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51.
In-migration to popular ‘sea change’ and ‘tree change’ regions has produced conflicts between rural land users. In the Northern Rivers region of New South Wales, new residential developments have been built on much of what was previously prime agricultural land, while farmers (in particular, those negatively affected by the deregulation of the dairy industry) have sought to secure retirement incomes by subdividing land for sale. Although developers, local councils and individual farmers sometimes see eye to eye on the mutual benefits of in-migration and population growth, land use has none the less become the subject of a hotly contested local political battle. Conflicts occur at the interface of growing urban developments and surrounding farmland, with new residents finding the sights, sounds and smells of rural production intrusive. More generally, there is considerable concern that the best farmland in the region may be lost to urbanisation and rural residential subdivision. This paper discusses the results of a survey that collected opinions from local residents about the pressures on the region's land uses by in-migration, the future role of farmland as both an economic and cultural landscape, and views on proposed measures to protect prime farmland in the region. Results highlighted a strong and consistent ‘pro-farmland’ and ‘pro-protection’ attitude throughout the region, and across social groups. Yet, variations emerged when respondents were asked about why they attribute value to agricultural landscapes. For some, ‘economic’ values dominated, while for others, value was attributed in ways that reflected an emerging ethos of ‘localism’ and village lifestyle. Although values differed, a clear message from this study is that the population of Australia's pre-eminent ‘sea change’ region strongly support measures to curb urban development and the more destructive consequences of a dynamic property market. 相似文献
52.
XU Wang ZHENG Guodong MA Xiangxian Danielle FORTIN David R. HILTON LIANG Shouyun CHEN Zhi HU Guoyi 《《地质学报》英文版》2018,92(6):2201-2213
Organic-inorganic interactions occurring in petroleum-related mud volcanoes can help predict the chemical processes that are responsible for methane emissions to the atmosphere. Seven samples of mud breccia directly ejected from one crater were collected in the Dushanzi mud volcano, along with one argillite sample of the original reddish host rocks distal from the crater, for comparison purposes. The mineral and chemical compositions as well as iron species of all samples were determined using XRD, XRF and M?ssbauer spectroscopy, respectively. The results indicate that a series of marked reactions occurred in the mud volcano systems, more specifically in the mud breccia when compared to the original rocks. Changes mainly included: (1) some conversion of clay minerals from smectite into chlorite and illite, and the precipitation of secondary carbonate minerals such as calcite and siderite; (2) silicon depletion and significant elemental enrichment of iron, manganese, magnesium, calcium and phosphorus; and (3) transformation of iron from ferric species in hematite and smectite into ferrous species in siderite, chlorite and illite. These geochemical reactions likely induced the color changes of the original reddish Neogene argillite to the gray or black mud breccia, as a result of reduction of elements and/or alteration of minerals associated with the oxidation of hydrocarbons. Our results also suggest that greenhouse gases emitted from the mud volcanoes are lowered through a series of methane oxidation reactions and carbon fixation (i.e., through carbonate precipitation). 相似文献
53.
54.
Karen L. Bushaw-Newton Danielle A. Kreeger Sarah Doaty David J. Velinsky 《Estuaries and Coasts》2008,31(4):694-703
Phragmites australis has been invading Spartina-alterniflora-dominated salt marshes throughout the mid-Atlantic. Although, Phragmites has high rates of primary production, it is not known whether this species supports lower trophic levels of a marsh food
web in the same manner as Spartina. Using several related photochemical and biological assays, we compared patterns of organic matter flow of plant primary
production through a key salt marsh metazoan, the ribbed mussel (Geukensia demissa), using a bacterial intermediate. Dissolved organic matter (DOM) was derived from plants collected from a Delaware Bay salt
marsh and grown in the laboratory with 14C-CO2. Bacterial utilization of plant-derived DOM measured as carbon mineralization revealed that both species provided bioavailable
DOM to native salt marsh bacteria. Total carbon mineralization after 19 days was higher for Spartina treatments (36% 14CO2 ± 3 SE) compared with Phragmites treatments (29% ±2 SE; Wilcoxon–Kruskal–Wallis rank sums test, P < 0.01). Pre-exposing DOM to natural sunlight only enhanced or decreased bioavailability of the DOM to the bacterioplankton
during initial measurements (e.g., 7 days or less) but these differences were not significant over the course of the incubations.
Mixtures of 14C-labeled bacterioplankton (and possibly organic flocs) from 14C-DOM treatments were cleared by G. demissa at similar rates between Spartina and Phragmites treatments. Moreover, 14C assimilation efficiencies for material ingested by mussels were high for both plant sources ranging from 74% to 90% and
not significantly different between plant sources. Sunlight exposure did not affect the nutritional value of the bacterioplankton
DOM assemblage for mussels. There are many possible trophic and habitat differences between Spartina- and Phragmites-dominated marshes that could affect G. demissa but the fate of vascular plant dissolved organic carbon in the DOM to bacterioplankton to mussel trophic pathway appears
comparable between these marsh types. 相似文献
55.
In this paper we prove the convergence of a finite volume scheme for the discretization of an elliptic–parabolic problem, namely Richards equation β(P)t?div(K(β(P))× ?(P+z))=0, together with Dirichlet boundary conditions and an initial condition. This is done by means of a priori estimates in L2 and the use of Kolmogorov's theorem on relative compactness of subsets of L2. 相似文献
56.
Ayrton F. Martins Tibiriçá G. Vasconcelos Danielle M. Henriques Carla da S. Frank Armin König Klaus Kümmerer 《洁净——土壤、空气、水》2008,36(3):264-269
This study was carried out to evaluate the occurrence of the fluoroquinolone antimicrobial agent ciprofloxacin (CIP) in the effluent of the Hospital of the Federal University of Santa Maria (HUSM). Measured environmental concentrations (MECs) of CIP in the hospital wastewater, both before (P1) and after (P2) cesspit/filter system treatment (CFTS), were determined by means of solid phase extraction and reversed‐phase liquid chromatography with fluorescence detection (LC‐FLD) and reversed‐phase liquid chromatography with mass spectrometric detection (LC‐MS/MS). The MECs (n = 7 daily composed samples) were 19 to 155 μg L–1 (average: 54 ± 21 μg L–1) and 32 to 99 μg L–1 (average: 65 ± 45 μg L–1) in P1 and P2, respectively. No relevant removal was observed from P1 to P2. In a worst case scenario, the final effluent was regarded as MECs of surface water. These MECs were generally 5 to 20,000‐fold higher than what was previously known. If the present data is drawn on to form a model of the situation in developing countries, the picture provides a first rough indication that the environmental risk associated with the use and emission of pharmaceuticals into the environment in developing countries might be higher than in developed countries. 相似文献
57.
The abrasion of coastal rock platforms by individual or clusters of clasts during transport has not been quantitatively assessed. We present a study which identifies the types of abrasion and quantifies erosion due to the transport of clasts during three storms in February and March 2016. We explore relationships between platform roughness, determined by the fractal dimension (D) of the topographic profiles, geomorphic controls and the type and frequency of abrasion feature observed. Clast transport experiments were undertaken in conjunction with the measurement of wave energy to assess transport dynamics under summer and winter (non‐storm) conditions. Platform abrasion occurred extensively during the storms. We identify two types of clast abrasion trails: simple and complex. In addition, we find two forms of erosion occur on these trails: Scratch marks and Percussion marks. An estimated 13.6 m2 of the platform surface was eroded by clast abrasion on simple abrasion trails during the three storms. We attribute approximately two thirds of this to scratch‐type abrasion. The total volume of material removed by abrasion was 67 808 cm3. Despite the larger surface area affected by scratch marks, we find that the volume of material removed through percussion impact was almost seven times greater. We also find that the type and frequency of abrasion features is strongly influenced by the effect of platform morphometry on transport mode, with impact‐type abrasion dominating areas of higher platform roughness. Results of the clast transport experiments indicate that abrasion occurs under non‐storm wave energy conditions with observable geomorphological effects. We suggest that abrasion by clasts is an important component of platform erosion on high energy Atlantic coastlines, particularly over longer timescales, and that the morphogenetic link between the cliff and the platform is important in this context as the sediment supplied by the cliff is used to abrade the platform. © 2018 John Wiley & Sons, Ltd. 相似文献
58.
Increased criminal activity has been linked to rapid natural resource development, particularly in rural areas. These “boomtowns” often experience rapid population growth, resulting in “social disruption”. This research examines one component of social disruption, crime, in the context of unconventional energy development in Pennsylvania. We employ quantitative longitudinal methods to examine the association between county-level arrest rates for four types of minor crimes and unconventional natural gas well density in Pennsylvania from 2005 to 2014 controlling for demographic and socioeconomic variables. Results indicate that well density is positively associated with driving under the influence and disorderly conduct arrest rates, but is not associated with arrest rates for drug abuse violations or public drunkenness. Findings suggest the need to look beyond broad categories of criminal activity to particular types of crime related to energy development, and to what extent these indicate broader patterns of social disruption. 相似文献
59.
Zarine Kakalia Charuleka Varadharajan Erek Alper Eoin L. Brodie Madison Burrus Rosemary W. H. Carroll Danielle S. Christianson Wenming Dong Valerie C. Hendrix Matthew Henderson Susan S. Hubbard Douglas Johnson Roelof Versteeg Kenneth H. Williams Deborah A. Agarwal 《水文研究》2021,35(6):e14243
The U.S. Department of Energy's (DOE) Colorado East River Community Observatory (ER) in the Upper Colorado River Basin was established in 2015 as a representative mountainous, snow-dominated watershed to study hydrobiogeochemical responses to hydrological perturbations in headwater systems. The ER is characterized by steep elevation, geologic, hydrologic and vegetation gradients along floodplain, montane, subalpine, and alpine life zones, which makes it an ideal location for researchers to understand how different mountain subsystems contribute to overall watershed behaviour. The ER has both long-term and spatially-extensive observations and experimental campaigns carried out by the Watershed Function Scientific Focus Area (SFA), led by Lawrence Berkeley National Laboratory, and researchers from over 30 organizations who conduct cross-disciplinary process-based investigations and modelling of watershed behaviour. The heterogeneous data generated at the ER include hydrological, genomic, biogeochemical, climate, vegetation, geological, and remote sensing data, which combined with model inputs and outputs comprise a collection of datasets and value-added products within a mountainous watershed that span multiple spatiotemporal scales, compartments, and life zones. Within 5 years of collection, these datasets have revealed insights into numerous aspects of watershed function such as factors influencing snow accumulation and melt timing, water balance partitioning, and impacts of floodplain biogeochemistry and hillslope ecohydrology on riverine geochemical exports. Data generated by the SFA are managed and curated through its Data Management Framework. The SFA has an open data policy, and over 70 ER datasets are publicly available through relevant data repositories. A public interactive map of data collection sites run by the SFA is available to inform the broader community about SFA field activities. Here, we describe the ER and the SFA measurement network, present the public data collection generated by the SFA and partner institutions, and highlight the value of collecting multidisciplinary multiscale measurements in representative catchment observatories. 相似文献
60.
Danielle Bailey 《Ground Water Monitoring & Remediation》2013,33(3):92-100
Vapor intrusion pathway evaluations commonly begin with a comparison of volatile organic chemical (VOC) concentrations in groundwater to generic, or Tier 1, screening levels. These screening levels are typically quite low reflecting both a desired level of conservatism in a generic risk screening process as well as limitations in understanding of physical and chemical processes that impact vapor migration in the subsurface. To study the latter issue, we have collected detailed soil gas and groundwater vertical concentration profiles and evaluated soil characteristics at seven different sites overlying chlorinated solvent contaminant plumes. The goal of the study was to evaluate soil characteristics and their impacts on VOC attenuation from groundwater to deep soil gas (i.e., soil gas in the unsaturated zone within 2 feet of the water table). The study results suggest that generic screening levels can be adjusted by a factor of 100× at sites with fine‐grained soils above the water table, as identified by visual observations or soil air permeability measurements. For these fine‐grained soil sites, the upward‐adjusted screening levels maintain a level of conservatism while potentially eliminating the need for vapor intrusion investigations at sites that may not meet generic screening criteria. 相似文献