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351.
Jim CY 《Environmental monitoring and assessment》2006,116(1-3):53-80
Urban trees serve important environmental, social and economic functions, but similar to other natural endowments they are
not customarily depicted in monetary terms. The needs to augment protection, funding and community support for urban greening
call for proper valuation. Heritage trees (HTs), the cream of urban-tree stock, deserve special attention. Existing assessment
methods do not give justice to outstanding trees in compact cities deficient in high-caliber greenery, and to their social-cultural-historical
importance. They artificially separate evaluation from valuation, which should be a natural progression from the former. Review
of tree valuation methods suggested the formula approach to be more suitable than contingent valuation and hedonic pricing,
and provided hints on their strengths and weaknesses. This study develops an alternative formulaic expert method (FEM) that
integrates evaluation and valuation, maximizes objectivity, broadly encompasses the key tree, tree-environment and tree-human
traits, and accords realistic monetary value to HTs. Six primary criteria (dimension, species, tree, condition, location,
and outstanding consideration) branched into 45 secondary criteria, each allocated numerical marks. Each primary criterion
was standardized to carry equal weight, and a tree's maximum aggregate score is capped at 100. A Monetary Assignment Factor
(MAF) to consign dollar value to each score unit was derived from three-year average per m2 sale price of medium-sized residential flats. The applicability of FEM was tested on selected HTs in compact Hong Kong. The
aggregate score of a tree multiplied by MAF yielded monetary value, which was on average 66 times higher than the result from
the commonly-adopted Council of Tree and Landscape Appraisers method. The computed tree values could be publicized together
with multiple tree benefits to raise understanding and awareness and rally support to protect HTs. The property-linked FEM
could be flexibly applied to other cities, especially to assess HTs in compact developing cities. 相似文献
352.
By mechanical-biological treatment (MBT) of residual municipal solid waste the behaviour of landfills can be significantly improved. After MBT the organic content (COD and BOD5), total organic carbon, and total nitrogen in the leachate, as well as the gas production rate, are reduced to values lower than 90% of the fresh untreated waste. The volume of the stabilized material to be disposed on landfills decreases enormously, by up to 70%. The monitoring effort for a landfill constructed under these conditions is reduced to a minimum and the stabilized material can be used in other ways, as material for reforestation, for cover material or for thermal utilization to produce energy. Environmental conditions are important in MBT, as well as waste characteristics. This paper describes the results of a pilot project of MBT performed in Rio de Janeiro, Brazil. The results have shown that this technology can be used successfully in developing countries, with economy for the society and important results for the environment. 相似文献
353.
Qiao WM Song Y Yoon SH Korai Y Mochida I Yoshiga S Fukuda H Yamazaki A 《Waste management (New York, N.Y.)》2006,26(6):592-598
Efficient removal of chlorine from PVC achieved by two-stage heat-treatment (280 and 410 degrees C) provided chlorine-free isotropic pitch containing additive. The pitch was stabilized and carbonized into porous carbons with surface areas of approximately 300 m2/g. Resultant porous carbons showed three pore structures of supermicropore, micropore and mesopore. The generation of CO2 from the decomposition of the CaCO3 additive in waste PVC is responsible for the development of porous structures. The surface area of the carbonized product increased after the removal of CaO. 相似文献
354.
TUGAI: An Integrated Simulation Tool for Ecological Assessment of Alternative Water Management Strategies in a Degraded River Delta 总被引:1,自引:0,他引:1
Schlüter M Rüger N Savitsky AG Novikova NM Matthies M Lieth H 《Environmental management》2006,38(4):638-653
The development of ecologically sound water allocation strategies that account for the needs of riverine ecosystems is a pressing
issue, especially in semiarid river basins. In the Aral Sea Basin, a search for strategies to mitigate ecological and socioeconomic
deterioration has been in process since the early 1990s. The Geographic Information System–based simulation tool TUGAI has
been developed to support the policy determination process by providing a simple, problem-oriented method to assess ecological
effects of alternative water management strategies for the Amudarya River. It combines a multiobjective water allocation model
with simple, spatially explicit statistical and rule-based models of landscape dynamics. Changes in environmental conditions
are evaluated by a fuzzy habitat suitability index for Populus euphratica, which is the dominant species of the characteristic riverine Tugai forests. Water management scenarios can be developed
by altering spatiotemporal water distribution in the delta area or the amount of water inflow into the delta. Outcomes of
scenario analysis are qualitative comparisons of the ecological effects of different options for a time period of up to 28
years. The given approach utilizes different types of knowledge, from quantitative hydrological data to qualitative local
expert knowledge. The main purpose of the tool is to integrate the knowledge in a comprehensive way to make it available for
discussions on alternative policies in moderated workshops with stakeholders. In this article, the modules of the tool, their
integration, and three hypothetical scenarios are presented. Based on the experience gained when developing the TUGAI tool,
we propose that the general framework can be transferred to other areas where tradeoffs in water allocation between the environment
and other water users are of major concern. The potential for a simulation tool to structure and inform a complex resource
management situation by involving local experts and stakeholders in the development of possible future scenarios will become
increasingly valuable for transparent and participatory resource management. 相似文献
355.
Dimitrakopoulos PG Siamantziouras AS Galanidis A Mprezetou I Troumbis AY 《Environmental management》2006,37(6):826-839
We conducted a field experiment using constructed communities to test whether species richness contributed to the maintenance
of ecosystem processes under fire disturbance. We studied the effects of diversity components (i.e., species richness and
species composition) upon productivity, structural traits of vegetation, decomposition rates, and soil nutrients between burnt
and unburnt experimental Mediterranean grassland communities. Our results demonstrated that fire and species richness had
interactive effects on aboveground biomass production and canopy structure components. Fire increased biomass production of
the highest-richness communities. The effects of fire on aboveground biomass production at different levels of species richness
were derived from changes in both vertical and horizontal canopy structure of the communities. The most species-rich communities
appeared to be more resistant to fire in relation to species-poor ones, due to both compositional and richness effects. Interactive
effects of fire and species richness were not important for belowground processes. Decomposition rates increased with species
richness, related in part to increased levels of canopy structure traits. Fire increased soil nutrients and long-term decomposition
rate. Our results provide evidence that composition within richness levels had often larger effects on the stability of aboveground
ecosystem processes in the face of fire disturbance than species richness per se. 相似文献
356.
Temporal and spatial distributions of sediment total organic carbon in an estuary river 总被引:1,自引:0,他引:1
Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC. 相似文献
357.
358.
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
359.
Z. Aslıgül Göçmen James A. LaGro Jr. 《Journal of Environmental Planning and Management》2016,59(8):1513-1535
Smart growth and sustainability planning have, in recent years, become central issues in planning discourse. Scholars have argued that planning capacity at the local government level is critical for smart growth planning, and that planners have a fundamental role to play in advancing local and regional sustainability. In this paper, we investigate the extent to which local planning capacity enables communities to promote more sustainable, smart growth residential development. Based on a 2013 survey of 38 county and 53 municipal governments in the state of Wisconsin, USA, this study finds that the majority of the sample communities have permitted residential developments characterized as transit-oriented, New Urbanist, mixed use, infill developments, or conservation subdivisions as alternatives to low-density, automobile-dependent conventional developments. The study also finds that jurisdictions with higher planning capacities are more likely to overcome significant barriers to more sustainable residential development. 相似文献
360.