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1.
Regional Environmental Change - The calculation of robust estimates of future greenhouse gas emissions due to agriculture is essential to support the framing of the Brazilian climate change...  相似文献   

2.
Modelling land management for ecosystem services   总被引:1,自引:0,他引:1  
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3.
Health impact assessments (HIAs) inform policy and decision making by providing information regarding future health concerns, and quantitative HIAs now are being used for local and urban-scale projects. HIA results can be expressed using a variety of metrics that differ in meaningful ways, and guidance is lacking with respect to best practices for the development and use of HIA metrics. This study reviews HIA metrics pertaining to air quality management and presents evaluative criteria for their selection and use. These are illustrated in a case study where PM2.5 concentrations are lowered from 10 to 8 μg/m3 in an urban area of 1.8 million people. Health impact functions are used to estimate the number of premature deaths, unscheduled hospitalizations and other morbidity outcomes. The most common metric in recent quantitative HIAs has been the number of cases of adverse outcomes avoided. Other metrics include time-based measures, e.g., disability-adjusted life years (DALYs), monetized impacts, functional-unit based measures, e.g., benefits per ton of emissions reduced, and other economic indicators, e.g., cost-benefit ratios. These metrics are evaluated by considering their comprehensiveness, the spatial and temporal resolution of the analysis, how equity considerations are facilitated, and the analysis and presentation of uncertainty. In the case study, the greatest number of avoided cases occurs for low severity morbidity outcomes, e.g., asthma exacerbations (n = 28,000) and minor-restricted activity days (n = 37,000); while DALYs and monetized impacts are driven by the severity, duration and value assigned to a relatively low number of premature deaths (n = 190 to 230 per year). The selection of appropriate metrics depends on the problem context and boundaries, the severity of impacts, and community values regarding health. The number of avoided cases provides an estimate of the number of people affected, and monetized impacts facilitate additional economic analyses useful to policy analysis. DALYs are commonly used as an aggregate measure of health impacts and can be used to compare impacts across studies. Benefits per ton metrics may be appropriate when changes in emissions rates can be estimated. To address community concerns and HIA objectives, a combination of metrics is suggested.  相似文献   

4.
基于中国家庭追踪调查(CFPS)2014年农村住户数据,采用多元probit模型实证检验了农户土地流转决策、农户种植经济作物决策和非农劳动力转移决策之间的相互影响。研究发现:①农户土地流转与劳动力非农转移和经济作物种植生计决策相互关联。总体而言,土地转入与种植经济作物决策正相关,与非农劳动力转移决策负相关。土地转出与非农劳动力转移决策正相关,与种植经济作物决策负相关。②土地流转与农户非农劳动力转移和经济作物种植等生计策略的关系与农地流转规模相关,小规模和中等规模的土地转入与非农劳动力转移之间未有显著关系,与经济作物种植决策具有显著正向关系,但大规模的土地转入与农户经济作物种植决策和非农就业决策显著负相关。③土地流转是否影响农户生计多样化决策还取决于地区机械化程度。机械化程度较高的平原地区土地转入决策与农户非农劳动力转移和经济作物种植决策未有显著关系,而机械化程度较低的高山、丘陵、高原等地区土地转入决策与农户种植经济作物和非农就业决策分别存在正相关和负相关关系,表明随着机械化对农业劳动力替代程度的增强,土地流转对农户劳动力配置的影响效应减弱。政策建议是:①统筹推进农村土地、劳动力市场发展,推动农户土地流转参与,促进转出户生计向非农专业化转移,促进转入户农地适度规模经营;②完善农机社会化服务市场,提高农机和农技融合使用深度和广度,提高农机对农业劳动力的替代弹性,增强转入户农业劳动力农地规模经营的能力,增加农业生产比较收益。  相似文献   

5.
Regional Environmental Change - Land use and land cover (LULC), as well as their geographical and temporal variations, affect landslide occurrence and the related risk, in ways that are difficult...  相似文献   

6.
The study presents three scenarios of land use and cover change (LUCC), the most important factor for environmental degradation in southern Mexico. We developed story lines and quantitative projections for regional scenarios based on historic LUCC processes, environmental policies, socioeconomic drivers, stakeholder consultations and official planning documents to gain a better understanding of drivers of LUCC, and quantitative scenarios were modeled with DINAMICA-EGO. Regionally specific interactions between social and natural systems are recognized, and detrimental policies and policy options for landscape conservation and management for sustainability are acknowledged in a base line, variant and alternative scenario. Incongruent policies and ineffective ground implementation of conservation actions were identified as the critical underlying drivers of deforestation and forest degradation that could lead to a severe reduction in natural forests, while the local socioeconomic situation stays precarious. The baseline scenario parts from an analysis of historic LUCC processes and shows the consequences of LUCC tendencies: 73% of temperate forests and 50% of tropical forests would get deforested until 2030. In the variant scenario, these tendencies are adjusted to planning goals extracted from official documents and recent changes in public policies. The alternative scenario further addresses policy options for fostering conservation and sustainable development, but because of the time lag of implementation, still 59% of temperate forests and 36% of tropical forest would get lost until 2030. Nevertheless, this represents a reduction of 13% of forest loss and 11% less pastureland due to the proposed measures of conservation, and sustainable management, including strategies for reforming agricultural systems, agricultural and forestry policies and trade, land tenure and livelihood risk management.  相似文献   

7.
A longitudinal survey was applied to 499 smallholder agriculturalist households in Mexico’s southern Yucatán region to determine whether different cultural expectations had led to the formation and coexistence of different types of human–environment interactions. A three center cluster analysis was used, and two agricultural adaptive strategies were found to coexist: a diversified subsistence strategy built largely by individuals who were smallholder agriculturalists in their place of origin, and one generated mostly by non-agriculturalists who migrated to the southern Yucatán to make agriculture their business during the last agrarian reform. Each strategy followed unique family trajectories and established distinct human–environment interactions. The findings suggest that those who emphasize commercial agriculture have a better standard of living. Nevertheless, their improved on-farm livelihoods—judged by material, physiological, and educational indicators—comes at the cost of higher risks to their adaptive system and adverse environmental consequences.  相似文献   

8.
This paper proposes two novel approaches for the problem of energy management in hybrid electric vehicles. Shuffled frog-leaping algorithm (SFLA) is a recently proposed population-based optimization algorithm. This paper first formulates energy management as an optimization problem and optimizes the problem using SFLA. Then the paper makes use of SFLA as a training algorithm to train artificial neural network (ANN) and this SFLA-trained ANN is used for energy management. Interestingly, the proposed approaches of this paper are found to be robust and more efficient than contemporary approaches.  相似文献   

9.
Regional Environmental Change - Land degradation in many Pacific Island Countries (PICs) has become an emerging concern in recent years. The causes of land degradation in PICs include:...  相似文献   

10.
Agricultural crops are affected by climate change due to the relationship between crop development, growth, yield, CO2 atmospheric concentration and climate conditions. In particular, the further reduction in existing limited water resources combined with an increase in temperature may result in higher impacts on agricultural crops in the Mediterranean area than in other regions. In this study, the cropping system models CERES-Wheat and CROPGRO-Tomato of the Decision Support System for Agrotechnology Transfer (DSSAT) were used to analyse the response of winter durum wheat (Triticum aestivum L.) and tomato (Lycopersicon esculentum Mill.) crops to climate change, irrigation and nitrogen fertilizer managements in one of most productive areas of Italy (i.e. Capitanata, Puglia). For this analysis, three climatic datasets were used: (1) a single dataset (50?km?×?50?km) provided by the JRC European centre for the period 1975–2005; two datasets from HadCM3 for the IPCC A2 GHG scenario for time slices with +2°C (centred over 2030–2060) and +5°C (centred over 2070–2099), respectively. All three datasets were used to generate synthetic climate series using a weather simulator (model LARS-WG). Adaptation strategies, such as irrigation and N fertilizer managements, have been investigated to either avoid or at least reduce the negative impacts induced by climate change impacts for both crops. Warmer temperatures were primarily shown to accelerate wheat and tomato phenology, thereby resulting in decreased total dry matter accumulation for both tomato and wheat under the +5°C future climate scenario. Under the +2°C scenario, dry matter accumulation and resulting yield were also reduced for tomato, whereas no negative yield effects were observed for winter durum wheat. In general, limiting the global mean temperature change of 2°C, the application of adaptation strategies (irrigation and nitrogen fertilization) showed a positive effect in minimizing the negative impacts of climate change on productivity of tomato cultivated in southern Italy.  相似文献   

11.
Land use change is the main driving force of global environmental change and is considered as very central to the ongoing debate on sustainable development. Even though large volume of literature materials is available of land use/land cover (LU/LC) change for many areas, very little is known of it in the floodplain of the Sokoto Rima River Basin of Nigeria despite the basin’s strategic importance. Thus, this study characterized the basin’s LU/LC and its change using computer-based digital classification of near-anniversary Landsat 5 TM imagery of November 23, 1998, and Landsat 8 OLI of December 2, 2013. The results of the digital classification were complimented with field-based observations on major observable characteristics of every LU/LC identified. Thirteen classes (forest area, dense grassland, grassy fallow, grazed open grassland, open cultivation, open grain fallow farmland, pepper cultivation, rice farmland, scrubland, sugarcane farmland, dry bare land, sand deposit and wetland/water) were characterized and the nature and extent of their changes assessed. 40 % of the basin’s uses is under cultivation, 22 % is under fallow, 27 % is either degraded or non-cultivable, while 11 % is forested. Change events include forest loss, increase in area cultivated, expansion of shrub/scrubland and pervasiveness of grazing. The changes were more pronounced in the upper than either the central and southern segments of the basin. In general LU/LC changes in the basin are reflection of increased human population pressure and effects of climate change. The LU/LC patterns and changes suggest underutilization and mismanagement of the floodplain which have impact on soil, hydrology and biodiversity with serious implication for livelihood and food security. The study recommends that interventions are needed to promote enhanced and sustainable management of land, water and vegetation resources in the basin, with particular emphasis on empowering the local land users to participate actively toward sustainable management of the floodplain.  相似文献   

12.
Regional Environmental Change - The State of Mato Grosso in Brazil has undergone intensive land use changes over the past decades. Native ecosystems have been converted into agrosystems for the...  相似文献   

13.
The transfer of radiocaesium, one of the most important and widespread contaminants following a nuclear accident, to the fibre crops hemp (Cannabis sativa L.) and flax (Linum usitatissimum L.) as well as the distribution of radiocaesium during crop conversion were studied for sandy soil under greenhouse and lysimeters conditions. Soil parameters did not unequivoqually explain the transfer factors (TF) observed. TFs to flax stems ranged from 1.34 to 2.80x10(-3) m2 kg(-1). TFs to seeds are about a factor of 4 lower. During the retting process for separating the fibres from the straw, more than 95% of the activity was removed with the retting water. For hemp, the TF to the stem was about 0.6x10(-3) m2 kg(-1). For hemp, straw and fibres were mechanically separated and TF to straw was about 0.5x10(-3) m2 kg(-1) and to fibres 1.0x10(-3) m2 kg(-1). Generally, the TFs to the useable plant parts both for hemp and flax, are low enough to allow for the production of clean end-products (fibre, seed oil, biofuel) even on heavily contaminated land. Given the considerable decontamination during retting, contamination levels in flax fibres would only exceed the exemption limits for fibre use after production in extreme contamination scenarios (>12,300kBq m(-2)). Since hemp fibres are mechanically separated, use of hemp fibres is more restricted (contamination <740kBq m(-2)). Use of stems as biofuel is restricted to areas with contamination levels of <250 and 1050kBq m(-2) for flax and hemp, respectively. Use of seeds for edible oil production and flour is possible almost without restriction for flax but due to the high TFs to seed observed for hemp (up to 3x10(-3) m2 kg(-1)) consumption of hemp seed products should be considered with care.  相似文献   

14.
15.
Sulphur Mustard, or "Mustard Gas" is in fact an oily liquid which was used as a chemical weapon primarily for its vesicant action which necessitates whole body protection. It is also now recognised as a carcinogenic agent upon chronic exposure. Soil contaminated with Sulphur Mustard continues to present both acute and chronic human health risks and risks to groundwater, surface water and the wider ecology at a number of sites globally and, in some cases, has done for many decades. This is at odds with the simple aqueous chemistry of the compound which would suggest that it should be short lived in the environment, especially in the presence of water. A number of studies have examined the possible factors for this longevity and, though the causes are generally assumed to be understood, the precise reasons have not yet been definitively determined and the evidence in support of the existing theories is at best circumstantial. At present, the prevailing view is that Sulphur Mustard is somehow protected by oligomeric or polymeric sulphonium species produced during incomplete hydrolysis reactions. The following review discusses the pertinent degradation mechanisms in the environment; hydrolysis and thermal degradation and the reasons put forward for the longevity of Sulphur Mustard in the literature. Other factors, such as the role of polymeric species in Sulphur Mustard droplets in modifying the mobility of the agent are also examined. Ultimately, without a thorough understanding of the abiotic fate of the Sulphur Mustard, uncertainties will remain in the application of risk assessment and remediation strategies to such sites, potentially compromising the validity or effectiveness of such actions.  相似文献   

16.
Land reform is identified as a key tool in fostering development in South Africa. Twenty years after the advent of democracy in South Africa, the land question remains a critical issue for policy makers. Several frameworks have been put in place by the government to identify land that is strategically located for land reform. However, many of these frameworks are not well aligned and not objective in defining strategically located land for land reform and often lead to unsustainable land use management practices. This has hampered the government’s land reform initiative in promoting agricultural land reform and food security. Accordingly, there is a need to develop a decision support tool that facilitates the identification of strategically located land for land reform. This study proposes the use of geographic information systems (GIS) and multi-criteria decision analysis (MCDA) to develop a strategically located land index (SLLI) to identify land suitable for agricultural land reform. Participatory workshops and the group analytical hierarchy process were utilised to identify and weigh criteria used in computing the SLLI. The results indicate that land that is suitable for agricultural land reform is scarce, and there are also competing needs on the highly suitable land for agriculture. The study demonstrates that GIS and MCDA are invaluable tools in facilitating evidence-based decision-making for land reform and sustainable land use management practices. The SLLI is not the panacea to land identification; there is also need to appreciate the contested nature of land in South Africa.  相似文献   

17.
18.
Regional Environmental Change - Agricultural large-scale land acquisition (LSLA) is a process that is currently not captured by land change models. We present a novel land change modeling approach...  相似文献   

19.
This article examines the changes in land-use/cover types in the Irangi Hills, central Tanzania during the last 45 years and how such changes have influenced environmental and agricultural sustainability in the area. The spatial and temporal changes of land-use/cover were analysed through aerial photographs interpretation. Local perceptions and experiences of changes were addressed through household interviews and field observations. Results from this study show that during the last 45 years open and wooded grasslands, and other tree-cover types covered about 40% of the land area, ranging from 29% in 1960 to 43–45% between 1977 and 1992. Also, during the same period both the total area and spatial distribution of cultivated fields varied greatly. The cultivated area increased from 31% in 1977 to 35% in 1992, mainly due to agricultural expansion into areas formerly used for grazing and in sandy watercourses that shrunk by 55% between 1977 and 1992. The spatial distribution of the different land-use/cover types is influenced by variations in the scale of soil erosion and soil-conservation initiatives implemented in the Irangi Hills since the early 1970s. However, with increasing pressure on the land, and the declining capacity of the soil conservation authority, sustaining agricultural production in the area remains a major challenge.  相似文献   

20.
Land capability classification systems define and communicate biophysical limitations on land use, including climate, soils and topography. They can therefore provide an accessible format for both scientists and decision-makers to share knowledge on climate change impacts and adaptation. Underlying such classifications are complex interactions that require dynamic spatial analysis, particularly between soil and climate. These relationships are investigated using a case study on drought risk for agriculture in Scotland, which is currently considered less significant than wetness-related issues. The impact of drought risk is assessed using an established empirical system for land capability linking indicator crops with water availability. This procedure is facilitated by spatial interpolation of climate and soil profile data to provide soil moisture deficits and plant available water on a regular 1-km grid. To evaluate potential impacts of future climate change, land capability classes are estimated using both large-scale ensemble (multi-simulation) data from the HadRM3 regional climate model and local-scale weather generator data (UKCP09) derived from multiple climate models. Results for the case study suggest that drought risk is likely to have a much more significant influence on land use in the future. This could potentially act to restrict the range of crops grown and hence reduce land capability in some areas unless strategic-level adaptation measures are developed that also integrate land use systems and water resources with the wider environment.  相似文献   

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