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1.
The hydrogeomorphic (HGM) approach to wetland classification and functional assessment is becoming more widespread in the United States but its use has been limited by the length of time needed to develop appropriate data sets and functional assessment models. One particularly difficult aspect is the transferability among geographic regions of specific models used to assess wetland function. Sharing of models could considerably shorten development and implementation of HGM throughout the United States and elsewhere. As hydrology is the driving force behind wetland functions, we assessed the comparability of hydrologic characteristics of three HGM subclasses (slope, headwater floodplain, mainstem floodplain) using comparable long-term hydrologic data sets from different regions of the United States (Ridge and Valley Province in Pennsylvania and the Willamette Valley in Oregon). If hydrology by HGM subclass were similar between different geographic regions, it might be possible to more readily transfer extant models between those regions. We found that slope wetlands (typically groundwater-driven) had similar hydrologic characteristics, even though absolute details (such as depth of water) differed. We did not find the floodplain subclasses to be comparable, likely due to effects of urbanization in Oregon, regional differences in soils and, perhaps, climate. Slight differences in hydrology can shift wetland functions from those mediated by aerobic processes to those dominated by anaerobic processes. Functions such as nutrient cycling can be noticeably altered as a result. Our data suggest considerable caution in the application of models outside of the region for which they were developed.  相似文献   

2.
Detailed studies on pollutants genesis, path and transformation are needed in agricultural catchments facing coastal areas. Here, loss of nutrients should be minimized in order to protect valuable aquatic ecosystems from eutrophication phenomena. A soil system N budget was calculated for a lowland coastal area, the Po di Volano basin (Po River Delta, Northern Italy), characterized by extremely flat topography and fine soil texture and bordering a network of lagoon ecosystems. Main features of this area are the scarce relevance of livestock farming, the intense agriculture, mainly sustained by chemical fertilizers, and the developed network of artificial canals with long water residence time. Average nitrogen input exceeds output terms by ~60 kg N ha?1 year?1, a relatively small amount if compared to sub-basins of the same hydrological system. Analysis of dissolved inorganic nitrogen in groundwater suggests limited vertical loss and no accumulation of this element, while a nitrogen mass balance in surface waters indicates a net and significant removal within the watershed. Our data provide multiple evidences of efficient control of the nitrogen excess in this geographical area and we speculate that denitrification in soil and in the secondary drainage system performs this ecosystemic function. Additionally, the significant difference between nitrogen input and nitrogen output loads associated to the irrigation system, which is fed by the N-rich Po River, suggests that this basin metabolizes part of the nitrogen excess produced upstream. The traditionally absent livestock farming practices and consequent low use of manure as fertilizer pose the risk of excess soil mineralization and progressive loss of denitrification capacity in this area.  相似文献   

3.
The river Don catchment area in Sheffield and Rotherham offers a good place for a case study of flood risk management, given the impact of a flooding event in 2007 and the way in which local events have become entwined with national and international policy shifts. To interpret local policy, a combination of systems-based and socio-cultural theory is used. Both the theories and the case study serve to disentangle the multiple meanings of resilience. Understood in opposition to flood resistance, resilience has only limited applicability in an area such as the case study where engineering works protect employment and infrastructure. Resilience as a policy discourse also lacks political transparency and a recognition of socio-cultural influences. Underlying the shift towards resilient styles of management is an appreciation of the importance of capacity, to learn and to act. The case study identifies blockages to the realisation of that capacity.  相似文献   

4.
African governments, like most countries in the developing world, face daunting tasks in their attempts to provide effective and equitable water and sanitation services for their ever increasing urban populations. Consequently, the past few years have witnessed increased private sector participation in urban water and sanitation provision, as many African governments strive to improve access to water and sanitation services for their citizens in line with Millennium Development Goal 7 (MDG7). Since the early 1990s, the government of Ghana and many local authorities have entered into various forms of public-private partnerships in urban water and sanitation provision. This article examines the outcome of such partnerships using the Tamale Metropolitan Area (TMA) as a case study with the aim of providing policy guidelines for the way forward. The article argues that the public-private arrangement for water supply and sanitation infrastructure management in the Tamale Metropolis has done nothing that an invigorated public sector could not have possibly achieved. It concludes that there can be no sustainable improvement in water and sanitation provision without political commitment, stakeholder ownership, and strong support for community driven initiatives.  相似文献   

5.
Protected areas cannot be considered as elements isolated from the human groups that inhabit them. Consideration of the social factor is fundamental to guarantee the success of any management model. In this sense, analyzing the perception of people who live in protected areas can be a key tool for the formulation of proposals for improving the existing models. This article explores perceptions of local residents in the Sierra Nevada Protected Area in Southern Spain and identifies the socio-demographic factors that affect these perceptions. The main objective is to generate relevant data for the protected area management team. The recommendations we can offer entail a review of the communication plan and participatory strategy considering social differences in perceptions of the local population.  相似文献   

6.
The present research focused on using spatial analysis to determine relationships among land ownership property sizes and landscape structure, with a focus on conservation management implications. Indices and metrics of ownership property sizes and landscape structure were calculated for 20 km buffer areas around 31 North American Breeding Bird Survey transects, 12 located within the Edwards Plateau ecoregion and 18 in contiguous ecoregions. The number of bird species observed at each transect provided a measure of avian species richness associated with land cover classes for each respective transect (González in Urban influence on diversity of avifauna in the Edwards Plateau of Texas: effect of property sizes on rural landscape structure, Texas A&M University, 2005). Spatial correlations were calculated between each pair of the landscape indices. Spatial analysis identified a “threshold of habitat fragmentation” for the 500 acre (ac) ownership property size. Significant spatial correlations among variables showed that property sizes lower than 500 ac produced habitat fragmentation represented by a decrease in mean patch size (MN) and proximity among habitat patches (Index PROX). Spatial analysis also made possible the prioritization of ecological sub-regions of the Edwards Plateau for conservation or restoration. The Live Oak-Mesquite Savannah showed the highest average ownership property size (7305 ac) and the highest values of patch richness. Based on the results, management in the Live Oak-Mesquite Savannah sub-region should focus on the conservation of land mosaic diversity to assure native avian species turnover (Whittaker 1972). In Balcones Canyon Lands, 64 % of land was covered by farms smaller than 500 ac and the overall average ownership property size was above the threshold of fragmentation (1440 ac), implying that management policies there should focus both on habitat conservation and on restoration. In contrast, 71 % of land in the Lampasas Cut Plains was covered by farms smaller than 500 ac, and average ownership property size was very close to the fragmentation threshold (625 ac). Consequently, the results indicate that management in the Lampasas Cut Plains sub-region should focus on habitat restoration (e.g., corridors that connect isolated habitat patches). In general, the threshold of ownership property size, 500 ac, is important for conservation planning because below that threshold of property size, habitat patch size begins to decrease and the distance between equivalent patches of habitat increases. Isolated patches act as islands within a sea of less suitable habitat which produce negative effects on biodiversity. Identifying the spatial characteristics indicative of habitat fragmentation, or the likelihood thereof, is an important issue for conservation planning in places with urban sprawl influence.  相似文献   

7.
Macroinvertebrates were examined on an impounded valley marsh in Stonington, Connecticut, that has changed from aTypha-dominated system to one with typical salt-marsh vegetation during 13 years following the reintroduction of tidal exchange. Animal populations on this restored impounded marsh were evaluated by comparing them with populations on a nearby unimpounded valley marsh of roughly the same size. Populations of the high marsh snail,Melampus bidentatus Say, were quantitatively sampled along transects that extended from the water-marsh edge to the upland; those of the ribbed mussel,Geukensia demissa Dillwyn, were sampled in low marsh areas on transects along the banks of creeks and mosquito ditches. The occurrence of other marsh invertebrates also was documented, but their abundance was not measured. The mean density ofMelampus was 332±39.6 SE/m2 on the restored impounded marsh and 712±56.0 SE/m2 on the unimpounded marsh. However, since snails were larger on the restored impounded marsh, the difference in snail biomass was less pronounced than the difference in snail density. MeanMelampus biomass was 4.96±0.52 SE g dry wt/m2 on the restored impounded marsh and 6.96±0.52 SE g dry wt/m2 on the unimpounded marsh. On the two marshes, snail density and biomass varied in relation to plant cover and other factors. The density and biomass ofGeukensia at the edge of the marsh were comparable on the restored impounded and unimpounded marshes. Mean mussel densities ranged from 80 to 240/m2 and mean mussel biomass varied from 24.8–64.8 g dry wt/m2 in different low marsh areas. In contrast, below the impoundment dike, meanGeukensia density was 1100±96.4 SE/m2 and meanGeukensia biomass was 303.6±33.28 SE g dry wt/m2. A consideration of all available evidence leads to the conclusion that the impounded marsh is in an advanced phase of restoration.  相似文献   

8.
ABSTRACT

This study explores the experience of the sub-urban slum residents in Okpoko (Anambra State), Ngwa-road Aba (Abia State), Ajegunle (Lagos State) and Gwagwalada (Abuja), to underscore the elitist and western contexts of Covid-19 lockdown and physical distancing policies. The study apprehends these policies as being counter-productive due to Nigeria’s peculiar socio-economic circumstances, and brainstorms on the need and prospects for adaption and institutionalisation of an indigenous Afro-centred approach towards the containment of the Covid-19 pandemic. The use of herbal mixtures or local concoctions such as parboiled garlic cloves, lemon and ginger juice in the treatment and/or prevention of Covid-19 pandemic is a popular home-grown indigenous approach/practice which is generally believed to have inhibitory effects against Covid-19 by majority of the local people. These herbal remedies should be formally investigated, validated and encouraged in Nigeria as an alternative indigenous approach for the prevention and treatment of Covid-19 pandemic.  相似文献   

9.
ABSTRACT

This article explores the need to recognise and compensate the plurality of environmental justice claims, while paying close attention to the outcomes of the most marginalised groups – cultural and ecological – in political decision-making to avoid vestiges of hegemony. The early history of the Movimiento dos Trabalhadores Rurais sem Terra (MST) serves as a case study in which environmental justice claims clash with indigenous rights claims. In recent decades, the MST has refused settling Amazonian indigenous territories, consistent with the organisation’s Via Campesina platform, which focuses on redistributing the 50% of national territory controlled privately by Brazil’s richest 4%. Yet, in the 1970s and early 1980s, Brazil’s military government pitted landless peasants and indigenous people’s struggles against each other, circumventing land reform potentially disruptive to the country’s de facto colonial fazenda land system. This tactic pressured competing groups – landless peasants and indigenous people – to fight against each other, concluding predictably: the most powerful factions ended up getting their way, conceding less in negotiations than their less-advantageously positioned, marginalised counterparts. When marginalised groups gain concessions in environmental justice struggles, often the goods comprising those concessions come at a cost to marginalised groups with even less political visibility. Hegemonic structures of power remain non-negotiable in the process of alleviating other injustices in perceived zero-sum politics. Such systemic displacement and dispersion of violence in systems built on violence suggests hegemony affects not just to other marginalised groups, but to nonhumans too.  相似文献   

10.
Electronic waste (e‐waste) is one of the fastest growing waste streams in the world. Notwithstanding increasing concern worldwide, e‐waste has not yet been discussed in depth in the Middle East and North Africa (MENA) region. This study first reviews the literature regarding the estimation of e‐waste in the MENA region. It then gives an estimate of the past and future trends in the generation of obsolete computers in Algeria. For this purpose, the study combines two models: the Carnegie Mellon model and the market supply (distribution delay) model. The Carnegie Mellon model offers the following options for obsolete computers and monitors: the device could be reused, stored, or discarded. The amounts of devices falling into each category were determined based on these options. The outcomes from the market supply (distribution delay) model show that high amounts of computer and monitor waste were registered for the period from 2014 to 2016.  相似文献   

11.
In this article, I explain the role that scientific studies play in shaping collaboration and conflict over mining exploration in the Ecuadorian highlands. Toronto-based IAMGOLD conducted water quality studies to simultaneously fulfill legal obligations and secure support for drilling in an environmentally sensitive zone. With these studies, IAMGOLD generated collaborative relations with local authorities and university scientists. However, water quality studies were also used by dairy farmers to establish new connections for an opposition movement. The scientific studies enabled IAMGOLD and the dairy farmers to make competing claims about the responsibility for contamination of an important watershed. This article analyzes the conflict that resulted and challenges conventional wisdom that distinguishes a corporation's legal obligations from its voluntary CSR programs.  相似文献   

12.
Adsorption of Pb and Cd in the presence and absence of organochlorine pesticides (OCPs) on natural surface coatings (NSCs), which were collected in the Nanhu Lake in Changchun, China, was measured in order to investigate the effect of the OCPs on the adsorption of heavy metals on the NSCs. Adsorption of Pb/Cd was carried out under controlled laboratory conditions (mineral salt solution with defined species, ionic strength 0.05 mol/l, 25 degrees C and pH 6.0) with initial Pb and Cd concentrations ranging from 0.2 to 2.5 mol/l. The classical Langmuir adsorption isotherm was applied to estimate the equilibrium coefficients of the adsorption of Pb and Cd on the NSCs. Adsorption interference between Pb/Cd and the OCPs on the NSCs indicated that the adsorption of Pb/Cd on the NSCs was influenced by the OCPs, and competitive adsorption between Pb and the OCPs was observed while adsorption of Cd was enhanced by addition of the OCPs. Adsorption data fit the Langmuir isotherm well for the NSCs treated with the OCPs at different equilibrium concentrations. The results showed that the amount of adsorbed Pb decreased by more than 40% while the amount of adsorbed Cd increased by over 60% with an increase in the initial concentrations of the OCPs ranging from 0 to 5.0 microg/l and that adsorption of Pb/Cd on the NSCs was strongly affected by the OCPs. This preliminary study highlights the importance of the OCPs on the NSCs in controlling the transport, fate, biogeochemistry, bioavailability and toxicity of trace metals in aquatic environments.  相似文献   

13.
This paper explores the nature of tri-sector partnerships applied to community development in the mining sector. The case study approach was used to examine an initiative for environmental improvement and socio-economic development in the diamond province of the Republic of Sakha (Yakutia), in the Russian Federation. The study follows the journey of this initiative from a potential tri-sector partnership model between the diamond mining company ALROSA, the Government of the Republic of Sakha (Yakutia) and the SAPI Foundation, to a bi-lateral partnership between ALROSA and the Government represented by the Target Fund. The study explores the community development in the diamond province in the light of economic and political transition within the mining sector of the Russian Federation.  相似文献   

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Urban green/blue spaces are put under pressure as urban areas grow, develop and evolve. It is increasingly recognized, however, that green/blue spaces provide important ecosystem services, stimulate higher real estate prices and prevent flooding problems. This paper aims to assess and compare the socio-economic impacts of potential green/blue space, urban residential and road infrastructure development scenarios in the Lyon Confluence project area (France), using the Sustainable Urbanizing Landscape Development (SULD) hedonic pricing simulation model. Results show four major tendencies regarding the value-added of green/blue spaces in urban landscapes: (1) cities become more compact; (2) population densities increase; (3) real estate values rise; and (4) demographic distribution patterns change. The magnitude of these impacts depends, however, on the quality and size of the intervention, the social classes attracted to the intervention area and on the location of the intervention relative to existing residential areas, urban centres, road infrastructure and environmental amenities.  相似文献   

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Japan's rural regions have been shrinking for the entire post-war period, and successive efforts to revitalise rural society have failed. This article examines whether the Great East Japan Earthquake and tsunami, and the subsequent meltdown at the Fukushima Daiichi nuclear power plant, present the Japanese state and society with a watershed opportunity to rethink regional revitalisation and national energy procurement strategies. The article begins by summarising the events of March and April 2011, examines possible approaches to the reconstruction of communities in the Tōhoku region, and critiques problems of governance in post-war Japan that the disaster reveals. It concludes by pulling together the information and analysis presented into a discussion of the prospects for achieving the three-point vision for a safe, sustainable, and compassionate society that Prime Minister Naoto Kan set the Reconstruction Design Council.  相似文献   

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