Towards a national reference center for environmental information in The Netherlands: A review

For improvement of the accessibility and use of environmental information a prototype national reference center (CIMI) was constructed in the Netherlands in 1986. Target groups were identified on the basis of an analysis of the demand side. They were questioned about their needs in the field of environmental information. On the basis of these experiences an automated integrated system has been built that is composed of subsystems for reference to expertise in organizations (specialisms), literature, research, and databases of site-specific data. This system is also equipped with a thesaurus. The system has been tested and examined in several ways. The outcome of these independent tests and investigations confirm the usefulness of this center for information transfer. The reference center can be helpful in providing overviews on and structuring of environmental information in the Netherlands. The results of the activities have been presented in several ways and were described extensively in a number of reports.     

A Review of Waste Tyre Utilisation in the Marine Environment

Waste tyres pose a major disposal problem on land creating a fire hazard and, in warmer climates, providing breeding pools for mosquitoes. the void space in tyres makes them unsuitable for land burial. Schemes to use shredded tyres for road bases and asphalt filler are being pursued in the USA. Tyre combustion for electricity production is being investigated in the UK.

The widespread availability and durability of tyres has led to their use in the marine environment for breakwaters/coastal defence structures and as artificial reefs for promoting fisheries.

Tyres have a low density and have been used in floating breakwaters. Schemes have been proposed to protect and strengthen shorelines with tyre structures.

The void space in tyres facilitates the construction of artificial reefs to attract fish. the most intensive use is in the south west Pacific and Australia. Tyre surfaces are colonised by algae and a wide range of faunal species, including corals and shellfish. the wide acceptance of tyres as a suitable reef construction material appears to be based largely on these observations. Experience of initial poor deployment practices in the USA led to tyres washing ashore after storms and resulted in the banning or restriction of their use in coastal states of the USA. A review of the scientific literature has yielded limited information on the environmental impact of tyres and in particular the leaching of heavy metals and organic compounds from tyres into sea water.

Preliminary results of tyre dust/sea water leaching studies are presented. These identify zinc as the major leachate (totalling 10mg/tyre after 3 months). Diluted leachates have not shown significant effects of the growth of the phytoplankton Phaeodactylum and Isocrysis.

Further work to characterise the sea water leaching of tyre compounds is recommended.     

Information as a management tool: An evaluation of the Pemigewasset Wilderness management plan

The newly instituted management plan for the Pemigewasset Wilderness area of New Hampshire, USA, which relies principally on providing information to visitors, represents a departure from traditional plans. Logit analysis of survey data indicates limited evidence of the plan having much direct impact on visitor behavior. There is evidence of success in information dissemination to area users; however, the type of information that is being relayed to backcountry users does not appear to be that which the management plan is attempting to promote.     

DEVELOPMENT AND TESTING OF A SNOWMELT-RUNOFF FORECASTING TECHNIQUE1

ABSTRACT: The snowmelt-runoff model (SRM) was used to produce accurate simulations of streamfiow during the snowmelt period (April-September) for ten years on the Rio Grande Basin (3419 km²) near Del Norte, Colorado, U.S.A. In order to use SRM in the forecast situation, it was necessary to develop a family of snow cover depletion curves for each elevation zone based on accumulated snow water equivalent on April 1. Selection of an appropriate curve for a particular year from snow course measurements allows input of the daily snow cover extent to SRM for forecast purposes. Data from three years (1980, 1981, and 1985) were used as a quasi-forecast test of the procedure. In these years forecasted snow cover extent data were input to SRM, but observed temperature and precipitation data were used. The resulting six-month hydrographs were very similar to the hydrographs in the ten simulation years previously tested based on comparisons of performance evaluation criteria. Based on this result, the Soil Conservation Service (SCS) requested SRM forecasts for 1987 on the Rio Grande. Using the same procedure but with SCS estimated temperature and precipi-tation data, SRM produced a forecast hydrograph that had a r²= 0.82 and difference in seasonal volume of 4.4 percent. To approximate actual operational conditions, SRM computed daily flows were updated every seven days with measured flows. The resulting forecast hydrograph had a R²= 0.90 and a difference in volume of 3.5 percent. The method developed needs to be refined and tested on additional years and basins, but the approach appears to be applicable to operational runoff forecasting using remote sensing data.     

Ultrasound diagnostic features of twin reversed arterial perfusion sequence

Two cases of twin reversed arterial perfusion (TRAP) sequence with relevant ultrasound features that would help an accurate diagnosis are described. Available management options are proposed and discussed.     

Characterization of non-extractable residues of the fungicide dithianon in soil using 13C/14C-labelling techniques

The fate of the (14)C-labelled fungicide dithianon in soil is characterized by the formation of non-extractable, "bound" residues of approximately 63% of applied amount in 64 d. Humic acids containing these "bound" residues were isolated after conducting degradation studies of the active ingredient in an orthic luvisol under standardized conditions. In the same way, (13)C-labelled dithianon was incubated in an artificial soil which was produced by humification of (13)C-depleted straw in an incinerated soil. The "bound" residues of the (13)C-labelled dithianon in the humic acid fraction of the artificial soil were analyzed using (13)C-NMR techniques. There was no evidence of a covalent bonding of the residues to the humic substances. Results of polarity gradient high performance thin layer chromatography (AMD-HPTLC) of "bound" residues of the (14)C-labelled dithianon in the humic acid fraction indicate a sequestration process of metabolites into the humic substance as a possible binding mechanism.     

Impact of engine lubricant properties on regulated gaseous emissions of 2000-2001 model-year gasoline vehicles

The impact of the sulfur (S) content in lubricating oil was evaluated for four ultra-low-emission vehicles and two super-ultra-low-emission vehicles, all with low mileage. The S content in the lube oils ranged from 0.01 to 0.76%, while the S content of the gasoline was fixed at 0.2 ppmw. Vehicles were configured with aged catalysts and tested over the Federal Test Procedure, at idle and at 50-mph cruise conditions. In all testing modes, variations in the S level of the lubricant did not significantly affect the regulated gas-phase tailpipe emissions. In addition to the regulated gas-phase emissions, a key element of the research was measuring the engine-out sulfur dioxide (SO2) in near-real-time. This research used a new methodology based on a differential optical absorption spectrometer (DOAS) to measure SO2 from the lubricants used in this study. With the DOAS, the contribution of SO2 emissions for the highest-S lubricant was found to range from less than 1 to 6 ppm on a gasoline S equivalent basis over the range of vehicles and test cycles used. The development and operation of the DOAS is discussed in this paper.     

Experiments on gravity currents propagating on unbounded uniform slopes

Gravity currents propagating on \(12^\circ \), \(9^\circ \), \(6^\circ \), \(3^\circ \) unbounded uniform slopes and on an unbounded horizontal boundary are reported. Results show that there are two stages of the deceleration phase. In the early stage of the deceleration phase, the front location history follows \({(x_f+x_0)}^2 = {(K_I B)}^{1/2} (t+t_{I})\), where \((x_f+x_0)\) is the front location measured from the virtual origin, \(K_I\) an experimental constant, B the total buoyancy, t time and \(t_I\) the t-intercept. In the late stage of the deceleration phase for the gravity currents on \(12^\circ \), \(9^\circ \), \(6^\circ \) unbounded uniform slopes, the front location history follows \({(x_f+x_0)}^{8/3} = K_{VS} {{B}^{2/3} V^{2/9}_0 }{\nu }^{-1/3} ({t+t_{VS}})\), where \(K_{VS}\) is an experimental constant, \(V_0\) the initial volume of heavy fluid, \(\nu \) the kinematic viscosity and \(t_{VS}\) the t-intercept. In the late stage of the deceleration phase for the gravity currents on a \(3^\circ \) unbounded uniform slope and on an unbounded horizontal boundary, the front location history follows \({(x_f+x_0)}^{4} = K_{VM} {{B}^{2/3} V^{2/3}_0 }{\nu }^{-1/3} ({t+t_{VM}})\), where \(K_{VM}\) is an experimental constant and \(t_{VM}\) the t-intercept. Two qualitatively different flow morphologies are identified in the late stage of the deceleration phase. For the gravity currents on \(12^\circ \), \(9^\circ \), \(6^\circ \) unbounded uniform slopes, an ‘active’ head separates from the body of the current. For the gravity currents on a \(3^\circ \) unbounded uniform slope and on an unbounded horizontal boundary, the gravity currents maintain an integrated shape throughout the motion. Results indicate two possible routes to the final stage of the gravity currents on unbounded uniform slopes.