Gastropod communities, vegetation dynamics and landscape changes along an old-field succession in Provence, France

Studies about the relationships between land snail communities and landscape are scarce. The abandonment of many cultivated lands in Provence since the end of the last century gives us the opportunity of an analysis of the organisation pattern of gastropod communities in relation to the recent history and the present day structure of a Mediterranean landscape. The dynamics of a 40 ha landscape, mapped on a raster mode, was studied using cadaster data for seven periods between 1890 and 1990. These data were computed using MCA and PCA. Both floristic and malacological relevés were made at a scale of one grid cell. At the stand level, the patterns of gastropod communities are strongly correlated with the vegetation structure and composition. At the landscape level, the analysis of gastropod communities permits a very good perception of the present day landscape structure, as well as insight into the recent landscape history. However, even if the fits obtained are good, they should be improved in order to take into account scale dependences of snail communities.     

山地城市土地集约利用与开发策略——以遵义市为例

我国山地城市分布广泛,普遍面临着用地紧张的问题。本文以遵义市为例,以遥感,GIS为技术平台,综合高程、坡度、坡向、地形起伏度、河流水系、植被覆盖等6要素,进行城市建设适宜性评价,得到城市建设用地的最大潜力及空间分布,重点提出综合功能选择、组团空间布局、循序开发时序等山地利用策略,为我国其他山地城市的规划与建设提供参考。     

Choctaw Eco-Industrial Park: an ecological approach to industrial land-use planning and design

This project investigates the concepts of industrial ecology and eco-industrial parks and applies those concepts to the redesign of an existing industrial park in Choctaw, OK. The opportunity for developing an eco-industrial park on this site comes from the availability of waste water for non-potable water needs, and the abundance of waste tires as raw materials for products to drive a new set of industrial partnerships. These industrial partnerships include the City of Choctaw Waste Water Treatment Plant, a tire shredding company, a tire pyrolysis company, a hydroponics industry, a hard rubber tire manufacturer, a screen printer, a plastics manufacturer, a toner manufacturer, and a toner cartridge manufacturer. The nature of this relationship and the design of the eco-industrial park is contained within this report. The result of this investigation is a new, common sense, approach to industrial land use that combines economic growth and environmental protection.     

Evaluating environmental impact of STPs situated on streams in the Czech Republic: an integrated approach to biomonitoring the aquatic environment

Sewage water treatment plants (STPs) are frequently associated with the release of xenobiotics and, consequently, with biological responses of fish to these substances. The impact of three STPs situated on small streams was assessed in 2009. Brown trout (Salmo trutta fario L.), captured upstream and downstream of these STPs, were used as biomonitors. The concentrations of 39 organic pollutants (PCBs, OCPs, PBDEs, HBCDs, and MCs), and the biological responses related to oxidative stress (lipid peroxidation and carbonyl protein), and antioxidant responses (superoxide dismutase, glutathione peroxidase and glutathione reductase) were measured. Through chemometrics of these parameters, three groups with 97.62% of the total accumulated variance were distinguished. Integration of the assessed biomarkers using the IBR index, ranked environment impact on sites as: DS Pacov > DS Prachatice > DS Brloh > US Pacov > US Prachatice > US Brloh (most to least affected). STPs are a major source of xenobiotic pollution in streams of the Czech Republic. The combined use of chemical analysis and biological responses is necessary to validate the efficacy of a battery of biomarkers chosen to detect environmental stress due to pollution.     

Life-cycle assessment and repair of the railway transition zones of an existing bridge using geocomposite materials

The railway infrastructure is a very important component of the world’s total transportation network. Investment in its construction and maintenance is therefore significant on a global scale. Up to now, some results of the life-cycle assessment (LCA) of open railway line, as well as railway bridges and tunnels, have been published, but detailed analyses of transition zones have not so far been performed. In railway networks, transitional zones are a critical area where the transition from open rail to solid bridge construction can cause significant settlements. The goal of these analyses was to compare two different types of track renewal methods for railway transition zones. In the first method, traditional cement stabilisation is used, whereas the second solution makes use of a geocomposite anchored by steel anchors. The paper presents some results from an environmental study for railway transition zones based on the demonstration case. The results of the performed LCA showed that, in the case of track renewal for transition zones by means of a geocomposite and anchors, the environmental impact is lower than in the case when cement stabilisation works are performed. Less extensive excavation works and thus lower quantities of used material are additional benefits.     

Promoting cooperation in construction projects: an integrated approach of contractual incentive and trust

Contractual incentive and trust are two commonly used governance mechanisms that help to promote inter-organizational cooperation. Little is known, however, about the boundary conditions for the complementation of these two governance mechanisms. The aim is to investigate the interaction of contractual incentive and trust in promoting inter-organizational cooperation. A three-staged Stackelberg model was established and then solved by backward induction. Research results indicate that contractual incentive can motivate the contractor’s task behaviours, while the effect of trust on relational behaviours is path-dependent. Three levels of factors (intra-organizational, inter-organizational and project factors) would affect the selection of the optimal incentive coefficient. Moreover, when the changing rate of the client’s cost of effort is less than or equal to a threshold, contractual incentive and trust can be complementary. The study contributes to theory by offering nuanced insights into the governance mechanisms and addressing the complex contracting issues when mutual trust exists. In addition, this study can help to create favourable circumstances for the complementation between contractual incentive and trust, achieving a better project outcome and relational benefit.     

Explaining lake and catchment change using sediment derived and written histories: an Australian perspective

Palaeolimnological records can be powerfully combined with documentary data to explain the impact of modern industry and agriculture on lake systems and their catchments. Such an approach is highly appropriate in Australia since modern society was imposed on a continent until recently populated solely by hunter-gatherers and because there is a wealth of historical data to draw upon. Confounding factors such as the influence of climate change, depopulation of the indigenous community and non-linear responses to human impact must be considered in analysis of the relative importance of various land use changes upon lake pollution.     

Overhanging rock slope by design: An integrated approach using rock mass strength characterisation,large-scale numerical modelling and limit equilibrium methods

Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.     

Cost assessment and ecological effectiveness of nutrient reduction options for mitigating Phaeocystis colony blooms in the Southern North Sea: an integrated modeling approach

Nutrient reduction measures have been already taken by wealthier countries to decrease nutrient loads to coastal waters, in most cases however, prior to having properly assessed their ecological effectiveness and their economic costs. In this paper we describe an original integrated impact assessment methodology to estimate the direct cost and the ecological performance of realistic nutrient reduction options to be applied in the Southern North Sea watershed to decrease eutrophication, visible as Phaeocystis blooms and foam deposits on the beaches. The mathematical tool couples the idealized biogeochemical GIS-based model of the river system (SENEQUE-RIVERSTRAHLER) implemented in the Eastern Channel/Southern North Sea watershed to the biogeochemical MIRO model describing Phaeocystis blooms in the marine domain. Model simulations explore how nutrient reduction options regarding diffuse and/or point sources in the watershed would affect the Phaeocystis colony spreading in the coastal area. The reference and prospective simulations are performed for the year 2000 characterized by mean meteorological conditions, and nutrient reduction scenarios include and compare upgrading of wastewater treatment plants and changes in agricultural practices including an idealized shift towards organic farming. A direct cost assessment is performed for each realistic nutrient reduction scenario. Further the reduction obtained for Phaeocystis blooms is assessed by comparison with ecological indicators (bloom magnitude and duration) and the cost for reducing foam events on the beaches is estimated. Uncertainty brought by the added effect of meteorological conditions (rainfall) on coastal eutrophication is discussed. It is concluded that the reduction obtained by implementing realistic environmental measures on the short-term is costly and insufficient to restore well-balanced nutrient conditions in the coastal area while the replacement of conventional agriculture by organic farming might be an option to consider in the nearby future.     

Performing a microfiltration integrated with photocatalysis using an Ag-TiO2/HAP/Al2O3 composite membrane for water treatment: Evaluating effectiveness for humic acid removal and anti-fouling properties

Membrane filtration has been increasingly used for water treatment and wastewater reclamation in recent years. To further improve the effectiveness of membrane process and reduce membrane fouling, a highly reactive photocatalytic membrane, Ag-TiO₂/hydroxiapiate (HAP, Ca₁₀(PO₄)₆(OH)₂)/Al₂O₃, was employed to realize microfiltration (MF) coupling photocatalysis for surface water treatment. The effectiveness on the potential of membrane was investigated by removing humic acid (HA) test under different feed total organic carbon (TOC), light intensity and transmembrane pressure (TMP). The HA removal and anti-fouling property of as-prepared membrane was improved under UV irradiation, likely due to photocatalytic degradation of foulants along with filtration simultaneously. Under given feed water composition, increasing the light intensity resulted in increased removal of HA from aqueous solution. However, a limiting TMP seems to exist beyond which the increased HA removal cannot be sustained. Fouling behavior analysis indicated that the transition in fouling mode from initial pore blocking to cake filtration occurred much slower as UV irradiated. Furthermore, a superior efficiency on removal of trace organic contaminants, as well as milder flux reduction, was presented from surface water treatment, which demonstrated that the integrated system with enhanced performance is foreseen as an emerging technique for water treatment.     

Quantification of stormwater runoff using a combined GIS and curve number approach: a case study for an urban watershed in the Ozark Highlands,USA

Managing stormwater runoff is crucial to preserving water quality in rapidly developing urban watersheds. The objective of this study was to develop a methodology to test existing stormwater drainage infrastructure, identify potential areas of improvement, and estimate potentially contaminated runoff by combining two widely used stormwater runoff prediction models. A watershed containing much of the University of Arkansas-Fayetteville campus was targeted for this study because stormwater from this watershed drains into a local river designated as an impaired water body due to siltation. The curve number method was used to estimate runoff for various flood-return periods and antecedent moisture conditions, while a flow-direction model integrated topography, land use, and stormwater drainage infrastructure in a GIS. The methodology developed and results generated will help stormwater planners visualise localised runoff and potentially adapt existing drainage networks to accommodate runoff, prevent flooding and erosion, and improve the stormwater quality entering nearby surfacewater bodies.     

Evaluating short-term changes in recreational water quality during a hydrograph event using a combination of microbial tracers, environmental microbiology, microbial source tracking and hydrological techniques: A case study in Southwest Wales, UK

Quantitative assessment of multiple sources to short-term variations in recreational water quality, as indexed by faecal indicator organism (FIO) concentrations, is becoming increasingly important with adoption of modern water quality standards and catchment-based water quality management requirements (e.g. the EU Water Framework Directive, Article 11 ‘Programmes of Measures’ and the US Clean Water Act, ‘Total Maximum Daily Loads’). This paper describes a study combining microbial tracers, intensive FIO measurement, open channel hydrology and molecular microbial source tracking (MST) to enhance understanding of recreational water quality at Amroth in southwest Wales, UK. Microbial tracers were released from four stream inputs during a moderate hydrograph event. Tracers from two local streams impacted simultaneously with a period of maximum FIO concentrations at the near-shore compliance monitoring site. Connection between these inputs and this site were rapid (9-33 min). Water quality impairment from a more remote stream input followed, 12.85 h after tracer release, sustaining FIO concentrations above desired compliance levels. MST analysis showed dominance of ruminant Bacteroidales genetic markers, associated with agricultural pollution. This integration of tracers and MST offers additional information on the movement and individual sources causing water quality impairment.