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791.
Lukas Löschner Mathew Herrnegger Benjamin Apperl Tobias Senoner Walter Seher Hans Peter Nachtnebel 《Regional Environmental Change》2017,17(2):311-322
This paper analyses the influence of climate change and land development on future flood risk for selected Austrian flood-prone municipalities. As part of an anticipatory micro-scale risk assessment we simulated four different inundation scenarios for current and future 100- and 300-year floods (which included a climate change allowance), developed scenarios of future settlement growth in floodplains and evaluated changes in flood damage potentials and flood risk until the year 2030. Findings show that both climate change and settlement development significantly increase future levels of flood risk. However, the respective impacts vary strongly across the different cases. The analysis indicates that local conditions, such as the topography of the floodplain, the spatial allocation of vulnerable land uses or the type of land development (e.g. residential, commercial or industrial) in the floodplain are the key determinants of the respective effects of climate change and land development on future levels of flood risk. The case study analysis highlights the general need for a more comprehensive consideration of the local determinants of flood risk in order to increase the effectiveness of an adaptive management of flood risk dynamics. 相似文献
792.
Keith E. Schilling Calvin F. Walter 《Journal of the American Water Resources Association》2005,41(6):1333-1346
Nineteen variables, including precipitation, soils and geology, land use, and basin morphologic characteristics, were evaluated to develop Iowa regression models to predict total streamflow (Q), base flow (Qb), storm flow (Qs) and base flow percentage (%Qb) in gauged and ungauged watersheds in the state. Discharge records from a set of 33 watersheds across the state for the 1980 to 2000 period were separated into Qb and Qs. Multiple linear regression found that 75.5 percent of long term average Q was explained by rainfall, sand content, and row crop percentage variables, whereas 88.5 percent of Qb was explained by these three variables plus permeability and floodplain area variables. Qs was explained by average rainfall and %Qb was a function of row crop percentage, permeability, and basin slope variables. Regional regression models developed for long term average Q and Qb were adapted to annual rainfall and showed good correlation between measured and predicted values. Combining the regression model for Q with an estimate of mean annual nitrate concentration, a map of potential nitrate loads in the state was produced. Results from this study have important implications for understanding geomorphic and land use controls on streamflow and base flow in Iowa watersheds and similar agriculture dominated watersheds in the glaciated Midwest. 相似文献
793.
Joanna M. T. Krajewski Amy C. Schumacher Kajsa E. Dalrymple 《Environmental Communication: A Journal of Nature and Culture》2019,13(2):255-275
Water is essential for human life, yet safe drinking water is a limited resource. Critical to fighting the global water crisis are public awareness campaigns, including Public Service Announcements (PSAs). While YouTube has become a popular medium for disseminating prosocial content such as PSAs, environmental communication efforts on this platform remain largely uninvestigated. This study examines the content and characteristics of global water crisis PSAs on YouTube by applying two communication models: the Extended Parallel Process Model, and the Elaboration Likelihood Model. These models are used to evaluate the potential effectiveness of the PSAs. Content analysis reveals that threat messages often outweigh efficacy messages in the videos, central route processing cues are more prevalent than peripheral route cues, and a focus on quality or quantity issues differed by sponsoring organization (non-profit, for-profit, government). Implications and avenues for potential future research are discussed. 相似文献
794.
Andrea.?J.?Santana Walter.?N.?L.?dos?Santos Laiana?O.?B.?Silva Cesário?F.?das?VirgensEmail author 《Environmental monitoring and assessment》2016,188(5):293
Mercury is a highly toxic substance that is a health hazard to humans. This study aims to investigate powders obtained from the peel of the fruit of Pachira aquatica Aubl, in its in natura and/or acidified form, as an adsorbent for the removal of mercury ions in aqueous solution. The materials were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The infrared spectra showed bands corresponding to the axial deformation of carbonyls from carboxylic acids, the most important functional group responsible for fixing the metal species to the adsorbent material. The thermograms displayed mass losses related to the decomposition of three major components, i.e., hemicellulose, cellulose, and lignin. The adsorption process was evaluated using cold-vapor atomic fluorescence spectrometry (CV AFS) and cold-vapor atomic absorption spectrometry (CV AAS). Three isotherm models were employed. The adsorption isotherm model, Langmuir-Freundlich, best represented the adsorption process, and the maximum adsorption capacity was predicted to be 0.71 and 0.58 mg g?1 at 25 °C in nature and acidified, respectively. Adsorption efficiencies were further tested on real aqueous wastewater samples, and removal of Hg(II) was recorded as 69.6 % for biomass acidified and 76.3 % for biomass in nature. Results obtained from sorption experiments on real aqueous wastewater samples revealed that recovery of the target metal ions was very satisfactory. The pseudo-second-order model showed the best correlation to the experimental data. The current findings showed that the investigated materials are potential adsorbents for mercury(II) ion removal in aqueous solution, with acidified P. aquatica Aubl being the most efficient adsorbent. 相似文献
795.
796.
797.
Walter W. Heck Allen S. Heagle 《Journal of the Air & Waste Management Association (1995)》2013,63(2):97-99
With newly developed monitoring techniques, investigators used the sensitive tobacco variety, Bel-W3, as a monitor for photochemical air pollution at different locations within 75 miles of Cincinnati, Ohio. Observations during the summers of 1966 through 1968 revealed almost daily injury to monitoring plants, fairly uniform total seasonal injury at all locations, and a marked variation in both oxidant and injury from one season to another within the city. The relationship between oxidant level and injury was not found to be consistent. 相似文献
798.
799.
Seymour Hochheiser Joseph Santner Walter F. Ludmann 《Journal of the Air & Waste Management Association (1995)》2013,63(5):266-271
Atmospheric samples collected in several American cities were analyzed for SO2 concentration using various analytical methods. The methods were: (1) electroconductivity, (2) West-Gaeke, (3) West-Gaeke with membrane prefdter, (4) West-Gaeke with glass-fiber prefilter, (5) hydrogen peroxide, (6) hydrogen peroxide with membrane prefilter, and (7) hydrogen peroxide with glass-fiber prefilter. The relationships among SO2 data produced by these methods were evaluated statistically. Where statistical differences among methods, at the 95% confidence level, were determined then relationships were further delineated. Factors considered in these comparisons were: (1) location, {2) time of day, (8) concentration range, (4) particulate concentration, and (5) humidity. Laboratory evaluations of these methods show that each method is subject to different interfering substances. Laboratory evaluations of these methods show that each method is subject to different interfering substances. The relationship among methods obtained in these studies will complement these data and perhaps provide for further laboratory and field evaluation of methods used to measure SO2. The relationship among SO2 data produced by these methods should be useful in relating atmospheric SO2 concentration to its effects and to those involved in establishing ambient air quality standards. 相似文献
800.
Walter L. Cranor David A. Alvarez James N. Huckins Jimmie D. Petty 《Atmospheric environment (Oxford, England : 1994)》2009,43(20):3211-3219
To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (kua) and no SPMD air partitioning coefficient (Ksa) existed for vapor-phase contaminants. This research was conducted to expand the existing body of kinetic data for SPMD air sampling by determining kua and Ksa for a number of airborne contaminants including the chemical classes: polycyclic aromatic hydrocarbons, organochlorine pesticides, brominated diphenyl ethers, phthalate esters, synthetic pyrethroids, and organophosphate/organosulfur pesticides. The kuas were obtained for 48 of 50 chemicals investigated and ranged from 0.03 to 3.07 m3 g?1 d?1. In cases where uptake was approaching equilibrium, Ksas were approximated. Ksa values (no units) were determined or estimated for 48 of the chemicals investigated and ranging from 3.84E+5 to 7.34E+7. This research utilized a test system (United States Patent 6,877,724 B1) which afforded the capability to generate and maintain constant concentrations of vapor-phase chemical mixtures. The test system and experimental design employed gave reproducible results during experimental runs spanning more than two years. This reproducibility was shown by obtaining mean kua values (n = 3) of anthracene and p,p′-DDE at 0.96 and 1.57 m3 g?1 d?1 with relative standard deviations of 8.4% and 8.6% respectively. 相似文献