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421.
Public trust in organizations focused on improving environmental quality is important for increasing awareness and changing behaviors that have water quality implications. Few studies have addressed trust in soil and water quality information sources, particularly for both agricultural and nonagricultural respondents of the same watersheds. Surveys in 19 watersheds across five states in the Midwest assessed trust in, and familiarity with, soil and water quality information sources. Overall, respondents most trusted University Extension, Soil and Water Conservation Districts, and the Natural Resource Conservation Service, while lawn care companies, environmental groups, and land trusts were less trusted. Significant differences in trusted sources were found between watersheds, and between agricultural and nonagricultural respondents across and within watersheds. Among agricultural respondents, a clear relationship exists between familiarity and trust; as familiarity with an organization increases, so too does level of trust. This relationship is less clear‐cut for nonagricultural respondents in this region. We highlight implications of these findings for soil and water quality outreach efforts.  相似文献   
422.
Infiltration of PCE in a system containing spatial wettability variations   总被引:2,自引:0,他引:2  
A two-dimensional infiltration experiment was conducted to investigate and quantify the effect of spatial wettability variations on DNAPL migration and entrapment in saturated sands. Experimental observations of tetrachloroethylene (PCE) infiltration showed that organic-wet sand lenses acted as very effective capillary barriers, retaining PCE and inhibiting its downward migration. A multiphase numerical simulator was used to model this sand box experiment. The simulator incorporates wettability-modified van Genuchten and Brooks-Corey capillary pressure/saturation relationships as well as Burdine and Mualem relative permeability relationships. PCE mass distributions, estimated by image analysis of digital photographs taken during the infiltration event, were compared to simulation results. Although both relative permeability models were qualitatively able to predict the PCE retention in the organic-wet layers, simulations with the Mualem model failed to capture the observed rate of PCE migration. A traditional multiphase simulator, incorporating water-wet capillary retention relations, failed to predict both PCE pathways and retention behavior. This study illustrates the potential influence of subsurface wettability variations on DNAPL migration and entrapment and supports the use of modified capillary relations in conjunction with the Burdine model in multiphase flow simulators.  相似文献   
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