equilibrium. Secondly, the NBHC in the more general model requires both a reduction in profits in response to an increase in the number of firms and a fall in the real wage rate in response to an increase in labor at the symmetric equilibrium. Thirdly, we show that NBHCs obtained in some analyses are special cases of our model. Moreover, we show that the NBHC includes the stability condition for the short-run equilibrium. Therefore the NBHC is not affected by relative speed of labor movement and entry/exit of firms.Received: November 2002/Accepted: March 2004     

Experimental investigation of the aerodynamic stability of the “Endless Column”, Romania

Wind tunnel tests have been performed on several models of the “Endless Column”, a 30 m tall sculpture, created by C. Brancusi in 1938. In spite of its slenderness, the Column, located in Targul Jiu, Romania, has shown a great stability against wind. In order to clarify if the symmetric, original shape has influence upon its stability, we have carried out tests on section models of “Endless Column” shape (EC models) and square shape (SQ models), of various Sc numbers. Across-wind response was determined in smooth flow for wind speeds in wind tunnel of 1–10 m/s (Re=4000–46,000) for angles of attack 0°, 10° and 45°. Furthermore, an aerolastic full model was created and tests under smooth and turbulent flow conditions were performed for angles of attack between 0° and 45°. For low wind speeds, in the area of vortex-induced vibrations, the EC models had similar response with the SQ models; however, for higher wind speeds the EC models proved to be more stable. Based on measurements of aerodynamic drag and lift coefficients and by a verification of Glauert den Hartog criterion, it could be concluded that is a very low possibility for EC model to encounter galloping; for extremely high wind speeds though, this might not be impossible.     

The extent of the Aznalcóllar pyritic sludge spill and its effects on soils

This paper presents some initial results from the Instituto Tecnológico Geominero de Espa?a's (ITGE) study of the Aznalcóllar mine spill. The spatial distribution of the pyritic sludge released was surveyed by using remote sensing data, aerial photography, and more than 700 field measurements on the sludge thickness. Initial estimation of the extent of the sludge was provided by radar data. Maps at 1:10,000 scale, drawn on the basis of field data and interpretation of aerial photos, show the distribution of the sludge, divided into 168 subsections on the basis of average thickness. GIS analysis provided estimates of the area and volume of the sludge. Three approaches were followed in order to survey the effects of the spill on the Guadiamar river alluvial soils: (1) Mineralogical and chemical characterization of the sludge and its evolution until its removal. Alteration products of the pyritic sludge were also analyzed. (2) Determination of geochemical background of soils in the Guadiamar river basin, in order to establish the content of heavy metals and other elements in the soil before the spill. (3) Assessment of the sludge effect on soils caused by the acid water and the deposited sludge, by comparison of the heavy metal content of soil under the sludge layer with that of background soil. Finally, an airborne multispectral survey was carried out over the Aznalcóllar-Do?ana area to evaluate its efficiency for monitoring soil condition during and after sludge removal.     

A Review of “Miami: Mistress of the Americas”

Coastal zone management arose as a response to pervasive conflict between the increasingly well-recognized environmental values of the coastal zone and various development activities. In enacting the 1972 federal Coastal Zone Management Act, Congress explicitly called for a balancing of developmental and environmental concerns, leaving the states and territories considerable leeway in how the balance would be struck. The result has been great variation among the states both in the methods of weighing environmental and developmental objectives and in the emphasis given to each in implementation.     

Improved design of “Anytown” distribution network using structured messy genetic algorithms

The recently introduced Structured Messy Genetic Algorithm model for optimising water distribution network rehabilitation is expanded to include not only pipe rehabilitation decisions but also pumping installations and storage tanks as variables. The formulation of the model is detailed with two approaches presented for handling the design of storage within the system. The application of the model to the benchmark “Anytown” problem is used as an example of its capabilities, with cheaper designs being produced than any previously published.     

Study of the unexpected collapse of the Ampurdán tunnel (Spain) using a finite elements model

This paper presents the case study of the Ampurdán tunnel that suffered an unexpected partial collapse during construction due to the weathering of the claystone groundmass after excavation and wetting by infiltration water. To overcome the problems encountered, a finite elements model was used to understand the behaviour of the tunnel and surrounding ground to determine the geotechnical properties that lead to failure, allowing engineers to choose suitable procedures for the construction of the tunnel. The parametric study performed simulated the deformations measured in situ and related to the tunnel collapse. The geotechnical parameters used for the weathered claystone, when compared with the intact portion, correspond to a wide range of reductions between 8 % in the apparent density and in the effective friction angle, up to 40 % in the effective cohesion and 56 % in the Young modulus.     

The Study of Rationalization of the Economic Functions in Shanghai——the Study Group of the “Same topic”

From the PersPective of the systemsaPProaeh,the urban eeonomie functions re-fer to the role Played by the eeonomy of theeity in its surrounding areas.Beeause of different geograPhieal loeations,historiealeonditions,the various roles and funetionsof the eities in the national economy,theeeonomie funetions of a eity may be of sin-gle