Removal of atmospheric particles by leaves and twigs of urban trees: Some preliminary observations and assessment of research needs

This paper reviews the various lines of evidence that support the hypothesis that above-ground plant parts remove particulates from the atmosphere. Some scanning electron microscope observations of the particulate burden on leaves of London planetree are discussed. The authors present an outline of the kinds of research required to support or reject the hypothesis that urban woody plants are important air filters.     

Assessing the ecosystem service of air pollutant removal by urban trees in Guangzhou (China)

In Chinese cities, air pollution has become a serious and aggravating environmental problem undermining the sustainability of urban ecosystems and the quality of urban life. Besides technical solutions to abate air pollution, urban vegetation is increasingly recognized as an alternative ameliorative method by removing some pollutants mainly through dry deposition process. This paper assesses the capability and monetary value of this ecosystem service in Guangzhou city in South China. The results indicated an annual removal of SO(2), NO(2) and total suspended particulates at about 312.03Mg, and the benefits were valued at RMB90.19 thousand (US$1.00=RMB8.26). More removal was realized by recreational land use due to a higher tree cover. Higher concentration of pollutants in the dry winter months induced more removal. The lower cost of pollution abatement in China generated a relatively subdued monetary value of this environmental benefit in comparison with developed countries. Younger districts with more extensive urban trees stripped more pollutants from the air, and this capacity was anticipated to increase further as their trees gradually reach final dimensions and establish a greater tree cover. Tree cover and pollutant concentration constitute the main factors in pollutant removal by urban trees. The efficiency of atmospheric cleansing by trees in congested Chinese cities could be improved by planting more trees other than shrubs or grass, diversifying species composition and biomass structure, and providing sound green space management. The implications for greenery design were discussed with a view to maximizing this ecosystem service in Chinese cities and other developing metropolises.     

A framework for assessing the impact of land use policy on community exposure to air toxics

Our research focuses on the linkage between land use planning policy and the spatial pattern of exposure to air toxics emissions. Our objective is to develop a modeling framework for assessment of the community health risk implications of land use policy. The modeling framework is not intended to be a regulatory tool for small-scale land use decisions, but a long-range planning tool to assess the community health risk implications of alternative land use scenarios at a regional or subregional scale. This paper describes the development and application of an air toxic source model for generating aggregate emission factors for industrial and commercial zoning districts as a function of permitted uses. To address the uncertainty of estimating air toxics emission rates for planned general land use or zoning districts, the source model uses an emissions probability mass function that weights each incremental permitted land use activity by the likelihood of occurrence. We thus reduce the uncertainty involved in planning for development with no prior knowledge of the specific industries that may locate within the land use district. These air toxics emission factors can then be used to estimate pollutant atmospheric mass flux from land use zoning districts, which can then be input to air dispersion and human health risk assessment models to simulate the spatial pattern of air toxics exposure risk. The model database was constructed using the California Air Toxics Inventory, 1997 US Economic Census, and land assessment records from several California counties. The database contains information on more than 200 air toxics at the 2-digit Standard Industrial Classification (SIC) level. We present a case study to illustrate application of the model. LUAIRTOX, the interactive spreadsheet model that applies our methodology to the California data, is available at http://www2.bren.ucsb.edu/~mwillis/LUAIRTOX.htm.     

Rice and Bricks: Environmental Issues and Mapping of the Unusual Crop Rotation Pattern in the Kathmandu Valley,Nepal

The Kathmandu Valley in Nepal has experienced a very rapid increase in population resulting in considerable land use/land cover change and also a series of environmental problems. One of the results of the population increase is an expansion of brick manufacturing within the Valley because most structures are brick. The brick kilns are intense in several locations of the Valley and have an interesting pattern of using the same lands for bricks during the dry season and then conversion to rice during the wet, summer monsoon months. The increase in brick production has contributed to environmental problems including decreased soil productivity, lowered ground water levels, and particularly air pollution. Brick manufacturing has little, if any, effective regulation. There is a lack of current, accurate data on brick production that could be resolved by remote sensing methods. Controls should be established and more information acquired on the location and impacts of brick production.     

Use of a geographic information system for storm runoff prediction from small urban watersheds

The use of computer-assisted map analysis techniques for prediction of storm runoff from a small urban watershed in the United States is investigated. An automated procedure for calculating input parameters for the US Soil Conservation Service (SCS) method of predicting storm runoff volume and peak timing is presented. Advanced techniques of spatial analysis are used to characterize spatial coincidence, surface configuration and effective hydrologic distance. A limited verification of the automated procedure indicates that the model reasonably characterizes water flow. A sensitivity analysis of basin disaggregation suggests that the SCS method yields increased volume and peak discharge predictions as the watershed is divided into smaller and smaller subunits. As a means to demonstrate the practical application of the automated procedure, a simulation of the effects on surface runoff for a potential residential development is presented.     

Risk assessment for atmospheric environmental management: a case study in the Hunter Region of New South Wales,Australia

The theoretical framework of a risk assessment scheme is applied to air quality assessment in a developing region in Australia, the Hunter Valley in the state of New South Wales. It is found that the application of such a scheme high-lights a number of inadequacies in the air quality management. New modeling methodologies are found to be necessary to assess some air quality impacts, as existing knowledge is inadequate. The importance of extensive data bases is underlined as is the need for social surveys to supplement air pollution monitoring when gauging aesthetic effects of air pollutants.A visiting fellow on leave from the School of Australian Environmental Studies, Griffith University, Brisbane, Queensland, Australia.     

A regional environmental information system for analyzing and predicting the impacts of nonferrous mining on an agricultural environment

Mineral exploitation is a necessary component of China's economic development goals. Such exploitation brings with it the potential for serious environmental degradation. Careful environmental impact assessments of mining projects are required in order to implement China's environmental protection law and identify measures for protecting surrounding agricultural environments. This article describes an environmental information system that has been developed for the purpose of assisting with the environmental impact assessment of nonferrous mining operations with a particular focus on agricultural impacts. An application of the environmental information system to the Yongping copper mine, located in Jiangxi Province, is discussed. The role of the environmental information system is analyzing and predicting soil contamination from heavy metals and other types of impacts from this mining operation is described. The environmental information system is designed for implementation on an IBM PC/XT microcomputer. The experience gained from the Yongping copper mine application and the growing popularity of microcomputers in China indicate a significant potential for the effective use of a microcomputer-based environmental information system in other parts of China.     

Multi-criteria decision analysis for the optimal management of nitrate contamination of aquifers

We present an integrated methodology for the optimal management of nitrate contamination of ground water combining environmental assessment and economic cost evaluation through multi-criteria decision analysis. The proposed methodology incorporates an integrated physical modeling framework accounting for on-ground nitrogen loading and losses, soil nitrogen dynamics, and fate and transport of nitrate in ground water to compute the sustainable on-ground nitrogen loading such that the maximum contaminant level is not violated. A number of protection alternatives to stipulate the predicted sustainable on-ground nitrogen loading are evaluated using the decision analysis that employs the importance order of criteria approach for ranking and selection of the protection alternatives. The methodology was successfully demonstrated for the Sumas-Blaine aquifer in Washington State. The results showed the importance of using this integrated approach which predicts the sustainable on-ground nitrogen loadings and provides an insight into the economic consequences generated in satisfying the environmental constraints. The results also show that the proposed decision analysis framework, within certain limitations, is effective when selecting alternatives with competing demands.     

Greenhouse effect and coastal wetland policy: How Americans could abandon an area the size of Massachusetts at minimum cost

Climatologists generally expect an anthropogenic global warming that could raise sea level 30–150 cm in the next century and more thereafter. One of the impacts would be the loss of coastal wetlands. Although the inundation of adjacent dryland would enable new wetlands to form, much of this land is or will soon be developed. If developed areas are protected, wetlands will be squeezed between an advancing sea and the land being protected, which has already happened in China and the Netherlands, where people have built dikes for centuries. Unlike those countries, the United States has enough land to accommodate the landward migration of wetlands; but governments lack the funds to purchase all the coastal lowlands that might be inundated and the legal authority to prohibit their development. We propose a third approach: allowing property owners to use coastal lowlands today as they choose, but setting up a legal mechanism to ensure that the land is abandoned if and when sea level rises enough to inundate it. Although compensation may be required, this approach would cost less than 1% as much as purchasing the land, and would be (1) economically efficient by enabling real estate markets to incorporate expectations of future sea level rise; (2) constitutional by compensating property owners; and (3) politically feasible by pleasing people who care about the long-term fate of the coastal environment without disturbing people who either are unconcerned about the distant future or do not believe sea level will rise. This article demonstrates that it would be irrational to delay policy formulation until sea level rise projections are more precise. The cost will be small if we act now but great if we wait, and sea level is already rising along most coasts. The US government should develop a strategy in the next three years. The opinions expressed in this paper do not necessarily reflect the views of EPA and no official endorsement should be inferred.     

Application of an entropy-based Bayesian optimization technique to the redesign of an existing monitoring network for single air pollutants

We apply the entropy-based Bayesian optimizing approach of Le and Zidek to the spatial redesign of the extensive air pollution monitoring network operated by Metro Vancouver, in the Lower Fraser Valley, British Columbia. This method is chosen because of its statistical sophistication, relative to other possible approaches, and because of the very rich, two-decade long data record available from this network. The redesign analysis is applied to ozone, carbon monoxide and PM_2.5 pollutants.     

Predicting the Impacts of Future Sea-Level Rise on an Endangered Lagomorph

Human-induced global climate change presents a unique and difficult challenge to the conservation of biodiversity. Despite increasing attention on global climate change, few studies have assessed the projected impacts of sea-level rise to threatened and endangered species. Therefore, we estimated the impacts of rising sea levels on the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) across its geographic distribution under scenarios of current conditions, low (0.3-m), medium (0.6-m), and high (0.9-m) sea-level rise. We also investigated the impacts of allowing vegetation to migrate upslope and not allowing migration and of two land-use planning decisions (protection and abandonment of human-dominated areas). Not surprisingly, under all simulations we found a general trend of decreasing total potential LKMR habitat with increasing sea-level rise. Not allowing migration and protecting human-dominated areas both tended to decrease potential LKMR habitat compared with allowing migration and abandoning human-dominated areas. In conclusion, conservation strategies at multiple scales need to be implemented in order to reduce the impact of global climate change on biodiversity and endangered species. At the regional level, managers must consider land-use planning needs that take into account the needs of both humans and biodiversity. Finally, at the local scale those agencies that are in charge of endangered species conservation and ecosystem management need to rethink static approaches to conservation or else stand by and watch ecosystems degrade and species go extinct. This can be accomplished by bioclimatic reserve systems where climatically underrepresented areas are included in conservation planning along with the standard concerns of threat, opportunity, connectivity, and viability.     

A GIS-based approach for assessing the regional conservation status of genetic diversity: an example from the southern Appalachians

Conserving genetic diversity requires an assessment of the distribution of genetic variants in relation to patterns of land use and environmental variation at a regional scale. This assessment requires a novel approach to integrating and analyzing the genetic and environmental data across spatial scales. To explore the integration of genetic data with other geospatial data sets, we developed a GIS-based approach for examining patterns of genetic diversity for several species of salamanders in southern Appalachians. The genetic data, from allozyme surveys in the genetics literature, were integrated into a GIS database along with related attributes including population identifications and spatial locations. Using existing geospatial data, we classified sample locations as being either protected from anthropogenic disturbance (e.g., National Parks, Wilderness Areas) or as unprotected (e.g., private lands, multiple-use lands in National Forests). We used multidimensional scaling of allelic frequencies and contributions of populations to interpopulation differences in allelic richness to determine which populations had genetic characteristics most different from other populations in the sample. Measures of genetic differentiation were integrated into the GIS database to facilitate spatial analysis and visualization of the indices in relation to land use. This approach was useful for both identification of populations with components of genetic variation that were not well represented at protected sites and for identifying areas of species distributions where more genetic sampling would be necessary to make informed management decisions. Our approach could be readily adapted for use by managers and geneticists working with other species and types of genetic markers.     

Managing stormwater for urban sustainability: an evaluation of local comprehensive plans in the Chesapeake Bay watershed region

This study uses a developed plan coding protocol in evaluating the quality of 76 comprehensive plans to examine whether local comprehensive plans have adequately integrated the concepts of sustainable stormwater management. The Chesapeake Bay watershed was chosen for the investigation because degraded stormwater runoff from nearby urban and suburban jurisdictions have critically polluted the watershed. The findings indicate that the majority of local governments have not sufficiently incorporated the sustainable stormwater management principles into their comprehensive plans. Five plan components (factual basis, goals and objectives, inter-organizational cooperation, policies, tools and strategies, and implementation) appear weak in realizing the concepts. The current study concludes by providing policy implications and recommendations to increase awareness and understanding of sustainable stormwater management concepts and to produce better implementation plans that integrate stormwater, ecosystem, and environmental planning comprehensively.     

The integrated project AquaTerra of the EU sixth framework lays foundations for better understanding of river-sediment-soil-groundwater systems

The integrated project "AquaTerra" with the full title "integrated modeling of the river-sediment-soil-groundwater system; advanced tools for the management of catchment areas and river basins in the context of global change" is among the first environmental projects within the sixth Framework Program of the European Union. Commencing in June 2004, it brought together a multidisciplinary team of 45 partner organizations from 12 EU countries, Romania, Switzerland, Serbia and Montenegro. AquaTerra is an ambitious project with the primary objective of laying the foundations for a better understanding of the behavior of environmental pollutants and their fluxes in the soil-sediment-water system with respect to climate and land use changes. The project performs research as well as modeling on river-sediment-soil-groundwater systems through quantification of deposition, sorption and turnover rates and the development of numerical models to reveal fluxes and trends in soil and sediment functioning. Scales ranging from the laboratory to river basins are addressed with the potential to provide improved river basin management, enhanced soil and groundwater monitoring as well as the early identification and forecasting of impacts on water quantity and quality. Study areas are the catchments of the Ebro, Meuse, Elbe and Danube Rivers and the Brévilles Spring. Here we outline the general structure of the project and the activities conducted within eleven existing sub-projects of AquaTerra.