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11.
Phosphorus export dynamics and hydrobiogeochemical controls across gradients of scale,topography and human impact 
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下载免费PDF全文 Genevieve Ali Henry Wilson Jane Elliott Amber Penner Aminul Haque Cody Ross Maliheh Rabie 《水文研究》2017,31(18):3130-3145
Concentration‐discharge (c‐Q) plots are routinely used as an integrated signal of watershed response to infer solute sources and travel pathways. However, the interpretation of c‐Q data can be difficult unless these data are fitted using statistical models. Such models are frequently applied for geogenic solutes, but it is unclear to what extent they might aid in the investigation of nutrient export patterns, particularly for total dissolved phosphorus (TDP) which is a critical driver of downstream eutrophication problems. The goal of the present study was therefore to statistically model c‐Q relations (where c is TDP concentrations) in a set of contrasting watersheds in the Northern Great Plains—ranging in size from 0.2 to 1000+ km2—to assess the controls of landscape properties on TDP transport dynamics. Six statistical models were fitted to c‐Q data, notably (a) one linear model, (b) one model assuming that c‐Q relations are driven by the mixing of end‐member waters from different landscape locations (i.e., hydrograph separation), (c) one model relying on a biogeochemical stationarity hypothesis (i.e., power law), (d) one model hypothesizing that c‐Q relations change as a function of the solute subsurface contact time (i.e., hyperbolic model), and (e) two models assuming that solute fluxes are mostly dependent on reaction rates (i.e., chemical models). Model performance ranged from mediocre (R2 < 0.2) to very good (R2 > 0.9), but the hydrograph separation model seemed most universal. No watershed was found to exhibit chemostatic behaviour, but many showed signs of dilution or enrichment behaviour. A tendency toward a multi‐model fit and better model performance was observed for watersheds with moderate slope and higher effective drainage area. The relatively poor model performance obtained outside these conditions illustrates the likely importance of controls on TDP concentrations in the region that are independent of flow dynamics. 相似文献
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Urban Māori is a term that describes indigenous people in Aotearoa New Zealand living in urban environments. It includes Māori who hold traditional authority over land (mana whenua) and Māori who have moved away from their traditional homes (mātāwaka). This article describes the heterogeneity of the urban Māori population through the spatial analysis of iwi (tribal) census data for four urban centres. The results show complex variation in the distribution of mana whenua and mātāwaka populations and help to inform a discussion about the rights and interests of all urban Māori in the development and planning of cities, and subsequent policy responses. 相似文献
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Estuarine sediment deposition during wetland restoration: A GIS and remote sensing modeling approach
Michelle Elizabeth Newcomer Amber Jean Michael Kuss Tyler Ketron Alex Remar Vivek Choksi J. W. Skiles 《国际地球制图》2013,28(4):451-467
Restoration is currently underway in the industrial salt flats of San Francisco Bay, California. Remote sensing of suspended sediment concentration and other GIS predictor variables were used to model sediment deposition within recently restored ponds. Suspended sediment concentrations were calibrated to reflectance values from Landsat TM 5 and ASTER satellite image data using three statistical techniques—linear regression, multivariate regression, and Artificial Neural Network (ANN) regression. Multivariate and ANN regressions using ASTER proved to be the most accurate methods, yielding r2 values of 0.88 and 0.87, respectively. Predictor variables such as sediment grain size and tidal frequency were used in the Marsh Sedimentation (MARSED) model for predicting deposition rates. MARSED results show a root mean square deviation (RMSD) of 66.8 mm (<1σ) between modeled and field observations. This model was applied to a pond breached in November 2010 and indicated that the pond will reach sediment equilibrium levels after 60 months of tidal inundation. 相似文献
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Umair A. Qureshi Amber R. Solangi Saima Q. Memon Syed I. H. Taqvi Najma Memon 《洁净——土壤、空气、水》2012,40(6):630-639
This study evaluated the adsorptive properties of dibutyl phthalate (DBP) on room temperature ionic liquid (RTIL) modified XAD‐4 resin. The modified RTIL‐XAD 4 sorbent was characterized by FTIR. Effect of varying experimental conditions such as pH, contact time, temperature, shaking speed, concentrations, and interfering species were investigated by batch adsorption experiments. Adsorption was found to be most favorable at pH 6 within 30 min. Experimental data were evaluated in terms of kinetic, equilibrium, and thermodynamic modeling. Kinetics of the sorption was found to follow pseudo second order rate equation whereas Freundlich and D–R isotherms were the most suitable models to explain sorption phenomenon. Thermodynamically sorption was endothermic, irreversible, and spontaneous in nature. 相似文献
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The fear of crime can significantly reduce the quality of life of individuals, yet little is known about what neighbourhood‐level factors drive feelings of vulnerability in New Zealand. Even less is known about the impact that recorded crime has on individuals' fear in the country. In this study, we examined the neighbourhood‐level factors related to fear of crime in Christchurch, focusing specifically on whether recorded crime in neighbourhoods influences fear. The fear of crime in Christchurch was found to be the greatest in more affluent, ethnically homogenous and residentially stable neighbourhoods, while recorded crime levels were found to be relatively lower in these neighbourhoods. 相似文献
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Amber Wutich Melissa Beresford Julia C. Bausch Weston Eaton Kathryn J. Brasier Clinton F. Williams 《社会与自然资源》2020,33(7):941-948
AbstractThis study compares the efficiency of two analytic approaches—qualitative and quantitative—to social network analysis for identifying stakeholder groups. Social network data were collected from 23 water and agriculture stakeholders in Arizona, USA, and analyzed quantitatively and qualitatively. Analysis of the sample in the original order of data collection found qualitative analysis was more efficient, in that it yielded a stable result—the identification of four stakeholder groups—within 16 interviews. In contrast, the quantitative analysis did not produce a stable result after 23 interviews. Repeated analyses with randomized order and reverse order samples found qualitative approaches yielded more stable results, took about the same number of interviews to yield results, and produced slightly fewer stakeholder groups compared to quantitative approaches. Our findings suggest that, in resource-constrained projects, qualitative social network analysis for identifying stakeholder groups can provide an efficient alternative to conventional quantitative social network analysis. 相似文献
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J. Gordon Arbuckle Jr. Linda Stalker Prokopy Tonya Haigh Jon Hobbs Tricia Knoot Cody Knutson Adam Loy Amber Saylor Mase Jean McGuire Lois Wright Morton John Tyndall Melissa Widhalm 《Climatic change》2013,117(4):943-950
A February 2012 survey of almost 5,000 farmers across a region of the U.S. that produces more than half of the nation’s corn and soybean revealed that 66 % of farmers believed climate change is occurring (8 % mostly anthropogenic, 33 % equally human and natural, 25 % mostly natural), while 31 % were uncertain and 3.5 % did not believe that climate change is occurring. Results of initial analyses indicate that farmers’ beliefs about climate change and its causes vary considerably, and the relationships between those beliefs, concern about the potential impacts of climate change, and attitudes toward adaptive and mitigative action differ in systematic ways. Farmers who believed that climate change is occurring and attributable to human activity were significantly more likely to express concern about impacts and support adaptive and mitigative action. On the other hand, farmers who attributed climate change to natural causes, were uncertain about whether it is occurring, or did not believe that it is occurring were less concerned, less supportive of adaptation, and much less likely to support government and individual mitigative action. Results suggest that outreach with farmers should account for these covariances in belief, concerns, and attitudes toward adaptation and mitigation. 相似文献
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Understanding public perceptions of climate change is fundamental to both climate science and policy because it defines local and global socio-political contexts within which policy makers and scientists operate. To date, most studies addressing climate change perceptions have been place-based. While such research is informative, comparative studies across sites are important for building generalized theory around why and how people understand and interpret climate change and associated risks. This paper presents a cross-sectional study from six different country contexts to illustrate a novel comparative approach to unraveling the complexities of local vs global perceptions around climate change. We extract and compare ‘cultural knowledge’ regarding climate change using the theory of ‘culture as consensus’. To demonstrate the value of this approach, we examine cross-national data to see if people within specific and diverse places share ideas about global climate change. Findings show that although data was collected using ethnographically derived items collected through place-based methods we still find evidence of a shared cultural model of climate change which spans the diverse sites in the six countries. Moreover, there are specific signs of climate change which appear to be recognized cross-culturally. In addition, results show that being female and having a higher education are both likely to have a positive effect on global cultural competency of individuals. We discuss these result in the context of literature on environmental perceptions and propose that people with higher education are more likely to share common perceptions about climate change across cultures and tentatively suggest that we appear to see the emergence of a ‘global’, cross-cultural mental model around climate change and its potential impacts which in itself is linked to higher education. 相似文献
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Niki A. Rust Amber Abrams Daniel W. S. Challender Guillaume Chapron Arash Ghoddousi Jenny A. Glikman 《社会与自然资源》2017,30(10):1304-1310
Qualitative methods are important to gain a deep understanding of complex problems and poorly researched areas. They can be particularly useful to help explain underlying conservation problems. However, the significance in choosing and justifying appropriate methodological frameworks in conservation studies should be given more attention to ensure data are collected and analysed appropriately. We explain when, why, and how qualitative methods should be used and explain sampling strategies in qualitative studies. To improve familiarity with qualitative methods among natural scientists, we recommend expanding training in social sciences and increasing collaboration with social scientists. Given the scale of human impacts on the environment, this type of nuanced analytical skill is critical for progressing biodiversity conservation efforts. 相似文献