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51.
玉田啤酒厂饮用天然矿泉水井位于城关镇三里屯西200m,玉田酒厂院内,矿泉水赋存于第四系砂、砾卵石层中,属含锶、偏硅酸的重碳酸钙·镁型矿泉水,现已开发利用。 相似文献
52.
塔中地区卡塔克1区块东河砂岩地震储层预测研究 总被引:1,自引:0,他引:1
采用基于地震波形分类的地震相分析与沉积相解释、波阻抗约束稀疏脉冲反演、地震多属性储层预测及油气检测等针对岩性油气藏的储层地震预测技术,从塔中地区卡塔克1区块泥盆系东河砂岩储层的生储盖组合条件及相关的地震地质特点出发,利用卡1三维地震资料开展目的层系的目标精细解释,结合已有的钻探、测井和测试等资料,揭示了东河砂岩储层砂体的空间展布特征,圈定出砂岩发育带,并对有利储层段的潜在含油气性进行了综合预测和评价。 相似文献
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54.
黄河是多沙性河流,引黄必带进大量泥沙,沉沙池沉粗排细,能有效处理泥沙。当沉沙池淤满,失去自流沉沙作用时,采用"以挖待沉"可以延长灌区运行年限,但没有扬水沉沙方案优越。根据黄河下游地上河的特殊地貌条件,如果能在河漫滩上建沉沙池,可以解决沉沙占地的难题。 相似文献
55.
R. W. G. Carter 《地球表面变化过程与地形》1980,5(1):81-89
Magilligan Point is a recurved cuspate foreland at the mouth of Lough Foyle. Two wave regimes intersect in the estuary mouth and the manner of their interplay controls shoreline changes. Ocean swell waves from the N and NE are refracted around the recurve, losing both height and energy longshore. Width of the surf zone decreases and waves tend to steepen, although both these changes and wave refraction owe something to nearshore geometry. Angle of wave approach becomes more acute and a westerly flowing longshore current moves sand S and SW along the beach. Estuary waves from the S and SW are wind-driven with high-frequencies and steepnesses. They generate a northeasterly current which returns material N, but dies out as the waves become obliterated by nearshore attenuation and breaking of swell. It is possible to identify a time-averaged null-point where shoreline wave power is balanced, although this tends to shift over short periods causing rapid morphological changes. The existence of two independent, but counteractive cells ensures the long-term maintenance of the foreland, without requiring major or continuous supplies of fresh sediment. 相似文献
56.
The beaches of Liguria have been intensively affected by human activities for over a century, transforming nearly the entire coastline from natural to urbanised and significantly upsetting beach ecological properties. The present study aims to investigate 9 Ligurian beaches characterised by different degree of urbanisation, to test if and to what extent the organic-matter (OM) recycling processes can be linked to the human activity. Swash zone sediment, sampled during the spring–summer–autumn period, when the anthropogenic influence is at its maximum due to tourism, was analysed for OM features and recycling processes. Multivariate statistical analyses showed that huge amounts of detrital OM accumulated in the more urbanised sites, where the anthropogenic influence was at its peak, deriving from higher inhabitant number and density, from the presence of crowded roads very near to the swash zone and sewage treatment plants. The presence of torrent outlets on the beaches provided further OM accumulation. Lipids, carbohydrates and degraded autotrophic pigments were the OM fractions mainly responsible of the differentiation, and rather constant, high labile phosphorus contents were found in the more urbanised sites. The high activity values of the hydrolytic enzymes indicate the response of the microbial system to the OM accumulation in the urban sites. However, a decoupling of the trends of some enzymatic activities (namely glucosidase and lipase) and their target OM was observed in the highly urbanised conditions. 相似文献
57.
58.
Bonilla TD Nowosielski K Cuvelier M Hartz A Green M Esiobu N McCorquodale DS Fleisher JM Rogerson A 《Marine pollution bulletin》2007,54(9):1472-1482
Fecal indicator levels in nearshore waters of South Florida are routinely monitored to assess microbial contamination at recreational beaches. However, samples of sand from the surf zone and upper beach are not monitored which is surprising since sand may accumulate and harbor fecal-derived organisms. This study examined the prevalence of fecal indicator organisms in tidally-affected beach sand and in upper beach sand and compared these counts to levels in the water. Since indicator organisms were statistically elevated in sand relative to water, the study also considered the potential health risks associated with beach use and exposure to sand. Fecal coliforms, Escherichia coli, enterococci, somatic coliphages, and F(+)-specific coliphages were enumerated from sand and water at three South Florida beaches (Ft. Lauderdale Beach, Hollywood Beach, and Hobie Beach) over a 2-year period. Bacteria were consistently more concentrated in 100g samples of beach sand (2-23 fold in wet sand and 30-460 fold in dry sand) compared to 100ml samples of water. Somatic coliphages were commonly recovered from both sand and water while F(+)-specific coliphages were less commonly detected. Seeding experiments revealed that a single specimen of gull feces significantly influenced enterococci levels in some 3.1m(2) of beach sand. Examination of beach sand on a micro-spatial scale demonstrated that the variation in enterococci density over short distances was considerable. Results of multiple linear regression analysis showed that the physical and chemical parameters monitored in this study could only minimally account for the variation observed in indicator densities. A pilot epidemiological study was conducted to examine whether the length of exposure to beach water and sand could be correlated with health risk. Logistic regression analysis results provided preliminary evidence that time spent in the wet sand and time spent in the water were associated with a dose-dependent increase in gastrointestinal illness. 相似文献
59.
This paper presents a case study that assessed spatial variations in the tectonic uplift rates of beach deposits in the relict Kujukuri strand plain, situated on the northeastern coast of the Boso Peninsula, eastern Japan. The southern Boso Peninsula is tilted downward to the northeast due to plate subduction along the Sagami Trough. However, the cause of the northeastern coast uplift creating the relict strand plain is unclear, due to the absence of a Holocene raised marine terrace sequence. Elevations and ages of beach deposits were collected from drilled cores and ground-penetrating radar profiles along three shore-normal sections in the southern Kujukuri strand plain. From this, alongshore variations in the relative sea level since the mid-Holocene could be seen. These corresponded to north-to-northeast downward tilting at a rate of 0.4 m/ka for an interval 10 km and are concordant with the longer term tilting of the last interglacial marine terrace surrounding the plain. Although it is difficult to assess shore-normal variations of uplift based on the present dataset, the recognized tilting apparently continues to the tilting of the southern Boso Peninsula, implying the Sagami Trough probably affects the uplift of the Kujukuri coast. 相似文献
60.