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11.
Deep-well injection has been used to dispose of municipal liquid wastes in southwestern Florida since 1988. The liquid wastes
are injected into an extremely high-transmissivity zone of fractured dolomite in the Early Eocene Oldsmar Formation of the
Floridan aquifer system; this zone is commonly referred to as the Boulder Zone. Data collected during the drilling and operational
testing of southwestern Florida injection wells provide insights into the nature of the injection zone and overlying confining
beds. The location of high-transmissivity zones that are capable of accepting large quantities of waste water is vertically
and horizontally variable and cannot be predicted with certainty. A 40.9-m thick high-permeability interval in one injection
well, for example, was absent in a well drilled only 85.4 m away. Some upward migration of low-density injected fluids has
occurred, but at no site were the injected liquids detected in deep monitor wells, such as occurred at injection-well sites
along the coasts of southeastern, west-central, and east-central Florida. The primary confinement of the injected liquids
(i.e., deepest effective confining beds) consists of unfractured beds of low-permeability dolomite within the Oldsmar Formation,
whose locations are also laterally and vertically variable. The origin and controls of the distribution of fractures in the
Oldsmar Formation are poorly understood.
Received, December 1997 Revised, June 1998, August 1998 Accepted, August 1998 相似文献
12.
Solute‐Transport Predictive Uncertainty in Alternative Water Supply,Storage, and Treatment Systems 
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下载免费PDF全文 Robert G. Maliva David Barnes Kapo Coulibaly Weixing Guo Thomas M. Missimer 《Ground water》2016,54(5):627-633
Alternative water supply, storage, and treatment (AWSST) systems, which utilize aquifers to supply, store, and naturally treat water, are increasingly being implemented globally to address water scarcity and safety. The failure of some AWSST systems to meet water quality expectations was caused by conceptual model error, in which local hydrogeological conditions were less favorable than recognized or considered during project feasibility assessments, economic analyses, and design. More successful implementation of AWSST projects requires that conceptual model error be explicitly and rigorously addressed. Recommended approaches to addressing conceptual model uncertainty include more detailed aquifer characterization, recognition of a wide suite of possible alternative conceptual models, and then screening the models as to whether or not they are plausible and relevant in terms of materially impacting predictive results. Subjective professional judgement remains the basis for assigning probabilities to relevant conceptual models (contingencies). 相似文献
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Integrated Futures for Europe’s Mountain Regions: Reconciling Biodiversity Conservation and Human Livelihoods 总被引：1，自引：1，他引：0
Introduction Europe's mountains cover nearly half of the continent's area (Price et al. 2004) and land cover varies significantly (European Commission 2004). In most massifs, except for Sicily, southern Greece, and the British Isles, forest cover is dominant. In northern Europe, grassland is proportionately more important, and much of the mountains of the British Isles is covered by moorland. In central and southern Europe, arable land is of far greater importance than grassland, with Med… 相似文献
16.
Fresh water resources within the Kingdom of Saudi Arabia are a rare and precious commodity that must be managed within a context of integrated water management. Wadi aquifers contain a high percentage of the naturally occurring fresh groundwater in the Kingdom. This resource is currently overused and has become depleted or contaminated at many locations. One resource that could be used to restore or enhance the fresh water resources within wadi aquifers is treated municipal waste water (reclaimed water). Each year about 80 percent of the country's treated municipal waste water is discharged to waste without any beneficial use. These discharges not only represent a lost water resource, but also create a number of adverse environmental impacts, such as damage to sensitive nearshore marine environments and creation of high-salinity interior surface water areas. An investigation of the hydrogeology of wadi aquifers in Saudi Arabia revealed that these aquifers can be used to develop aquifer recharge and recovery (ARR) systems that will be able to treat the impaired-quality water, store it until needed, and allow recovery of the water for transmittal to areas in demand. Full-engineered ARR systems can be designed at high capacities within wadi aquifer systems that can operate in concert with the natural role of wadis, while providing the required functions of additional treatment, storage and recovery of reclaimed water, while reducing the need to develop additional, energy-intensive desalination to meet new water supply demands. 相似文献
17.
Late Miocene fluvial sediment transport from the southern Appalachian Mountains to southern Florida: An example of an old mountain belt sediment production surge 下载免费PDF全文
下载免费PDF全文 Past geomorphological models assume that erosion of sediments from old mountain belts occurred at a relatively constant rate, based on comparatively uniform isostatic adjustment caused by unloading. Late Miocene strata of the south‐eastern United States provide an example of pulsed tectonism resulting in a surge in siliciclastic sediment production and transport. Regional tectonism (uplift of the southern Appalachian Mountains) and climatic conditions during the Late Miocene resulted in the long‐distance (up to 1000 km) fluvial transport of coarse siliciclastic sediments onto a stable carbonate platform in southern Florida. The sediments are unusual in that they are significantly coarser than marine‐transported sands in southern Florida, with discoidal quartz and quartzite clasts up to 40 mm in diameter locally present, and have relatively high potassium feldspar contents (up to 16% in some sample fractions), whereas feldspar is rare in modern Florida beach sands. It is suggested that previously documented rejuvenation of the southern Appalachian Mountains during the Middle to Late Miocene time, coupled with the Messenian sea‐level low, generated the increased rate of sediment production and necessary hydraulic gradient to allow rapid transport of coarse sediments. Tectonic influence on the river pathway in Florida, as well as in the southern Appalachian Mountains, may have maintained the river on the narrow carbonate platform. The Florida Platform during the Late Miocene must also have had a sufficiently wet climate to cause episodic transport of the coarse sediments. Siliciclastic sediment transport on the Florida Platform during the Late Miocene greatly differed from Pleistocene to modern conditions, which are dominated by the transport of fine‐grained sands by longshore marine processes. 相似文献
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SK Pathan VK Shukla RG Patel BR Patel KS Mehta 《Journal of the Indian Society of Remote Sensing》1991,19(2):95-112
Proper urban planning and effective implementation requires reliable urban land use statistics. In this context, satellite remote sensing data has been studied using both visual and digital techniques. A portable eight-band radiometer has been used to collect spectral signatures of surface features present in Ahmedabad city and its environs. Using these signatures a suitable approach employing visual and digital techniques has been developed for urban land use/sprawl mapping. Urban land-use maps of Ahmedabad city and its environs were prepared on 1:25,000 scale and for Ahmedabad Urban Development Authority Area on 1:50,000 scale using this methodology. It has been found that edge-enhancement techniques are useful to enhance the contrast among different urban land uses. Classification techniques such as MXL and Bayes classifiers are not successful in discriminating urban land uses. Tonal characteristics alongwith other elements of interpretation are required to classify urban land uses such as residential, industrial etc. Spatial distribution of various urban and uses and the space devoted to each urban land use has been brought out. 相似文献
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A TEST OF SIGNIFICANCE FOR PARTIAL LEAST SQUARES REGRESSION 总被引：1，自引：0，他引：1
IAN N. WAKELING JEFF J. MORRIS AFRC Institute of Food Research Earley Gate Whiteknights Ro Reading RG EF U.K.Zeneca Pharmaceuticals Mereside Alderley Park Macclesfiel Cheshire SK TG U.K. 《地理学报(英文版)》1993,(4)
Partial least squares (PLS) regression is a commonly used statistical technique for performingmultivariate calibration, especially in situations where there are more variables than samples. Choosingthe number of factors to include in a model is a decision that all users of PLS must make, but iscomplicated by the large number of empirical tests available. In most instances predictive ability is themost desired property of a PLS model and so interest has centred on making this choice based on aninternal validation process. A popular approach is the calculation of a cross-validated r~2 to gauge howmuch variance in the dependent variable can be explained from leave-one-out predictions. Using MonteCarlo simulations for different sizes of data set, the influence of chance effects on the cross-validationprocess is investigated. The results are presented as tables of critical values which are compared againstthe values of cross-validated r~2 obtained from the user's own data set. This gives a formal test forpredictive ability of a PLS model with a given number of dimensions. 相似文献
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Communities and water utilities are increasingly being forced to implement more hydrogeologically complex alternative water supply and storage options to meet increasing freshwater demands. The performance of managed aquifer recharge projects, including aquifer storage and recovery, is controlled by the movement and mixing of stored freshwater and native groundwater, and fluid–rock interactions, which, in turn, are strongly influenced by aquifer heterogeneity. Advanced borehole geophysical logging techniques developed for the oil and gas industry such as neutron-gamma ray spectroscopy, microresistivity imaging, and nuclear magnetic resonance, can provide hitherto unavailable fine-scale data on porosity (total and effective), hydraulic conductivity, salinity, and the mineralogical composition of aquifers. Data on aquifer heterogeneity obtained from advanced borehole geophysics logs, combined with information on larger-scale aquifer hydraulics obtained from pumping tests, have the potential for improving aquifer characterization and modeling needed for feasibility assessments and the design and optimization of the operation of managed aquifer recharge systems. 相似文献