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41.
2 semiarid irrigated area with salt-affected soils. The available soil map is at 1:100,000 scale and its mapping units are
used for the land evaluation with the FAO framework. These data are then elaborated using the index value method. This procedure
gives a map of land evaluation units and a table that rates the productive potential of these units for six crops: alfalfa,
barley, maize, rice, sunflower, and wheat. 相似文献
42.
43.
Land systems are described based on various characteristics, including land cover composition and agricultural production. However, it is uncertain to what extent livestock, particularly monogastric livestock, determines land systems. We included monogastrics in a land system classification, and statistically analyzed the land cover composition and agricultural production of otherwise similar land systems with and without monogastric livestock. The results indicate that land systems with monogastrics are statistically different from their counterparts in the classification without monogastrics in terms of grassland area and crop yields, but are less different in terms of tree area, crop area, and ruminant livestock production. We then used a land systems map that includes monogastrics in the classification and a similar map that does not include monogastrics to project future changes in a novel manner that integrates livestock as a determinant of land systems. The results show that including monogastrics in otherwise similar projections yields less cropland intensification and more cropland expansion in several world regions, including Northern Africa and the Middle East. Other regions, such as Europe and Australia, were characterized by less decrease or more increase in tree area in the application with monogastrics, mainly due to the occurrence of open forests with monogastrics. This study prompts a call for improved characterization of land systems for land use and cover change (LUCC) assessments in order to better represent LUCC driven by monogastric livestock. 相似文献
44.
Recent wetland area trends were estimated from the National Resources Inventory (NRI) for nonfederal rural lands for the period
1982–1987. NRI-based estimates of wetland area for states comprising the conterminous United States were highly correlated
with estimates made by the US Fish and Wildlife Service and with estimates of coastal salt marsh wetlands made by the National
Oceanic and Atmospheric Administration. Net wetland area declined by 1.1% (≈363,200 ha) during the five-year study period.
Conversion to open water, primarily caused by natural flooding in western inland basins, was responsible for altering extensive
wetland areas (≈171,400 ha). Of the human-induced wetland conversions, urban and built-up land was responsible for 48% of
the wetland loss, while agricultural development was indicated in 37% of the converted wetland area. A decrease in rural land,
and increases in both population, and urban and built-up land were associated with wetland loss among states. Potential reasons
for wetland loss were different in 20 coastal states than in 28 inland states. Proportionately, wetland loss due to development
was three times greater in coastal states than inland states, while agriculturally induced wetland losses were similar in
both groups. The proportionate declines of forested vs nonforested wetlands were not significantly different among states. 相似文献
45.
46.
《Process Safety and Environmental Protection》2014,92(6):598-615
Four strategies can be used to achieve safety in chemical processes: inherent, passive, active and procedural. However, the strategy that offers the best results is the inherent safety approach, especially if it is applied during the initial stages of a project. Inherently Safer Design (ISD) permanently eliminates or reduces hazards, and thus avoids or diminishes the consequences of incidents. ISD can be applied using four strategies: substitution, minimization, moderation and simplification. In this paper, we propose a methodology that combines ISD strategies with Quantitative Risk Assessment (QRA) to optimize the design of storage installations. As 17% of major accidents in the chemical industry occur during the storage process and cause significant losses, it is essential to improve safety in such installations. The proposed method applies QRA to estimate the risk associated with a specific design. The design can then be compared to others to determine which is inherently safer. The risk analysis may incorporate complex phenomena such as the domino effect and possible impacts on vulnerable material and human elements. The methodology was applied to the San Juanico tragedy that occurred in Mexico in 1984. 相似文献
47.
Jon D. Unruh 《Natural resources forum》2008,32(2):103-115
Land tenure plays a primary role in sustainable development efforts. However armed conflict and its repercussions reconfigure the network of social relations upon which all land tenure systems depend. In post‐conflict settings new laws have the opportunity to address tenure issues in the context of what people are already doing ‘on the ground’, with a view to moving from the fluidity of post‐conflict situations to a more solidified and peaceful social and legal environment. However there exists a lack of tools to analyze postwar land tenure and the prospects for reconstituting tenure systems to support recovery and development. This paper uses the Sustainable Livelihoods framework to examine postwar land tenure issues in order to draw out latent opportunities within emergent informal smallholder tenure constructs which may have utility in the reconstitution of national tenure systems. 相似文献
48.
U. Martin Persson Christian Azar 《Mitigation and Adaptation Strategies for Global Change》2007,12(7):1277-1304
The possibility of adopting national targets for carbon dioxide (CO2) emissions from tropical deforestation in a future international climate treaty has received increasing attention recently.
This attention has been prompted by proposals to this end and more intensified talks on possible commitments for developing
countries beyond the United Nations Framework Convention on Climate Change Kyoto Protocol. We analyze four main scientific
and political challenges associated with national targets for emissions from tropical deforestation: (1) reducing the uncertainties
in emission inventories, (2) preserving the environmental integrity of the treaty, (3) promoting political acceptance and
participation in the regime, and (4) providing economic incentives for reduced deforestation. We draw the following conclusions.
(1) Although there are large uncertainties in carbon flux from deforestation, these are in the same range as for other emissions
included in the current Kyoto protocol (i.e., non-CO2 GHGs), and they can be reduced. However, for forest degradation processes the uncertainties are larger. A large challenge
lies in building competence and institutions for monitoring the full spectrum of land use changes in developing countries.
(2 and 3) Setting targets for deforestation is difficult, and uncertainties in future emissions imply a risk of creating ‘tropical
hot air’. However, there are proposals that may sufficiently deal with this, and these proposals may also have the advantage
of making the targets more attractive, politically speaking. Moreover, we conclude that while a full carbon accounting system
will likely be politically unacceptable for tropical countries, the current carbon accounting system should be broadened to
include forest degradation in order to safeguard environmental integrity. (4) Doubts can be cast over the possible effect
a climate regime alone will have on deforestation rates, though little thorough analysis of this issue has been made.
相似文献
U. Martin PerssonEmail: |
49.
Maria Lumbierres Prabhat Raj Dahal Moreno Di Marco Stuart H. M. Butchart Paul F. Donald Carlo Rondinini 《Conservation biology》2022,36(3):e13851
Area of habitat (AOH) is defined as the “habitat available to a species, that is, habitat within its range” and is calculated by subtracting areas of unsuitable land cover and elevation from the range. The International Union for the Conservation of Nature (IUCN) Habitats Classification Scheme provides information on species habitat associations, and typically unvalidated expert opinion is used to match habitat to land-cover classes, which generates a source of uncertainty in AOH maps. We developed a data-driven method to translate IUCN habitat classes to land cover based on point locality data for 6986 species of terrestrial mammals, birds, amphibians, and reptiles. We extracted the land-cover class at each point locality and matched it to the IUCN habitat class or classes assigned to each species occurring there. Then, we modeled each land-cover class as a function of IUCN habitat with (SSG, using) logistic regression models. The resulting odds ratios were used to assess the strength of the association between each habitat and land-cover class. We then compared the performance of our data-driven model with those from a published translation table based on expert knowledge. We calculated the association between habitat classes and land-cover classes as a continuous variable, but to map AOH as binary presence or absence, it was necessary to apply a threshold of association. This threshold can be chosen by the user according to the required balance between omission and commission errors. Some habitats (e.g., forest and desert) were assigned to land-cover classes with more confidence than others (e.g., wetlands and artificial). The data-driven translation model and expert knowledge performed equally well, but the model provided greater standardization, objectivity, and repeatability. Furthermore, our approach allowed greater flexibility in the use of the results and uncertainty to be quantified. Our model can be modified for regional examinations and different taxonomic groups. 相似文献
50.
日本国土开发利用及对我国的启示 总被引:1,自引:0,他引:1
日本在战后经历了经济高速增长,工业化和城市化快速推进的发展历程,其间土地利用在结构、规模、价格、集约利用等方面发生了巨大变动。本文全面分析了二战之后,日本在经济高速增长、产业结构巨大变动、城市化迅速推进的发展过程中.农业用地、工业用地和城市用地在结构、规模、价格、集约利用程度等方面的特征;日本政府针对经济发展和土地利用的变动和影响。制订的一系列规划调整措施和政策法规体系。通过以上分析,探讨日本在有限的土地资源条件下实现经济高速增长的原因、途径和措施,以及对我国的启示。 相似文献