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Environmental problems and production losses associated with irrigated agriculture, such as salinity, degradation of receiving waters, such as rivers, and deep percolation of saline water to aquifers, highlight water-quality concerns that require a paradigm shift in resource-management policy. New tools are needed to assist environmental managers in developing sustainable solutions to these problems, given the nonpoint source nature of salt loads to surface water and groundwater from irrigated agriculture. Equity issues arise in distributing responsibility and costs to the generators of this source of pollution. This paper describes an alternative approach to salt regulation and control using the concept of “Real-Time Water Quality management”. The approach relies on a continually updateable WARMF (Watershed Analysis Risk Management Framework) forecasting model to provide daily estimates of salt load assimilative capacity in the San Joaquin River and assessments of compliance with salinity concentration objectives at key monitoring sites on the river. The results of the study showed that the policy combination of well-crafted river salinity objectives by the regulator and the application of an easy-to use and maintain decision support tool by stakeholders have succeeded in minimizing water quality (salinity) exceedances over a 20-year study period.

The emission of inhalable particulates (PM10) from coal comminution processing is detrimental to the air quality. However, limited works have been carried out for the estimation of emission and dispersion of PM10 from coal crushers and its ancillary operations. In this study, field-based measurements and regulatory dispersion model coupled with Weather Research Forecasting (WRF) were applied to investigate the assimilative capacity (AC) of a region with operational coal crushers. The model run was found ‘acceptable’ when compared with measured values according to set performance criteria. Furthermore, the validated model parameterization was used to forecast the dispersion effects by various emission control alternatives recommended by regulators viz. covering of conveyor belts, paving of the unpaved road, reducing feed rate, etc. Results suggested that the major contribution of PM10 was from transportation and loading of coal after crushing, while PM10 levels from crushing dissipated in a smaller area. Paving of transport roads and bunker/silo-based loading were effective control measures as emissions reduced by 30.67%–52.51%. The relationship between distance and emission load revealed that PM10 concentrations below 100 μg/m3 were achieved at approximately 750 m away from emission sources in the present study. Crusher's operations with existing emissions of 23.43 g/day/m2 were detrimental for the region's AC and needed to be stepped down to 11.71 g/day/m2. In particular, using modeled meteorological data provided reasonable forecasts for allowable emissions and planning to site crusher operations. Correction to the low-wind conditions resulted in a better simulation of mean annual estimates than daily estimates of PM10. Such visualization of spatially explicit frameworks will guide policymakers in strengthening regulations.

Industrial and urban development, Population growth and settlement are common cause of increased pollution. Pollutants are in many instances discharged untreated to rivers due to lack of adequate treatment facilities and high treatment cost. This paper considers assimilative capacity as an important water quality index when the river point source pollution is controllable. The simulation of pollution transport in the river and calculation of assimilation capacity is based on the mathematical equations of pollution propagation with no turbulent flow. The proposed procedure for water quality protection is applied in a hypothetical case study and the obtained results are expressed. The results demonstrate that the river flow variation can modify the assimilation capacity up to 97%. [ABSTRACT FROM AUTHOR]

Environmental problems and production losses associated with irrigated agriculture, such as salinity, degradation of receiving waters, such as rivers, and deep percolation of saline water to aquifers, highlight water-quality concerns that require a paradigm shift in resource-management policy. New tools are needed to assist environmental managers in developing sustainable solutions to these problems, given the nonpoint source nature of salt loads to surface water and groundwater from irrigated agriculture. Equity issues arise in distributing responsibility and costs to the generators of this source of pollution. This paper describes an alternative approach to salt regulation and control using the concept of “Real-Time Water Quality management”. The approach relies on a continually updateable WARMF (Watershed Analysis Risk Management Framework) forecasting model to provide daily estimates of salt load assimilative capacity in the San Joaquin River and assessments of compliance with salinity concentration objectives at key monitoring sites on the river. The results of the study showed that the policy combination of well-crafted river salinity objectives by the regulator and the application of an easy-to use and maintain decision support tool by stakeholders have succeeded in minimizing water quality (salinity) exceedances over a 20-year study period.

One of the important problems of the environmental economics is the development of methodology for quantifying the assimilative capacity (AC) of a territory. The article analyzes the existing approaches to determining and assessing the AC of a territory. We justify the advantages of using the energy approach. The authors’ method consists in using the maximum permissible energy load (MPEL) for quantitative assessment of the AC of a territory. MPEL is a value that the ecological and economic system can withstand for a long time without changing its properties. We determine MPEL on the basis of data on the ability of various categories of land to absorb greenhouse gases (GHG), as well as the specific GHG emissions per ton of conventional fuel. Further, we compare the calculated value of MPEL in fuel equivalents with the actual consumption of fuel resources for the needs of the national economy. These values ratio can serve as a standard for measuring and balancing the environmental and economic system. The authors have validated the described method on the example of the Sverdlovsk region, which is characterized by a high level of man’s impact. Calculations show that the actual consumption of fossil fuels in the region exceeds MPEL. That indicates an imbalance in the ecological and economic system and may lead to further deterioration of the environmental quality in the region. The proposed methodological approach and calculations can be used when developing strategic planning documents for a territory, including its energy strategy

One of the most significant causes of poor water quality is the presence of pathogens. To reduce the cost of human exposure to microbial contamination, monitoring of Fecal Indicator Bacteria (FIB), as a surrogate for the presence of pathogens in natural waters, has become the norm. A total maximum daily load (TMDL) framework is used to establish limits for microbial concentrations in impaired waterbodies. In order to meet microbial loads determined by the TMDLs, reductions in microbial sources varying from 50% to almost complete elimination are required. Such targets are fairly difficult, if not impossible, to achieve. A natural attenuation (NA) framework is proposed that takes into account the connectivity between freshwater streams and their receiving coastal estuaries. The framework accounts for destructive and non-destructive mechanisms and defines three regimes: NA 1 - reaction-dilution mixing at the freshwater-tidal interface, NA 2 - advection-reactions within the tidally influenced coastal stream, and NA 3 - dilution-discharge at the interface with the estuary. The framework was illustrated using the Houston Metropolitan area freshwater streams, their discharge into the Houston Ship Channel (HSC) and into Galveston Bay. FIB concentrations in Galveston Bay were much lower when compared to FIB concentrations in Houston streams. Lower enterococci concentrations in tributary tidal waters were found compared to their counterparts in fresh waters (NA1 regime). Additionally, 70% reduction in FIB loads within the HSC was demonstrated as well as a decreasing trend in enterococci geometric means, from upstream to downstream, on the order of 0.092 day−1 (NA2 regime). Lower enterococci concentrations in Galveston Bay at the confluence with the HSC were also demonstrated (NA3 regime). Statistical testing showed that dilution, tide-associated processes, and salinity are the most important NA mechanisms and indicated the significant effect of ambient temperature and rainfall patterns on FIB concentrations and the NA mechanisms. Natural attenuation regimes for freshwater-coastal-estuarine systems allow linkages between components and their pathogen concentrations and load interactions and lead to more achievable reduction targets. Unlabelled Image • Proposes a flow dependent natural attenuation framework for pathogens in estuaries: freshwater-coastal, coastal stream, and coastal-estuary • Lines of evidence developed for each regime with associated reductions in indicator bacteria • Proposed framework provides linkages between natural water system components and total maximum daily loads (TMDLs) • Results indicate more achievable source reduction targets are likely using natural attenuation [ABSTRACT FROM AUTHOR]

Abstract Water quality of river Ramganga, a major tributary of the Ganga, was monitored by monthly sampling at selected 23 stations (17 on the main stem and 6 on tributaries) during two calendar years 2014 and 2015 for 24 parameters. Cluster analysis grouped the sites in three statistically significant clusters, highly polluted, moderately polluted and less polluted, based on the similarities or differences in water quality parameter values. Discriminant Analysis helped in identifying the most representative discriminant parameters in entire dataset with more than 86% correct assignment in both temporal and spatial analysis. Despite high organic load in the middle stretch of Ramganga, the observed dissolved oxygen values were higher than 4 mg/l at almost all sampling stations on the main stem, even in lean flow period of a year. About 16–49% BOD load reduction from various point sources was estimated to maintain the desired dissolved oxygen levels (5–6 mg/l) for aquatic species during lean flow season in river Ramganga. This implies that primary treatment alone of discharge from these sources is sufficient from the point of view of sustenance of indigenous aquatic flora and fauna. Comparison of water quality of Ramganga and Ganga (before and after the confluence with Ganga) for lean flow season revealed that Ramganga does not significantly contribute to the decline in water quality of river Ganga in terms of parameters such as dissolved oxygen and heavy metals. Highlights • Discriminant analysis identified 6 parameters with more than 86% correct assignment. • Observed DO values were found higher than 4 mg/l at all sampling stations on main stem. • Reduction of 31%, 30%, and 49% BOD loads to maintain DO values more than 6 mg/l. • Dhela and Kosi are the most polluted tributaries of Ramganga. • Ramganga does not significantly contribute to the decline in water quality of Ganga. [ABSTRACT FROM AUTHOR]

Most formal optimal pollution control models in environmental economics assume a constant natural assimilative capacity, despite the biophysical evidence on feedback effects that can degrade this environmental function, as is the case with the reduction of ocean carbon sinks in the context of climate change. The few models that do consider this degradation establish a bijective relation between the pollution stock and the assimilative capacity, thus ignoring the inertia mechanism at stake. Indeed the level of assimilative capacity is not solely determined by the current pollution stock but also by the history of this stock and by the length of time the ecosystem remains above the degradation threshold. We propose an inertia assessment tool that tests the sustainability of any benchmark optimal pollution path when the inertia of the assimilative capacity degradation process is taken into account. Our simulations show a strong sensitivity to both the inertia degradation speed and the discount rate, thus stressing the need for increased monitoring of natural assimilative capacity in environmental policies. [ABSTRACT FROM AUTHOR]

The phosphorus and nitrogen loads on Lake Onego, including individual components of the nutrients from different sources, were estimated from the data on the chemical composition and the water volume of the sources that form the hydrochemical regime of Lake Onego, and from the data on the volumes of commercial trout farming in the lake catchment. Natural and anthropogenic load on the lake was determined, and the latter was compared to the lake’s assimilative capacity. Nutrient load estimates based on observed data are in good agreement with the results of mathematical modeling carried out at the Institute of Limnology RAS by means of the ILLM model.

All maritime states have the challenge of maintaining the environmental quality of their seas while at the same time maximising their economic potential thus requiring appropriate science, governance and management measures. In Europe, directives and regulations are used to address the pressures affecting the health and sustainability of marine resources, and to promote Good Environmental Status (GES) (e.g. the Marine Strategy Framework Directive, MSFD), while having a coherent and integrated pattern of sea use (e.g. the Maritime Spatial Planning Directive, MSPD). Therefore, an approach is required to meet these challenges for all maritime states including, for Europe, the joint adoption of these two directives. As such an approach does not yet exist, one is proposed here based on a hypothetical example and a Best Expert Judgement (BEJ) methodology. Forty-two marine science, management and impact assessment specialists provided views on a hypothetical marine scenario to derive and interrogate a framework applicable to marine areas with multiple uses and users. The scenario allowed the severity of the activity effects-footprints to be determined on the 11 MSFD Descriptors of GES with that severity being weighted according to the area of each activity effect-footprint. In turn, this allowed the calculation of marine regional environmental status thereby indicating whether the adoption of quality assessment and spatial planning can be mutually beneficial, or are antagonistic in meeting environmental targets. This paper uses the proposed approach to discuss maximising the assimilative capacity of a marine area and minimising the environmental degradation due to new activities. It especially shows the role of BEJ in cases where marine adaptive management is still required despite their being an often paucity of information or data on which to base management decisions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seagrass treat waste through assimilating nitrogen, often discharged by land-based sources. • Using a replacement cost model, treatment can be valued demonstrating a previously unaccounted benefit to society. • Seagrass waste treatment has been valued at $729 – $1784 per hectare per year. • When seagrass is lost, the waste treatment value is also lost. • Realization of this value can only come with sustainable use, promoting seagrass conservation. Seagrass inhabit a large proportion of the world's coastal waters, but these waters are used as a sink for vast loads of nitrogen pollution from many sources. Seagrass assimilate nitrogen, an essential nutrient, for growth, some is stored in sinks, while a proportion is transformed and lost from the system. When anthropogenic nitrogen is discharged into coastal waters, seagrass (and other vegetated coastal ecosystems) will assimilate nitrogen and treat wastes providing a critical ecosystem service. However, nutrient over enrichment will result in degradation and eventually loss of seagrass habitats and loss of services. The monetary value of the waste treatment ecosystem service provided by Posidonia seagrass has been valued using Adelaide, South Australia as a case study site. Posidonia leaf nitrogen content was used to estimate the nitrogen assimilation capacity across the Adelaide coastal waters, a highly oligotrophic system. By establishing a Posidonia baseline measured nutrient requirement for the region, coupled with estimates of nitrogen retention and export, the study demonstrates that nitrogen assimilation above the baseline, can be considered waste treatment ecosystem service. This waste treatment has been valued with a replacement cost model using monetary values determined from nitrogen reduction technology from wastewater treatment plants, stormwater and industry. The Posidonia seagrass along Adelaide's coast has the potential waste treatment value of $729 – 1784 per hectare per year for Posidonia seagrass depending on three different treatment scenarios tested. Importantly, this work shows that when seagrass area or density declines, the waste treatment value also declines. This method of calculating waste treatment service for seagrass can be applied for seagrass meadows throughout the world, but consideration of waste treatment needs to be closely coupled to a long term and comprehensive monitoring program to ensure that any discharges are sustainable for the seagrass meadows and do not result in irreversible impacts to biodiversity, ecosystem services and value to society. [ABSTRACT FROM AUTHOR]

The article presents the assessment of assimilative capacity of the license area “North Caspian area” in relation to petroleum products and polycyclic aromatic hydrocarbons, implemented using the new "synoptic" method.

A key methodological challenge in understanding the relationship between the economy and the underlying ecosystem base resides in how to account for the ecosystem's degradation and the decline of associated ecosystem services. In this study, we use information on nutrients and metals concentrations from the Environmental Change Network (ECN) database and the Scottish Environment Protection Agency (SEPA) for the period 2000-2010 in order to assess the assimilation capacity of water systems. The research covers five upstream sites and 17 downstream sites in northeast Scotland. Our results highlight the relevance of considering a number of pollutants, and suggest that elements such as arsenic, lead and mercury can pose a threat to ecosystems' sustainability and health. However, little research has been done in terms of their assimilation capacity and their impact on grey water footprint assessments. In addition, the results indicate that background conditions might be relevant when performing sustainability analysis at different spatial scales. The study also poses relevant questions in relation to land management approaches versus traditional 'end-of-pipe' water treatment approaches, and the definition of maximum and background concentrations. In this regard, further studies will be required to understand the trade-offs between different ecosystem services depending on how these concentrations are defined. [ABSTRACT FROM AUTHOR]

This study addresses water quality conditions across several distinct hydrologic regimes in the Upper Taylor Slough (UTS) region of Everglades National Park and briefly considers implications for long-term water quality management. Due to upstream changes in water delivery and construction of a detention area, Taylor Slough has experienced a significant change in hydrology over a 27-year period, progressing from direct discharge at varying amounts to sheet flow via groundwater conditions. Cumulative flow and rainfall relationships at the inflow and outflow of UTS demonstrate distinct break points. These changes in water delivery and subsequent upstream water management have resulted in a change in water quality conditions within the UTS region. Since 1986, total phosphorus (TP) flow-weighted mean concentrations exiting UTS have significantly decreased from 10 µg/L in the late 1980s to 4 µg/L or less since 2010. Based on analysis of surface water ion ratios, saltwater intrusion is unlikely and rather hyporheic exchange could be occurring between the inflow and outflow of the UTS region. Based on the analysis of existing water quality data, the UTS region is a resilient oligotrophic wetland system retaining strong assimilation capacity in the face of major management changes. While TP concentrations remain extremely low, restoration is not complete for Taylor Slough and adjacent coastal basins will inevitably bring additional nutrient loading. Management of the Slough should recognize this and consider what water quality condition is best for long-term sustainability of Taylor Slough's ecology. [ABSTRACT FROM AUTHOR]

A Bayesian hierarchical modeling approach is introduced to pool data properly from multiple flow-through wetlands to estimate wetland-specific long-term phosphorus retention capacity. By pooling data from multiple wetlands, we overcome the difficulties in estimating the effectiveness of using constructed and natural wetlands for nutrient reduction. The Bayesian hierarchical modeling approach reduces estimation uncertainty by shrinking wetland-specific estimates towards the overall average of the same quantity from multiple wetlands, facilitating information sharing across sites, thereby reducing the demand on sample sizes from individual wetlands and avoiding several common pitfalls of using large data (i.e., from multiple systems) induced by Simpson's paradox. In this paper, we develop a sequential updating framework to alleviate the computational burden of compiling and modeling data from multiple wetlands. We then demonstrate the sequential updating process to estimate retention capacity of a suite of wetlands in Ohio, USA. A total of four wetlands, representing both natural and constructed wetlands, were used. The estimated total phosphorus retention capacities range less than 0.01 to well over 1 ton per year per system. As wetland restoration initiatives expand around the Laurentian Great Lakes and nationally, this model serves as an important initial step in developing tools to meet nutrient reduction goals and standards. Extending this work, we have developed a publicly accessible on-line open computation platform that can help natural resource specialists better plan for wetland efficacy in the future. [ABSTRACT FROM AUTHOR]

Assimilative capacities of sulfur dioxide (SO2) and oxides of nitrogen (NOx) in the largest petrochemical industrial complex in Thailand were evaluated in this study. AERMOD dispersion model was simulated to compute for ground level concentrations and spatial distributions of SO2 and nitrogen dioxide (NO2) within a radius of 5 km from Maptaphut industrial area. Emission input consisted of 419 stacks which total amount of 2,071.82 and 2,163.66 g/s of SO2 and NOx were used as baseline emissions. Maximum hourly average and annual concentrations predicted at 8 ambient air quality monitoring stations in the study domain were used to evaluate an assimilative capacity of these pollutants. Emissions of SO2 and NOx were adjusted to the limit that predicted concentrations will not exceed their ambient air quality standards. Results indicated that in order to achieve both hourly and annual standards, NOx emissions must be reduced by at least 40% from its baseline value. As for SO2, emissions can be increased up to about 130% from current level. Results of this study indicated that an existing regulation in controlling individual emission source by using emission standard is insufficient. Analysis of air pollution as area-based approach by taking into consideration entire emission sources can support for better planning and management of pollution. [ABSTRACT FROM AUTHOR]

Ezra Mishan's (1967) famous articulation of the costs of economic growth included amongst others the rearrangement and loss of nature. This paper builds on this theme by recourse to two important concepts in science, namely the assimilative capacity of nature and the entropy of law of thermodynamics. These concepts enable the formulation of an alternative conceptual framework for the explanation of national income ( Y) in terms of factor-utilization. In this framework, environmental capital (KN) is an explicit factor besides manufactured capital (KM) and labor ( L). A simple methodology that permits the estimation of the volume of KN utilized is used towards demonstrating that economic growth is an entropic process. Empirical illustration of KN utilization as point-estimates is made for Australia and South Korea. [ABSTRACT FROM AUTHOR]

Seeking critical assets is known to be a key motivation for emerging economy firms to make acquisitions in foreign markets, especially those in developed economies. In this study, we probe this motivation further by identifying two categories of asset-seeking acquisitions: resource deepening and resource extension. Using a sample of 1004 cross-border acquisitions conducted by Indian firms during the period 2000-2010, we find support for the hypothesis that the type of resources sought and their intended utility impacts acquisition performance. Additionally, for resource extension acquisitions, we find that acquisition performance outcomes vary by the assimilative capacity of the firm and the extent of experience in acquisitions at the firm and business group level. [ABSTRACT FROM AUTHOR]

The mathematical physics underlying the adsorption and subsequent desorption of dissolved oxygen (DO) in a water body subject to effluent loading had been rarely investigated. The current state of play in this field although reflects use of different analysis, the combine use of hat matrix and bootstrapping techniques to study the phenomenon of chemical adsorption and desorption of DO at molecular level in a polluted waterbody has not been thoroughly investigated. This study seeks to use a matrix projector, H-hat (Ĥ), to cast virtual spectral rays on pollutant loadings in a water body and in the process unravel the dynamics of chemical and biological gravitation of dissolved oxygen towards constituents of effluent pollutants in water body. This approach is anchored on the ordinary least squares methodology of multivariate linear regression. The method hypothecated is studded by a mathematical physics analysis of the phenomenon. Bootstrapping was used to establish means and variances of regression parameters, and subsequently, the confidence intervals of point estimates of parameters. Tricking technique adopted facilitated the development of extreme values of the dissolved oxygen and hence the supremum and infimum of assimilative capacity of the river which fluctuates with intensity of effluent loadings and season of the year (rainy, dry, and harmattan seasons). The result of bootstrapping revealed that assimilative capacity fluctuated widely from the values detected by point estimates of regression parameters thus suggesting that tricking of regression parameters, in turn, tunes up the regression model, and hence, fine tunes the value of assimilative capacity through necessary adjustments of model parameters. The results of this study obviates the need to deploy eudiometer for laborious direct measurement of dissolved oxygen in a body of polluted water. Thus an elegant technique for crossing the stream where it is shallowest has been developed in this study. The method is considered as a great improvement on previous approaches that seem to dawdle. [ABSTRACT FROM AUTHOR]

The assimilative capacity of a water body requires knowledge of the river characteristics, pattern of effluent loading, river hydraulic resilience and far-Held mixing to effectively determine it, hence it is considered appropriate that diverse models and approaches are utilized in its determination". This study evaluated the assimilative capacity of Ikpoba River using different approaches namely: homogeneous differential equation, ANOVA/Duncan Multiple rage test, Grst and second order differential equations, correlation analysis, Eigen values and eigenvectors, multiple linear regression, bootstrapping and far-Geld mixing Analytics. In the rainy, dry, and harmattan seasons the values of assimilative capacity for Guinness, Ewa road and UBTH point sources of effluent discharge are as follows: 1.07 × 1010kg/day, 1.07 × 1010 kg/day and 129 × 1010 kg/day; 8.1 × 109 kg/day, 9.07 × 109 kg/day and 1.05 × 1010 kg/day; 1.28 × 1010 kg/day, 1.03 × 109 kg/day and 1.95 × 1010 kg/day in that order. It was also discovered that by model tricking assimilative capacity had a range of values that varied from 231.09 mg/l upper limit to -222.27 mg/l lower limit at 95%significance level and beyond this range, the model developed will breakdown, and its robustness weakened by poor predictive capacity. The upper control limit for each of the various pollutants considered indicates die saturated value of the dissolved oxygen (DO), and the negative lower control limits depict dissolved oxygen debt whereby the DO falls below critical (anoxia) to harsh critical level. At this level any reaeration or reoxygenation effort is not practically palpable until recovery is made up to critical level. The eclectic approaches adopted have crossed the stream where it is shallowest. [ABSTRACT FROM AUTHOR]