Stitching the World: Embroidered Maps and Women's Geographical Education          下载免费PDF全文

Christina Dando 《Geographical review》2017,107(3):e29-e32

  相似文献   

Young people and the aesthetics of health promotion: Beyond reason,rationality and risk          下载免费PDF全文

Christina R. Ergler 《New Zealand geographer》2017,73(3):220-221

  相似文献   

A cyber-enabled spatial decision support system to inventory Mangroves in Mozambique: coupling scientific workflows and cloud computing     

Wenwu Tang  Wenpeng Feng  Meijuan Jia  Jiyang Shi  Huifang Zuo  Christina E. Stringer 《International journal of geographical information science》2017,31(5):907-938

Mangroves are an important terrestrial carbon reservoir with numerous ecosystem services. Yet, it is difficult to inventory mangroves because of their low accessibility. A sampling approach that produces accurate assessment while maximizing logistical integrity of inventory operation is often required. Spatial decision support systems (SDSSs) provide support for integrating such a sampling design of fieldwork with operational considerations and evaluation of alternative scenarios. However, this fieldwork design driven by SDSS is often computationally intensive and repetitive. In this study, we develop a cyber-enabled SDSS framework to facilitate the computationally challenging fieldwork design that requires the efficacious selection of base camps and plots for the inventory of mangroves. Our study area is the Zambezi River Delta, Mozambique. Cyber-enabled capabilities, including scientific workflows and cloud computing, are integrated with the SDSS. Scientific workflows enable the automation of data and modeling tasks in the SDSS. Cloud computing offers on-demand computational support for interoperation among stakeholders for collaborative scenario evaluation for the fieldwork design of mangrove inventory. Further, this framework allows for harnessing high-performance computing capabilities for accelerating the fieldwork design. The cyber-enabled framework provides significant merits in terms of effective coordination among science and logistical teams, assurance of meeting inventory objectives, and an objective basis to collectively and efficaciously evaluate alternative scenarios.  相似文献   

Lateral bedrock erosion and valley formation in a heterogeneously layered landscape,Northeast Kansas     

Abbey L. Marcotte  Christina M. Neudorf  Abigail L. Langston 《地球表面变化过程与地形》2021,46(11):2248-2263

In this study, we present direct field measurements of modern lateral and vertical bedrock erosion during a 2-year study period, and optically stimulated luminescence (OSL) ages of fluvial material capping a flat bedrock surface at Kings Creek located in northeast Kansas, USA. These data provide insight into rates and mechanisms of bedrock erosion and valley-widening in a heterogeneously layered limestone-shale landscape. Lateral bedrock erosion outpaced vertical incision during our 2-year study period. Modern erosion rates, measured at erosion pins in limestone and shale bedrock reveal that shale erosion rate is a function of wetting and drying cycles, while limestone erosion rate is controlled by discharge and fracture spacing. Variability in fracture spacing amongst field sites controls the size of limestone block collapse into the stream, which either allowed continued lateral erosion following rapid detachment and transport of limestone blocks, or inhibited lateral erosion due to limestone blocks that protected the valley wall from further erosion. The OSL ages of fluvial material sourced from the strath terrace were older than any material previously dated at our study site and indicate that Kings Creek was actively aggrading and incising throughout the late Pleistocene. Coupling field measurements and observations with ages of fluvial terraces can be useful to investigate the timing and processes linked to how bedrock rivers erode laterally over time to form wide bedrock valleys.  相似文献   

Cryogenic Core Collection and Preservation of Subsurface Samples for Biomolecular Analysis     

Richard L. Johnson  Christina N. Brow  Reid O'Brien Johnson  Holly M. Simon 《Ground Water Monitoring & Remediation》2013,33(2):38-43

A cryogenic coring system for the collection and preservation of biomolecules in unconsolidated subsurface solid samples is presented here. The sampler is based on existing direct‐push coring technology, with the addition of a cryogenic step to freeze the sample in situ. Once brought to the surface, the frozen cores can be packed in dry ice and shipped to the laboratory for further processing and analysis. The approach prevents redistribution of fluids during sample recovery and shipping, and because the cores are frozen in situ there is little loss of solid material during retrieval to ground surface. To evaluate the performance of the approach, DNA analyses of samples collected by cryogenic coring in a very large physical model are compared with results from water samples and horizontal core samples taken in close proximity. The data indicate that the vertical distribution of DNA within the cryogenic core can be measured at the centimeter scale, providing unprecedented characterization of subsurface biogeochemical interfaces.  相似文献   

A Review of “Civic Discipline: Geography in America, 1860–1890”     

Christina E. Dando 《The Professional geographer》2013,65(2):309-310

  相似文献   

Water and carbon fluxes of European ecosystems: an evaluation of the ecohydrological model RHESSys     

Bärbel Zierl  Harald Bugmann  Christina L. Tague 《水文研究》2007,21(24):3328-3339

This study investigated whether the regional hydro-ecological simulation system RHESSys is a suitable tool for long-term global change impact studies under selected climatic conditions of Europe, taking advantage of the strongly varying climate along elevational gradients in mountain regions. We performed a validation of RHESSys using daily, monthly and yearly data on (1) streamflow and snow cover in five Alpine catchments and (2) water and carbon fluxes at 15 EUROFLUX sites. The simulation results generally agreed well with observations. RHESSys reasonably reproduced daily and monthly streamflow, as well as the seasonal cycle and amplitude of typical Alpine discharge regimes. Furthermore, RHESSys was capable of capturing the key features of the carbon cycle of various forested ecosystems, including significant differences between managed and close-to-natural forests, and more subtle distinctions between coniferous and deciduous systems. Our analyses confirmed that RHESSys is a suitable tool for studying global change impacts on mountain hydrology. Regarding the simulation of the carbon cycle, this investigation detected some data and model limitations that are discussed in detail. Finally, suggestions for model improvements are made, mainly concerning the formulations of decomposition and respiration rates in biogeochemical models. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Application of Plutonium Isotopes to the Sediment Geochronology of Coarse-Grained Sediments from Englebright Lake,California (USA)     

Christina R. Pondell  Aaron J. Beck  Steven A. Kuehl  Elizabeth A. Canuel 《Aquatic Geochemistry》2016,22(2):97-115

The determination of sediment accumulation rates in environments with temporal variations in texture is challenging using traditional radioisotope methods, largely due to low activities associated with coarse sediments. This study used Englebright Lake, an impoundment in northern California, as a model system to examine the application of plutonium isotopes in lacustrine environments where the interlayering of coarse and fine sediments complicates the geochronology. Inductively coupled plasma mass spectrometry was used to quantify plutonium isotopes and low limits of detection allowed for the measurement of plutonium in sand, clay, and silt fractions. Although measurable levels of plutonium were found in sand fractions, over 75 % of the total plutonium activity was found in fine-grain-size fractions (<63 μm). Correlations between cesium-137 and plutonium activities in fine-grained sediments (r = 0.81–0.98, p < 0.005) suggest that plutonium isotopes may be substituted for cesium isotopes in coarse-grained sediments where cesium is typically below detectable levels. Sediment accumulation rates calculated from grain-size normalized plutonium activity profiles ranged from 6 to 145 cm year^?1 in Englebright Lake and identified a sediment depocenter at the delta front upstream of Englebright Dam. Progradation of the delta front reflected changes in sediment supply from the watershed in response to flood events, whereas average annual accumulation responded to human impacts. This study extends the application of plutonium isotopes for sediment geochronology to aquatic environments dominated by coarse sediments and provides new information that contributes to a better understanding of the processes influencing sediment deposition in Englebright Lake.  相似文献   

A comparison of the updated very high resolution model RegCM3_10km with the previous version RegCM3_25km over the complex terrain of Greece: present and future projections     

Konstantia Tolika  Christina Anagnostopoulou  Kondylia Velikou  Christos Vagenas 《Theoretical and Applied Climatology》2016,126(3-4):715-726

  相似文献   

Integrated geophysical and geological methods to investigate the inner and outer structures of the Quaternary Mýtina maar (W-Bohemia,Czech Republic)     

Christina?FlechsigEmail author  Jens?Heinicke  Jan?Mrlina  Horst?K?mpf  Tobias?Nickschick  Alina?Schmidt  Tomá??Bayer  Thomas?Günther  Carsten?Rücker  Elisabeth?Seidel  Michal?Seidl 《International Journal of Earth Sciences》2015,104(8):2087-2105

The Mýtina maar is the first known Quaternary maar in the Bohemian Massif. Based on the results of Mrlina et al. (J Volcanol Geother Res 182:97–112, 2009), a multiparametric geophysical (electrical resistivity tomography, gravimetry, magnetometry, seismics) and geological/petrochemical research study had been carried out. The interpretation of the data has provided new information about the inner structure of the volcanic complex: (1) specification of the depth of post-volcanic sedimentary fill (up to ~100 m) and (2) magnetic and resistivity signs of one (or two) hidden volcanic structures interpreted as intrusions or remains of a scoria cone. The findings at the outer structure of the maar incorporate the (1) evidence of circular fracture zones outside the maar, (2) detection and distribution of volcanic ejecta and tephra-fall deposits at the surface, and (3) indications from electrical resistivity tomography and gravity data in the area between the Mýtina maar and ?elezná h?rka scoria cone, interpreted as a palaeovalley, filled by volcaniclastic rocks, and aligned along the strike line (NW–SE) of the Tachov fault zone. These findings are valuable contributions to extend the knowledge about structure of maar volcanoes in general. Because of ongoing active magmatic processes in the north-east part of the Cheb Basin (ca. 15–30 km north of the investigation area), the Mýtina maar-diatreme volcano and surroundings is a suitable key area for research directed to reconstruction of the palaeovolcanic evolution and assessment of possible future hazard potential in the Bohemian Massif.  相似文献