The Self Diagnosis Method. A new methodology to assess environmental management in sea ports

A methodology has been designed to assess the performance of the environmental management in sea ports. The Self Diagnosis Method, developed by two research teams and about sixty sea ports, allows the comparison of the current environmental situation with that corresponding to previous years and the assessment of the opportunities for improvement. The main objective is to review the management activities and procedures that affect the environment and the way the port authority handles significant environmental aspects. It has been designed as a "first level" tool: it can be applied in approximately six hours by a non-expert user. It is based on the ISO 14001 vocabulary, requirements and structure, and it can be considered as a first step in the voluntary implementation of an environmental management system for port communities.     

A dynamic programming segmentation procedure for hydrological and environmental time series

We present a procedure for the segmentation of hydrological and environmental time series. The procedure is based on the minimization of Hubert’s segmentation cost or various generalizations of this cost. This is achieved through a dynamic programming algorithm, which is guaranteed to find the globally optimal segmentations with K=1, 2, ..., K _max segments. Various enhancements can be used to speed up the basic dynamic programming algorithm, for example recursive computation of segment errors and “block segmentation”. The “true” value of K is selected through the use of the Bayesian information criterion. We evaluate the segmentation procedure with experiments which involve artificial as well as temperature and river discharge time series.     

A hidden Markov model segmentation procedure for hydrological and environmental time series

In this paper we present a procedure for the segmentation of hydrological and enviromental time series. We consider the segmentation problem from a purely computational point of view which involves the minimization of Huberts segmentation cost; in addition this least squares segmentation is equivalent to Maximum Likelihood segmentation. Our segmentation procedure maximizes Likelihood and minimizes Huberts least squares criterion using a hidden Markov model (HMM) segmentation algorithm. This algorithm is guaranteed to achieve a local maximum of the Likelihood. We evaluate the segmentation procedure with numerical experiments which involve artificial, temperature and river discharge time series. In all experiments, the procedure actually achieves the global minimum of the Likelihood; furthermore execution time is only a few seconds, even for time series with over a thousand terms.     

Resolving sea level contributions by identifying fingerprints in time-variable gravity and altimetry

We have studied the ability of the GRACE gravimetry mission and Jason-1 altimetry to resolve ice and glacier induced contributions to sea level rise, by means of a fingerprint method. Here, the signals from ice sheet and land glacier changes, steric changes, glacial isostatic adjustment and terrestrial hydrology are assumed to have fixed spatial patterns. In a joint inversion using GRACE and Jason-1 data the unknown temporal components can then be estimated by least-squares. In total, we estimate temporal components for up to ∼ 80 individual patterns. From a propagation of the full error-covariance from GRACE and a diagonal error-covariance from Jason-1 altimetry we find that: (1) GRACE almost entirely explains the mass related parameters in the joint inversion, (2) an inversion using only Jason-1 data has a marginal ability to estimate the mass related parameters, while the steric parameters have much better formal accuracy. In terms of mean sea level rise the steric patterns have a maximum formal accuracy of 0.01 mm for an 11 week running mean. In general, strong negative error correlations (ρ < − 0.9) exists between the high and low elevation parts of the ice sheet drainage basins, when those are estimated independently. The largest formal errors found are in the order of 40 Gton for small high elevation subbasins in the southern Greenland ice sheet, which are difficult to separate. In a simplified joint inversion, merging high and low elevation basins, we have investigated the ability of the GRACE and Jason-1 data to separate the geocenter motion into a present-day contribution and a contribution from glacial isostatic adjustment (GIA). We find that the GIA related signal is larger than the present-day component with a maximum of −0.71 mm/year in the Z direction. Total geocenter motion rates are found to be −0.28, 0.43, −1.08 mm/year for the X, Y and Z components, respectively. The inversion results have been propagated to the Jason-1 along-track measurements. Over the time period considered, we see that a large part of the variability in the Pacific, Atlantic and Indian ocean can be explained by our inversion results. The applied inversion method therefore seems a feasible way to separate steric from mass induced sea level changes. At the same time, the joint inversion would benefit from more advanced parameterizations, which may aid in fitting remaining signal from altimetry.     

An efficient algorithm for identifying pulse‐like ground motions based on significant velocity half‐cycles

Ground motions with strong velocity pulses are of particular interest to structural earthquake engineers because they have the potential to impose extreme seismic demands on structures. Accurate classification of records is essential in several earthquake engineering fields where pulse‐like ground motions should be distinguished from nonpulse‐like records, such as probabilistic seismic hazard analysis and seismic risk assessment of structures. This study proposes an effective method to identify pulse‐like ground motions having single, multiple, or irregular pulses. To effectively characterize the intrinsic pulse‐like features, the concept of an energy‐based significant velocity half‐cycle, which is visually identifiable, is first presented. Ground motions are classified into 6 categories according to the number of significant half‐cycles in the velocity time series. The pulse energy ratio is used as an indicator for quantitative identification, and then the energy threshold values for each type of ground motions are determined. Comprehensive comparisons of the proposed approach with 4 benchmark identification methods are conducted, and the results indicate that the methodology presented in this study can more accurately and efficiently distinguish pulse‐like and nonpulse‐like ground motions. Also presented are some insights into the reasons why many pulse‐like ground motions are not detected successfully by each of the benchmark methods.     

A spatial disaggregation procedure for precipitation

Abstract

A disaggregation procedure is presented to render forecast values of precipitation from an atmospheric model with spatial resolution of 11 × 11 km suitable as input for a distributed hydrological model with spatial resolution of 1.1 × 1.1 km. Statistical and morphological properties of the input field, such as spatial mean, variance, correlation structure and intermittency, are respected in the disaggregated field. The adopted approach is a combination of interpolation and simulation. The four nodal points of the atmospheric model grid cell are used both for determining the parameters of the exponential distribution for simulating precipitation values, and in a simple interpolation procedure to determine the spatial location of the precipitation values. A shifted distribution with two parameters is used in the case of full coverage of the grid cell, and a one-parameter distribution with a theoretically derived intermittency parameter is used if intermittency is present. The results are promising with respect to the statistical and morphological properties of the disaggregated field.     

水位电信号干扰识别的新方法

通过对"十五"台站水位数据干扰原因进行调查分析,得到一类受电信号变换干扰影响明显的台站。通过对该类台站的水位数据进行小波分解,利用小波模极大值原理,得到水位受明显干扰的时刻。通过对多个台站不同时段内电信号变换影响的水位数据分析,得到该类干扰的典型动态,以及识别方法。     

一种震相拾取误差的自动判别和计算方法

本文给出了一个主要用于深地震测深数据的震相识别误差（不确定性）的判别和计算方法.该方法集中讨论从记录截面拾取震相这一过程所引起的判别误差.以震相前后一定时窗内的地震记录振幅的均方根之比为判别依据,找出误差分布范围并给出走时误差与振幅比的分级相关函数.由此,当震相确定后,计算程序将根据记录数据自动算出识别误差.实践证明该方法不仅更加客观真实、方便快捷,而且为今后震相提取工作的进一步科学规范打下了基础.     

A design procedure for tied braced frames

The paper deals with the analysis of the seismic behaviour and design of tied braced frames (TBFs). The behavioural properties of TBFs are described and a comparison drawn with standard eccentrically braced frames. A design procedure is then proposed that aims to achieve optimal collapse seismic behaviour, i.e. a global collapse mechanism characterized by uniform plastic rotations of links. The procedure is based on the displacement‐based approach so as to achieve direct and efficient control of the peak ground acceleration of collapse. Applications are carried out on systems with different numbers of storeys and lengths of links to obtain confirmation of the accuracy of the design hypotheses and methodologies. Copyright © 2007 John Wiley & Sons, Ltd.     

A procedure for the calibration of gravimeters

Summary Taking into account some recent results showing that the observations carried out with Worden gravimeters are influenced by temperature, a method of calibration has been followed which aims to neutralize both the effect of drift and to affort complete symmetry to every value observed.

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Résumé En tenant compte de récents resultats qui montrent comme les lectures faites avec les gravimètres Worden soient influencées par la température, on a suivi pour l'étalonnage de ces gravimètres une méthode qui a le but outre que de neutralizer l'effet de la derive, d'assurer la complète symétrie aux valeurs observées.

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Riassunto Tenendo conto dei risultati di alcune recenti ricerche che mostrano come le letture fatte ai gravimetri Worden siano influenzate dalla temperatura, si è seguito un metodo di taratura che ha il duplice scopo di neutralizzare l'effetto della deriva e di trattare con la massima simmetria ogni singolo valore osservato.

     

A scavenging model for trace elements in the deep sea

A vertical diffusion-advection model with a scavenging removal rate which is first-order in concentration is applied to the deep-water Geosecs-I profiles of four trace metals. The actual model scavenging rates are obtained by calibration of the vertical advection velocity with the radiocarbon profile from the same station — the¹⁴C data givew = 3.7m/yr. “Scavenging residence times”, τ_ψ, of 1400 years for Cu, 3200 years for Sb, and 2500 years for Sc are obtained. For these three elements the fit of the data to the scavenging-model equation is better than the fit to a conservative mixing model with no in-situ removal. TheF_χ comparison test is used to assess the probability that the improved fit given by the scavenging model is due merely to a random selection of data from an infinite set of values with a distribution governed by the stable-conservative model. This probability is found to be only 0.6% for Cu and only 3% for Sb. For Sc, however, the probability is 19% so that the two models cannot be distinguished for this element. The Ni profile shows no effect of scavenging; a lower limit of 3000 years is estimated for τ_ψ but the value is probably much greater. The association of Cu and Pb as two elements with definite indication of scavenging in deep water is consistent with experimental adsorption studies; the lack of indication of scavenging of Ni is consistent with the hypothesis that clay minerals are the scavenging agent for Pb and Cu. The method of comparing scavenging and conservative mixing-model fits to the profiles provides a mechanism for defining a set of trace elements which show consistent scavenging effects over large ocean areas, so that the reality of the deep-sea scavenging process for non-radioactive elements can be tested.     

A Bayesian hierarchical spatio-temporal model for significant wave height in the North Atlantic

Bad weather and rough seas continue to be a major cause for ship losses and is thus a significant contributor to the risk to maritime transportation. This stresses the importance of taking severe sea state conditions adequately into account in ship design and operation. Hence, there is a need for appropriate stochastic models describing the variability of sea states, taking into account long-term trends related to climate change. Various stochastic models of significant wave height are reported in the literature, but most are based on point measurements without considering spatial variations. As far as the authors are aware, no model of significant wave height to date exploits the flexible framework of Bayesian hierarchical space-time models. This framework allows modelling of complex dependence structures in space and time and incorporation of physical features and prior knowledge, yet at the same time remains intuitive and easily interpreted. This paper presents a Bayesian hierarchical space-time model for significant wave height. The model has been fitted by significant wave height data for an area in the North Atlantic ocean. The different components of the model will be outlined, and the results from applying the model to monthly and daily data will be discussed. Different model alternatives have been tried and long-term trends in the data have been identified for all model alternatives. Overall, these trends are in reasonable agreement and also agree fairly well with previous studies. Furthermore, a discussion of possible extensions to the model, e.g. incorporating regression terms with relevant meteorological data will be presented.     

Biodegradation and environmental behavior of biodiesel mixtures in the sea: An initial study

Biodiesel, a mixture of fatty acid methyl esters (FAMEs) derived from animal fats or vegetable oils, is rapidly moving towards the mainstream as an alternative source of energy. However, the behavior of biodiesel, or blends of biodiesel with fossil diesel, in the marine environment have yet to be fully understood. Hence, we performed a series of initial laboratory experiments and simple calculations to evaluate the microbial and environmental fate of FAMEs. Aerobic seawater microcosms spiked with biodiesel or mixtures of biodiesel and fossil diesel revealed that the FAMEs were degraded at roughly the same rate as n-alkanes, and more rapidly than other hydrocarbon components. The residues extracted from these different microcosms became indistinguishable within weeks. Preliminary results from physical-chemical calculations suggest that FAMEs in biodiesel mixtures will not affect the evaporation rates of spilled petroleum hydrocarbons but may stabilize oil droplets in the water column and thereby facilitate transport.     

广东非天然地震的特征与识别

概述了非天然地震的范畴、广东非天然地震的类型。通过对非天然地震事件和天然地震的震相分析、统计计算、分析研究得出广东非天然地震的一些规律与特征．如非天然地震的振幅比AS／AP和波的持续时间τ值比天然地震小．发震时间比较规律等．讨论了非天然地震的识别方法。     

A novel ATR‐FTIR technique for identifying colloid composition in natural waters

Although understanding colloid composition has been frequently cited as essential to predicting contaminant transport in natural waters, most current methods to collect and identify colloid composition chemically alter the colloids prior to analysis and fail to identify colloid mineralogy and organic components. This paper presents a new, low‐cost method employing attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) to identify colloids including organic material in concentrated suspensions. The concentration method employing tangential ultrafiltration at a steady temperature prevents redistribution of dissolved phase and suspended sediments into the colloidal fraction through post‐sampling reactions. ATR‐FTIR allows for direct analysis of concentrated suspensions rather than requiring drying that may alter composition in the colloidal phase, for example, by precipitating carbonates in samples from karst waters. The ability of this technique to monitor variation in colloidal composition is demonstrated through the examination of colloids under two different flow conditions in a karst aquifer and the West Branch of the Susquehanna River in Central Pennsylvania. Copyright © 2014 John Wiley & Sons, Ltd.     

A simple statistical estimation procedure for Monte Carlo Inversion in geophysics

Summary This paper examines the use of Monte Carlo Inversion (MCI) as an effective means for inverting ((geo)physical) data. Press, following Keilis-Borok and Yanovskaya, has used it successfully as an independent method for density modelling. However, to-date, no statistical basis for the interpretation of the results determined by it in geophysical applications has been developed. Since its future success and credibility will rest heavily on the development of such a basis, we give a simple statistical estimation procedure which defines in a natural way the procedure which must be used when applying, and interpreting the results obtained from, MCI. In addition, it is shown that MCI complements, rather than competes with, the work of Backus and Gilbert.     

Review of oil and HNS accidental spills in Europe: identifying major environmental monitoring gaps and drawing priorities

The European Atlantic area has been the scene of a number of extensive shipping incidents with immediate and potential long-term impacts to marine ecosystems. The occurrence of accidental spills at sea requires an effective response that must include a well executed monitoring programme to assess the environmental contamination and damage of the affected marine habitats. Despite a number of conventions and protocols developed by international and national authorities that focused on the preparedness and response to oil and HNS spills, much remains to be done, particularly in relation to the effectiveness of the environmental monitoring programmes implemented after oil and HNS spills. Hence, the present study reviews the status of the environmental monitoring programmes established following the major spill incidents over the last years in European waters, aiming at identifying the key monitoring gaps and drawing priorities for an effective environmental monitoring of accidental spills.     

Building over faults: A procedure for evaluating risk

This paper examines the risk from fault offset to a building constructed over the surface trace of a fault. An expression relating the magnitude of surface offset to its return period is derived using classical seismic hazard analysis. The risk from fault offset is compared with that due to ground shaking by comparing offsets and MM intensities with equal likelihoods of occurrence. The comparison of risks is useful since it enables risk from fault movement to be related to levels of community acceptance as expressed in building codes for design against ground shaking effects. Relative risk is independent of fault activity rate, but does depend on regional constants, principally those describing the attenuation of MM intensities. For a site over an isolated fault in the Wellington, New Zealand region the risk of damage from fault rupture appears to be about equal to that from ground shaking for buildings with poor earthquake resistance (e.g. unreinforced masonry structures). But for structures designed to have some resistance to ground shaking, the risk due to fault rupture is considerably greater than that due to ground shaking.