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161.
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
162.
分子筛生产废水中悬浮物的絮凝与回用 总被引:2,自引:0,他引:2
对分子筛生产废水进行了絮凝沉降分离试验,确定了絮凝剂、助凝剂及絮凝敢分离条件。试验结果表明,絮凝沉降所得到的絮凝物料的化学组成、结构、性能与絮凝前原废水中的悬浮物基本一致,可返回原生产工序中使用。 相似文献
163.
含氟废气对农业环境的影响 总被引:5,自引:0,他引:5
叙述了某厂氢氟酸生产过程排出的含氟废气对厂区周围水稻和蔬菜的污染及其与气象条件的关系,并提出了防止农业环境氟污染的措施。 相似文献
164.
O/W型乳化液的处理 总被引:3,自引:0,他引:3
采用药剂破乳-电解破乳工艺处理O/W型乳化液,药剂破乳选用聚合硫酸铁为破乳剂,破乳时最佳PH为8,聚合硫酸铁的最佳投量为1500mg/L,电解破乳选用铁作阳极,铝作阴极,电流密度0.86A/dm^2,极距25mm,电解时间3h。在上述条件下,破乳效果良好,出水清澈透明,COD总去除率可达到96-97%。 相似文献
165.
Ongoing eutrophication is changing the Baltic Sea ecosystem. Aquaculture causes relatively small-scale nutrient emissions,
but local environmental impact may be considerable. We used substance flow analysis (SFA) to identify and quantify the most
significant flows and stocks of nitrogen (N) and phosphorus (P) related to rainbow trout aquaculture in Finland. In 2004–2007,
the input of nutrients to the system in the form of fish feed was 829 t N year−1 and 115 t P year−1. Around one-fifth of these nutrients ended up as food for human consumption. Of the primary input, 70% ended up in the Baltic
Sea, directly from aquaculture and indirectly through waste management. The nutrient cycle could be closed partially by using
local fish instead of imported fish in rainbow trout feed, thus reducing the net load of N and P to a fraction. 相似文献
166.
Charles Hofer Claus Holzapfel 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1207-1213
The use of passerine species as bioindicators of metal bioaccumulation is often underutilized when examining the wildlife habitat value of polluted sites. In this study we tested feathers of nestlings of two common bird species (house wren and American robin) for accumulation of Pb, Zn, As, Cr, Cu, Fe in comparison of a polluted, urban brownfield with a rural, unpolluted site. House wren nestlings at the study site accumulated significantly greater concentrations of all target metals except Zn. At the polluted site we found significant species differences of metal concentrations in feathers, with house wrens accumulating greater concentrations of Pb, Fe, and Zn but slightly lesser accumulations of Cr and Cu than American robins. Although house wren nestlings demonstrated significant accumulation of metals, these concentrations showed little effect on size metrics or fledge rates during the breeding season compared to nestlings from the control site. 相似文献
167.
Evolutionary psychology has been proposed as an analytic framework for the behavioral effects of landscapes displayed in advertising. In this study, an evolutionary and environmental psychology approach is used to analyze affective reactions to advertising depicting specific natural environments or urban scenes, both prominent ingredients of contemporary advertising imagery. The experimental field study exposed 750 participants at random to one advert of a set of 13 experimental green energy advertisements, each displaying a different biome. Six basic emotional responses (pleasure, arousal, happiness, freedom, safety, and interest) as well as attitude toward the ad and brand attitude were assessed subsequently. Anova and structural equation analysis were used for data analysis. Results of the study confirm the leading opinion on generalized more positive behavioral effects toward visual stimuli representing nature scenes with biospheric contents as opposed to pictures of urban environments or desert settings. In line with earlier empirical research, further findings do not support the hypothesis on an innate preference for savanna landscapes in adults but confirm preferences for images of lush green landscapes with water and familiar biomes. Overall results give significant support to the application of environmental and evolutionary psychology to advertising. 相似文献
168.
Jeffrey J. Opperman Ryan Luster Bruce A. McKenney Michael Roberts Amanda Wrona Meadows 《Journal of the American Water Resources Association》2010,46(2):211-226
Opperman, Jeffrey J., Ryan Luster, Bruce A. McKenney, Michael Roberts, and Amanda Wrona Meadows, 2010. Ecologically Functional Floodplains: Connectivity, Flow Regime, and Scale. Journal of the American Water Resources Association (JAWRA) 46(2):211-226. DOI: 10.1111/j.1752-1688.2010.00426.x Abstract: This paper proposes a conceptual model that captures key attributes of ecologically functional floodplains, encompassing three basic elements: (1) hydrologic connectivity between the river and the floodplain, (2) a variable hydrograph that reflects seasonal precipitation patterns and retains a range of both high and low flow events, and (3) sufficient spatial scale to encompass dynamic processes and for floodplain benefits to accrue to a meaningful level. Although floodplains support high levels of biodiversity and some of the most productive ecosystems on Earth, they are also among the most converted and threatened ecosystems and therefore have recently become the focus of conservation and restoration programs across the United States and globally. These efforts seek to conserve or restore complex, highly variable ecosystems and often must simultaneously address both land and water management. Thus, such efforts must overcome considerable scientific, technical, and socioeconomic challenges. In addition to proposing a scientific conceptual model, this paper also includes three case studies that illustrate methods for addressing these technical and socioeconomic challenges within projects that seek to promote ecologically functional floodplains through river-floodplain reconnection and/or restoration of key components of hydrological variability. 相似文献
169.
Eric C. Merten Nathaniel A. Hemstad Randall K. Kolka Raymond M. Newman Elon S. Verry Bruce Vondracek 《Journal of the American Water Resources Association》2010,46(4):733-743
Merten, Eric C., Nathaniel A. Hemstad, Randall K. Kolka, Raymond M. Newman, Elon S. Verry, and Bruce Vondracek, 2010. Recovery of Sediment Characteristics in Moraine, Headwater Streams of Northern Minnesota After Forest Harvest. Journal of the American Water Resources Association (JAWRA) 46(4): 733-743. DOI: 10.1111/j.1752-1688.2010.00445.x Abstract: We investigated the recovery of sediment characteristics in four moraine, headwater streams in north-central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin-scale year effects were significant (p < 0.001) for all responses when evaluated by repeated-measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment. 相似文献
170.
Gregory M. Southard Loraine T. Fries Aaron Barkoh 《Journal of the American Water Resources Association》2010,46(1):14-23
Southard, Gregory M., Loraine T. Fries, and Aaron Barkoh, 2010. Prymnesium parvum: The Texas Experience. Journal of the American Water Resources Association (JAWRA) 46(1):14-23. DOI: 10.1111/j.1752-1688.2009.00387.x Abstract: Golden alga Prymnesium parvum was first identified in Texas during a fish kill investigation on the Pecos River in 1985. Since then golden alga kills occurred sporadically in a variety of waters in the western part of the state until 2001 when the alga became endemic in the Brazos, Canadian, Colorado, Red, and Rio Grande river systems, including the water supplies of two public fish hatcheries, the Possum Kingdom and Dundee state fish hatcheries. The increasing area adversely affected by the alga and frequent massive fish kills heightened public and political awareness and concerns regarding the ecological and economic impacts of P. parvum blooms. The Texas Parks and Wildlife Department (TPWD), the wildlife conservation agency of the state, responded to these concerns with a program to assess the ecological and economic impacts and to develop management options. To date 33 water bodies have been affected and losses are conservatively estimated at 34 million fish valued at US$13 million. Several sport fisheries, including smallmouth bass Micropterus dolomieu, striped bass Morone saxatilis, channel catfish Ictalurus punctatus, and blue catfish Ictalurus furcatus, have been severely affected. Additionally, 26 imperiled fish species occur in the affected water basins and some have been adversely affected. Economic losses associated with reduced fishing and other water-based recreational activities appear considerable. The combined economic losses to three counties (Palo Pinto, Stephens, and Young) surrounding Possum Kingdom reservoir for 2001 and 2003 were estimated at US$2.8 million and US$1.1 million, respectively. This paper describes how the TPWD responded to public and political concerns relative to the emergence of golden alga, its harmful effects to fisheries, and its historic and current statewide distribution. 相似文献