A Sensitivity Analysis of an Integrated Modelling Approach to Assess the Risk of Wind-borne Spread of Foot-and-mouth Disease Virus from Infected Premises

The sensitivity of an integrated model to assess the potential for wind-borne spread of foot-and-mouth disease (FMD) to variations in key parameters controlling different physical and biological processes was evaluated. The estimated number of farms at risk is sensitive to the virus strain used and the accompanying effective contact rate. The C Noville strain increased the estimated number of exposed farms ranked as high and medium risk of being infected by a factor of 5, compared to the baseline, based on the O UKG 2001 strain. The inclusion of a model for biological ageing of the virus can also have a significant effect on the concentration patterns arising from transport and dispersion of the virus. Its inclusion has the practical advantage of markedly reducing the time required for the calculations. The estimated number of farms affected by exposure to high and medium virus concentrations is not grossly sensitive to attenuation caused by temperature or relative humidity effects. Changes in susceptibility to infection, as determined by the parameter θ in the exposure-risk model, does not change the configuration of the virus plumes, but it does change the distribution of farms at risk by risk category. These findings suggest that a good understanding of characteristics (excretion rates from infected animals, susceptibility of different species to infection, virus survival, etc.) of the virus strain involved in an FMD outbreak is necessary to provide a reliable assessment of the risk of wind-borne spread. In the event of an incursion of FMD, provision for laboratory studies on the virus will be an essential component of the disease response and should be factored into contingency plans.

Assessing national livestock populations for the production of methane emission inventories

In an effort to accurately assess national methane (CH₄) production levels, many African countries are producing inventories of their national livestock populations. Conducting accurate livestock surveys is an expensive and time-consuming process, but is necessary because the most readily available data on livestock production are often incomplete or unsatisfactory. This paper looks at practical approaches to collecting data on livestock production and on the reproductive parameters for livestock, with special reference to African pastoralist populations, and makes qualified recommendations as to how inventory teams might be able to produce more accurate assessments of their total livestock populations. The methodology used during Nigeria's National Livestock Census (1990–92) serves as a basis for a discussion of the issues.     

Development and Application of Computer Simulation Tools for Ecological Risk Assessment

Based on a review of available models for ecological risk estimation, most are site-specific and their applications are limited. However, general models, which can be easily adapted to other sites, remain few, in addition, they are simple and associated with significant uncertainties. In this paper, an approach is introduced for an ecological risk assessment (ERA) model that can be modified for site-specific conditions. Using computer simulation as a screening tool for ecological risk assessment can assist environmental managers and policy decision-makers in the planning and implementation of potentially highly focused assessments and remediation, should the ERA dictate the need. The model was integrated with a Windows-based interface and interactive database management system (DBMS) as a user-friendly software package. In addition, based on trophic sources, a food web has been integrated into the framework of the DBMS. In an effort to evaluate the model, a case study was implemented to characterize the effects on an ecosystem of replacing electroplated chromium coatings with sputtered tantalum at U.S. Army Yuma and Aberdeen Proving Grounds. Potential exposure pathways included ingestion, inhalation, and dermal absorption for terrestrial animals; root and foliar uptake for plants; and direct absorption for aquatic species. Overall, results showed that the most significant exposure resulted from molybdenum and hexavalent chromium, which posed higher risks to select aquatic and terrestrial species at both sites. On the other hand, tantalum (with vanadium as the surrogate) resulted in the least risk to all receptors within the studied areas. A sensitivity analysis demonstrated that soil-water distribution coefficients have a significant impact on the results. Based on the results, neither molybdenum nor chromium are recommended as a coating in gun barrels, and further study would be essential to address any affected firing range area. Tantalum is recommended for use, although for those species receiving a slight adverse risk, field investigations that include receptor sampling maybe necessary once soil/sediment and water sampling validates projected concentrations.     

GIS and multiple-criteria evaluation for the optimisation of tsetse fly eradication programmes

Tsetse flies are the vectors of trypanosomes, the causal agent of trypanosomiasis, a widespread disease of livestock and people in Africa. Control of tsetse may open vast areas of land to livestock-keeping, with the associated benefits of developing mixed crop-livestock production systems. However, as well as possible positive impacts there are also risks: bush clearing would accelerate and cattle numbers would rise, leading to a reduction of vegetation cover, and an increase in runoff and erosion; there may also be increased pressure on conserved areas and reductions in biodiversity. The objective of this study is to show how remotely sensed and other environmental data can be combined in a decision support system to help inform tsetse control programmes in a manner that could be used to limit possible detrimental effects of tsetse control. For Zambia, a methodology is developed that combines a tree-based decision-support approach with the use of Multiple-Criteria Evaluation (MCE), within a Geographical Information System (GIS), in order to target areas for tsetse control. The results show clear differentiation of priority areas under a series of hypothetical scenarios, and some areas (e.g. northwest of Petauke in the Eastern Province of Zambia) are consistently flagged as high priority for control. It is also demonstrated that priority areas do not comprise isolated tsetse populations, meaning that disease control using an integrated approach is likely to be more economically viable than local eradication.     

A Note on the Use of Conservation Practices in U.S. Agriculture

This article measures the effect of an increase in productivityattributable to an increase in soil organic carbon associated with theincrease in the use of conservation practices in agriculture in theUnited States. Both the direct and indirect effects are calibrated. Theanalytical approach used consists of a dynamic computable generalequilibrium model composed of 14 producing sectors, 10 consumingsectors, seven household categories classified by income, and agovernment. The results suggest that the impact of a change inproductivity is an increase in output over a six year period starting in1998 in field crops. The most significant impact is felt in thelivestock sector. This is because field crops are a major input in theproduction of livestock. The food processing sector also exhibits arelatively large increase because of the increase in inputs of both fieldcrops and livestock. Manufacturing output increases primarily becauseoverall investment rises and most investment utilizes manufacturinggoods. The other producing sectors are generally unaffected by theincrease in agricultural production due to an increase in soil organiccarbon. Coincident with the increase in the production of field cropsis a relatively large decrease in the price of field crops. Othernoticeable price reductions occur in the livestock sector and the foodprocessing sector. For the consuming sectors, the consumption offood and alcohol and tobacco increase but consumption in all of theother sectors remains basically unchanged. Prices in the food andalcohol and tobacco sectors decline by about 1% while theprices in the other sectors remain static. Household welfare increasesin the aggregate by only 0.1% with this increase occurringuniformly across all household categories. Revenue received by thegovernment increases a modest 2% in response to an increase inoutput and, hence, an increase in taxes paid. The results indicate thatthere are significant production benefits for several sectors that can berealized by an increase in the use of conservation practices inagricultural production which, in turn, enhances soil organic carbon.There are a number of policy options available to promote the use ofconservation practices. These include education and technicalassistance, financial assistance, research and development, landretirement, and regulation and taxes.     

Modelling Environmental Risk Using the Upper Partial Moment: a Safety-First Approach

The objective of the paper is to model economic-environmental trade-offs using a safety-first approach. The novelty of the approach is in the use of the empirically estimated flexible production risk and environmental risk functions that create a clear link between the source of the pollution, the production risk due to input use and the environmental outcome. Simulated production data and an environmental indicator were used to estimate a production function and environmental response function for every production year. The response functions were incorporated into an upper partial moment model, which ensures compliance to the user-specified environmental goal by enforcing the environmental constraint. Production decisions are significantly impacted by the presence of an environmental constraint due to the substantial compliance costs. Any changes in the intensive and extensive margin made by risk-averse decision-makers impact the size of the compliance cost faced by producers. The presence of an environmental constraint impact production decisions significantly with substantial compliance costs. While, fertiliser application technique have very little effect on the size of compliance costs. The greatest difference in compliance cost is therefore due to changes in the use of fixed resources.     

遗传神经网络在累积性环境风险评价中的应用

以太湖流域常州段为研究对象，构建了累积性水环境风险评价指标体系，利用主成分分析法选取输入变量，并应用MATLAB建立遗传神经网络综合评价模型。运用遗传算法对BP神经网络的权值和阈值进行优化，将遗传算法全局搜索能力和BP算法局部搜索能力相结合，提高了收敛速度和精度。应用模型对2004—2009年常州市累积性水环境风险进行了综合评价，结果表明：2004—2009年风险综合指数总体上处在中级与高级之间，累积性水环境风险较大；2008—2009年风险综合指数不断增大，趋于低级；农业和畜禽养殖业等面源风险源、污水处理和风险管理投资等控制机制以及人口和环境敏感目标等风险受体是造成太湖流域常州段累积性水环境风险较大的主要原因。     

A GIS-based approach for the long-term prediction of human health risks at contaminated sites

A Health Index/Risk Evaluation Tool (HIRET) has been developed for the integration of risk assessment and spatial planning using GIS capabilities. The method is meant to assist decision makers and site owners in the evaluation of potential human health risk with respect to land use. Human health risk defined as the potential adverse effects on human life or health is generally accepted as the most important aspect for site assessment and planning of remediation strategies. It concerns polluted sites that endanger human health on one hand and derelict land that does not cause the immediate risk on the other hand. In current state-of-the-art risk-assessment, long-term spatial and temporal changes of risks, in relation to changes in contamination patterns and land use functions, are not taken into account. The aim of this paper is to demonstrate the methodology developed for human health risk assessment in aspect of spatial and temporal domain. HIRET was developed as an extension for ESRI software ArcView 3.2 and allows performing dynamic human health risk assessment in long-term period, which is relevant for land use planning. The paper illustrates how such methodology can assist in environmental decision-making to enhance the efficiency of contaminated land management. A case study of contaminated site is given showing how data can be used within a GIS framework to produce maps indicating areas of potential human health risk.     

Renewable energy from gasification of manure: an innovative technology in search of fertile policy

After describing an innovative technology, the close-coupled gasification and cyclonic combustor, this article explores the policy issues that inhibit a superior sustainable solution fromflourishing. Discussion of technology includes defining biomass,explaining what biomass to energy means, what the advantages of biomass to energy are, and why gasification is a superior biomassto energy technology. Specifically the environmental benefits ofalternatives to landspreading of traditional manure management arediscussed, as well as the advantages of gasification versus traditional combustion techniques for high nitrogen fuels. The policy environment is explored, particularly regarding sustainability, manure management, and renewable energy. Artificial, non-sustainable barriers to renewable energy, and the impact of wide jurisdictional variability are discussed. North Carolina is identified as a unique jurisdiction to monitor because of its high volume of livestock manure, and laggard position in renewable energy advocacy. The authors contend that these two positions are unsustainable, and that pressures can beexpected to force the state to modify its renewable energy policies or risk losing market share in livestock production tomore pro-sustainable policy oriented states.     

新冠疫情期间无锡市环境空气质量分析

通过对无锡市区环境空气污染物的连续监测,对新冠疫情期间环境空气质量进行研究分析。结果表明,2月疫情期间,无锡市环境空气质量同比与环比均有明显好转,AQI指数在24~80,均为优良天。这可能与全社会生产、生活、活动有极大变动有关,可指导空气污染防治工作的努力方向。从单项指标看,除O₃以外的其他5项指标均有不同程度的好转。这可能与O₃的产生、消除机理不同,也可能与疫情期间大量消毒产品的使用有关,这值得我们下一步深入探讨。     

A GIS tool to estimate West Nile virus risk based on a degree-day model

West Nile virus (Flaviviridae: Flavivirus) is a serious infectious disease that recently spread across the North America continent. A spatial analysis tool was developed on the ArcMap 9.x platform to estimate potential West Nile virus activity using a spatially explicit degree-day model. The model identifies when the virus Extrinsic Incubation Period (EIP) is completed within the vector longevity during mid-summer months. The EIP is treated as a threshold indicator of the potential for virus emergence and activity. Comparing the number of West Nile virus cases in Wyoming reported from 2003 to 2005 with model results, actual cases and predicted events of West Nile virus activity match relatively well. The model represents a useful method for estimating potential West Nile virus activity in a large spatial scale.     

Assessing health consequences in an environmental impact assessment: The case of Amsterdam Airport Schiphol

In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside.     

A thematic review of life cycle assessment (LCA) applied to pig production

Commercial livestock production is known to have significant impacts on the environment. Pig production is a complex system which involves the production of animal feed, transportation, animal rearing and waste management. One tool for assessing the environmental performance of such complex systems is life cycle assessment (LCA). LCA has been applied to pig production considerably to date. This paper provides a chronological review of state-of-the-art pig production LCAs under three themes: feed production; entire-system livestock rearing; and waste management. The study considers how LCA applications have addressed technological improvements in animal husbandry, and highlights methodological limitations, particularly related to cross-study comparisons. Recent research demonstrates crude protein reduction in feed and anaerobic treatment of pig excreta resulting in bioenergy production are the key targets for environmental performance improvements related to pig production.     

Monitoring sediment oxygen demand for assessment of dissolved oxygen distribution in river

Sediment oxygen demand (SOD) has become an integral part of modeling dissolved oxygen (DO) within surface water bodies. Because very few data on SOD are available, it is common for modeler to take SOD values from literature for use within DO models. SOD is such an important parameter in modeling DO that this approach may lead to erroneous results. This paper reported on developing an approach for monitoring sediment oxygen demand conducted with undisturbed sediment core samples, where the measured results were incorporated into a water quality model for simulating and assessing dissolved oxygen distribution in the Xindian River of northern Taiwan. The measured results indicate that a higher freshwater discharge results in a lower SOD. Throughout a 1-year observation in 2004, the measured SOD ranged from 0.367 to 1.246 g/m(2)/day at the temperature of 20°C. The mean values of the measured SOD at each station were adopted in a vertical two-dimensional water quality model to simulate the DO distribution along the Xindian River. The simulating results accurately depict the field-measured DO distribution during the low and high flow conditions. Model sensitivity analyses were also conducted with increasing and decreasing SOD values for the low and high flow conditions and revealed that SOD had a significant impact on the DO distribution along the Xindian River. The present work combined with field measurements and numerical simulation should assist in river water quality management.     

Accumulation of ammonia and other potentially noxious gases on live export shipments from Australia to the Middle East

Noxious gases on ships are irritant pollutants that have potential impacts on the comfort and health of both livestock and humans. Identification of environmental influences on the pollutants will assist live exporters to control them. Ammonia, hydrogen sulphide and carbon dioxide, as well as wet and dry bulb temperature, dew point, air speed and depth of faeces that the sheep stood in, were measured on two ship voyages in which sheep were transported from Australia to the Middle East. Daily measurements were made at 20 measurement locations over 12 days. At four sites, the mean ammonia concentration for the voyage was above the recommended maximum limit for the live export industry (25 ppm). The mean ammonia concentrations at the remaining 16 sites were below 18 ppm and considered safe. High ammonia concentrations were localised and occurred particularly on closed decks, as well as at the front of the vessel and near the engine block on open decks. Ammonia concentration on the open decks was correlated with cumulative wind during the voyage, air speed, dew point, wet bulb temperature and faecal pad depth, and on the closed decks with dew point, and wet and dry bulb temperature. Hydrogen sulphide (<1.8 ppm) and carbon dioxide (<1900 ppm) concentrations were low and did not pose a risk to animal or human welfare or health. The results suggest that high ammonia concentrations occur in those parts of the ship where there is insufficient ventilation and/or high temperatures and humidity.     

Tailoring a non-path-dependent model for environmental risk management and polycentric urban land-use planning

This study attempts to develop a non-path-dependent model for environmental risk management and polycentric urban land-use planning in Gorgan Township area, Iran. Applying three suitability layers of environmental risk (soil erosion, flood risk, fire risk, and land susceptibility), urbanization potential, and integrated surface (environmental risk plus urbanization potential layers), a non-path-dependent Cellular Automata-Markov Chain (CA-MC) model was configured to execute three scenarios of polycentric urban growth allocation. Specifically, the modeling approach improved the traditional functionality of the CA-MC model from a prediction algorithm into an innovative land allocation tool. Besides, due to its flexibility, the non-path-dependent model was able to explicitly include different characteristics of the landscape structure ranging from physical land attributes to landscape functions and processes (natural hazards). Accordingly, three polycentric urban growth allocation efforts were undertaken and compared in terms of connectivity and compactness of the resultant patterns and consumption of other land resources. Based on results, the polycentric allocation procedure based on integrated suitability layer produced a more manageable pattern of urban landscape, while the growth option based on environmental risk layer was more successful for protecting farmlands against excessive urbanization. This study suggests that polycentric urban land-use planning under the strategy of rural land development programs is an available option for designing an urban landscape with lower exposure to natural hazards and more economic benefits to rural residents. Finally, the non-path-dependent modeling is a recommended approach, when highly flexible and interactive decision-support systems as well as trend-breaking scenarios are desired.     

A simple method to identify areas of environmental risk due to manure application

The management of swine manure is becoming an important environmental issue in Chile. One option for the final disposal of manure is to use it as a biofertilizer, but this practice could impact the surrounding environment. To assess the potential environmental impacts of the use of swine manure as a biofertilizer, we propose a method to identify zones of environmental risk through indices. The method considers two processes: nutrient runoff and solute leaching, and uses available information about soils, crops and management practices (irrigation, fertilization, and rotation). We applied the method to qualitatively assess the environmental risk associated with the use of swine manure as a biofertilizer in an 8,000-pig farm located in Central Chile. Results showed that the farm has a moderate environmental risk, but some specific locations have high environmental risks, especially those associated with impacts on areas surrounding water resources. This information could assist the definition of better farm-level management practices, as well as the preservation of riparian vegetation acting as buffer strips. The main advantage of our approach is that it combines qualitative and quantitative information, including particular situations or field features based on expert knowledge. The method is flexible, simple, and can be easily extended or adapted to other processes.     

Study on phosphorus loadings in ten natural and agricultural watersheds in subtropical region of China

Water eutrophication in subtropical regions of southern China threatens watershed health and is of major concern. However, annual phosphorus (P) loading and its dominant causes are still unclear, especially at the watershed scale. In this study, we investigated dynamic P loadings and associated factors (e.g., land use, livestock production, and runoff depth) in ten watersheds that varied in area from 9 to 5,212 ha in a hilly area of Hunan Province, China. A flowmeter was installed at the outlet of each watershed, and total P (TP) and soluble P (SP) concentrations were monitored periodically from June 2010 to October 2012. The results showed that annual P loadings (APLs) in the ten watersheds ranged from 22.8 to 247.8 kg P/km² and that P loss primarily occurred from April to June of each year during the main rainfall season in the study area. In addition, the average eutrophication (>0.05 mg P/L) ratio for stream waters was 86.7 % during the study period, which was indicative of a potentially serious condition for the local water environments. Annual P loadings were linearly related to livestock density (LD; R?=?0.92, p?<?0.01), whereas the eutrophication ratio of stream water was significantly (p?<?0.05) correlated with LD (R?=?0.61), percentage cropland (R?=?0.71), and percentage forest cover (R?=??0.68). Thus, it is concluded that the control of livestock production has the greatest potential for reducing P loadings in watersheds in this subtropical area. This will be beneficial to the amelioration and protection of local environment.     

Combinatorial optimization of elk habitat effectiveness and timber harvest volume

Forest resource planning processes in the western United States have been placing an increasing emphasis on wildlife and fish habitat goals. With this in mind, we developed a method that incorporates a Habitat Effectiveness Index (HEI) for Roosevelt elk (Cervus elaphus roosevelti) into the objective function of a mathematical forest planning model. In addition, a commodity production goal is proposed (maximum timber production), and the habitat and commodity production goals are allowed to act as goals in a multi-objective goal programming planning problem. A heuristic programming technique (tabu search) is used to develop feasible solutions to the resulting non-linear, integer programming problem. Using a hypothetical example, we illustrate results of five scenarios, where the emphasis of the achievement of one or both goals is altered. The main contribution of this approach is the ability to measure and evaluate the trade-offs among achieving a certain level of a complex wildlife goal and achieving commodity production goals. These trade-offs are measured using a flexible model, allowing planners to formulate non-linear spatial goals as objectives of a problem, rather than forcing them to rely on posterior evaluations of the suitability of management plans to goals such as elk HEI.