Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Estimation of the emission factors of PAHs by traffic with the model of atmospheric dispersion and deposition from heavy traffic road.

In order to consider the total atmospheric loadings of the PAHs (polycyclic aromatic hydrocarbons) from traffic activities, the emission factors of PAHs were estimated and from the obtained emission factors and vehicle transportation statistics, total atmospheric loadings were integrated and the loadings into the water body were estimated on a regional scale. The atmospheric concentration of PAHs was measured at the roadside of a road with heavy traffic in the Hiroshima area in Japan. The samplings were conducted in summer and winter. Atmospheric particulate matters (fine particle, 0.6-7 microm; coarse particle, over 7 microm) and their PAH concentration were measured. Also, four major emission sources (gasoline and diesel vehicle emissions, tire and asphalt debris) were assumed for vehicle transportation activities, the chemical mass balance method was applied and the source partitioning at the roadside was estimated. Furthermore, the dispersion of atmospheric particles from the vehicles was modelled and the emission factors of the sources were determined by the comparison to the chemical mass balance results. Based on emission factors derived from the modelling, an atmospheric dispersion model of nationwide scale (National Institute of Advanced Industrial Science and Technology - Atmospheric Dispersion Model for Exposure and Risk assessment) was applied, and the atmospheric concentration and loading to the ground were calculated for the Hiroshima Bay watershed area.     

Nutrient emissions from diffuse and point sources into the River Danube and its main tributaries for the period of 1998-2000--results and problems.

Nutrient emissions by point and diffuse sources were estimated for 388 sub-catchments of the Danube river basin for the period 1998-2000 by means of the Model MONERIS. For nitrogen total emissions of 684 kt/a N were estimated for the Danube basin. 80% of these emissions were caused by diffuse sources (mainly groundwater, urban areas and tile drainage). For phosphorus the emission was 57 kt/a P, with a contribution of diffuse sources to this sum of 58%. The comparison of calculated and observed loads shows that the mean deviation for the investigated sub-catchments of the Danube river basin is 20% for dissolved inorganic nitrogen and 34% for phosphorus. The spatial resolution of the emission calculations allows the identification of regional hot spots and the derivation of specific regional measures to reduce the emissions into the Danube and consequently into the Western Black Sea.     

Modelling non-structural best management practices--focus on reductions in stormwater pollution.

This paper describes a modelling approach for evaluating the efficiency of different non-structural best management practices for stormwater management. A scenario with a set of source reduction practices was simulated using the substance flow model SEWSYS for an urban catchment in the city of G?teborg, Sweden. The scenario is based on a hypothetical control program that includes prevention, education and regulations. The simulation shows relatively high reductions of copper and PAH, 77% and 50%, respectively. The reduction in copper is mainly due to less copper roof corrosion and brake wear, while reduced road wear has the greatest effect for PAH. An important result from this study is that the nonstructural BMPs applied did not give a sufficient reduction in pollution to meet the desirable environmental quality criteria. To meet these criteria, additional BMPs must be implemented, preferably a combination of both non-structural and structural measures.     

Ecological Problems of Thermal Power Plants

The main legislative documents in the field of environmental protection and ecological standards for newly developed equipment of thermal power plants (TTP) of Russia are presented. Problems of raising the efficiency TTP and reducing harmful emissions are considered. Modern methods and process for lowering nitrogen oxide emissions for different kinds of fuel, fields of application of sulfur-removing technologies, and ways for updating fly-ash collectors are discussed. The tendency to tightening of standards regulating the volume of contaminating substances is shown. Data on TTP wastewaters and maximum permissible concentrations (MPC) of primary contaminants are presented. Reduction of atmospheric emissions and of contaminating due TTP wastewaters is estimated until 2010.__________Translated from Elektricheskie Stantsii, No. 1, January 2005, pp. 17–27     

A Hydrologist's Plan to Combat the Greenhouse Effect

ABSTRACT

Some of the gases that industrial society routinely spews into the air by burning fossil fuel sami cooling our buildings are trapping heat in the earth's atmosphere and warming the planet. This is called the greenhouse effect. This decade has seen the four hottest years of the last century and the first five months of 1988 were the warmest on record. Since 1880, mean global temperatures have increased more than 0.78 Celsius degrees. James Hansen of NASA'S Goddard Institute for space studies declared that he is certain that the greenhouse effect is here and will continue to increase: however, this view is not shared by many atmospheric scientists who have not detected the greenhouse ‘signal’ in the global temperature data. Since 1958 concentrations of carbon dioxide in the atmosphere have increased 25 percent, mostly the result of burning oil and coal. North America. Western Europe, the U.S.S.R and Soviet-block countries are responrible for about 67 percent of the emissions. The level of carbon dioxide is increasing at the rate of about 29 billion tons per year.

After examining the concentration of carbon dioxide since 3.5 billion years ago and the global climatic changes of the past 18,000 years as compiled by COHMAP. it appears that carbon dioxide has always played a dominant role in controlling the climate of the globe. About 10,000 years B.P., the global climate was moist and cooler and the carbon dioxide level was between 260 and 290 ppm.

I suggest planting trees to remove excess carbon dioxide from the atmosphere. In order to do this we must capture 2.9 billion tons per year of carbon dioxide. A minimum area of 465 million hectares would be needed. We should grow trees in the desert areas of Western USA., where there is a huge quantity of water being discharged by evapotranspiration. Many large sedimentary basins have huge freshwater resources (i.e., Australia, India, Bangladesh, Nepal, China, Saudi Arabia, U.S.S.R. and North Africa), but little vegetation. It is proposed that we develop the water resources of these basins for agroforestry as has already been accomplished on a smaller scale for basins in Libya, Egypt, Saudi Arabia and North Kazakhstan, U.S.S.R. A number of fast growing trees are suggested for forestation that may be suitable for saline, and waterlogged areas stretching from Senegal to Bangladesh. These forests may reduce the global temperature, increase food production, and reclaim saline and waterlogged lands. It may eventually be possible to sequester the requisite 2.9 billion tons of carbon dioxide yearly as well as induce more rainfall and recharge the aquifers. According to Martin a further reduction of 1.8 billion tons of carbon dioxide may be possible by enhancing the growth of phytoplankton in southern oceans.     

Nährstoffbewirtschaftung im Donauraum

A pressing management question in the Danube river basin is how to reduce nutrient emissions so as to improve the status of the Danube and the Black Sea. This article describes the fundamentals and goals of nutrient management, presents the current level of nutrient load and input pathways, and offers insights into efforts to reduce nutrient emissions. With the help of the simulation model MONERIS we have been able to quantify the nutrient emissions from household and industrial wastewater, from atmospheric deposition and from agriculture, and to analyze the temporal and spatial effects of various management scenarios. Major investments have been and are being made in wastewater treatment plants in the Danube countries, and the EU-wide limit on the phosphate content in household detergents marks a major success. Through European environmental policy and the EU’s Common Agricultural Policy (CAP), efforts are being made to more quickly arrive at agricultural methods that are safer for our waters. At the same time, awareness campaigns and a “greening” of the CAP are already underway.     

Future increase in harmful algal blooms in the North Sea due to climate change.

In temperate seas such as the North Sea harmful (toxic) algal blooms will probably increase as a result of climate change. This conclusion was reached after investigating the projected effect of climate change for the year 2100 in Dutch coastal waters (4 degrees C temperature rise and increased water column stratification) on the growth rates of six harmful and two non-harmful phytoplankton species. Micro algae form the basis of the marine food chain. However, toxin-producing species may seriously disrupt the food web and lead to fish kills and human intoxication. Two species with estimated doubled growth rates in 2100, F. japonica and C. antiqua, entered Europe via ship's ballast water or shellfish imports. This stresses the need to legally regulate such invasion routes in order to prevent the import of novel species. Future toxic phytoplankton blooms may further devaluate ecosystem deliverables such as fish production or recreational use. This devaluation can be estimated by monetary value assessments that are needed in cost-benefit analyses for policy guidance. The lack of understanding of future climate, ecosystem functioning and its response to climate change calls for a scientific effort to improve our knowledge on present day coastal ecosystem functioning and its resilience.     

Turbidity Sources in Lake Superior

Landsat data and measurements of turbidity profiles with depth, suspended solids and particle sizes are used in analysis of red clay turbidityplumes in westernLakeSuperior for a variety of wind conditions. The measurements allow for an estimate of the relative contribution to lake turbidity arising from shore erosion, runoff, and bottom sediment resuspension. The major source of turbidity is due to erosion, yielding an estimated 2.3 × 10° metric tons of material removed per year from the shores of Douglas County, Wisconsin. This is equivalent to a shore recession rate of nearly 1.2 m/year.During the months of May through November when all three turbidity sources contribute, 70% of the total suspended load observed in the lake is due to shore erosion, 10% is due to precipitation runoff from the rivers (with major input in this category coming from the Nemadji River), and 20% of the load is due to resuspension.     

Methane and nitrous oxide measured throughout Lake Erie over all seasons indicate highest emissions from the eutrophic Western Basin

Eutrophication has been linked to increased greenhouse gas emissions from inland waters. Phytoplankton blooms in Lake Erie have increased since the 1990s, although its greenhouse gas emissions are not well characterized. We measured CH₄ and N₂O concentrations and diffusive fluxes in four seasons around the entire lake, and CO₂ fluxes in one summer season. Lake Erie is a source of CH₄ all year across the lake, concentrated in spring and summer in the Western Basin. Methane emissions ranged from 0.03 to 14.87 mg C m⁻² d^-1. Methane is predominantly biogenic, and natural gas leaks are an insignificant source. While Lake Erie is an overall N₂O source, it is an N₂O sink in winter and occasionally during summer. Emissions of N₂O ranged from −0.08 to 1.22 mg N m⁻² d^-1. We also measured CO₂ fluxes in summer only, when Lake Erie is a small atmospheric CO₂ sink. While areal fluxes of CH₄ and N₂O are similar to those observed elsewhere, total fluxes from Lake Erie are higher due to its surface area. Lake Erie emits ~ 6300 (±19%) metric tons of CH₄-C yr⁻¹ and ~600 (±37%) metric tons N₂O-N yr⁻¹: almost 500,000 metric tons CO₂-eq yr⁻¹ total. This is the first comprehensive dataset of CH₄ and N₂O concentrations and diffusive emissions in a very large lake. More measurements and monitoring are needed to determine whether increased eutrophication in the Great Lakes is tied to increased emissions of these powerful climate forcers in a possible positive feedback to climate warming.     

Water quality and quantity in Jordan's Dead Sea wadis

An evaluation of a potential water supply for the city of Amman, Jordan was conducted for five tributaries (wadis) to the Dead Sea. The total average discharge of approximately 0.85 m³/s (26.8 million cubic metres (MCM)/year) represents a significant quantity of water given the limited fresh-water supplies in the region. Although the raw water concentrations sometimes exceeded allowable concentrations for metals and pathogens, standard drinking water treatment associated with desalination facilities should alleviate most water quality concerns. The total construction cost is estimated to be between $85 and $95 million. Assuming a 15-year design life, this corresponds to a cost of $0.22/m³. This is feasible compared to alternative water supply options.     

风景区隧道施工粉尘对大气环境影响评价研究

为了评价风景区隧道施工粉尘对大气环境的影响程度，结合雪山梁隧道施工实际，采用现场测试的方式研究施工粉尘在隧道内的浓度及分布规律，并估算出隧道施工粉尘排放量和粉尘影响区域的大气环境容量，进而通过比较两者大小得出评价结论：雪山梁隧道施工对黄龙景区大气环境的影响十分有限。研究成果可为类似风景区隧道施工大气环境影响评价提供参考。     

On the Assessment of Atmospheric Deposition of Sulfur and Nitrogen Species to the Surface of Large Inland Lakes—Lake Champlain

Early work indicated that wet deposition of radioactive fallout to the water surface of a lake greatly exceeded dry, when calculated as annual averages. To test whether this result also applies to the deposition rates of soluble trace gases from the lower atmosphere, data collected at land sites near Lake Champlain have been used to estimate deposition rates to the lake itself, using an analysis of the wind speed-up factor as an intermediate step. The contribution of dry deposition of the major nitrogen and sulfur chemical species is estimated to have been less than 20% of the total atmospheric deposition. However, this result must not be extrapolated to the watershed in which Lake Champlain resides, since evidence obtained elsewhere indicates that the dry deposition contribution over the entire watershed will likely be similar to the wet. The analysis indicates that for the period from 1992 to 1997 the annual total deposition rates of oxidized nitrogen and sulfur ranged from 300 to 500 tonnes per year and 600 to 1,100 tonnes per year, respectively.     

Dynamics of PCBs in the Food Web of Lake Winnipeg

The bioaccumulation of polychlorinated biphenyls (PCBs) is examined in the food web of Lake Winnipeg using measured contaminant concentrations, stable isotopes of nitrogen, and a food web model. Measured concentrations of the sum of 103 PCB congeners are higher in south basin water, sediment, and biota compared with the north. The trophic positions of the top predators as well as the extent of biomagnification of PCBs per unit trophic level do not differ significantly between the north and the south basins. We therefore conclude that the higher PCB concentrations in the south basin are due primarily to higher PCB loadings via riverine sources to the south rather than food web processes. In contrast, the data from the north basin suggest lower total loadings of which a higher fraction is from atmospheric deposition. We find that rainbow smelt (Osmerus mordax) are not associated with elevated exposure of contaminants to top predators of the north basin. This surprising result is attributed to their reduced fitness in this relatively shallow and warm system, which may prevent them from feeding at an elevated trophic level compared with other forage fish. Finally, we hypothesize that high nutrient associated DOC in water decreases PCB bioavailability to lower trophic level organisms and hence the entire food web.     

化学需氧量、二氧化硫排污权价格测算

为了推行排污权交易,以排污权交易基本制度为依据,测算可交易COD、SO2削减成本及排污权价格的地区系数,确定排污权价格。以台州市为例测算COD、SO2排污权价格,结果分别为50 340.0元/t2、4 801.6元/t。     

How uncertain is model-based prediction of copper loads in stormwater runoff?

In this paper, we conduct a systematic analysis of the uncertainty related with estimating the total load of pollution (copper) from a separate stormwater drainage system, conditioned on a specific combination of input data, a dynamic conceptual pollutant accumulation-washout model and measurements (runoff volumes and pollutant masses). We use the generalized likelihood uncertainty estimation (GLUE) methodology and generate posterior parameter distributions that result in model outputs encompassing a significant number of the highly variable measurements. Given the applied pollution accumulation-washout model and a total of 57 measurements during one month, the total predicted copper masses can be predicted within a range of +/-50% of the median value. The message is that this relatively large uncertainty should be acknowledged in connection with posting statements about micropollutant loads as estimated from dynamic models, even when calibrated with on-site concentration data.     

Spatial Distribution of Total Cadmium,Copper, and Zinc in the Zebra Mussel (Dreissena polymorpha) Along the Upper St. Lawrence River

The zebra mussel (Dreissena polymorpha) was utilized to assess the spatial distribution of three trace metals, cadmium, copper, and zinc, in the upper St. Lawrence River and to test the hypothesis that outflow from Lake Ontario influenced levels of these metals in near-shore biota. Zebra mussels, collected from twelve sites along the southern shore, were analyzed for total cadmium, copper, and zinc in their soft tissues. Total cadmium and copper concentrations were elevated at all sites compared to relatively uncontaminated waters and were highest at sites near the outflow of Lake Ontario and an industrial area farthest downstream. Total zinc concentrations approached levels found at uncontaminated sites. Concentrations were rarely related to animal size at any site. However, body burdens (metal content per individual) showed strong positive relationships with size. To facilitate comparisons among sites, body burdens were calculated for standard length (2.0 cm) mussels. Highest body burdens occurred at the outflow of the lake and at one relatively uncontaminated site downstream. Lowest body burdens occurred at sites in the industrial area, although concentrations in the tissues were high. Expected total cadmium concentrations in tissues were estimated using a bio-energetic based kinetic model. Observed cadmium concentrations were lower than predicted, suggesting that near-shore areas may comprise significant depositional areas subject to enrichment with contaminants carried in the outflow from Lake Ontario. Long-term studies of inter-annual variability in metal concentrations, metal burdens, and growth rates should enhance the usefulness of D. polymorpha as a biomonitor and help in understanding the fate of trace metals in the upper St. Lawrence River.     

Modeling historical trends in Lake Superior total nitrogen concentrations

Nitrate concentrations in Lake Superior increased fivefold between 1900 and 1980, and have remained nearly constant since that time. Such rapid changes in concentration in a lake with a long hydraulic residence time (~ 190 years) are surprising. We developed a model to better understand the causes of the historical changes and to predict future changes in nitrate concentrations. Historical loadings were reconstructed based on average national NO_x emissions estimates, recent (past ~ 30 years) atmospheric N deposition data, recent tributary concentration data, and basin-wide runoff estimates. Increases in atmospheric N deposition alone were insufficient to have resulted in the observed trends. However, model runs combining increased atmospheric deposition with increased tributary N loading and/or decreased burial + denitrification mid-century reproduced the observed accumulation of N. Because internal N fluxes are an order of magnitude greater than external fluxes, relatively small changes in the lake's internal N cycle may produce relatively large changes in total N concentrations. Land-use changes in the watershed, particularly increases in logging activity, may have altered riverine N inputs. Regardless of the historical mechanisms leading to the rise in nitrate concentrations, it appears as though the system is currently at or is approaching peak N content.     

Trends and patterns of PCB,DDE, and mercury contamination in bald eagle nestlings in the upper Midwest

We analyzed concentrations and trends of DDE, total PCBs, and mercury in bald eagle (Haliaeetus leucocephalus) nestlings at six study areas in the upper Midwest, 2006–2015, and long-term trends at two Lake Superior sites, 1989–2015. Eaglet plasma from the Apostle Islands in Lake Superior had the highest concentrations of DDE (geometric mean [GM]?=?10.6?μg/L), and DDE concentrations decreased at 5.8% per year across the region from 2006 to 2015, and at 5.5% per year at Lake Superior sites from 1989 to 2015. Concentrations of the sum of 75 PCB congeners (ΣPCB₇₅) were highest at Pools 3 and 4 of the Mississippi River (GM?=?114.8?μg/L) and did not decline significantly region-wide (all study areas together) between the years of 2006 and 2011. However, at Lake Superior, ΣPCB₇₅ declined from 1995 to 2011 along the south shore at 3.6% per year, with a non-significant decline at the Apostle Islands. Concentrations of mercury in nestling breast feathers were highest at the upper St. Croix River (GM?=?6.66?μg/g wet weight). At Lake Superior study areas, mercury declined at 1.6% per year from 1991 to 2015; however, from 2006 to 2015 we found no significant trend at one of these same study areas and mercury concentrations apparently increased at two study areas. Mean concentrations of contaminants were below levels associated with significant impairment of reproduction at all sites and mean reproductive rates were?>?1.4 young per nest. However, increasing concentrations of mercury in some areas, combined with relatively high concentrations at some nests, suggest that continued monitoring of mercury should be a management priority.     

Assessing migratory bottlenecks and escapement of silver eel (Anguilla anguilla) in the highly urbanized North Sea Canal basin,the Netherlands

Habitat fragmentation and migration barriers have attributed to the decline of European eel (Anguilla anguilla). The migration of silver eels through pumping stations, ship locks, and migration facilities within the North Sea Canal basin using acoustic telemetry and overall escapement by mark–recapture was studied. A network of 61 acoustic receivers and three PIT-tag stations was built, and 305 silver eels were tagged with acoustic transmitters and 3923 with PIT-tags. Of all the silver eels that were detected, 55% passed barriers between the polders and the canal and 46% also passed the barrier complex at IJmuiden to sea, mainly via the ship locks. Overall, silver eel escapement to the North Sea per year averaged 81,629 silver eels and 14.3% suffered mortality in the pumping station at IJmuiden. Migration speed was lower for silver eels that initiated their migration upstream compared with silver eels further downstream, higher for silver eels passing barriers later in the migration period, and highest at sea. This study of silver eel movement and escapement in the North Sea canal basin indicated several bottlenecks. Passage success along barriers varied strongly between sites and types of barriers. While at two smaller locations, silver eels migrated through the pedal valves in the ship lock gates, a small passage facility and the pedal valves in a ship lock at complex IJmuiden did not enhance silver eel migration. The barriers and unnatural canal system caused additional delay during silver eel migrations. Mitigation measures for management could include installing fish-friendly pumps, using pumping stations only during the day, and in addition opening ship locks and pedal valves at the beginning of the night.