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Marios Sophocleous 《Hydrogeology Journal》2002,10(2):348-348
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Marios Sophocleous 《Ground water》2012,50(6):831-839
The water‐level decline of the High Plains/Ogallala aquifer is one of the largest water management concerns in the United States. The economy and livelihood of people living in that vast region depend almost exclusively on water extracted from that aquifer. A debate about its future is ongoing, and questions remain as to how best to conserve the groundwater resource. Maintaining the aquifer will require reductions in pumping and irrigated hectarage and adopting additional conservation measures. Eventually, the agricultural system will have to be based dominantly on the renewable water resources of the region. In effect, this means a limited‐irrigation and/or dry‐farming regime. What Kansas is currently doing to further extend the life of the aquifer is presented here together with additional measures that could be taken. A key management approach to help sustain the aquifer in western Kansas is to divide the aquifer into subunits on which to base localized management decisions. Another recently adopted measure is the establishment of local enhanced management areas, which would allow locally agreed upon specific corrective controls in those areas. History has shown that incentive and voluntary plans alone have not been successful in halting water‐level declines. Thus, limits and timelines need to be set and checks must be in place to enforce strict administration of conservation measures. It is advocated that water laws be reformed and modernized so that “water rights” are constrained by the current availability of water and the preservation of the resource base for future generations. 相似文献
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Three‐dimensional beam–truss model for reinforced concrete walls and slabs – part 2: modeling approach and validation for slabs and coupled walls 
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下载免费PDF全文 A three‐dimensional beam–truss model (BTM) for reinforced concrete (RC) walls that explicitly models flexure–shear interaction and accurately captures diagonal shear failures was presented in the first part of this two‐paper series. This paper extends the BTM to simulate RC slabs and coupled RC walls through slabs and beams. The inclination angle of the diagonal elements for coupled RC walls is determined, accounting for the geometry of the walls and the level of coupling. Two case studies validate the model: (1) a two‐bay slab–column specimen experimentally tested using cyclic static loading and (2) a five‐story coupled T‐wall–beam–slab specimen subjected to biaxial shake table excitation. The numerically computed lateral force–lateral displacement and strain contours are compared with the experimentally measured response and observed damage. The five‐story specimen is characterized by diagonal shear failure at the bottom story of the walls, which is captured by the BTM. The BTM of the five‐story specimen is used to study the effects of coupling on shear demand for lightly reinforced RC coupled walls. The effect of mesh refinement and bar fracture of non‐ductile transverse reinforcement is studied. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Marios Sophocleous 《Ground water》1985,23(1):52-58
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Abstract. Benthic samples were taken at 26 stations during a two year period (1975–1977) in the Gulf of Thermaïkos, Greece. The topography and relevant physicochemical characteristics of the area are presented and discussed. Both density and biomass increase towards the northern limits in the Bay of Thessaloniki and in the Gulf of Thermaïkos, the difference between them being the degree of change in a north-south direction. Analyses of the degree of concurrence of the dominant species show the existence of a number of groups of concurrent dominant species with characteristic distributional patterns and differing areal coverage in the study area. The observed quantitative and qualitative differences in the benthos are causally related to the differing environmental conditions prevailing in the two subareas. 相似文献