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Monitoring Schemes (monitoring + scheme)
Selected AbstractsEnhanced process monitoring for wastewater treatment systemsENVIRONMETRICS, Issue 6 2008Chang Kyoo Yoo Abstract Wastewater treatment plants (WWTPs) remain notorious for poor data quality and sensor reliability problems due to the hostile environment, missing data problems and more. Many sensors in WWTP are prone to malfunctions in harsh environments. If a WWTP contains any redundancy between sensors, monitoring methods with sensor reconstruction such as the proposed one can yield a better monitoring efficiency than without a reconstruction scheme. An enhanced robust process monitoring method combined with a sensor reconstruction scheme to tackle the sensor failure problems is proposed for biological wastewater treatment systems. The proposed method is applied to a single reactor for high activity ammonia removal over nitrite (SHARON) process. It shows robust monitoring performance in the presence of sensor faults and produces few false alarms. Moreover, it enables us to keep the monitoring system running in the case of sensor failures. This guaranteed continuity of the monitoring scheme is a necessary development in view of real-time applications in full-scale WWTPs. Copyright © 2007 John Wiley & Sons, Ltd. [source] Habitat influences on urban avian assemblagesIBIS, Issue 1 2009KARL L. EVANS Urbanization is increasing across the globe and there is growing interest in urban ecology and a recognition that developed areas may be important for conservation. We review the factors influencing urban avian assemblages, focusing on habitat type and anthropogenic resource provision, and analyse data from a common bird monitoring scheme to assess some of these issues. The review suggests that (1) local factors are more important than regional ones in determining the species richness of urban avian assemblages, raising the potential for the management of urban sites to deliver conservation; (2) habitat fragmentation frequently influences urban avian assemblages, with the effects of patch size being greater than those of isolation, and (3) urban bird assemblages appear to respond positively to increasing the structural complexity, species richness of woody vegetation and supplementary feeding, and negatively to human disturbance. Data from Britain's Breeding Bird Survey, combined with habitat data obtained from aerial photographs, were used to assess a number of these issues at the resolution of 1-km squares. Green-space constituted 45% of these squares, and domestic gardens contributed 50% of this green-space, though their contribution to large continuous patches of green-space was negligible. There was no significant positive correlation between the densities of individual species in urban areas and surrounding rural areas. Rural species richness declined with increasing latitude, but urban species richness was not correlated with latitude. This contrast contributes to slightly higher avian species richness in rural squares in Southern England than urban ones. Occupancy and abundance were strongly positively correlated in urban avian assemblages, and some indicator species of conservation concern occurred in few urban areas and at low densities. Such species will require conservation action to be precisely targeted within urban areas. Of the urban indicators of conservation concern, only the House Sparrow Passer domesticus and Common Starling Sturnus vulgaris were more abundant in urban than rural areas. Moreover, the densities of these two species were strongly and positively correlated, indicating that they may be limited by shared resources, such as nest-sites or supplementary food. There was little evidence that high densities of nest-predating corvids were associated with reduced densities of their prey species. Species richness and the densities of individual species frequently declined with an increasing number of buildings. Current trends for the densification of many British urban areas are thus likely to be detrimental for many bird species. [source] Simulation of transient flow in pipelines for computer-based operations monitoringINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3 2004H. E. Emara-Shabaik Abstract Computer models can provide the basis for real-time monitoring and control of fluid flow in pipelines. Problems of fluid flow in pipelines are mathematically represented by a non-linear system of coupled partial differential equations. In this paper, several numerical techniques are evaluated with respect to their suitability for the purpose of real-time monitoring of fluid flow in pipelines. The proposed techniques are evaluated in terms of the L1, the L2, and the L, error norms. Moreover, the developed simulators will be compared in terms of their speed of response and settling time which are essential factors for an effective real-time monitoring scheme. Finally, the selected simulation scheme is further tested under assumed pipeline leak conditions. Copyright © 2004 John Wiley & Sons, Ltd. [source] Evaluating the power of monitoring plot designs for detecting long-term trends in the numbers of common guillemotsJOURNAL OF APPLIED ECOLOGY, Issue 3 2006MICHELLE SIMS Summary 1In recent years concerns have been raised regarding the status of the common guillemot Uria aalge in the UK. Numbers have declined in several regions, highlighting the need for continued monitoring of this internationally important population. However, the extent to which the current monitoring scheme is capable of detecting declines and options for improving efficiency has received little attention. 2We investigated the power of different monitoring design options for detecting long-term trends in abundance at a colony of guillemots. The ability to detect trends in abundance was reduced by the large temporal and spatial variability in colony attendance. Taking a linear mixed model approach, we obtained details on the sources and sizes of the variance components using count data collected from monitoring plots on the Isle of May, Scotland, and assessed how best to allocate sampling effort in the light of the count variability structure. 3Our results indicated that trend detection will be improved by counting birds in more plots rather than by increasing the number of counts at existing plots. 4The revisit pattern of counts at the monitoring plots during the seasonal counting period had little effect on trend detection power. However, given the practical issues associated with counting guillemots, alternative revisit patterns to the current approach are preferred. 5For a fixed number of visits per plot, power is strongly influenced by the choice of revisit design if the day-to-day variation in colony attendance is increased. 6Synthesis and applications. Aspects of the UK seabird monitoring scheme can be improved. Changes to the allocation of sampling effort and the plot-revisit pattern will improve both the statistical power to detect long-term trends and the efficiency of conducting the survey. We stress the importance of considering the structure and magnitude of the count variation in a power analysis because judicious design decisions depend on the relative magnitude of these variance components. [source] A spatial model for the needle losses of pine-trees in the forests of Baden-Württemberg: an application of Bayesian structured additive regressionJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 1 2007Nicole H. Augustin Summary., The data that are analysed are from a monitoring survey which was carried out in 1994 in the forests of Baden-Württemberg, a federal state in the south-western region of Germany. The survey is part of a large monitoring scheme that has been carried out since the 1980s at different spatial and temporal resolutions to observe the increase in forest damage. One indicator for tree vitality is tree defoliation, which is mainly caused by intrinsic factors, age and stand conditions, but also by biotic (e.g. insects) and abiotic stresses (e.g. industrial emissions). In the survey, needle loss of pine-trees and many potential covariates are recorded at about 580 grid points of a 4 km × 4 km grid. The aim is to identify a set of predictors for needle loss and to investigate the relationships between the needle loss and the predictors. The response variable needle loss is recorded as a percentage in 5% steps estimated by eye using binoculars and categorized into healthy trees (10% or less), intermediate trees (10,25%) and damaged trees (25% or more). We use a Bayesian cumulative threshold model with non-linear functions of continuous variables and a random effect for spatial heterogeneity. For both the non-linear functions and the spatial random effect we use Bayesian versions of P -splines as priors. Our method is novel in that it deals with several non-standard data requirements: the ordinal response variable (the categorized version of needle loss), non-linear effects of covariates, spatial heterogeneity and prediction with missing covariates. The model is a special case of models with a geoadditive or more generally structured additive predictor. Inference can be based on Markov chain Monte Carlo techniques or mixed model technology. [source] Process monitoring for correlated gamma-distributed data using generalized-linear-model-based control chartsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 6 2003Duangporn Jearkpaporn Abstract A model-based scheme is proposed for monitoring multiple gamma-distributed variables. The procedure is based on the deviance residual, which is a likelihood ratio statistic for detecting a mean shift when the shape parameter is assumed to be unchanged and the input and output variables are related in a certain manner. We discuss the distribution of this statistic and the proposed monitoring scheme. An example involving the advance rate of a drill is used to illustrate the implementation of the deviance residual monitoring scheme. Finally, a simulation study is performed to compare the average run length (ARL) performance of the proposed method to the standard Shewhart control chart for individuals. Copyright © 2003 John Wiley & Sons, Ltd. [source] Using simple species lists to monitor trends in animal populations: new methods and a comparison with independent dataANIMAL CONSERVATION, Issue 3 2007R. L. Roberts Abstract There is an urgent need to develop simple and inexpensive methods for monitoring wildlife populations in resource-poor countries. List-based methods have been advocated as simple yet potentially useful biodiversity monitoring tools, and systems have recently been launched in a number of countries to collect species lists. We attempt to advance the use of systematic list-based monitoring by (1) suggesting improvements to the way in which list reporting rates are calculated; (2) assessing the extent to which degrading effort-corrected measures of abundance into simple species lists results in loss of information on population trends; (3) comparing long-term trends in list reporting rates with population trends from a wholly independent monitoring scheme. Daily species lists of birds were derived from regular trapping at a nature reserve in southern England. Most species showed a strong correlation across years between the proportion of lists on which they occurred, adjusted for list length (adjusted list reporting rate; ALRR), and an effort-corrected measure of abundance (captures per unit effort; CPUE). ALRR revealed almost as much about annual variation in abundance as CPUE for all but the most frequently captured species. Long-term (>20 years) trends in ALRRs at the nature reserve were positively correlated with UK national population trends recorded over the same period by an independent, labour-intensive monitoring scheme that counted birds at a large number of widely spread sites. Our results support previous claims that simple species lists could generate data useful for monitoring long-term population trends, particularly where such lists are collected systematically. However, further research on the efficiency of list reporting rates relative to more sophisticated methods is necessary, before list-based methods can be advocated for dedicated monitoring schemes in resource-poor regions. [source] Multivariate Statistical Process Monitoring Using Kernel Density EstimationASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1-2 2005J. Liang In this paper, a general kernel density estimator has been introduced and discussed for multivariate processes in order to provide enhanced real-time performance monitoring. The proposed approach is based upon the concept of kernel density function, which is more appropriate to the underlying probability distribution of industrial process data in the development of a real-time monitoring scheme, to overcome the limitations of the conventional approach of defining the normal operating region based upon the assumption of normality. An optimal bandwidth selection rule is given based on the so-called mean integrated squared error index, and that is the normal operating region of process calculated using the optimal kernel density estimator before new process data are projected onto the normal operating region. The results of a case study of an industrial reheating furnace clearly demonstrates the power and advantages (e.g. decreasing the number of false alarms, identifying abnormal behaviour earlier, and reducing data sparsity) of the kernel density estimator-based approach over the conventional approach under the assumption of normality, which is still widely used. [source] Local Participation in Natural Resource Monitoring: a Characterization of ApproachesCONSERVATION BIOLOGY, Issue 1 2009FINN DANIELSEN conservación; evaluación de la biodiversidad; esquemas de monitoreo; intereses locales; manejo de recursos naturales Abstract:,The monitoring of trends in the status of species or habitats is routine in developed countries, where it is funded by the state or large nongovernmental organizations and often involves large numbers of skilled amateur volunteers. Far less monitoring of natural resources takes place in developing countries, where state agencies have small budgets, there are fewer skilled professionals or amateurs, and socioeconomic conditions prevent development of a culture of volunteerism. The resulting lack of knowledge about trends in species and habitats presents a serious challenge for detecting, understanding, and reversing declines in natural resource values. International environmental agreements require signatories undertake systematic monitoring of their natural resources, but no system exists to guide the development and expansion of monitoring schemes. To help develop such a protocol, we suggest a typology of monitoring categories, defined by their degree of local participation, ranging from no local involvement with monitoring undertaken by professional researchers to an entirely local effort with monitoring undertaken by local people. We assessed the strengths and weaknesses of each monitoring category and the potential of each to be sustainable in developed or developing countries. Locally based monitoring is particularly relevant in developing countries, where it can lead to rapid decisions to solve the key threats affecting natural resources, can empower local communities to better manage their resources, and can refine sustainable-use strategies to improve local livelihoods. Nevertheless, we recognize that the accuracy and precision of the monitoring undertaken by local communities in different situations needs further study and field protocols need to be further developed to get the best from the unrealized potential of this approach. A challenge to conservation biologists is to identify and establish the monitoring system most relevant to a particular situation and to develop methods to integrate outputs from across the spectrum of monitoring schemes to produce wider indices of natural resources that capture the strengths of each. Resumen:,El monitoreo de tendencias en el estatus de especies o hábitats es rutinario en los países desarrollados, donde es financiado por el estado o por grandes organizaciones no gubernamentales y a menudo involucra a grandes números de voluntarios amateurs competentes. El monitoreo de recursos naturales es menos intenso en los países en desarrollo, donde las agencias estatales tienen presupuestos pequeños, hay menos profesionales o amateurs competentes y las condiciones socioeconómicas limitan el desarrollo de una cultura de voluntariado. La consecuente falta de conocimientos sobre las tendencias de las especies y los hábitats presenta un serio reto para la detección, entendimiento y reversión de las declinaciones de los recursos naturales. Los tratados ambientales internacionales requieren que los signatarios realicen monitoreos sistemáticos de sus recursos naturales, pero no existe un sistema para guiar el desarrollo y la expansión de los esquemas de monitoreo. Para ayudar al desarrollo de tal protocolo, sugerimos una tipología de categorías de monitoreo, definidas por el nivel de participación local, desde ningún involucramiento local con el monitoreo realizado por investigadores profesionales hasta un esfuerzo completamente local con el monitoreo llevado a cabo por habitantes locales. Evaluamos las fortalezas y debilidades de cada categoría de monitoreo, así como su sustentabilidad potencial en países desarrollados o en desarrollo. El monitoreo basado localmente es particularmente relevante en los países en desarrollo, donde puede llevar a decisiones rápidas para resolver amenazas clave sobre sus recursos naturales, puede facultar a las comunidades locales para un mejor manejo de sus recursos naturales y puede refinar las estrategias de uso sustentable para mejorar la forma de vida local. Sin embargo, reconocemos que la precisión y exactitud del monitoreo llevado a cabo por comunidades locales en situaciones diferentes requiere de mayor estudio y los protocolos de campo requieren de mayor desarrollo para obtener lo mejor del potencial de este método. Un reto para los biólogos de la conservación es la identificación y establecimiento del sistema de monitoreo más relevante para la situación particular, así como el desarrollo de métodos para integrar los resultados de una gama de esquemas de monitoreo para producir índices de recursos naturales más amplios que capturen las fortalezas de cada uno. [source] Geographic variation in the field response of male European pine sawflies, Neodiprion sertifer, to different pheromone stereoisomers and estersENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2000O. Anderbrant Abstract The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae), is a widespread and economically important forest insect. The sex pheromone communication system of this species has been previously investigated in North America, Japan and Europe, with the acetate or propionate of the alcohol (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) shown to be the main pheromone component. In some locations, male attraction either increased or decreased by the addition of the (2S,3R,7R)-diprionyl acetate isomer. However, these studies were made with different batches of synthetic pheromones, with different types of traps and according to different procedures, so the observed differences might not reflect true geographic variation. Here we investigate the geographic pattern of male sawfly response by using identical chemicals, traps and experimental procedures at eight field sites ranging from Japan in the east to Canada in the west. We found an increased inhibitory effect of the (2S,3R,7R)-isomer from Japan and Siberia to Europe. At the eastern sites, increasing amounts of the (2S,3R,7R)-isomer up to and equal to the amount of the (2S,3S,7S )-isomer, did not influence the trap catch, whereas at sites in Europe, as little as 1% of the (2S,3R,7R)-isomer almost completely inhibited the attraction. The response of the North American population was intermediate. The only site in which the (2S,3R,7R)-isomer was essential for the attraction of males was in Siberia. A similar pattern was found for the (2S,3R,7S)-isomer. Both the acetate and the propionate form of the (2S,3S,7S)-isomer were attractive by themselves in Japan, Europe and North America, and neither the (2S,3R,7S)-isomer nor the (2S,3R,7R)-isomer alone were attractive, in the acetate or propionate form. We discuss the significance of our findings for the development of more efficient monitoring schemes and for the causes of population divergence and speciation in the European pine sawfly. [source] Distribution of direct recall costs along the milk chainAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 4 2009A.G.J. Velthuis The relation between time and the direct recall costs of one batch of milk was investigated in this study. We developed a Monte Carlo simulation model of a farm-to-consumer supply chain associated with one batch of milk of 150,000,kilograms. The direct recall costs of recalling a batch are less than ,100,000 in the first 16 hours after the milk has been collected from the farms, but the costs increase rapidly to more than ,140,000. With this study, we showed that a modeling approach can give insight into the relation between recall costs and time, and it can support the development of monitoring schemes at the chain level. [EconLit citations: D210, Q180]. © 2009 Wiley Periodicals, Inc. [source] A CUSUM scheme with variable sample sizes and sampling intervals for monitoring the process mean and varianceQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2007Zhang Wu Abstract The adaptive control feature and CUSUM chart are two monitoring schemes that are much more effective than the traditional static Shewhart chart in detecting process shifts in mean and variance. However, the designs and analyses of the adaptive CUSUM chart are mathematically intractable and the operation is very laborious. This article proposes a VSSI WLC scheme, which is a weighted-loss-function-based CUSUM (WLC) scheme using variable sample sizes and sampling intervals (VSSI). This scheme detects the two-sided mean shift and increasing standard deviation shift based on a single statistic WL (the weighted loss function). Most importantly, the VSSI WLC scheme is much easier to operate and design than a VSSI CCC scheme which comprises three individual CUSUM charts (two of them monitoring the increasing and decreasing mean shifts and one monitoring the increasing variance shift). Overall, the VSSI WLC scheme is much more effective than the static &S charts (by 72.36%), the VSSI &S charts (by 30.97%) and the static WLC scheme (by 50.94%) for detection. It is even more effective than the complicated VSSI CCC scheme for most cases. Copyright © 2006 John Wiley & Sons, Ltd. [source] Using Profile Monitoring Techniques for a Data-rich Environment with Huge Sample SizeQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 7 2005Kaibo Wang Abstract In-process sensors with huge sample size are becoming popular in the modern manufacturing industry, due to the increasing complexity of processes and products and the availability of advanced sensing technology. Under such a data-rich environment, a sample with huge size usually violates the assumption of homogeneity and degrades the detection performance of a conventional control chart. Instead of charting summary statistics such as the mean and standard deviation of observations that assume homogeneity within a sample, this paper proposes charting schemes based on the quantile,quantile (Q,Q) plot and profile monitoring techniques to improve the performance. Different monitoring schemes are studied based on various shift patterns in a huge sample and compared via simulation. Guidelines are provided for applying the proposed schemes to similar industrial applications in a data-rich environment. Copyright © 2005 John Wiley & Sons, Ltd. [source] Change-point monitoring in linear modelsTHE ECONOMETRICS JOURNAL, Issue 3 2006Alexander Aue Summary, We consider a linear regression model with errors modelled by martingale difference sequences, which include heteroskedastic augmented GARCH processes. We develop asymptotic theory for two monitoring schemes aimed at detecting a change in the regression parameters. The first method is based on the CUSUM of the residuals and was studied earlier in the context of independent identically distributed errors. The second method is new and is based on the squares of prediction errors. Both methods use a training sample of size m. We show that, as m,,, both methods have correct asymptotic size and detect a change with probability approaching unity. The methods are illustrated and compared in a small simulation study. [source] Identifying important areas for butterfly conservation in ItalyANIMAL CONSERVATION, Issue 1 2009M. Girardello Abstract The current study combines the use of niche modelling with a site prioritization method to identify important areas for butterfly conservation in Italy. A novel machine learning method (bagging predictors) was used to predict the distribution of 232 species of butterflies across the Italian Peninsula. The results of the models were used to identify high-value sites with a multispecies prioritization method called zonation. In order to identify important areas for species of conservation concern, we incorporated a species weighting scheme to zonation analyses. We also used the results of the zonation analyses to identify a series of management landscapes on the basis of the similarity in species composition among sites. The basic zonation showed that most important areas for butterfly conservation are located in the Alps, the Appennine, the Apulia region and in the island of Sardinia. The inclusion of a species weighting scheme in the zonation analyses revealed the importance of two new areas located in Southern Italy and emphasized the importance of the Alps for species of conservation concern. The landscape identification procedure selected a series of landscapes, which provide protection to a full range of species ranging from the Alps to Mediterranean areas. Our study shows that the areas selected in our analyses should be given high priority in future conservation plans and monitoring schemes. [source] Using simple species lists to monitor trends in animal populations: new methods and a comparison with independent dataANIMAL CONSERVATION, Issue 3 2007R. L. Roberts Abstract There is an urgent need to develop simple and inexpensive methods for monitoring wildlife populations in resource-poor countries. List-based methods have been advocated as simple yet potentially useful biodiversity monitoring tools, and systems have recently been launched in a number of countries to collect species lists. We attempt to advance the use of systematic list-based monitoring by (1) suggesting improvements to the way in which list reporting rates are calculated; (2) assessing the extent to which degrading effort-corrected measures of abundance into simple species lists results in loss of information on population trends; (3) comparing long-term trends in list reporting rates with population trends from a wholly independent monitoring scheme. Daily species lists of birds were derived from regular trapping at a nature reserve in southern England. Most species showed a strong correlation across years between the proportion of lists on which they occurred, adjusted for list length (adjusted list reporting rate; ALRR), and an effort-corrected measure of abundance (captures per unit effort; CPUE). ALRR revealed almost as much about annual variation in abundance as CPUE for all but the most frequently captured species. Long-term (>20 years) trends in ALRRs at the nature reserve were positively correlated with UK national population trends recorded over the same period by an independent, labour-intensive monitoring scheme that counted birds at a large number of widely spread sites. Our results support previous claims that simple species lists could generate data useful for monitoring long-term population trends, particularly where such lists are collected systematically. However, further research on the efficiency of list reporting rates relative to more sophisticated methods is necessary, before list-based methods can be advocated for dedicated monitoring schemes in resource-poor regions. [source] Lessons from Environmental Regulation for the Nonprofit SectorANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 3 2002Renee A. Irvin As the third sector's economic and social impact grows worldwide, efforts by governments to regulate the sector have focused on increasing compliance in tax,exempt organizations. This article turns to the environmental sector for guidance, summarizing key characteristics of environmental regulation and noting what strategies are likely to prove useful for application to regulation of nonprofit organizations. The article finds some value in promotion of market,based enforcement schemes, but little value in promulgation of laws specifying governance structures and performance standards by a central authority. The most promising opportunity for improvement of the nonprofit regulatory process involves incorporation of financial incentives into monitoring schemes. [source] Assessing ecological changes in and around marine reserves using community perceptions and biological surveysAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2010M. Yasué Abstract 1. Well-enforced partial or total no-fishing zones (collectively known as marine protected areas, or MPAs) can help restore degraded coral reefs and enhance fish populations. 2. A comparison was made of community perceptions of ecological changes in an MPA with concurrent scientific data on these changes in the same MPA. Such analyses are particularly important in community-based MPAs where local support is a key determinant of ecological success. 3. The no-take MPA in question was initially launched in partnership with the community in 1995 and formalized in 1998. The perceptions data come from interviews with community members in 1999 and 2004, the biological data come from underwater visual censuses of the MPA from 1998 to 2004. 4. Community members perceived more fish within the MPA and slight increases in catch outside the MPA. In contrast, fish censuses showed a high degree of stochastic variation and only minor increases in fish abundance, size and diversity in and around the MPA between 1998 and 2004. 5. Possible explanations for these discrepancies include different temporal, spatial or species frames of reference and/or limitations to the biological survey technique. Other options include wishful thinking, external influences, a desire to please, or confounding with other benefits. 6. This study demonstrates some of the strengths and weaknesses of community perceptions and biological data. In order to improve our understanding about the changes that occur over time in an MPA and engender community support for the long-term viability of MPAs, it is important to develop diverse and efficient monitoring schemes. Copyright © 2010 John Wiley & Sons, Ltd. [source] Developments in EU biofuels policy related to sustainability issues: overview and outlookBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 4 2007Marc Londo Abstract In the current debate on present and future biofuels policy, sustainability issues play an important role. In this perspective, we discuss a number of factors in the framing of the biofuels sustainability debate, and describe their role over the last 25 years or so in which biofuels have been on the political agenda. Our first conclusion is that biofuels policy is related to several underlying objectives, such as climate change, security of supply and other drivers. Therefore, the policy will structurally need to be monitored in its impacts, in order to keep these impacts in concordance with these objectives. In the long term, biofuels policy might be substituted by instruments that more directly relate to the objectives. Second, current sustainability issues concerning biofuels relate to either the production chain or to the regional system in which biofuels compete for land. Finding suitable indicators and setting up monitoring schemes are key challenges. Furthermore, a safeguarding scheme needs to meet two conflicting requirements: on the one hand it is important to implement it over many regions and many sectors (including non-energy), but on the other hand the problem requires implementation in the short term. Starting with monitoring only may cause an issue of legitimacy. Finally, we propose some elements for a robust development strategy. This includes pushing forward with a sustainability safeguarding scheme, within the given constraints. During the start-up period of such schemes, non-certified biofuels and feedstock might be discouraged, simultaneously stimulating production initiatives operating under certification. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd [source] | ||||||||||||||||||||||