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851.
D. Vienneau K. de Hoogh R. Beelen P. Fischer G. Hoek D. Briggs 《Atmospheric environment (Oxford, England : 1994)》2010,44(5):688-696
Land-use regression models have increasingly been applied for air pollution mapping at typically the city level. Though models generally predict spatial variability well, the structure of models differs widely between studies. The observed differences in the models may be due to artefacts of data and methodology or underlying differences in source or dispersion characteristics. If the former, more standardised methods using common data sets could be beneficial. We compared land-use regression models for NO2 and PM10, developed with a consistent protocol in Great Britain (GB) and the Netherlands (NL).Models were constructed on the basis of 2001 annual mean concentrations from the national air quality networks. Predictor variables used for modelling related to traffic, population, land use and topography. Four sets of models were developed for each country. First, predictor variables derived from data sets common to both countries were used in a pooled analysis, including an indicator for country and interaction terms between country and the identified predictor variables. Second, the common data sets were used to develop individual baseline models for each country. Third, the country-specific baseline models were applied after calibration in the other country to explore transferability. The fourth model was developed using the best possible predictor variables for each country.A common model for GB and NL explained NO2 concentrations well (adjusted R2 0.64), with no significant differences in intercept and slopes between the two countries. The country-specific model developed on common variables for NL but not GB improved the prediction.The performance of models based upon common data was only slightly worse than models optimised with local data. Models transferred to the other country performed substantially worse than the country-specific models. In conclusion, care is needed both in transferring models across different study areas, and in developing large inter-regional LUR models. 相似文献
852.
Mark Hixson Abdullah Mahmud Jianlin Hu Song Bai Debbie A. Niemeier Susan L. Handy Shengyi Gao Jay R. Lund Dana Coe Sullivan Michael J. Kleeman 《Atmospheric environment (Oxford, England : 1994)》2010,44(4):552-562
Future air pollution emissions in the year 2030 were estimated for the San Joaquin Valley (SJV) in central California using a combined system of land use, mobile, off-road, stationary, area, and biogenic emissions models. Four scenarios were developed that use different assumptions about the density of development and level of investment in transportation infrastructure to accommodate the expected doubling of the SJV population in the next 20 years. Scenario 1 reflects current land-use patterns and infrastructure while scenario 2 encouraged compact urban footprints including redevelopment of existing urban centers and investments in transit. Scenario 3 allowed sprawling development in the SJV with reduced population density in existing urban centers and construction of all planned freeways. Scenario 4 followed currently adopted land use and transportation plans for the SJV. The air quality resulting from these urban development scenarios was evaluated using meteorology from a winter stagnation event that occurred on December 15th, 2000 to January 7th 2001. Predicted base-case PM2.5 mass concentrations within the region exceeded 35 μg m?3 over the 22-day episode. Compact growth reduced the PM2.5 concentrations by ~1 μg m?3 relative to the base-case over most of the SJV with the exception of increases (~1 μg m?3) in urban centers driven by increased concentrations of elemental carbon (EC) and organic carbon (OC). Low-density development increased the PM2.5 concentrations by 1–4 μg m?3 over most of the region, with decreases (0.5–2 μg m?3) around urban areas. Population-weighted average PM2.5 concentrations were very similar for all development scenarios ranging between 16 and 17.4 μg m?3. Exposure to primary PM components such as EC and OC increased 10–15% for high density development scenarios and decreased by 11–19% for low-density scenarios. Patterns for secondary PM components such as nitrate and ammonium ion were almost exactly reversed, with a 10% increase under low-density development and a 5% decrease under high density development. The increased human exposure to primary pollutants such as EC and OC could be predicted using a simplified analysis of population-weighted primary emissions. Regional planning agencies should develop thresholds of population-weighted primary emissions exposure to guide the development of growth plans. This metric will allow them to actively reduce the potential negative impacts of compact growth while preserving the benefits. 相似文献
853.
D.Y.C. Leung P. Wong B.K.H. Cheung A. Guenther 《Atmospheric environment (Oxford, England : 1994)》2010,44(11):1456-1468
This paper describes a study of local biogenic volatile organic compounds (BVOC) emissions from the Hong Kong Special Administrative Region (HKSAR). An improved land cover and emission factor database was developed to estimate Hong Kong emissions using MEGAN, a BVOC emission model developed by Guenther et al. (2006). Field surveys of plant species composition and laboratory measurements of emission factors were combined with other data to improve existing land cover and emission factor data. The BVOC emissions from Hong Kong were calculated for 12 consecutive years from 1995 to 2006. For the year 2006, the total annual BVOC emissions were determined to be 12,400 metric tons or 9.82 × 109 g C (BVOC carbon). Isoprene emission accounts for 72%, monoterpene emissions account for 8%, and other VOCs emissions account for the remaining 20%. As expected, seasonal variation results in a higher emission in the summer and a lower emission in the winter, with emission predominantly in day time. A high emission of isoprene occurs for regions, such as Lowest Forest-NT North, dominated by broadleaf trees. The spatial variation of total BVOC is similar to the isoprene spatial variation due to its high contribution. The year to year variability in emissions due to weather was small over the twelve-year period (?1.4%, 2006 to 1995 trendline), but an increasing trend in the annual variation due to an increase in forest land cover can be observed (+7%, 2006 to 1995 trendline). The results of this study demonstrate the importance of accurate land cover inputs for biogenic emission models and indicate that land cover change should be considered for these models. 相似文献
854.
M. Tainio J.T. Tuomisto J. Pekkanen N. Karvosenoja K. Kupiainen P. Porvari M. Sofiev A. Karppinen L. Kangas J. Kukkonen 《Atmospheric environment (Oxford, England : 1994)》2010,44(17):2125-2132
The emission-exposure and exposure-response (toxicity) relationships are different for different emission source categories of anthropogenic primary fine particulate matter (PM2.5). These variations have a potentially crucial importance in the integrated assessment, when determining cost-effective abatement strategies. We studied the importance of these variations by conducting a sensitivity analysis for an integrated assessment model. The model was developed to estimate the adverse health effects to the Finnish population attributable to primary PM2.5 emissions from the whole of Europe. The primary PM2.5 emissions in the whole of Europe and in more detail in Finland were evaluated using the inventory of the European Monitoring and Evaluation Programme (EMEP) and the Finnish Regional Emission Scenario model (FRES), respectively. The emission-exposure relationships for different primary PM2.5 emission source categories in Finland have been previously evaluated and these values incorporated as intake fractions into the integrated assessment model. The primary PM2.5 exposure-response functions and toxicity differences for the pollution originating from different source categories were estimated in an expert elicitation study performed by six European experts on air pollution health effects. The primary PM2.5 emissions from Finnish and other European sources were estimated for the population of Finland in 2000 to be responsible for 209 (mean, 95% confidence interval 6–739) and 357 (mean, 95% CI 8–1482) premature deaths, respectively. The inclusion of emission-exposure and toxicity variation into the model increased the predicted relative importance of traffic related primary PM2.5 emissions and correspondingly, decreased the predicted relative importance of other emission source categories. We conclude that the variations of emission-exposure relationship and toxicity between various source categories had significant impacts for the assessment on premature deaths caused by primary PM2.5. 相似文献
855.
B. Miljevic K.E. Fairfull-Smith S.E. Bottle Z.D. Ristovski 《Atmospheric environment (Oxford, England : 1994)》2010,44(18):2224-2230
Reactive oxygen species (ROS) and related free radicals are considered to be key factors underpinning the various adverse health effects associated with exposure to ambient particulate matter. Therefore, measurement of ROS is a crucial factor for assessing the potential toxicity of particles. In this work, a novel profluorescent nitroxide, BPEAnit, was investigated as a probe for detecting particle-derived ROS. BPEAnit has a very low fluorescence emission due to inherent quenching by the nitroxide group, but upon radical trapping or redox activity, a strong fluorescence is observed. BPEAnit was tested for detection of ROS present in mainstream and sidestream cigarette smoke. In the case of mainstream cigarette smoke, there was a linear increase in fluorescence intensity with an increasing number of cigarette puffs, equivalent to an average of 101 nmol ROS per cigarette based on the number of moles of the probe reacted. Sidestream cigarette smoke sampled from an environmental chamber exposed BPEAnit to much lower concentrations of particles, but still resulted in a clearly detectible increase in fluorescence intensity with sampling time. It was calculated that the amount of ROS was equivalent to 50 ± 2 nmol per mg of particulate matter; however, this value decreased with ageing of the particles in the chamber. Overall, BPEAnit was shown to provide a sensitive response related to the oxidative capacity of the particulate matter. These findings present a good basis for employing the new BPEAnit probe for the investigation of particle-related ROS generated from cigarette smoke as well as from other combustion sources. 相似文献
856.
This paper presents the present status of food security and ecological footprint, an indicator of environmental sustainability of the coastal zones of Bangladesh. To estimate the present status of the food security and ecological footprint of the coastal zone of Bangladesh, primary and secondary data were collected, and the present status of food security and environmental degradation (in terms of ecological footprint) were calculated. To estimate the household food security, primary data were also collected from all the households in a representative selected village. A quantitative method for computation of food security in grain equivalent based on economic returns (price) is developed, and a method of measuring sustainable development in terms of ecological footprint developed by Wackernagel is used to estimate the environmental sustainability (Wackernagel and Rees in Our ecological footprint: reducing human impact on the earth. New Society, Gabrioala, BC, 1996; Chambers et al. in Sharing nature’s interest-ecological footprint as an indicator of sustainability. Earthscan, London, 2000). Overall status of food security at upazila levels is good for all the upazilas except Shoronkhola, Shyamnager and Morrelgonj, and the best is the Kalapara upazila. But the status of food security at household levels is poor. Environmental status in the coastal zones is poor for all the upazilas except Kalapara and Galachipa. The worst is in the Mongla upazila. Environmental status has degraded mainly due to shrimp culture. This study suggests that control measures are needed for affected upazilas and any further expansion of the shrimp aquaculture to enhance the food security must take into account the environmental aspects of the locality under consideration. 相似文献
857.
Michael J. White Daniel E. Storm Philip Busteed Scott Stoodley Shannon J. Phillips 《Environmental management》2010,45(5):1164-1174
In the United States, many state and federally funded conservation programs are required to quantify the water quality benefits
resulting from their efforts. The objective of this research was to evaluate the impact of conservation practices subsidized
by the Oklahoma Conservation Commission on phosphorus and sediment loads to Lake Wister. Conservation practices designed to
increase vegetative cover in grazed pastures were evaluated using Landsat imagery and the Soil and Water Assessment Tool (SWAT).
Several vegetative indices were derived from Landsat imagery captured before and after the implementation of conservation
practices. Collectively, these indicators provided an estimate of the change in vegetative soil cover attributable to conservation
practices in treated fields. Field characteristics, management, and changes in vegetative cover were used in the SWAT model
to simulate sediment and phosphorus losses before and after practice implementation. Overall, these conservation practices
yielded a 1.9% improvement in vegetative cover and a predicted sediment load reduction of 3.5%. Changes in phosphorus load
ranged from a 1.0% improvement to a 3.5% increase, depending upon initial vegetative conditions. The use of fertilizers containing
phosphorus as a conservation practice in low-productivity pastures was predicted by SWAT to increase net phosphorus losses
despite any improvement in vegetative cover. This combination of vegetative cover analysis and hydrologic simulation was a
useful tool for evaluating the effects of conservation practices at the basin scale and may provide guidance for the selection
of conservation measures subsidized in future conservation programs. 相似文献
858.
Biodiversity conservation has undergone a profound change in philosophy, policies and management approaches over the last
forty years. The traditional top–down approach to nature protection has been widely criticized for failing to include critical
social elements in management practices, and is being gradually replaced by a slew of participatory strategies under the rubric
of bottom-up conservation. The new approach recognizes local communities as key partners in wildlife management and seeks
their participation in social development and biodiversity conservation. However, every social context is different in its
structure and functions, and in the way social groups respond to calls for participation. In order to gain a better understanding
of the approach and the barriers encountered in its implementation, a questionnaire survey of 188 households was employed
in the communities of the Upper Mustang extension of Annapurna Conservation Area (ACA) in Nepal. The study provides a comparative
analysis of community participation and its barriers between Non-Tourist (NT) and Tourist (TV) villages. The results revealed
important differences between the two groups in terms of their participation in community programs, barriers to participation,
and perception of benefits from participation. Owing to their distinct spatial, demographic and attitudinal differences, the
two village groups have their own sets of needs, values and motivation factors which cannot be generalized and treated as
such. The research clearly identifies the need for the conservation agency to be creative in devising strategies and initiatives
appropriate to specific social groups so as to optimize their input in participatory conservation. 相似文献
859.
Carbon Storage in Soil Size Fractions Under Two Cacao Agroforestry Systems in Bahia, Brazil 总被引:1,自引:0,他引:1
Emanuela F. Gama-Rodrigues P. K. Ramachandran Nair Vimala D. Nair Antonio C. Gama-Rodrigues Virupax C. Baligar Regina C. R. Machado 《Environmental management》2010,45(2):274-283
Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition
of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection
of soil organic C (SOC). The main objective of this study was to characterize SOC storage in relation to soil fraction-size
classes in cacao (Theobroma cacao L.) agroforestry systems (AFSs). Two shaded cacao systems and an adjacent natural forest in reddish-yellow Oxisols in Bahia,
Brazil were selected. Soil samples were collected from four depth classes to 1 m depth and separated by wet-sieving into three
fraction-size classes (>250 μm, 250–53 μm, and <53 μm)—corresponding to macroaggregate, microaggregate, and silt-and-clay
size fractions—and analyzed for C content. The total SOC stock did not vary among systems (mean: 302 Mg/ha). On average, 72%
of SOC was in macroaggregate-size, 20% in microaggregate-size, and 8% in silt-and-clay size fractions in soil. Sonication
of aggregates showed that occlusion of C in soil aggregates could be a major mechanism of C protection in these soils. Considering
the low level of soil disturbances in cacao AFSs, the C contained in the macroaggregate fraction might become stabilized in
the soil. The study shows the role of cacao AFSs in mitigating greenhouse gas (GHG) emission through accumulation and retention
of high amounts of organic C in the soils and suggests the potential benefit of this environmental service to the nearly 6
million cacao farmers worldwide. 相似文献
860.
A Generic Bio-Economic Farm Model for Environmental and Economic Assessment of Agricultural Systems 总被引:2,自引:0,他引:2
Janssen S Louhichi K Kanellopoulos A Zander P Flichman G Hengsdijk H Meuter E Andersen E Belhouchette H Blanco M Borkowski N Heckelei T Hecker M Li H Oude Lansink A Stokstad G Thorne P van Keulen H van Ittersum MK 《Environmental management》2010,46(6):862-877
Bio-economic farm models are tools to evaluate ex-post or to assess ex-ante the impact of policy and technology change on agriculture, economics and environment. Recently, various BEFMs have been developed, often for one purpose or location, but hardly any of these models are re-used later for other purposes or locations. The Farm System Simulator (FSSIM) provides a generic framework enabling the application of BEFMs under various situations and for different purposes (generating supply response functions and detailed regional or farm type assessments). FSSIM is set up as a component-based framework with components representing farmer objectives, risk, calibration, policies, current activities, alternative activities and different types of activities (e.g., annual and perennial cropping and livestock). The generic nature of FSSIM is evaluated using five criteria by examining its applications. FSSIM has been applied for different climate zones and soil types (criterion 1) and to a range of different farm types (criterion 2) with different specializations, intensities and sizes. In most applications FSSIM has been used to assess the effects of policy changes and in two applications to assess the impact of technological innovations (criterion 3). In the various applications, different data sources, level of detail (e.g., criterion 4) and model configurations have been used. FSSIM has been linked to an economic and several biophysical models (criterion 5). The model is available for applications to other conditions and research issues, and it is open to be further tested and to be extended with new components, indicators or linkages to other models. 相似文献