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31.
Benchmarking Optical/Thermal Satellite Imagery for Estimating Evapotranspiration and Soil Moisture in Decision Support Tools
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Jan M.H. Hendrickx Richard G. Allen Al Brower Aaron R. Byrd Sung‐ho Hong Fred L. Ogden Nawa Raj Pradhan Clarence W. Robison David Toll Ricardo Trezza Todd G. Umstot John L. Wilson 《Journal of the American Water Resources Association》2016,52(1):89-119
Generally, one expects evapotranspiration (ET) maps derived from optical/thermal Landsat and MODIS satellite imagery to improve decision support tools and lead to superior decisions regarding water resources management. However, there is lack of supportive evidence to accept or reject this expectation. We “benchmark” three existing hydrologic decision support tools with the following benchmarks: annual ET for the ET Toolbox developed by the United States Bureau of Reclamation, predicted rainfall‐runoff hydrographs for the Gridded Surface/Subsurface Hydrologic Analysis model developed by the U.S. Army Corps of Engineers, and the average annual groundwater recharge for the Distributed Parameter Watershed Model used by Daniel B. Stephens & Associates. The conclusion of this benchmark study is that the use of NASA/USGS optical/thermal satellite imagery can considerably improve hydrologic decision support tools compared to their traditional implementations. The benefits of improved decision making, resulting from more accurate results of hydrologic support systems using optical/thermal satellite imagery, should substantially exceed the costs for acquiring such imagery and implementing the remote sensing algorithms. In fact, the value of reduced error in estimating average annual groundwater recharge in the San Gabriel Mountains, California alone, in terms of value of water, may be as large as $1 billion, more than sufficient to pay for one new Landsat satellite. 相似文献
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The study aims to compare the detection of 16S rRNA gene of Dehalococcoides species and the microcosm study for biotransformation in predicting reductive dechlorination of chlorinated ethenes in ground water at hazardous waste sites. A total of 72 ground water samples were collected from 12 PCE or TCE contaminated sites in the United States. The samples were analyzed and used to construct microcosms in the laboratory. The results showed that the presence of Dehalococcoides DNA was well associated with dechlorination to ethene in the field. Nearly half of the wells where Dehalococcoides DNA was detected had ethene as a dechlorination end product. In comparison, for ground water samples of 16 wells where ethene was detected, ethene was produced in 11 of the corresponding microcosms. For most microcosms, during two years of incubation, dechlorination was less extensive than that observed in the field. 相似文献
34.
Michael D. Kaplowitz Felix K. Yeboah Laurie Thorp Aimee M. Wilson 《Resources, Conservation and Recycling》2009,53(11):612-623
With increasing environmental challenges confronting our planet, colleges and universities are trying different approaches for minimizing their adverse environmental impacts. Among the approaches being used to revitalize campus sustainability efforts, new waste management strategies have included attempts to improve campus-recycling programs. This paper presents select findings from a comprehensive study at a large, Tier I university aimed at, among other things, informing university administration and decision makers working on the planning and implementation of a new campus-wide recycling facility and program. The researchers used a mixed-method approach to help them develop an understanding of the campus community's (1) perceived barriers to recycling, (2) recycling knowledge, (3) program preferences, and (4) environmental attitudes. The results from a web-based survey (n = 3896, RR1 = 24.9%) suggest, communication efforts for recycling programming should focus more on messages concerning what, how, and where to recycle rather than messages on why to recycle. Furthermore, the results suggest recycling-related publicity approaches should differentiate their mode and content for different segments of the community. 相似文献
35.
Mathematical Modeling of Column and Field Dense Nonaqueous Phase Liquid Tracer Tests 总被引:2,自引:0,他引:2
David J. Wilson Ronald A. Burt Douglas S. Hodge 《Environmental monitoring and assessment》2000,60(2):181-216
Mathematical models for the simulation of dense nonaqueous phase liquid tracer tests (DTTs) in laboratory columns and in the field are developed and examined. The DTT technique is a means of estimating the quantity of dense nonaqueous phase liquid (DNAPL) in a domain of interest in an aquifer. The two-dimensional field DTT model uses the Method of Principal Directions and an asymmetrical upwind algorithm for describing advective transport. Both models include diffusion transport of tracer into and from low-permeability porous structures such as clay lenses, as well as the mass transport kinetics of partitioning tracer to and from the DNAPL droplets. The dependence of the effluent tracer concentration curves on the parameters of the models is explored, and conclusions are drawn regarding the applicability of, and several possible problems with, the DTT technique. Model results indicate that the DTT performs well at locating distributed droplets of DNAPL, but is unlikely to be useful in the assessment of pooled DNAPL. 相似文献
36.
Serum profiles of PCDDs and PCDFs, in individuals near the Escambia Wood Treating Company Superfund site in Pensacola, FL 总被引:3,自引:0,他引:3
The Escambia Wood Treating Company (ETC) Superfund site, Pensacola, FL, is contaminated with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), benzo(a)pyrene, lead and arsenic from pentachlorophenol (PCP), creosote, and other compounds used to treat utility poles and foundation pilings. Although ETC's operations ceased in 1982, soils in the areas surrounding the facility continue to exhibit elevated levels of contaminants attributable to ETC operations. In July 2000, individuals who may have been affected by contamination from the ETC site, including current and former residents and former workers and their household members were invited to participate in a study, which included a health and exposure history and routine blood analysis. We also conducted a toxicological health evaluation of a subset of these eligible workers/residents by analyzing serum levels of 17 PCDD/F congeners. Members of the ETC cohort exhibited elevated serum PCDD/F relative to the general population, and congener profiles in members of the cohort reflected patterns commonly observed in persons exposed to PCP. Hypertension prevalence in the cohort was found to correlate with PCDD/F levels, although no other significant relationships were identified with monitored health indices. 相似文献
37.
Chromosomal and nuclear characteristics of deep-sea hydrothermal-vent organisms: correlates of increased growth rate 总被引:2,自引:0,他引:2
A range of tissue and cell types from adult and juvenile stages of vent- and non-vent-dwelling deep-sea and shallow-water organisms were compared for signs of cell division, in preparation for a cytogenetic study of the different groups. Virtually all the Mid-Atlantic Ridge (MAR) vent species (bresiliid shrimp, bathymodiolid mussel, branchipolynoid polychaete, and a range of small gastropods) showed an abundance of metaphase chromosome spreads, indicating a generally high intrinsic rate of cell division, irrespective of their phylogenetic group. In comparison, similar tissues and life-history stages (i.e. gonad, developing eggs and gill) from two deep-sea bathypelagic crustaceans, Hymenodora and Gnathophausia, failed to yield any convincing evidence of cell division. This indicated that rates of growth and reproduction in the rest of the deep sea are extremely low. While much has been written about the contrasting growth rates of vent versus non-vent organisms, this is the first direct evidence of differences in cell-division rate between vent and non-vent species, which undoubtedly reflects contrasting conditions relating to food availability and temporal stability in these two deep-sea environments. The cells of shallow-water marine invertebrates (Mytilus, Nucella, Littorina, Pomatoceros and Crangon), based on the results of previous cytogenetic investigations, occupy an intermediate position with respect to their cell-division kinetics. When chromosome numbers, DNA content and nuclear diameters were compared between vent and non-vent species, this showed that no change had occurred in these characters since the time of vent colonisation. Representative chromosome spreads from hydrothermal-vent organisms are shown here for the first time. 相似文献
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39.
Maria C. Dzul Philip M. Dixon Michael C. Quist Stephen J. Dinsmore Michael R. Bower Kevin P. Wilson D. Bailey Gaines 《Environmental monitoring and assessment》2013,185(1):405-414
We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP larvae on nine plots were counted plot by plot. Statistical analysis of larval abundance included three components: (1) evaluation of power from various sample size combinations, (2) comparison of power in fixed and random plot designs, and (3) assessment of yearly differences in the power of the survey. Results indicated that increasing the sample size at the lowest level of sampling represented the most realistic option to increase the survey’s power, fixed plot designs had greater power than random plot designs, and the power of the larval survey varied by year. This study provides an example of how monitoring efforts may benefit from coupling variance components estimation with power analysis to assess sampling design. 相似文献
40.
José Carlos de Moura Xavier Irany de Andrade Azevedo Wilson Cabral de Sousa Junior Augusto Nishikawa 《Environmental monitoring and assessment》2013,185(2):1463-1471
Atmospheric pollutant monitoring constitutes a primordial activity in public policies concerning air quality. In São Paulo State, Brazil, the São Paulo State Environment Company (CETESB) maintains an automatic network which continuously monitors CO, SO2, NO x , O3, and particulate matter concentrations in the air. The monitoring process accuracy is a fundamental condition for the actions to be taken by CETESB. As one of the support systems, a preventive maintenance program for the different analyzers used is part of the data quality strategy. Knowledge of the behavior of analyzer failure times could help optimize the program. To achieve this goal, the failure times of an ozone analyzer—considered a repairable system—were modeled by means of the nonhomogeneous Poisson process. The rate of occurrence of failures (ROCOF) was estimated for the intervals 0–70,800 h and 0–88,320 h, in which six and seven failures were observed, respectively. The results showed that the ROCOF estimate is influenced by the choice of the observation period, t 0?=?70,800 h and t 7?=?88,320 h in the cases analyzed. Identification of preventive maintenance actions, mainly when parts replacement occurs in the last interval of observation, is highlighted, justifying the alteration in the behavior of the inter-arrival times. The performance of a follow-up on each analyzer is recommended in order to record the impact of the performed preventive maintenance program on the enhancement of its useful life. 相似文献