http://www.environmentalsystemsresearch.com The latest research articles published by Environmental Systems Research 2013-05-04T00:00:00Z Background: The purpose of this work was to demonstrate an approach to groundwater remedial design that is automated, cost-effective, and broadly applicable to contaminated aquifers in different geologic settings. The approach integrates modeling and optimization for use as a decision support framework for the optimal design of groundwater remediation systems employing pump and treat and re-injection technologies. The technology resulting from the implementation of the methodology, which we call Physics-Based Management Optimization (PBMO), integrates physics-based groundwater flow and transport models, management science, and nonlinear optimization tools to provide stakeholders with practical, optimized well placement locations for remediating contaminated groundwater at complex sites. Results: The algorithm implementation, verification, and effectiveness testing was conducted using groundwater conditions at the Umatilla Chemical Depot in Umatilla, Oregon, as a case study. This site was the subject of a government-sponsored remedial optimization study. Our methodology identified the optimal solution 40 times faster than other methods, did not fail to perform when the physics-based models failed to converge, and did not require human intervention during the solution search, in contrast to the other methods. The integration of the PBMO and Lipschitz Global Optimization (LGO) methods with standalone physically based models provides an approach that is applicable to a wide range of hydrogeological flow and transport settings. Conclusions: The global optimization based solutions obtained from this study were similar to those found by others, providing method verification. Automation of the optimal search strategy combined with the reliability to overcome inherent difficulties of non-convergence when using physics models in optimization promotes its usefulness. The application of our methodology to the Umatilla case study site represents a rigorous testing of our optimization methodology for handling groundwater remediation problems. http://www.environmentalsystemsresearch.com/content/2/1/6 Larry Deschaine Theodore Lillys János Pintér Environmental Systems Research 2013, null:6 2013-05-04T00:00:00Z doi:10.1186/2193-2697-2-6 /content/figures/2193-2697-2-6-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 6 2013-05-04T00:00:00Z PDF Background: Environmental concerns have promoted the rise of low emissions “green” power technologies such as solar power. In part to make these technologies of economic interest to investors, many green energy policies have been proposed, and a wide variety of green energy developments have been launched which take advantage of these policies. This paper studies the impact of the unpredictable solar insolation on two variables of key interest to solar plant developers: the repayment time and the cash flow at risk. Results: Using a bootstrap analysis of solar irradiation time series, we model solar farms which sell their power output at a Feed-In Tariff (FIT) rate motivated by one used in the province of Ontario, Canada. We show that the feed-in tariff level which existed in Ontario in March 2012 was more than sufficient to remove the financial risks inherent in financing a solar PV plant. Conclusions: We conclude that the Ontario Canada FIT 2012 program was an effective tool to encourage investment in solar PV plants. We also find that repayment time is strongly sensitive to FIT rates. So FIT is a very efficient tool to impact/control the volume risk. http://www.environmentalsystemsresearch.com/content/2/1/5 Bin Lu Matt Davison Environmental Systems Research 2013, null:5 2013-03-04T00:00:00Z doi:10.1186/2193-2697-2-5 /content/figures/2193-2697-2-5-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 5 2013-03-04T00:00:00Z XML Background: Soil salinity is a critical environmental problem in many countries around the world especially the arid and semi-arid countries like South Africa. The problem has great impact on soil fertility which in turns has a great effect on soil productivity. This paper addresses the use of remote sensing and GIS in the assessment of salinity using Landsat enhanced thematic mapper plus (ETM+) data of the Vaal-Harts irrigation scheme acquired with other field data sets and a topographical map to show the spectral classes and salt-affected areas for the years under assessment (1991 to 2005). Results: The results of the study indicated that salinity problem exists and may get worse. The supervised classification maps show that most of the salinity problems are located along the entire scheme. The Normalized Difference Vegetation Index (NDVI) tends to be higher along the irrigation canals. A plot of NDVI values and temperature trend give a correlation of 67% this is an indication that temperature is a major factor in the build up of salinity in the study area. The low salinity class increased by 4, 8618 km2, while medium and high salinity classes decreased by 4,296.4 km2 and 485.4 km2, showing an increase in the salinity trend over the years. Conclusions: Considering the trend of salinity development in VHS, there is an urgent need for management program to be established in order to control the spread of the menace and therefore reclaim the damaged land in order to make the scheme more viable. http://www.environmentalsystemsresearch.com/content/2/1/4 George Ochieng Olumuyiwa Ojo Fredrick Otieno Beason Mwaka Environmental Systems Research 2013, null:4 2013-02-25T00:00:00Z doi:10.1186/2193-2697-2-4 /content/figures/2193-2697-2-4-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 4 2013-02-25T00:00:00Z XML Background: The management of the health of urban lake systems is often reactive and is instigated in response to poor aesthetic quality or physicochemical measurements, rather than from an overall assessment of ecosystem health. Interpreting physicochemical monitoring data in isolation is problematic for two main reasons: the suite of parameters that are monitored may be limited; and the contribution that any single parameter has towards water quality or health varies considerably depending on the nature of the system of interest. Extending monitoring programs to include flora and fauna results in a better dataset of ecosystem status, but also increases the complexity in interpreting whether the status is good or poor. Results: This paper details a process by which a large set of quantitative biological, physical, chemical and social indicators may be transformed into a simple, but informative, numerical index that represents the overall ecosystem health, while also identifying the likely source and scale of pressure for remedial management action. The flexibility of the proposed approach means that it can be readily adapted to other lake systems and environments, or even to include or exclude different indicators. A case study is presented in which the model is used to assess a comprehensive longitudinal dataset that resulted from monitoring a constructed urban lake in Southeast Queensland, Australia. Conclusions: The sensitivity analysis and case study indicate that the model identifies how changes in individual monitoring parameters result in changes in overall ecosystem health, and thus illustrates its potential as a lake management tool. http://www.environmentalsystemsresearch.com/content/2/1/3 Aaron Wiegand Christopher Walker Peter Duncan Anne Roiko Neil Tindale Environmental Systems Research 2013, null:3 2013-02-09T00:00:00Z doi:10.1186/2193-2697-2-3 /content/figures/2193-2697-2-3-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 3 2013-02-09T00:00:00Z XML Background: In this paper, the performances of different forecasting systems are compared using the daily maximum ozone levels across three locations in Kuwait. The two analytical tools used in this study to forecast daily maximum ozone levels are time series modeling and fuzzy modeling. The structure of the two proposed forecasting models are derived from basic principles, which include a combination of persistence and daily maximum air temperature as input variables. Results: The two proposed forecasting models /showed significant improvement compared to the pure persistence forecast, which is the model currently used to forecast ambient air pollution in Kuwait. The performance of the two models suggests that daily maximum temperature explains a large proportion of the variation in ozone daily maximum levels. Conclusions: This study concludes that fuzzy modeling is the most reliable forecasting system, with the lowest number of false positives among the different models. http://www.environmentalsystemsresearch.com/content/2/1/2 Eiman Al-Shammari Environmental Systems Research 2013, null:2 2013-02-01T00:00:00Z doi:10.1186/2193-2697-2-2 /content/figures/2193-2697-2-2-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 2 2013-02-01T00:00:00Z XML Background: This paper examines a serious issue - whether future generations of utility should be discounted. The issue is of vital importance because future generations will never have the opportunity to reveal their preference regarding the current resource allocation and yet this will ultimately affect their utility. This paper addresses with this issue in the context of the phenomenon of global warming that is crucially connected with the emission and accumulation of CO2. Results: The analysis focuses on how the social optimum is attained under the constraint of sustainability and reveals the following relationship between the optimal policies: not discounting utility in social planning corresponds to adopting the socially optimal carbon tax rate in a decentralized economy.We also prove that the optimal carbon tax regime satisfies time consistency, indicating that policy is Pareto efficient for every generation given the sustainability constraint. In addition, it is shown that the theory can be extended to apply to an infinite horizon.Finally, the second-best proportional carbon tax rates are calculated using available data. The result astonishingly reveals that even if we apply a social discount rate of 5 per cent to annum in the planning economy, it is still equivalent to levying 32 per cent proportional carbon tax rate. Conclusions: Considering the actual absorption capacity of oceans concerning CO2, we can never be too prudent in discounting the utility of future generations with regard global climate change. This fact indicates the need for urgent introduction of a proportional carbon tax. http://www.environmentalsystemsresearch.com/content/2/1/1 Masayuki Otaki Environmental Systems Research 2013, null:1 2013-01-16T00:00:00Z doi:10.1186/2193-2697-2-1 /content/figures/2193-2697-2-1-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 1 2013-01-16T00:00:00Z XML Background: The Graph Model for Conflict Resolution methodology is used to formally investigate the nuclear power dispute that took place in the Canadian province of Ontario in order to obtain strategic insights into its resolution. This flexible systems methodology is used to study the nuclear conflict at two key points in time, 2008 and 2010. Results: The results of the 2008 analysis show that the only decision makers involved in the conflict who hold real power are the Federal and Ontario governments, although at the beginning of the investigation other organizations had also been considered as participating decision makers. According to a strategic analysis carried out for the conflict as it existed in 2010, the equilibria or potential resolutions of the 2008 analysis are found to be transitional states leading to the 2010 resolution. Moreover, a negative attitude by the Federal Government can cause an outcome to occur that is not highly preferred by either the Federal Government or the province of Ontario. Conclusions: By closely following the decision makers’ actions, a detailed analysis of the nuclear dispute in Ontario is carried out. Stability, sensitivity, and attitude analyses are performed, and the results are closely correlated with what happened in reality. http://www.environmentalsystemsresearch.com/content/1/1/11 Motahareh Armin Keith Hipel Mitali De Environmental Systems Research 2012, null:11 2012-10-29T00:00:00Z doi:10.1186/2193-2697-1-11 /content/figures/2193-2697-1-11-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 11 2012-10-29T00:00:00Z XML Background: Air pollution represents non uniform trends particularly in dense urban areas which arises the necessity for pollution monitoring at finer resolution. Since recent advancements in electrochemical technology have made it feasible to deploy economical wireless sensor nodes for environmental monitoring, we present a bed of cost effective referential sensors which replace the role of traditional weather stations. The system is intended to target lower income nations like Pakistan, where air pollution monitoring and regulation is a crucial issue, not receiving appropriate attention. Results: The project is specifically designed to be cost effective, compact, energy efficient and possesses the ability to be deployed in large numbers to overcome the limitations of conventional static environment monitoring sites. We have developed a system which aims at increasing awareness to the average citizen and policy makers regarding the prevailing environmental conditions. We go on to investigate the feasibility, reliability and accuracy of the project when deployed in an urban setting. Here we provide a brief summary on the calibration techniques we employed to achieve accurate results, along with providing details on the future research and development with respect to the project. Conclusion: The model proposed, was used to pilot a venture in Lahore, Pakistan and is deployed successfully. http://www.environmentalsystemsresearch.com/content/1/1/10 Jahangir Ikram Hasanat Kazmi Amer Tahir Zonia Khan Rabi Javed Usama Masood Environmental Systems Research 2012, null:10 2012-10-05T00:00:00Z doi:10.1186/2193-2697-1-10 /content/figures/2193-2697-1-10-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 10 2012-10-05T00:00:00Z XML This paper presents guidelines and examples of good practice for the usage of climate model simulation results and some rationale for their application. These guidelines are relevant to climate modellers as well as to climate impact modellers and users of direct climate model output, e.g., for decision support. The topics covered here encompass general information on climate model data as well as recommendations for their use, interpretation, and presentation. This includes subjects such as definition of ‘climate projection’ versus ‘climate forecast’, recommendations for the application of scenarios, temporal and spatial resolution, reference periods, treatment of model biases and significance, treatment of different model generations, and optimal use of colour selection and scaling. Special attention is given to results from multiple simulations (ensembles), as evidence is mounting that there is a need to take ensemble results into account for decision making.The paper represents the view of an ongoing discussion of German federal and state environmental agencies in a semi-annual meeting series and aims at framing a set of minimum requirements and prerequisites for climate impact projects and decision support. Thus, the recommendations we give are under constant further development and we don’t claim completeness. However, since we frequently are asked to share out our discussion results to other user groups we herewith provide some well discussed topics and hope to improve on the communication between the climate modellers and the users of climate model results. http://www.environmentalsystemsresearch.com/content/1/1/9 Frank Kreienkamp Heike Hübener Carsten Linke Arne Spekat Environmental Systems Research 2012, null:9 2012-09-28T00:00:00Z doi:10.1186/2193-2697-1-9 /content/figures/2193-2697-1-9-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 9 2012-09-28T00:00:00Z XML Background: Entropy is a measure of uncertainty and dispersion. Goodness-of-test for the inverse Gaussian distribution is studied based on new entropy estimation using simple random sampling (SRS), ranked set sampling (RSS) and double ranked set sampling (DRSS) methods. The critical values of the new tests are obtained using Monte Carlo simulations. The power of the suggested tests based on several alternative hypotheses using SRS, RSS, and DRSS is presented. Results: The suggested tests based on RSS and DRSS are performed better than SRS. Also, it turns out that the DRSS is superior to the RSS for all cases considered in this study. Conclusion: Since the suggested goodness-of-fit tests for the inverse Gaussian distribution using DRSS are more efficient than that based on RSS, then one may consider them using multistage RSS. http://www.environmentalsystemsresearch.com/content/1/1/8 Amer Al-Omari Abdul Haq Environmental Systems Research 2012, null:8 2012-09-15T00:00:00Z doi:10.1186/2193-2697-1-8 /content/figures/2193-2697-1-8-toc.gif Environmental Systems Research 2193-2697 ${item.volume} 8 2012-09-15T00:00:00Z XML