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381.
In this paper, we explore how scenarios of future water withdrawals in a river basin are influenced by scale-dependent quantifications of the driving forces for two global-scale storylines. Either global-scale information or region-specific information is used to do the quantifications. In addition, we analyze the impact of including or not some restricted regional-scale information in the employed water use model. To develop scenarios of water withdrawals in the German part of the Elbe River basin, we applied the modules for domestic, thermoelectric power and manufacturing water use of the global water model WaterGAP, using scale-dependent driving forces scenarios and other scale-dependent model input. In the global-scale quantitative interpretations of the storylines of the IPCC SRES scenarios A1 and B2, all major driving forces of water withdrawals in the basin—population, thermoelectric power production and industrial gross domestic product—show vigorous increases between 2000 and 2025, while from the regional perspective, smaller increases but mostly decreases appear to be plausible. These discrepancies are partly due to the fact that for the global-scale interpretations only the historic developments until 1990 were taken into account, and not until 2000 as in the regional case. The resulting scenarios of sectoral water withdrawals in 2025 differ strongly between the two scale-dependent interpretations of the storylines, with the global one leading to much higher absolute water withdrawals and much lower withdrawal decreases between 2000 and 2025. Therefore, for regional assessments of water withdrawals, we recommend to embed the scenario analysis in global-scale storylines by performing regional-scale quantifications of the global qualitative driving forces scenarios, based on a limited amount of region-specific information. 相似文献
382.
Spatial proximity of emissions sources to receptors may affect sensitivity to potential adverse human health effects. This research investigates whether receptor sensitivity to the location of emission sources can be utilized efficiently to minimize health risk in selecting sites for industrial enterprises, thermal electric stations, etc. A sensitivity function that is independent of the location of pre-existing emission sources is derived and applied to Minsk, Belarus. The function estimates exposures based on weather and climatic conditions as well as the distribution of population density at a given locality. Arraying prospective sites based on their sensitivity function magnitude provides a technique for minimizing health risk based on receptor sensitivity to the spatial proximity of atmospheric emissions sources. 相似文献
383.
Sourcing sediment using multiple tracers in the catchment of Lake Argyle,Northwestern Australia 总被引:5,自引:0,他引:5
Control of sedimentation in large reservoirs requires soil conservation at the catchment scale. In large, heterogeneous catchments,
soil conservation planning needs to be based on sound information, and set within the framework of a sediment budget to ensure
that all of the potentially significant sources and sinks are considered.
The major sources of sediment reaching the reservoir, Lake Argyle, in tropical northwestern Australia, have been determined
by combining measured sediment fluxes in rivers with spatial tracer-based estimates of proportional contributions from tributaries
of the main stream entering the lake, the Ord River. The spatial tracers used are mineral particle magnetics, the strontium
isotopic ratio, and the neodymium isotopic ratio. Fallout of 137Cs has been used to estimate the proportion of the sediment in Lake Argyle eroded from surface soils by sheet and rill erosion,
and, by difference, the proportion eroded from subsurface soils by gully and channel erosion. About 96% of the sediment in
the reservoir has come from less than 10% of the catchment, in the area of highly erodible soils formed on Cambrian-age sedimentary
rocks. About 80% of the sediment in the reservoir has come from gully and channel erosion. A major catchment revegetation
program, designed to slow sedimentation in the reservoir, appears to have had little effect because it did not target gullies,
the major source of sediment. Had knowledge of the sediment budget been available before the revegetation program was designed,
an entirely different approach would have been taken. 相似文献
384.
385.
Understanding the earth system requires that the two-way linkages between regions and the global system be well understood
and predictable. Most studies of global change are undertaken thematically across limited disciplinary boundaries; few are
attempted holistically across many disciplines within regions. The regional approach offers many advantages. Here a variety
of linkages associated with the regions of Southern Africa, South Asia, East Asia and Southeast Asia are presented to illustrate
the power of a regional approach to earth system science. Major findings include the extent to which long-range transport
of aerosols and nutrients affect terrestrial and marine ecosystem functioning in and around southern Africa. Aerosol transport,
and the development of a regional haze layer, over South Asia are shown to alter significantly the radiative forcing of change
in the atmosphere over the region. Changes in land cover and use over East Asia over along period of time are shown to have
affected the strength of the monsoon circulation significantly. Finally, rampant economic development and globalization in
Southeast Asia are demonstrated to have been a significant driver of regional change.
Electronic Publication 相似文献
386.
重大工业隐患的地域监控体系研究 总被引:6,自引:3,他引:3
沈立 《中国安全科学学报》2001,11(3):1-5
系统地分析了重大工业危险源与事故隐患 ;研究了地域监控、预警、应急预案的体系建设以及隐患监控的新技术应用基础 ;提出了职业安全卫生监控体系中的工业危险源和隐患监控。笔者认为 :应该分为过程安全监控和安全目标监控两个层次 相似文献
387.
388.
施用不同氮肥对坡耕地径流中N输出的影响 总被引:7,自引:2,他引:5
以山东省泰安东北部刘家庄村坡耕地为研究区域,通过实地监测多次天然降雨中农田养分的流失,研究施肥处理对氮素流失的影响.结果表明,施肥显著地增大了农田径流中氮素浓度及流失量;在相同施肥量的实验条件下,与碳酸氢铵和普通尿素相比,控释尿素可有效地降低氮素流失15%~25%;70%左右的氮素流失发生在监测的前期.合理施肥、降低表土中速效氮养分含量是减少农田氮流失的关键途径之一. 相似文献
389.
研究了郑州城区空气颗粒物中多环芳烃(PAHs)的稳定碳同位素组成特征并对其来源进行了解析.气相色谱/燃烧系统/同位素质谱(GC/C/IRMS)分析表明,PAHs 的δ13C 值在非采暖季为-29.4‰~-23.4‰,采暖季为-30.0‰~-24.2‰,随着分子量的增大,PAHs 中 13C 降低.统计表明不同采样点的样品中的 PAHs 的δ13C 区别不明显(0.1‰<σ<0.8‰).两个季节中,三环和四环多芳香烃化合物荧蒽、芘和苯并(a)蒽的δ13C没有明显的区别,其范围为-24.5‰~-23.4‰,但是,五环和六环芳烃的δ13C 值有明显差异.随着分子量的增大,采暖季环境空气颗粒物中 PAHs的碳同位素比值变小的程度比非采暖季的大.采暖季的苯并(a)芘、茚并(1,2,3-cd)芘、苯并(ghi)苝的δ13C 值分别为-26.6‰、-30.0‰和-28.1‰,而非采暖季为-24.5‰、-29.4‰和-26.3‰.利用二元复合同位素模型,估算了不同季节机动车尾气和煤的燃烧对郑州城区苯并(a)芘的贡献.在非采暖季机动车尾气排放的贡献率为 70%,在采暖季贡献率为 50%,煤的燃烧对六环化合物的贡献高于机动车排放的贡献. 相似文献
390.
顾及尺度效应的多源遥感数据“源”“汇”景观的大气霾效应 总被引:1,自引:0,他引:1
以武汉市为例,利用多源遥感数据研究城市"源""汇"景观格局与大气霾污染的相关关系.首先,基于武汉市Landsat8数据的地表覆盖分类结果,计算不同尺度下地表覆盖的整体异质性景观指数,选择异质性最大的尺度作为"源""汇"景观分析的最优尺度;在此基础上,用MODIS数据的气溶胶光学厚度(AOD)产品作为大气霾污染程度的度量,基于自相关性较小的"类别层"景观指数,使用地理加权回归分析模型对"源""汇"景观与AOD进行局部回归分析,并在工业区、商业区和居民区3种功能区内分析建筑物对大气霾污染影响的差异.结果表明:6 km是本文分析的最优尺度;大气霾污染的"源"景观为建筑物,"汇"景观为灌木和林地;减小"源"景观面积所占比例、增大其破碎化程度、"源""汇"穿插均匀分布,可以有效减小气溶胶光学厚度,降低大气霾污染;对于武汉市来说,其大气霾污染的主要来源为中心城区的商业区和居民区,即来自于市民生活.针对中心城区要发挥其经济、交通等功能,已有的建设用地不宜大面积改动这一现状,可以采取小幅度优化措施,而对于非建成区可采取建前合理规划"源""汇"景观空间分布的措施. 相似文献