Online Survey of Heterogeneous Users and Their Usage of the Interactive Mapping Platform WorldMap   总被引：1，自引：0，他引：1  

Alenka Poplin  Wendy Guan  Ben Lewis 《The Cartographic journal》2017,54(3):214-232

This article reports on the results of an online survey with 290 heterogeneous users of the interactive mapping platform WorldMap and provides insights into problems faced by such users. Heterogeneous users are users with a variety of GIS skills, educational background, gender, and age categories. We investigate how they interact with online maps and analyse their experience. WorldMap represents as a case study of an online mapping platform which aims to serve researchers and users across disciplines in viewing and creating online interactive maps. We concentrate on operations that are perceived as difficult and very difficult by the majority of users as well as operations that are rarely used. Our aim is to contribute to the discussions on how to improve the design of online GIS-based mapping platforms. We conclude the paper with reflections on the results of our study and ideas for further research.  相似文献   

Distribution and chemistry of manganese,iron, and suspended particulates in Orca Basin     

John H. Trefry  Bob J. Presley  Wendy L. Keeney-Kennicutt  Robert P. Trocine 《Geo-Marine Letters》1984,4(2):125-130

The intense halocline and redoxcline in the Orca Basin, northwest Gulf of Mexico, induce dramatic water column profiles for manganese, iron, and suspended particulates. Within a 17 m interval, the salinity of the basin water increases from 66 to 260 & permil and dissolved oxygen decreases to zero. Midway through this transition zone, concentrations of suspended matter peak at 900 g/liter. Dissolved iron and manganese concentrations in the anoxic brine increase from oceanic values to maxima of 1.6 and 22 mg/liter, respectively. Upward migration of dissolved manganese from the brine leads to production of manganese-rich particles in the slightly oxygenated overlying water.  相似文献   

Combining threat and efficacy messaging to increase public engagement with climate change in Beijing,China     

Wen Xue  Donald W. Hine  Anthony D. G. Marks  Wendy J. Phillips  Patrick Nunn  Shouying Zhao 《Climatic change》2016,137(1-2):43-55

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The redox chemistry of Pu(V)O₂⁺ interaction with common mineral surfaces in dilute solutions and seawater     

Wendy L. Keeney-kennicutt  John W. Morse 《Geochimica et cosmochimica acta》1985,49(12):2577-2588

It has long been recognized that the Pu⁴⁺ ion can be readily adsorbed on solid surfaces, but it has been assumed that the generally more abundant Pu(V)O₂⁺ ion should have little affinity for surfaces. Our results indicate that Pu(V)O₂⁺ can be adsorbed from dilute solutions and seawater on goethite, aragonite, calcite, and δ-MnO₂. Adsorption on δ-MnO₂ is severely depressed in seawater, probably as a result of site competition with seawater cations.The sorption behavior of PuO₂⁺ is influenced by oxidation-reduction reactions occurring on the mineral surfaces. Adsorption on δ-MnO₂ results in oxidation of adsorbed Pu(IV) and Pu(V) to Pu(VI). However, adsorption on goethite results in a reaction in which Pu(IV) and Pu(VI) are formed on the mineral surface. The Pu(VI) is slowly reduced to Pu(IV), leaving Pu(IV) as the dominant surface Pu species. This reaction can be photochemically catalyzed. PuO₂⁺ adsorbed on carbonate minerals behaves similarly to Np(V)O₂⁺ and undergoes little change in oxidation state after adsorption.  相似文献   

Partition coefficients for REE between garnets and liquids: implications of non-Henry's Law behaviour for models of basalt origin and evolution     

Wendy J. Harrison 《Geochimica et cosmochimica acta》1981,45(9):1529-1544

Partition coefficients for the rare earth elements (REE) Ce, Sm and Tm between coexisting garnets and hydrous liquids have been determined at high pressure and temperatures (30 kbar and 1300 and 1500°C). Two synthetic systems were studied, Mg₃Al₂Si₃O₁₂-H₂O and Ca₃Al₂Si₃O₁₂-H₂O, in addition to a natural pyrope-bearing system.Deviations from Henry's Law behaviour occur at geologically relevant REE concentrations. At concentrations < 3 ppm Ce, < 12 ppm Sm, < 80 ppm Tm in pyrope and < 100 ppm Ce, < 250 ppm Sm, < 1000 ppm Tm in grossular (at 30 kbar and 1300°C), D^{garnet liquid}_REE increases as the REE concentration in the garnet decreases. At higher concentrations, D_REE is constant. D^{grossular liquid}_REE also constant when the garnet contains less than about 2 ppm Sm or Tm. The REE concentration at which D_REE becomes constant increases with increasing temperature, decreasing REE ionic radius and increasing Ca content of the garnet.Partitioning behaviour of Ce, Sm and Tm between a natural pyrope-rich garnet and hydrous liquid is analogous to that in the synthetic systems and substantiates the substitution model proposed by Harrison and Wood (1980).Values of D_REE^{garnet/liquid} for which Henry's Law is obeyed are systematically higher for grossular than for pyrope (D^{pyrope/liquid} = 0.067(Ce), 0.108(Sm), 0.155(Tm) and D^{grossular/Liquid} = 0.65(Ce), 0.75(Sm), 4.55(Tm).The implications of non-Henry's Law partitioning of REE for models of basalt petrogenesis involving garnet are far-ranging. Deviations from Henry's Law permit refinements to be made to calculated REE abundances once basic model parameters have been defined.  相似文献   

Household Water Insecurity in the Global North: A Study of Rural and Periurban Settlements on the Texas–Mexico Border     

Wendy Jepson  Emily Vandewalle 《The Professional geographer》2016,68(1):66-81

This article examines household-level characteristics that predict water insecurity in low-income rural and periurban communities on the Texas–Mexico border. We employ two logistic regression models (binary and ordered) to identify household characteristics that are more likely to result in water insecurity. Our analyses yielded unexpected findings: Whereas socioeconomic factors are weak predictors, immigration status of household members is a significant variable that contributes to household water insecurity. Policymakers need to pay more attention to marginalized communities as “universal” water access still leaves populations without adequate, reliable, and affordable water in the Global North.  相似文献   

Dynamic hazard assessment of group-occurring debris flows based on a coupled model     

Nie  Yinping  Li  Xiuzhen  Zhou  Wendy  Xu  Ruichi 《Natural Hazards》2021,106(3):2635-2661

Natural Hazards - A scientific hazard zoning of debris flows can ensure that human activities are not performed therein, thereby reducing economic loss as much as possible. In this study, by...  相似文献   

Shifting paradigms for Nepal’s protected areas: history,challenges and relationships     

Babu R. Bhattarai  Wendy Wright  Buddi S. Poudel  Achyut Aryal  Bhupendra P. Yadav  Radha Wagle 《山地科学学报》2017,14(5):964-979

The modern history of protected area (PA) management in Nepal dates back to 1973 when the National Parks and Wildlife Conservation Act (1973) was promulgated and Chitwan National Park was established. In the years immediately following these key events, protected area acts and regulations were strictly applied and the role of local people in managing natural resources was neglected. However with the passage of time, and with changes in the socio-political and economic characteristics of Nepal, management regimes have shifted towards a more liberal model which recognizes more clearly the contributions of people living and working within protected areas. Recently, landscape level conservation models including the designation of multiple use areas have been utilized in the development of management plans for protected areas in Nepal. Conservation agencies have attempted to tackle challenges such as land use conflict, poaching and smuggling of wildlife parts and illegal harvesting of highly valued medicinal herbs through regulation, but these efforts are not always successful. We recommend a holistic conflict resolution approach which recognizes and resolves the different needs of all stakeholders.  相似文献   

The promise and pitfalls of Marine Stewardship Council certification: Maine lobster as a case study     

Wendy Goyert  Raphael Sagarin  John Annala 《Marine Policy》2010

As worldwide population continues to grow, so does demand for seafood by consumers. With this trend, interest in sustainably certified seafood is also increasing. The Maine lobster fishery is currently considering certification based on the Marine Stewardship Council (MSC) standard for sustainable and well-managed fisheries. Although certification is argued to provide a market-based incentive to improve sustainable fishing practices, it is a costly and time-consuming process, and often imposes additional requirements on fisheries in order to meet certification standards. To evaluate whether the costs of Maine lobster fishery certification are worth the presumed benefits, lobster industry members were interviewed to learn their opinions of MSC certification, seafood consumers were surveyed to understand their attitudes and purchasing preferences related to lobster, and lessons learned from other MSC-certified fisheries were compiled. MSC certification of the Maine lobster fishery could potentially provide benefits to the industry by differentiating Maine lobster and maintaining access to markets that are looking to exclusively source certified fish products. However, certification is unlikely to provide price premiums for the fishermen, and does not necessarily represent to consumers the most desirable aspects of Maine lobster. Certification programs may need to adapt to consumer preferences and market conditions if they are to continue to provide incentives for the sustainable management of fisheries.  相似文献   

A frozen record of density-driven crustal overturn in lava lakes: the example of Kīlauea Iki 1959     

Wendy K. Stovall  B. F. Houghton  A. J. L. Harris  D. A. Swanson 《Bulletin of Volcanology》2009,71(3):313-318

Lava lakes are found at basaltic volcanoes on Earth and other planetary bodies. Density-driven crustal foundering leading to surface renewal occurs repeatedly throughout the life of a lava lake. This process has been observed and described in a qualitative sense, but due to dangerous conditions, no data has been acquired to evaluate the densities of the units involved. Kīlauea Iki pit crater in Hawai`i houses a lava lake erupted during a 2 month period in 1959. Part of the surface of the Kīlauea Iki lake now preserves the frozen record of a final, incomplete, crustal-overturn cycle. We mapped this region and sampled portions of the foundering crust, as well as overriding and underlying lava, to constrain the density of the units involved in the overturn process. Overturn is driven by the advance of a flow front of fresh, low-density lava over an older, higher density surface crust. The advance of the front causes the older crust to break up, founder, and dive downwards into the lake to expose new, hot, low-density lava. We find density differences of 200 to 740 kg/m³ between the foundering crust and over-riding and under-lying lava respectively. In this case, crustal overturn is driven by large density differences between the foundering and resurfacing units. These differences lead, inevitably, to frequent crustal renewal: simple density differences between the surface crust and underlying lake lava make the upper layers of the lake highly unstable. Work originally presented at the American Geophysical Union Fall Meeting in San Francisco, California on December 11, 2007.  相似文献