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691.
A. V. Ivanov M. Braun D. G. Zamolodchikov S. Yu. Loshakov O. V. Pototskii 《Russian Journal of Ecology》2018,49(4):306-311
Carbon dioxide fluxes from the surface of coarse woody debris (CWD) have been measured in Korean pine forests of the southern Sikhote-Alin mountain range. The seasonal dynamics of oxidative conversion of CWD carbon have been evaluated, and average values of the CO2 emission rate have been determined for CWD fragments of three tree species at different stages of decomposition. The degree of decomposition is an important factor of spatial variation in CO2 emission rate, and temporal variation in this parameter is adequately described by an exponential function of both CWD temperature and air temperature (R2 = 0.65–0.75). 相似文献
692.
Heat waves and heat-related stresses are increasing environmental concerns in urban areas. The impact of heat waves is dependent on the intensity and duration of each event and on underlying environmental and socio-demographic factors which influence population vulnerability. In order to develop effective adaptation strategies, it is important to develop a method to clearly identify the most vulnerable areas based on these factors. The purpose of this study is to develop and map a heat wave vulnerability index combined with heat exposure analysis to identify areas where interventions can be targeted. The vulnerability index was derived from a principle component analysis of eight key variables that influence heat wave vulnerability. Eight proxy measures of vulnerability were obtained from 2010 census and land-use data for the 1904 census districts of Osaka City. Three principle components explained >77 % of the variance (age, employment and education; social isolation; density and lack of green space). The components were combined and weighted to produce a vulnerability score for each census district. The vulnerability scores ranged from 0 to 106, were categorised into eight vulnerability levels and were overlaid with fine-scale air temperature observations. The resulting output identified the distribution of population vulnerability and exposure. This assessment of vulnerability, combining exposure and sensitivity components, can provide precedent for efficient, targeted action to be taken to reduce the impact of heat waves at present and under climate change. 相似文献
693.
T. Chen M. Liu Y. Takahashi J.D. Mullen G.C.W. Ames 《Journal of Environmental Planning and Management》2016,59(6):948-966
Three different sizes of hog farms were selected to analyze the carbon emissions reduction and the cost–benefit of three methane digester systems. The sizes of the digesters are 2,200, 2,200 and 800 m3, respectively. The sales of slaughter hogs from them are 50,000, 35,000 and 10,000 head, respectively. The carbon emissions reductions were 5,237, 4,017, and 1,334 tons, respectively. The results show that while the methane digester systems have a significant effect on carbon emissions reduction, it is difficult to operate the systems sustainably. If the carbon emissions reduction can be traded at high enough prices in the carbon offset markets, then the systems will be profitable and sustainable. Newly established China's domestic carbon offset market could provide this possibility, but more government support is needed. In addition, this study shows that scale economies make the digester adoption relatively more profitable for larger farms than smaller ones. 相似文献
694.
Building a community that is resilient to disasters has become one of the main goals of disaster management. Communities that are more disaster resilient often experience less impact from the disaster and reduced recovery periods afterwards. This study develops a methodology for constructing a set of indicators measuring Community Disaster Resilience Index (CDRI) in terms of human, social, economic, environmental, and institutional factors. In this study, the degree of community resilience to natural disasters was measured for 229 local municipalities in Korea, followed by an examination of the relationship between the aggregated CDRI and disaster losses, using an ordinary least squares (OLS) regression method and a geographically weighted regression (GWR) method. Identifying the extent of community resilience to natural disasters would provide emergency managers and decision-makers with strategic directions for improving local communities' resilience to natural disasters while reducing the negative impacts of disasters. 相似文献
695.
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697.
Bison and cattle grazing management,bare ground coverage,and links to suspended sediment concentrations in grassland streams
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Bartosz P. Grudzinski Melinda D. Daniels Kyle Anibas David Spencer 《Journal of the American Water Resources Association》2016,52(1):16-30
This study quantified the impact of bison and cattle grazing management practices on bare ground coverage at the watershed, riparian, and forested riparian scales within the Flint Hills ecoregion in Kansas. We tested for correlations between bare ground coverage and fluvial suspended sediment concentrations during base‐flow and storm‐flow events. We used remotely sensed imagery combined with field surveys to classify ground cover and quantify the presence of bare ground. Base‐flow water samples were collected bi‐monthly during rain‐free periods and 24 h following precipitation events. Storm‐flow water samples were collected on the rising limb of the hydrograph, using single‐stage automatic samplers. Ungrazed treatments contained the lowest coverage of bare ground at the watershed, riparian, and forested riparian scales. Bison treatments contained the highest coverage of bare ground at the watershed scale, while high‐density cattle treatments contained the highest coverage of bare ground at the riparian and forested riparian scales. In bison and cattle‐grazed treatments, a majority of bare ground was located near fence lines, watershed boundaries, and third‐ and fourth‐order stream segments. Inorganic sediment concentrations at base flow were best predicted by riparian bare ground coverage, while storm‐flow sediment concentrations were best predicted by watershed scale bare ground coverage. 相似文献
698.
Temporal Trends in the Spatial Distribution of Impervious Cover Relative to Stream Location
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J. Wickham A. Neale M. Mehaffey T. Jarnagin D. Norton 《Journal of the American Water Resources Association》2016,52(2):409-419
Use of impervious cover is transitioning from an indicator of surface water condition to one that also guides and informs watershed planning and management, including Clean Water Act (33 U.S.C. §1251 et seq.) reporting. Whether it is for understanding surface water condition or planning and management, impervious cover is most commonly expressed as summary measurement (e.g., percentage watershed in impervious cover). We use the National Land Cover Database to estimate impervious cover in the vicinity of surface waters for three time periods (2001, 2006, 2011). We also compare impervious cover in the vicinity of surface waters to watershed summary estimates of impervious cover for classifying the spatial pattern of impervious cover. Between 2001 and 2011, surface water shorelines (streams and water bodies) in the vicinity of impervious cover increased nearly 10,000 km. Across all time periods, approximately 27% of the watersheds in the continental United States had proximally distributed impervious cover, i.e., the percentage of impervious cover in the vicinity of surface waters was higher than its watershed summary expression. We discuss how impervious cover spatial pattern can be used to inform watershed planning and management, including reporting under the Clean Water Act. 相似文献
699.
The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) have recently launched themselves as the UN-sanctioned instrument for conserving nature. They seek to establish themselves as the authority in this field alongside the well-known Intergovernmental Panel on Climate Change in climate science. Quickly following or even before recent publication of their conceptual framework in two biology journals, they were already underway building upon it. This headlong push, we believe, is ill advised. We show how the framework is unsound as a foundation for further work—in a number of ways and perhaps even by its authors’ own lights. It is therefore urgent that the IPBES thoroughly and thoughtfully reconsider their framework before too much effort is wasted. 相似文献
700.
Institutional Constraints on Cost‐Effective Water Management: Selenium Contamination in Colorado's Lower Arkansas River Valley
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Misti D. Sharp Dana L.K. Hoag Ryan T. Bailey Erica C. Romero Timothy K. Gates 《Journal of the American Water Resources Association》2016,52(6):1420-1432
Ground and surface water selenium (Se) contamination is problematic throughout the world, leading to harmful impacts on aquatic life, wildlife, livestock, and humans. A groundwater reactive transport model was applied to a regional‐scale irrigated groundwater system in the Lower Arkansas River Basin in southeastern Colorado to identify management practices that remediate Se contamination. The system has levels of surface water and groundwater Se concentrations exceeding the respective chronic standard and guidelines. We evaluate potential solutions by combining the transport model with an assessment of the cost to employ those practices. We use a framework common in economics and engineering fields alike, the Pareto frontier, to show the impact of four different best management practices on the tradeoffs between Se and cost objectives. We then extend that analysis to include institutional constraints that affect the economic feasibility associated with each practice. Results indicate that although water‐reducing strategies have the greatest impact on Se, they are the hardest for farmers to implement given constraints common to western water rights institutions. Therefore, our analysis shows that estimating economic and environmental tradeoffs, as is typically done with a Pareto frontier, will not provide an accurate picture of choices available to farmers where institutional constraints should also be considered. 相似文献