Engineering geology, in 1996, worldwide, was experiencing considerable turmoil due to the uncertain nature of national economies and the general situation of inadequate funds to meet the demands of failing of the national infrastructures that serve citizens. Aside from the previously war-damaged cities of Western Europe, new public service systems of transportation and utilities elsewhere often lagged well behind growth.
It will be some time before international aid and civil engineering contracts are initiated for anything other than humanitarian and basic emergency aid work in these areas.
Many countries in the western hemisphere, eastern Europe, the former Soviet Union and developing nations in particular are still in need of basic water and sewage services as well as repair and replacement of old existing systems. Continued partisan warfare in the Balkan states of Albania, Bosnia, Croatia and Serbia forecast the eventual need for redevelopment. Rumblings of broad-scale economic problems in Far-Eastern economies did little to make overseas contract opportunities in these areas very attractive.
Large consulting firms were challenged by an increasing number of individual and small practices who are prepared to operate on 1970's rates and prices for services and government and industry was taking advantage of that situation. More and more individuals were offering services in engineering geology and associated engineering fields and there was a sense of not having enough work to go around. Hence, price competition was again being promoted. Consequently in both Europe and the Americas, the variability of competence was enlarging and a significant amount of so-called ‘professional ’ work was lacking in overall quality. This was especially evident in ‘Environmental’ areas of work.
This begs the question: ‘Is not engineering geology, or any other aspect of applied geosciences, not environmental in nature and essence, fundamentally and in entirety?’
Environmental restoration demands were still being made by governments, but the pressure to complete such work was being relaxed on account of economics. Our clients were asking for more service at lower fees. Clients were still largely unwilling to openly acknowledge that less money spent on competent engineering geologic consultation means that more risk should be accepted by the owner or operator of projects. 相似文献
The New South Wales Olympic Co-ordination Authority, which is responsible for the redevelopment of the site for the Olympic Games 2000, Sydney, is committed to the rehabilitation of the remnant ecosystems remaining on the site. This paper describes a 3-year saltmarsh transplantation project, and resulting management approaches for the rehabilitation of other saline wetland areas on the site. Two series of cuttings (spring and autumn) were made, including three dominant species and three species rare in Sydney. It was found that all the species could be propagated without difficulty, but field survival and growth were much higher for the spring series than the autumn one. Measurement was also made of the colonisation of mangrove and saltmarsh species that occurred at the site over the course of the trials. New understandings of estuarine wetland colonisation have emerged, and the information has been used to develop methods of transplantation for other parts of the Olympic site, and to define management needs for monitoring success. 相似文献
Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower‐permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture‐dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high‐ and low‐permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured‐rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes. 相似文献
Continuous Plankton Recorder data suggest that the Irminger Sea supports a major proportion of the surface-living population of the copepod Calanus finmarchicus in the northern North Atlantic, but there have been few studies of its population dynamics in the region. In this paper, we document the seasonal changes in the demographic structure of C. finmarchicus in the Irminger Sea from a field programme during 2001/2002, and the associations between its developmental stages and various apparent bio-physical zones. Overwintering stages were found widely at depth (>500 m) across the Irminger Sea, and surviving females were widely distributed in the surface waters the following spring. However, recruitment of the subsequent generation was concentrated around the fringes of the Irminger Sea basin, along the edges of the Irminger and East Greenland Currents, and not in the central basin. In late summer animals were found descending back to overwintering depths in the Central Irminger Sea. The key factors dictating this pattern of recruitment appear to be (a) the general circulation regime, (b) predation on eggs in the spring, possibly by the surviving G0 stock, and (c) mortality of first feeding naupliar stages in the central basin where food concentrations appear to be low throughout the year.We compared the demographic patterns in 2001/2002 with observations from the only previous major survey in 1963 and with data from the Continuous Plankton Recorder (CPR) surveys. In both previous data sets, the basic structure of G0 ascent from the central basin and G1 recruitment around the fringes was a robust feature, suggesting that it is a recurrent phenomenon. The Irminger Sea is a complex mixing zone between polar and Atlantic water masses, and it has also been identified as a site of sporadic deep convection. The physical oceanographic characteristics of the region are therefore potentially sensitive to climate fluctuations. Despite this, the abundance of C. finmarchicus in the region, as measured by the CPR surveys, appears not to have responded to climate factors linked to the North Atlantic Oscillation Index, in contrast with the stocks in eastern Atlantic areas. We speculate that this may because biological factors (production and mortality), rather than transport processes are the key factors affecting the population dynamics in the Irminger Sea. 相似文献