geneGIS: Geoanalytical Tools and Arc Marine Customization for Individual‐Based Genetic Records     

Dorothy M. Dick  Shaun Walbridge  Dawn J. Wright  John Calambokidis  Erin A. Falcone  Debbie Steel  Tomas Follett  Jason Holmberg  C. Scott Baker 《Transactions in GIS》2014,18(3):324-350

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Uneven development of the sustainable city: shifting capital in Portland,Oregon     

Erin Goodling  Jamaal Green 《Urban geography》2013,34(4):504-527

Portland, Oregon, is renowned as a paradigmatic “sustainable city.” Yet, despite popular conceptions of the city as a progressive ecotopia and the accolades of planners seeking to emulate its innovations, Portland’s sustainability successes are inequitably distributed. Drawing on census data, popular media, newspaper archives, city planning documents, and secondary source histories, we attempt to elucidate the structural origins of Portland’s “uneven development,” exploring how and why the urban core of this paragon of sustainability has become more White and affluent while its outer eastside has become more diverse and poor. We explain how a “sustainability fix”—in this case, green investment in the city’s core—ultimately contributed to the demarcation of racialized poverty along 82nd Avenue, a major north–south arterial marking the boundary of East Portland. Our account of structural processes taking place at multiple scales contributes to a growing body of literature on eco-gentrification and displacement and inner-ring suburban change while empirically demonstrating how Portland’s advances in sustainability have come at the cost of East Portland’s devaluation. Our “30,000 foot” perspective reveals systemic patterns that might then guide more fine-grained analyses of particular political-socio-cultural processes, while providing cautionary insights into current efforts to extend the city’s sustainability initiatives using the same green development model.  相似文献   

Determining the impact of the Holocene highstand at the coastal‐fluvial interface,Shoalhaven River,south‐eastern Australia     

Stephanie J. Kermode  Martin R. Gibling  Brian G. Jones  Tim J. Cohen  David M. Price  James S. Daley 《地球表面变化过程与地形》2013,38(13):1481-1495

With enhanced rates of sea‐level rise predicted for the next century, the upstream extent of sea‐level influence across coastal plains is a topic of public importance. Australian coastal rivers provide a testing ground for exploring this issue because the area is tectonically stable, was not glaciated, and experienced a Holocene highstand between 7.4 and 2 ka of up to 1.5 m above Australian Height Datum (AHD). In the Shoalhaven River of New South Wales, investigation of a confined bedrock reach at Wogamia, 32 km inland, has identified a unit of dark, cohesive silt and sand with marine diatoms, shell fragments, and enhanced pyrite content, interpreted as estuarine. The unit is up to 13 m thick, thickens downstream, and is overlain by fluvial channel and floodplain deposits. The estuarine unit on‐laps a remnant Pleistocene terrace and extends to approximately +2.2 m AHD. Optically stimulated luminescence (OSL) and radiocarbon ages suggest that estuarine deposition commenced prior to 7.8 ka cal bp , predating the highstand by ~ 500 years, and that marine influence in the area continued to 5.3 ± 0.7 ka. During this period, a delta probably persisted at Wogamia, where a narrow upstream reach opens out, and subsequently advanced to fill the broad Shoalhaven coastal embayment. Although the effect of sea‐level rise depends on many factors, the results suggest that, during a highstand at or above present sea level, a strong marine influence may extend for tens of kilometres inland and penetrate confined bedrock reaches landward of coastal embayments. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Water Level Declines in the High Plains Aquifer: Predevelopment to Resource Senescence   总被引：1，自引：0，他引：1       下载免费PDF全文

Erin M. K. Haacker  Anthony D. Kendall  David W. Hyndman 《Ground water》2016,54(2):231-242

A large imbalance between recharge and water withdrawal has caused vital regions of the High Plains Aquifer (HPA) to experience significant declines in storage. A new predevelopment map coupled with a synthesis of annual water levels demonstrates that aquifer storage has declined by approximately 410 km³ since the 1930s, a 15% larger decline than previous estimates. If current rates of decline continue, much of the Southern High Plains and parts of the Central High Plains will have insufficient water for irrigation within the next 20 to 30 years, whereas most of the Northern High Plains will experience little change in storage. In the western parts of the Central and northern part of the Southern High Plains, saturated thickness has locally declined by more than 50%, and is currently declining at rates of 10% to 20% of initial thickness per decade. The most agriculturally productive portions of the High Plains will not support irrigated production within a matter of decades without significant changes in management.  相似文献   

A general scheme for modelling γ-ray burst prompt emission     

Pawan Kumar  Erin McMahon 《Monthly notices of the Royal Astronomical Society》2008,384(1):33-63

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A multi-perspective examination of heat waves affecting Metro Vancouver: now into the future     

Ronald E. Stewart  Daniel Betancourt  James B. Davies  Deborah Harford  Yaheli Klein  Robert Lannigan  Linda Mortsch  Erin O’Connell  Kathy Tang  Paul H. Whitfield 《Natural Hazards》2017,87(2):791-815

Using studies of places where heat waves are common, projected changes in heat waves in Metro Vancouver are assessed from a multi-disciplinary perspective with respect to the potential impacts of the physical change on the people and infrastructure with the intention of being better prepared for future events. Trends in maximum temperature parameters for Metro Vancouver for the past 75 years are generally not statistically significant; however, projections for 2041–2060 and 2081–2100 suggest that the region will experience such events more frequently in the future due to climate change. While Metro Vancouver, British Columbia (BC) generally does not typically experience heat waves it was strongly affected by a major heat event in July 2009, with temperature records being broken at Vancouver (≥31 °C) on the coast and at Abbotsford (≥36 °C) 65-km inland. A lack of sea breeze during this event meant that there was no cooling effect, and land surface temperatures over the downtown area approached 40 °C and excess deaths occurred. Many victims were either in the 65–74 age category, the vulnerable poor, or people with mental health issues. Because these events are rare, many buildings lack air-conditioning, and residents of Metro Vancouver under-anticipate their vulnerability. The costs of health-related impacts outweighed those related to higher electricity usage.  相似文献   

Modeling anthropogenic boron in groundwater flow and discharge at Volusia Blue Spring (Florida,USA)     

Erin M. Reed  Dingbao Wang  Steven J. Duranceau 《Hydrogeology Journal》2017,25(1):91-101

Volusia Blue Spring (VBS) is the largest spring along the St. Johns River in Florida (USA) and the spring pool is refuge for hundreds of manatees during winter months. However, the water quality of the spring flow has been degraded due to urbanization in the past few decades. A three-dimensional contaminant fate and transport model, utilizing MODFLOW-2000 and MT3DMS, was developed to simulate boron transport in the Upper Florida Aquifer, which sustains the VBS spring discharge. The VBS model relied on information and data related to natural water features, rainfall, land use, water use, treated wastewater discharge, septic tank effluent flows, and fertilizers as inputs to simulate boron transport. The model was calibrated against field-observed water levels, spring discharge, and analysis of boron in water samples. The calibrated VBS model yielded a root-mean-square-error value of 1.8 m for the head and 17.7 μg/L for boron concentrations within the springshed. Model results show that anthropogenic boron from surrounding urbanized areas contributes to the boron found at Volusia Blue Spring.  相似文献   

Joint cross-well and single-well seismic studies of CO₂ injection in an oil reservoir     

R. Gritto  T.M. Daley  L.R. Myer 《Geophysical Prospecting》2004,52(4):323-339

A series of time‐lapse seismic cross‐well and single‐well experiments were conducted in a diatomite reservoir to monitor the injection of CO₂ into a hydrofracture zone, based on P‐ and S‐wave data. A high‐frequency piezo‐electric P‐wave source and an orbital‐vibrator S‐wave source were used to generate waves that were recorded by hydrophones as well as 3‐component geophones. During the first phase the set of seismic experiments was conducted after the injection of water into the hydrofractured zone. The set of seismic experiments was repeated after a time period of seven months during which CO₂ was injected into the hydrofractured zone. The questions to be answered ranged from the detectability of the geological structure in the diatomic reservoir to the detectability of CO₂ within the hydrofracture. Furthermore, it was intended to determine which experiment (cross‐well or single‐well) is best suited to resolve these features. During the pre‐injection experiment, the P‐wave velocities exhibited relatively low values between 1700 and 1900 m/s, which decreased to 1600–1800 m/s during the post‐injection phase (?5%). The analysis of the pre‐injection S‐wave data revealed slow S‐wave velocities between 600 and 800 m/s, while the post‐injection data revealed velocities between 500 and 700 m/s (?6%). These velocity estimates produced high Poisson's ratios between 0.36 and 0.46 for this highly porous (～50%) material. Differencing post‐ and pre‐injection data revealed an increase in Poisson's ratio of up to 5%. Both velocity and Poisson's ratio estimates indicate the dissolution of CO₂ in the liquid phase of the reservoir accompanied by an increase in pore pressure. The single‐well data supported the findings of the cross‐well experiments. P‐ and S‐wave velocities as well as Poisson's ratios were comparable to the estimates of the cross‐well data. The cross‐well experiment did not detect the presence of the hydrofracture but appeared to be sensitive to overall changes in the reservoir and possibly the presence of a fault. In contrast, the single‐well reflection data revealed an arrival that could indicate the presence of the hydrofracture between the source and receiver wells, while it did not detect the presence of the fault, possibly due to out‐of‐plane reflections.  相似文献   

Process-based snowmelt modeling: does it require more input data than temperature-index modeling?   总被引：4，自引：0，他引：4  

M. Todd Walter  Erin S. Brooks  Donald K. McCool  Larry G. King  Myron Molnau  Jan Boll 《Journal of Hydrology》2005,300(1-4):65-75

Modeling snow hydrology for cold regions remains a problematic aspect of many hydro-environmental models. Temperature-index methods are commonly used and are routinely justified under the auspices that process-based models require too many input data. To test this claim, we used a physical, process-based model to simulate snowmelt at four locations across the conterminous US using energy components estimated from measured daily maximum and minimum temperature, i.e. using only the same data required for temperature-index models. The results showed good agreement between observed and predicted snow water equivalents, average R²>0.9. We duplicated the simulations using a simple temperature-index model best fitted to the data and results were poorer, R²<0.8. At one site we applied the process-based model without substantial parameter estimation, and there were no significant (=0.05) differences between these results and those obtained using temperature-estimated parameters, despite relatively poorly predicted specific energy budget components (R²<0.8). These results encourage the use of mechanistic snowmelt modeling approaches in hydrological models, especially in distributed hydrological models for which landscape snow distribution may be controlled by spatially distributed components of the environmental energy budget.  相似文献   

Rhizome growth dynamics of native and exotic haplotypes ofPhragmites australis (Common reed)     

Michael T. League  Erin P. Colbert  Denise M. Seliskar  John L. Gallagher 《Estuaries and Coasts》2006,29(2):269-276

Phragmites australis (common reed), a clonal grass, has expanded from a minor component of the mid-Atlantic wetlands to a dominant species. It has been suggested that invasive populations ofPhragmites are an exotic haplotype responsible for the dramatic increase in the distribution of the species. We used field observations and measurements and a greenhouse assay to compare native (haplotype F) and exotic (haplotype M) populations, growing adjacent to one another in a brackish marsh near Odessa, Delaware. In the marsh, shoots of the exotic strain emerged from the rhizomes earlier than those of the native and by March there was an order of magnitude more new shoots of the exotic strain than the native. In August, the exotic strain was 30% taller than the native, had twice the leaf biomass, and twice the total biomass. Nine of ten morphological and biomass characteristics measured differed significantly between the native and exotic strains. A greenhouse assay was conducted by planting rhizomes collected in March in shallow trays and growing them for 70 d followed by shoot harvest (Harvest 1). Rhizomes were measured, replanted, and grown for 35 d after which time they were measured and shoots were harvested (Harvest 2). At Harvest 1, shoot height was approximately 80% greater in the exotic strain, shoot biomass was three times higher, aboveground to belowground biomass ratio was twice as high, and rhizome internode length was 50% greater in the exotic strain than the native. These traits, in addition to number of shoots, were also greater in the exotic strain at Harvest 2. The number of rhizome buds at Harvest 1 was three times greater in the native than in the exotic strain. The greater number of rhizome buds in the native would seem to be an advantage, but it did not result in more shoot production. Buds were maintained in an inactive state that does not allow this strain to compete well in a wetland environment inhabited by a more efficient spreader. The earlier emergence of new shoots from the rhizomes, the greater aboveground structure, the greater rhizome internode length, and the quick transition of rhizome buds to shoot or rhizome explain in part the exotic strain's advantage over the native and the mechanisms for its invasive nature.  相似文献