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161.
Robert C. Borden Philip B. Bedient 《Journal of the American Water Resources Association》1987,23(4):629-636
ABSTRACT: A three well injection-production test was performed at the United Creosoting Company (UCC) site in Conroe, Texas, to estimate the effective in situ retardation factors for adsorption and to evaluate the significance of biotransformation in limiting the transport of polycydic aromatics present in the shallow aquifer. The field test was also used as a model to determine if this type of testing would be feasible at other hazardous waste sites. During the test, chloride, a non-reactive tracer and two organic compounds, naphthalene and paradichlorobenzene (pDCB), were injected into a center well for 24 hours followed by clean ground water for six days. Ground water was continuously produced from two adjoining wells and monitored to observe the breakthrough of these compounds. Data from the test were analyzed by comparing the statistical moments of the chloride and organics distributions. Retardation factors for naphthalene and pDCB were estimated to be 1.03 and 0.97 by comparison of the statistical moments. A significant loss of naphthalene and pDCB was also observed during the three well test, apparently due to biotransformation. These results suggest that biotransformation is the major process limiting the transport of naphthalene and similar compounds at the UCC site. 相似文献
162.
J. Philip Burkhalter Timothy C. Martin Richard G. Allen Jeppe Kjaersgaard Erin Wilson Ray Alvarado Jason S. Polly 《Journal of the American Water Resources Association》2013,49(3):498-517
We compared two methods of estimating crop water consumption to assess whether remote sensing techniques provide consumptive use (CU) estimates commensurate with conventional methods. Using available historical satellite and meteorological data, we applied Mapping EvapoTranspiration at high Resolution using Internalized Calibration (METRIC) to 317,455 ha in the South Platte basin, in northeastern Colorado, for the 2001 irrigation season. We then compared these derived CU estimates with values calculated by using the Colorado Water Conservation Board's South Platte Decision Support System StateCU model. Evaluating the data by irrigation ditch service area, we disaggregated the output to allow for comparison by service area size, crop type, irrigation method, water supply source, and water availability. We concluded that METRIC is a suitable alternative to StateCU in the South Platte basin and could help to identify areas with inhibited crop growth or deficit irrigation practices. In addition, METRIC could be used as a complement to StateCU to refine StateCU model parameters, allowing for more accurate estimates of crop water shortages and groundwater recharge associated with irrigation delivery and application. 相似文献
163.
Thomas Merckx Ruth E. Feber Philip Riordan Martin C. Townsend Nigel A.D. Bourn Mark S. Parsons David W. Macdonald 《Agriculture, ecosystems & environment》2009,130(3-4):177-182
How best to optimize the biodiversity gain from agri-environment schemes (AES) has recently been identified as a key policy-relevant question. Here, the effects of two features of lowland agricultural landscapes on the abundance and diversity of larger moths are contrasted. Although both features bring about positive effects, hedgerow trees have a larger impact than 6 m wide grassy field margins. Whilst AES payments are given to create and maintain grass margins, no financial reward is currently offered for the retention of hedgerow trees. Furthermore, it was only in areas where the amount of land under AES was experimentally increased, by targeting farmers, that the presence of hedgerow trees resulted in a substantially higher abundance (+60%) and diversity (+38%) of moths. Thus, by using larger moths as bio-indicators of landscape-scale quality, it is demonstrated that improvements to the cost-effectiveness of AES could be achieved, firstly, by providing more appropriate financial rewards to farmers for different landscape features, and secondly, through landscape-scale targeting of farmers to encourage participation in AES. 相似文献
164.
The authors present the beginnings of a planning support system (PSS) for agri-environmental measures exemplified by a virtual implementation of Colorfields and blooming strips on model farms, based on real-world data. This paper starts with an introduction to the Colorfields, a concept for transdisciplinary and sustainable landscape design of set-aside land. Colorfields comprise of blooming strips of flowering annual or biennial plants, which are designed and drilled in pattern on fallow land creating Land Art. The temporary scenic arrangements of the Colorfields combine the advantages of ecological strips, e.g. providing habitats for insects (especially bees), improving soil fertility through the cultivation of intercrops, with improvements of the social recognition of farmers as producers of pleasant landscapes instead of monoculture fields.The prototype of the PSS uses two software tools of different scientific origin, the bio-economic modeling system MODAM and the landscape visualization system Lenné3D, which are linked based on geo-data. The resulting system helps to assess the economic effects and visualizes the effects of the specific landuse patterns under different scenarios.The economic assessment of blooming strips on arable land and of one Colorfield on fallow land shows that these measures prove to be profitable from an economic viewpoint assuming the current area payments for the obligatory European Union set-aside program. Furthermore, the visualizations enable the design to be tested virtually by exploring the resultant scenery. They provide artists, planners and stakeholders including farmers with a tool to virtually wander through landscape scenarios supporting a collaborative design and a shared vision for the community.The results of the two model farms and previous case studies for Colorfields demonstrate how current policy conditions could be used for the improvement of environmental and scenic qualities. Furthermore, the ability of the tools, MODAM and Lenné3D, suggests to support and promote these activities. 相似文献
165.
Crickets can autotomize a limb in order to evade predation; however, this autotomy compromises their escape speed and, therefore,
their ability to avoid subsequent predation events. We recorded two measures of predator-avoidance behaviour in field crickets
(Gryllus bimaculatus) exposed to varying levels of predation threat, with the most extreme level leading to autotomy of a limb. Our first measure
of caution was time to emergence from cover, which was affected by perceived predation treatment, with both autotomized males
and females being significantly more cautious than intact individuals. For males (but not females), the presence of a calling
conspecific encouraged earlier emergence. Our second measure of caution was alteration of male calling behaviour. Autotomized
males remained silent for significantly longer time after disturbance than intact males, but there was no difference in call
rate once they had resumed calling, suggesting that behavioural changes were not merely a result of injury response but a
controlled modification of behaviour as a result of autotomy. These data suggest that autotomy in field crickets results in
altered calling behaviour, which was not significantly altered with different acoustic environments. 相似文献
166.
Margaret Lumia Charles A. Gentile Philip Efthimion Mark Gregory Robson 《补救:环境净化治理成本、技术与工艺杂志》2008,18(2):115-130
This article summarizes a study that evaluated a new decontamination technique for the mitigation and abatement of hazardous dust and particulates. Traditional decontamination methods are time‐consuming, expensive, can create airborne hazards, and do not always bring the concentration of the contaminant to acceptable levels. The use of the removable thin film coating will increase efficiency, will not generate airborne hazards, will decrease costs, and, with one application, will bring the hazardous dust concentrations to acceptable levels. Qualitative tests demonstrated that the removable thin film coating reduced the amount of visible luminescent dust (a surrogate for hazardous dust) from various surfaces. It also indicated that wherever there were minute scratches, the coating did not remove all of the dust. However, the qualitative tests showed that this decontamination method worked well as a preventative method, protecting clean areas from becoming contaminated when exposed to the luminescent dust. Further investigation was conducted using a scanning electron microscope (SEM) and carbon dust. Overall, the SEM experiment demonstrated that there was a statistically significant (p = 0.00007) removal of carbon dust (less than 10 μm in size) from surfaces with crevasses larger than 3 μm. The SEM also revealed that there were some limitations where there were large clusters of carbon dust; in these instances, the coating would tear and remain on the sample surface. One method to resolve this limitation involved adding KevlarTM fibers to the removable thin film coating. It was thought that this would increase the strength of the coating and eliminate the coating from tearing when removing large clusters of a contaminant. Unfortunately, this did not alleviate the issue. The use of an engineered textile, saturated with the coating, appeared to eliminate the problem with the coating not being able to remove the contaminant from the minute surface scratches and improved the removal process of the coating. © 2008 Wiley Periodicals, Inc. 相似文献
167.
Citrullinaemia was presumed to be excluded in a fetus at risk by the direct assay of argininosuccinate synthetase in chorionic villi. The diagnosis was confirmed after amniocentesis by normal argininosuccinate synthetase activity in the cultured amniotic fluid cells and by a normal citrulline concentration in the amniotic fluid. The prediction of a normal fetus was confirmed at term by the birth of a non-citrullinaemic boy. 相似文献
168.
The eminent crisis threatening biological and resource diversity is a global adversity. Global resource diversities are constantly disappearing and deteriorating at quite an alarming proportion, provoking renewed thinking regarding the effectiveness of existing environmental management approaches and practices. For the past four decades, several epochs of environmental management policies and practices disregarded the cultural imperative for safeguarding efficient environmental management outcomes, particularly at the community level. Even in the rouse of this reality, issues of spirituality and how it binds local community people to their natural environment appear to be given only a window dressing attention through the recognition of sacred natural sites. Eight sacred groves and shrines in the Bongo District were investigated based on an endogenous development framework. The data were collected using focus group discussions with stakeholders at the local and district levels and individual interviews with key local natural resource managers from four selected communities. The study revealed that the way indigenous people construct the worldviews and interactions with nature using ancestors and other spirit mediums can safeguard the environment against long periods of human interference and destruction. It also demonstrates that in certain places traditional institutions are becoming malleable and open to the use of external knowledge and resources in order to sustain places of sacred significance. It concludes that cultural imperative and the issues of spirituality are critical for the sustainable management of environmental resources. The study recommends revisiting local practice and cultural values that promote good environmental management practices within the local communities. 相似文献
169.
This article discusses an integrated management system that aligns and integrates the various environmental, health, and safety functions and disciplines. This model is easily adopted to provide performance measures required to satisfy Responsible Care®, ISO 14001, and the European Union EMAS requirements. 相似文献
170.