Geographical location in the information age: from destiny to opportunity?

This article argues for a possibly new significance of geographical location in the information age, a significance amounting to more than mere spatial anchoring, on the one hand, and to less and different than absolute destiny, on the other. Hence, we show a possible change in the significance of geographical location from destiny in the industrial age to potential opportunity in the information age, a transition which applies to geographical units (i.e. cities, regions) and to individuals. First we discuss geographical location as destiny in the industrial age for both geographical entities and individuals. Second, we highlight a transitional period spanning through the 1970s and 1980s during which geographical location lost much of its absolute nature, becoming more of an anchor. Third, we present a conceptual framework for geographical location possibly turning into opportunity in the information age, again for both geographical units and individuals. We demonstrate that this potential opportunity has only partially materialized by individuals in the international use of online shopping, showing that their adoption is wider in North America, and differentiated in Europe. We further demonstrate a partial dissemination of opportunities for cities and regions by focusing on FDI. Finally, in the fourth and concluding section, we briefly discuss pertaining policy issues for the enhancement of locational opportunities.     

Design of passive systems for control of inelastic structures

A design strategy for control of buildings experiencing inelastic deformations during seismic response is formulated. The strategy is using weakened, and/or softened, elements in a structural system while adding passive energy dissipation devices (e.g. viscous fluid devices, etc.) in order to control simultaneously accelerations and deformations response during seismic events. A design methodology is developed to determine the locations and the magnitude of weakening and/or softening of structural elements and the added damping while insuring structural stability. A two‐stage design procedure is suggested: (i) first using a nonlinear active control algorithm, to determine the new structural parameters while insuring stability, then (ii) determine the properties of equivalent structural parameters of passive system, which can be implemented by removing or weakening some structural elements, or connections, and by addition of energy dissipation systems. Passive dampers and weakened elements are designed using an optimization algorithm to obtain a response as close as possible to an actively controlled system. A case study of a five‐story building subjected to El Centro ground motion, as well as to an ensemble of simulated ground motions, is presented to illustrate the procedure. The results show that following the design strategy, a control of both peak inter‐story drifts and total accelerations can be obtained. Copyright © 2008 John Wiley & Sons, Ltd.     

Minimum‐cost optimization of nonlinear fluid viscous dampers and their supporting members for seismic retrofitting

This paper presents an effective approach for achieving minimum‐cost designs for seismic retrofitting using nonlinear fluid viscous dampers. The damping coefficients of the dampers and the stiffness coefficients of the supporting braces are designed by an optimization algorithm. A realistic retrofitting cost function is minimized subject to constraints on inter‐story drifts at the peripheries of frame structures. The cost function accounts for costs related to both the topology and the sizes of the dampers. The behavior of each damper‐brace element is defined by the Maxwell model, where the force–velocity relation of the nonlinear dampers is formulated with a fractional power law. The optimization problem is first posed and solved as a mixed integer problem. For the reduction of the computational effort required in the optimization, the problem is then reformulated with continuous variables only and solved with a gradient‐based algorithm. Material interpolation techniques, which have been successfully applied in topology optimization and in multi‐material optimization, play a key role in achieving practical final design solutions with a reasonable computational effort. Promising results attained for 3‐D irregular frames are presented and discussed. Copyright © 2017 John Wiley & Sons, Ltd.     

Modelling Vegetation-Atmosphere Co2 Exchange By A Coupled Eulerian-Langrangian Approach

A Eulerian-Lagrangian canopy microclimate model wasdeveloped with the aim of discerning physical frombiophysical controls of CO₂ and H₂O fluxes. The model couples radiation attenuation with mass,energy, and momentum exchange at different canopylevels. A unique feature of the model is its abilityto combine higher order Eulerian closure approachesthat compute velocity statistics with Lagrangianscalar dispersion approaches within the canopy volume. Explicit accounting for within-canopy CO₂,H₂O, and heat storage is resolved by consideringnon-steadiness in mean scalar concentration andtemperature. A seven-day experiment was conducted inAugust 1998 to investigate whether the proposedmodel can reproduce temporal evolution of scalar(CO₂, H₂O and heat) fluxes, sources andsinks, and concentration profiles within and above auniform 15-year old pine forest. The modelreproduced well the measured depth-averaged canopy surfacetemperature, CO₂ and H₂O concentrationprofiles within the canopy volume, CO₂ storageflux, net radiation above the canopy, and heat andmass fluxes above the canopy, as well as the velocitystatistics near the canopy-atmosphere interface. Implications for scaling measured leaf-levelbiophysical functions to ecosystem scale are alsodiscussed.     

Contamination of groundwater under cultivated fields in an arid environment, central Arava Valley, Israel

The purpose of this study is to obtain a better understanding of groundwater contamination processes in an arid environment (precipitation of 50 mm/year) due to cultivation. Additional aims were to study the fate of N, K, and other ions along the whole hydrological system including the soil and vadose zone, and to compare groundwater in its natural state with contaminated groundwater (through the drilling of several wells).

A combination of physical, chemical, and isotopic analyses was used to describe the hydrogeological system and the recharge trends of water and salts to the aquifers. The results indicate that intensive irrigation and fertilization substantially affected the quantity and quality of groundwater recharge. Low irrigation efficiency of about 50% contributes approximately 3.5–4 million m³/year to the hydrological system, which corresponds to 0.65 m per year of recharge in the irrigated area, by far the most significant recharge mechanism.

Two main contamination processes were identified, both linked to human activity: (1) salinization due to circulation of dissolved salts in the irrigation water itself, mainly chloride, sulfate, sodium and calcium, and (2) direct input of nitrate and potassium mainly from fertilizers.

The nitrate concentrations in a local shallow groundwater lens range between 100 and 300 mg/l and in the upper sub-aquifer are over 50 mg/l. A major source of nitrate is fertilizer N in the excess irrigation water. The isotopic compositions of δ¹⁵N–NO₃ (range of 4.9–14.8‰) imply also possible contributions from nearby sewage ponds and/or manure. Other evidence of contamination of the local groundwater lens includes high concentrations of K (20–120 mg/l) and total organic carbon (about 10 mg/l).     

Oxygen and hydrogen isotopes of rainfall and dripwater at DeSoto Caverns (Alabama, USA): Key to understanding past variability of moisture transport from the Gulf of Mexico

The Southeast and the US Gulf Coast in particular are notably lacking isotope data in the water cycle despite the fact that moisture transport from the Gulf of Mexico (GOM) has a considerable influence on both regional and continental rainfall patterns. This study reports time-series of oxygen and hydrogen isotopes acquired over a 3-year period (2005-2008) from GOM-derived rainfall, cave dripwater and shallow groundwaters, and offers valuable insights on the links between factors controlling regional rainfall and the ubiquitous karst hydrology.Amount-weighted mean monthly rainwater δ¹⁸O and δD values in Tuscaloosa, Alabama range from −1.5 to −8.3‰ and −1.2 to −49.5‰, respectively, and show mean seasonal amplitudes of ∼4‰ (δ¹⁸O) and ∼25‰ (δD). In comparison d-excess values display large seasonal amplitudes of 10-20‰ resulting from differences in the degree of evaporation from falling raindrops between summer and winter months, and correlate well with the coeval air temperature (r² = 0.59; p < 0.05). Deviations of the Gulf Coast Meteoric Water Line (GCMWL) slope and d-excess from the global meteoric water line (GMWL) are attributed to different rates of evaporation after condensation, and to humidity contrast between the cloud boundary layer and the surrounding atmosphere in the vapor source region, respectively. Rainfall amounts declined during the study interval from an excessive “wet” year, ascribed to six tropical storms incursions during an unusually active hurricane season in 2005, to an onset of a regional drought during 2007-2008 with monthly rainfall amounts substantially below normal values (30-year monthly means). An interannual trend of ¹⁸O and ²H enrichments is discerned from 2005 to 2008 (1.4‰ and 11.6‰, respectively) coeval with the decline in rainfall amounts.Dripwater samples from nearby DeSoto Caverns show weak δ¹⁸O and δD seasonal variations and record only 20% and 51% of the ¹⁸O and ²H enrichments, respectively, discerned in the rainwater 3-year time-trends. The seasonal and interannual amplitude attenuations in the dripwaters are attributed to a relatively thick overlying bedrock (∼30-40 m) and a relatively large, well-mixed, epikarst-storage reservoir. Residence time of water in the cave’s epikarst is estimated to be 1-3 months based on high-resolution flow-rate data.Our investigation suggests that global atmospheric circulation patterns (ENSO and Bermuda High) likely govern the interannual δ¹⁸O and δD isotope trends discerned in the water cycle compartments but much longer time-series are required to confirm our conjectures. The results of this study form a solid basis for future acquisition and interpretation of climate proxy records from regional speleothems.     

A unique human‐made trench at Tell es‐Sâfi/Gath,Israel: Anthropogenic impact and landscape response

Tell es‐Sâfi/gath is situated in the semiarid foothills of central Israel, adjacent to the coastal . plain. An enigmatic landscape feature, noted on aerial photographs, encircles the tell on three sides. This unique feature, unknown from other Near Eastern tells, was investigated. Methods of analysis include aerial photographs, field surveys, excavations, soil analyses, chronotypological ceramic classification, and radiocarbon dating. We concluded that (1) the peculiar landscape feature is a huge human‐made trench, over 2 km long, 5–6 m deep, and more than 8 m wide, cut through bedrock; (2) the trench was excavated during the Iron Age IIA (ca. 1000–800 B.C.E.), apparently as part of a siege system; (3) the extracted rock and soil material was dumped on the Iron Age landscape surface on one side of the trench, forming an elevated “berm”; (4) erosion processes transformed this landscape scar, as the trench filled with sediment; (5) stratigraphic analysis indicates two major phases of filling, separated by a period of landscape stability and soil formation (A horizon); (6) the two filling phases, exhibiting Iron Age IIA and Byzantine pottery (ca. 324—638 C.E.), appear to coincide with more intense human activity; and (7) the possible effect of climatic variations seems less obvious. © 2005 Wiley Periodicals, Inc.     

STRUCTURATION THEORY AND ATTEMPTS AT INTEGRATION IN HUMAN GEOGRAPHY*

Integration in human geography is achieved through multidimensional research or by the study of a variety of aspects of a whole. Giddens's structuration theory provides a new theoretical framework for integrative study in human geography in its attempt to connect individuals and societies, context and composition, time and space. Integrative studies in geography have focused on space (regional geography), time (historical geography) and society (time-geography). Structurationist analysis in geography can put society, space, or society and space at its focus. Thrift's spatial structurationist theory may lead to a new theoretically-based regionalism. On the other hand, integration at one level or between several elements may entail disintegration, at another level or element respectively.