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781.
The background nickel (Ni) concentrations in the sediments of two sub‐mountain reservoirs (Dobczyce and Czorsztyn) situated in the Carpathian Flysh (southern Poland) were evaluated. Ni concentrations (15.6–83.1 µg g?1 dry wt.) in both reservoir sediments were affected mainly by the high background content of Ni in the surrounding watershed. Distribution of elevated Ni concentrations mostly revealed an impact of long‐range transport influenced by the flow of the main tributary. Ni spatial pattern was mainly influenced by mineral compounds of Fe, Mn, and Al, and to a lesser degree by organic matter content and silt and clay fractions of the sediments of both investigated reservoirs. Spatial distribution was additionally modified by hydrological conditions (flood events and course of the old river‐bed). In both reservoirs, substantial portions of Ni were bound to potentially immobile phases, i.e., moderately reducible and residual phases (64–82% in total). Laboratory experiments showed that changes in pH affected Ni leaching from the sediment to a small degree (at pH ~3 up to 19.9%). Our results indicated that Ni in these reservoirs has low mobility and, therefore, poses a low toxicological risk to aquatic organisms. 相似文献
782.
Andrzej Zuber Kazimierz R��?a��ski Jaros?aw Kania Roland Purtschert 《Hydrogeology Journal》2011,19(1):53-69
Environmental tracers are used qualitatively for a better formulation of conceptual models and quantitatively for assessing groundwater ages with the aid of box models or for calibrating numerical transport models. Unfortunately, tracers often yield different ages that do not represent uniquely the water ages. Difficulties result also from different definitions of age, e.g. water age, advective age, tracer age, or radiometric tracer age, that are measured differently and depend on aquifer parameters and characteristics of particular tracers. Even the movement of an ideal tracer can be delayed with respect to the advective movement of water due to diffusion exchange between mobile and immobile water zones, which for fissured rocks or thin aquifers, may lead to significant differences between advective and tracer ages, i.e. also between advective and tracer velocities. The advective velocity is of importance in water resources considerations as being related to Darcy velocity, whereas the tracer velocity is a more useful term for the prediction of pollutant transport. When a groundwater system changes from one hydrodynamic steady state to another, environmental tracers need much more time to reach a new steady state. Several tracer studies are recalled as examples of tracer-specific effects on the estimations of groundwater age. 相似文献
783.
The recharge mechanism of a very large spring area in the town of Zieleniec in the Orlickie Mountains (part of the Sudety mountain chain) in southwestern Poland, was investigated and characterized. The spring area is located on a steep mountain slope at a high elevation, next to the continental water divide. It is estimated that at least 90% of the spring discharge comes from outside its topographic drainage basin. The study area has been strongly affected by tectonic episodes of different ages. Thus, there is a high density of fractures in the crystalline massif, which determines the water content of the area and the occurrence of large springs. The low variability in discharge of the Zieleniec spring area indicates the presence of a strong and stable component source of recharge. It has also been shown that gravitational drainage of solid-rock blocks and small fissures is also an important recharge component. The stable recharge component is associated with deep-water circulation from the B?lá River drainage basin in the Czech Republic, flowing beneath the continental divide. Water flows in conformity with a high hydraulic head gradient through deep, open, NW?CSE-oriented fissures. 相似文献
784.
The impacts of the Florida Energy and Climate Change Action Plan on the state's economy are analysed. The plan contains 50 policy recommendations developed through a stakeholder-driven, consensus-based process. The analysis carefully links each greenhouse gas mitigation/sequestration option to the workings of the Florida economy with the use of the Regional Economic Models, Inc. (REMI) Policy Insight model. The results indicate that most of the recommended options individually have positive impacts on the state's economy. When combined, the plan's recommendations would, on a net present value basis, increase the gross state product (GSP) by about $37.9 billion and increase employment by 148,000 full-time equivalent jobs by 2025. The Florida Renewable Portfolio Standard contributes the highest GSP gains, or nearly 50% of the total. The economic gains arise primarily from the ability of mitigation options to both lower the cost of production and increase consumer purchasing power. The results also stem from the stimulus of increased investment in plant and equipment. Sensitivity analyses of key assumptions and parameters indicate that the results are robust. 相似文献
785.
786.
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
787.
Several samples of peat from 6 bogs located in southern Poland were investigated for occurrence and distribution types of biomarkers present in their extractable organic matter fraction. It was found that there are inputs from two different sources of organic compounds differing in their characteristics and origin: (1) recent immature peat organic matter deposited in situ which is the source of all polar functionalized compounds, most of n-alkanes, and acyclic isoprenoids, and (2) mature fossil fuels, most probably bituminous coals from the Upper Silesia Coal Basin of vitrinite reflectance equivalent values of 0.9–1.1%. The latter compounds were most probably transported with fly ash to bogs from nearby settlements utilizing such fuel in domestic ovens. This group includes pentacyclic triterpenoids (hopanes and moretanes), minor amounts of n-alkanes, and numerous alkyl naphthalenes and alkyl phenanthrenes. All these compounds show distributions and values of geochemical ratios characteristic for mature organic matter confirming there ex situ origin. 相似文献
788.
Abdou Abouelmagd Mohamed Sultan Neil C. Sturchio Farouk Soliman Mohamed Rashed Mohamed Ahmed Alan E. Kehew Adam Milewski Kyle Chouinard 《Quaternary Research》2014
Sixteen groundwater samples collected from production wells tapping Lower Cretaceous Nubian Sandstone and fractured basement aquifers in Sinai were analyzed for their stable isotopic compositions, dissolved noble gas concentrations (recharge temperatures), tritium activities, and 14C abundances. Results define two groups of samples: Group I has older ages, lower recharge temperatures, and depleted isotopic compositions (adjusted 14C model age: 24,000–31,000 yr BP; δ18O: − 9.59‰ to − 6.53‰; δ2H: − 72.9‰ to − 42.9‰; < 1 TU; and recharge T: 17.5–22.0°C) compared to Group II (adjusted 14C model age: 700–4700 yr BP; δ18O: − 5.89‰ to − 4.84‰; δ2H: − 34.5‰ to − 24.1‰; < 1 to 2.78 TU; and recharge T: 20.6–26.2°C). Group II samples have isotopic compositions similar to those of average modern rainfall, with larger d-excess values than Group I waters, and locally measurable tritium activity (up to 2.8 TU). These observations are consistent with (1) the Nubian Aquifer being largely recharged prior to and/or during the Last Glacial Maximum (represented by Group I), possibly through the intensification of paleowesterlies; and (2) continued sporadic recharge during the relatively dry and warmer interglacial period (represented by Group II) under conditions similar to those of the present. 相似文献
789.
Adam Radzimski 《GeoJournal》2014,79(4):467-494
While a couple of decades ago homeownership used to be a privilege of the few, nowadays most households in developed countries are living in their own four walls. One of the reasons behind this shift are government policies aimed at promoting homeownership and making it more financially feasible. Among these policies, there is a wide range of instruments reducing the costs of mortgage loan interest. Recently, the promotion of homeownership has also become an important issue in some of the former socialist countries. An example of that is a policy of the Polish government called “Family’s own home”. The aim of this policy was to provide financial support for young households who are particularly vulnerable to the difficult housing situation in Poland. Due to huge price increases between 2006 and 2008, and in connection with a short supply of rental housing, many households have been unable to find an affordable dwelling in recent years. The “Family’s own home” policy, initiated in 2007, was the government’s response to this problem. The purpose of this paper is to investigate the outcomes of this policy, which was terminated at the end of 2012 because of a public finance crisis. Three research questions are addressed: (1) what was the relationship between government support and residential construction, housing prices, and mortgage loan interest rate, (2) what was the spatial distribution of government support, and (3) how was it related to the spatial distribution of housing prices, incomes, and housing affordability? 相似文献
790.
Tomasz Kamiński 《Singapore journal of tropical geography》2023,44(1):58-74
In a polycentric world, cities increasingly bear responsibility for implementing climate policies. To do so, they establish transnational city networks (TCNs), which produce ambitious imaginaries of the future of cities, such as ‘smart cities’ or ‘resilient cities’, based on ecological knowledge. This paper analyses Southeast Asian (SEA) cities’ participation in TCNs. First, this paper presents city networks operating in SEA. Then, drawing on a case study of Quezon City, this paper shows how SEA cities often position themselves in the network as knowledge consumers rather than (co)producers and prefer to learn from cities in the Global North. This research also shows how TCNs—with limited success—seek to counter this neo-colonial knowledge flow model. The paper contributes to the literature on TCNs, arguing that the ongoing North–South imbalance needs to be addressed if networks are to promote viable models of future SEA cities. Identifying the patterns of knowledge flows inside TCNs, this study argues that networks should assist cities in imagining possible city futures beyond the experiences of the select world and global cities. TCNs should pay more attention to supporting their SEA members in looking ‘outwards’ to comparable cities worldwide rather than merely ‘upwards’ to global and mega-cities. 相似文献