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The closed-form analytical stormwater quality models are developed for simulating urban catchment pollutant buildup and washoff processes. By integrating the rainfall–runoff transformation with pollutant buildup and washoff functions, stormwater quality measures, such as the cumulative distribution functions (CDFs) of pollutant loads, the expected value of pollutant event mean concentrations (EMCs) and the average annual pollutant load can be derived. This paper presents methodologies and major procedures for the development of urban stormwater quality models based on derived probability distribution theory. In order to investigate the spatial variation in model parameters and its impact on stormwater pollutant buildup and washoff processes as well as pollutant loads to receiving waters, an extended form of the original rainfall–runoff transformation which is based on lumped runoff coefficient approach is proposed to differentiate runoff generation mechanisms between the impervious and pervious areas of the catchment. In addition, as a contrast to the aggregated pollutant buildup models formulated with a single lumped buildup parameter, the disaggregated form of the pollutant buildup model is proposed by introducing a number of physically-based parameters associated with pollutant buildup and washoff processes into the pollutant load models. The results from the case study indicate that analytical urban stormwater management model are capable of providing results in good agreement with the field measurements, and can be employed as alternatives to continuous simulation models in the evaluation of long-term stormwater quality measures. 相似文献
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A derived distribution approach is developed for flood prediction in poorly gauged basins. This couples information on the expected storm scaling, condensed into Depth Duration Frequency curves, with soil abstractions modeled using Soil Conservation Service Curve Number method and hydrological response through Nash’s Instantaneous Unit Hydrograph. A simplified framework is given to evaluate critical duration for flood design. Antecedent moisture condition distribution is included. The method is tested on 16 poorly gauged Mediterranean watersheds in Tyrrhenian Liguria, North Western Italy, belonging to a homogeneous hydrological regions. The derived flood distribution is compared to the regional one, currently adopted for flood design. The evaluation of Curve Number is critical for peak flood evaluation and needs to be carefully carried out. This can be done including local Annual Flood Series data in the estimation of the derived distribution, so gathering the greatest available information. However, Curve Number influence decreases for the highest return periods. When considerable return periods are required for flood design and few years of data are available, the derived distribution provides more accurate estimates than the approach based on single site distribution fitting. A strategy based on data availability for application of the approach is then given. The proposed methodology contributes to the ongoing discussion concerning PUB (Prediction in Ungauged Basins) decade of the IAHS association and can be used by researchers and practitioners for those sites where no flood data, or only a few, are available, provided precipitation data and land use information are at hand. 相似文献
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伴随勒让德函数的一个注记 总被引：1，自引：0，他引：1
证明了伴随勒让德函数Ｐｎｋ （ｘ） 的导函数Ｐ′ｎｋ （ｘ） 相应于次ｋ 在〔－ １ ， １〕上关于权函数ρ（ｘ） ＝ １ － ｘ２ 具有部分正交性。 相似文献
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矿床具斑岩型铜矿化蚀变特征,从岩体中心向外,蚀变呈环带状分带发育,依次为强硅化带→钾硅化带→绢英岩化带→青磐岩化带。矿化在浅部表现为断裂破碎带控制的热液脉型Cu、Au、Pb、Ag矿床,深部则为斑岩型Cu、Mo矿床。 相似文献
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关于勒让德函数的两点注记 总被引：1，自引：0，他引：1
证明了勒让德多项式 Pn(x)的 k阶导数 P(k)n (x) ,在闭区间〔-1 ,1〕上关于权函数ρ(x) =(1 -x2 ) k具有正交性 ;伴随勒让德函数 Pnk(x)的导数 P′nk(x)在〔-1 ,1〕上关于权函数ρ(x) =1 -x2 具有部分正交性。 相似文献
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《Marine Geodesy》2012,35(1):23-43
AbstractRemote sensing is becoming common in the estimation of bathymetry for navigational charting through a process known as Satellite Derived Bathymetry (SDB). Most SDB techniques currently used by hydrographic offices employ an empirical approach, requiring the use of in-situ data to calibrate a relationship between spectral information and coincident depths. This article reports on a multi-site test of an alternative SDB method which uses photogrammetry to extract depths from stereo WorldView-2 imagery. In areas with heterogeneous seafloors, the empirical approach faces difficulties in establishing the relationship between colour and depth, while the photogrammetric approach uses the contrasting seafloor features for triangulation. Additionally, the photogrammetric method may be applied in areas lacking previous survey data. Five study areas in Nunavut, Canada were selected to test the robustness of the method in different environments and under different imaging conditions. Study areas were (with resulting RMSE/Bias given in metres) Coral Harbour (0.84/?0.47), Cambridge Bay (1.16/?0.15), Queen Maud Gulf (0.97/0.06), Arviat (0.99/?0.009), and Frobisher Bay, where extraction largely failed due to environmental conditions. Accuracies demonstrated here are similar to those seen using the empirical approach, suggesting that these two methods may be used in conjunction, each applied to regions where they are better suited. 相似文献
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三条大断裂形成三角形构造变形区,成为贯通岩石圈底部的通道。浅成斑岩多期入侵,以及内外接触带的破裂化和压扭破裂带的存在,为成矿创造有利条件。 相似文献
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H. Hellmann 《洁净——土壤、空气、水》1995,23(3):121-130
Fine Resolution of UV Spectra by Differentiation of 1st and 2nd Order in Hydrocarbon Analysis Basic UV spectra (0th order) in unpolar solvents such as cyclohexane are useful — though with some reservations — in characterizing mineral oils occuring in pure form and aromatic fractions in environmental samples separated by chromatographic techniques. The common standard raffinates, biogenic hydrocarbons or other mixes of hydrocarbons including polycyclic aromatics can be approximately identified. The spectra of 1st and 2nd order improve the reliability of the results and permit above all to detect polycondensated aromatics even in traces. Finally, partial spectra of 1st and 2nd order in the wavelength ranges 205…240, 220…260, and 260…320 nm allow because of their very specific structures a simple and fast practically definite assignment to the above-mentioned groups of aromatics. Analogously, substituted aromatics in detergents and other technical products have already been identified. The method is suitable as a fast preliminary test, at least. 相似文献