有机污染场地地下水风险评价指标体系构建的探讨

污染场地中的有机污染物严重威胁着地下水环境。本文针对化工企业排放的废水、废渣对地下水环境的影响,在地下水环境承载力影响因素、污染场地污染物渗入影响因素识别的基础上,依据指标选取的科学性、针对性、可操作性原则,构建了风险评价指标体系,给出了各指标的选取原则和赋值方法,并应用于典型有机污染场地进行地下水风险评价指标体系的检验。结果表明,在地下水天然防污能力低、污染场地潜在风险高的区域,地下水处于高风险区,而地下水天然防污能力高、污染场地潜在风险低的区域,地下水风险等级低,评价结果可靠。该指标体系的构建、指标的选取原则和赋值方法是合理的,具有实际运用价值。     

基于风险评估矩阵的输油管道河流穿越环境风险评估研究

为客观合理地评价油气长输管线穿越河流处的环境风险等级,提出一种基于风险评估矩阵的管道穿越环境敏感点风险评估方法.根据风险矩阵的基本原理,以肯特风险评估方法评估穿越处的管线风险,叠加环境敏感点的自身风险,对管线穿越河流敏感点处进行风险评估与分级.以中国某输油管线为倒,评估管线穿越的6处河流并依据得分结果划分风险等级,对管线穿越河流的风险管理、制定具体的维护维修和整治规划具有很好的指导意义并提供一定的决策支持.     

六安市城市生活垃圾产量的预测

阐述了六安市城市生活垃圾产量预测的两种方法——根据人均垃圾日产量指标预测和根据垃圾年增长率预测。为缺乏相关基础资料的小城市探索了一些新的垃圾产量的预测方法。     

Cs in a raised bog in central Sweden

The vertical distribution of ¹³⁷Cs activity in peat soil profiles and ¹³⁷Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004–2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of ¹³⁷Cs in 2005 was similar at both sites, 23?000 Bq m⁻². In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of ¹³⁷Cs activity was found in the uppermost 1–4 cm of Sphagnum layers, whereas at the low pine site ¹³⁷Cs was mainly found in deeper (10–12 cm) layers. The migration rate was 0.57 cm yr⁻¹ at the open bog site and the migration centre of ¹³⁷Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr⁻¹ and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest ¹³⁷Cs activity concentrations at both sites, 43.5 k Bq⁻¹ DM in 1989 decreasing to 20.4 in 2004–2007 on open bog and 22.3 k Bq kg⁻¹ DM in 1989 decreasing to 11.2 k Bq⁻¹ DM by the period 2004–2007 on the low pine site. ¹³⁷Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m² kg⁻¹ DM at the low pine site.     

What determines selection and abandonment of a foraging patch by wild giant pandas (Ailuropoda melanoleuca) in winter?

Background, aim, and scope  Foraging patches can be described as a nested hierarchy of aggregated resources, implying that study of foraging by wild animals should be directed across different spatial scales. However, almost all previous research on habitat selection by the giant panda has concentrated upon one scale. In this research, we carried out a field study to understand foraging patch selection by giant pandas in winter at both microhabitat and feeding site scales and, for the first time, attempted to understand how long it would stay at the feeding sites before moving on. Materials and methods  The field survey was conducted from November 2002 to March 2003 at Fengtongzhai Nature Reserve (102°48′–103°00′ E, 30°19′–30°47′ N), Baoxing County of Sichuan Province, China, to collect data in both microhabitat and control plots. The microhabitat plots were located by fresh feces or foraging traces left by giant pandas, and the control plots were established to reflect the environment. Within each microhabitat plot, one 1 × 1 m² plot was centralized at the center of each feeding site, in which numbers of old bamboos and old shoots, including eaten and uneaten, were counted, respectively. Results  The results showed that winter microhabitats selected by this species were characteristic of gentle slopes and high old-shoot proportions and that the latter was even higher at feeding sites. Two selection processes, namely, from the environment to microhabitats and from the latter to feeding sites, were found during this species’ foraging patch utilization. Giant pandas preferred to eat old shoots to old bamboo at feeding sites in winter and did not leave unless old-shoot density fell to lower than the average in the environment. Discussion  Both microhabitats and feeding sites selected by giant pandas were characteristic of high old-shoot density, indicating that the preferred food item had a significant influence upon its foraging patch selection. The preference for gentle slopes by giant pandas was presumed to save energy in movement or reflect the need to sit and free its fore-limbs to grasp bamboo culms when feeding but also seemed to be correlated with an easier access to old shoots. The utilization of old shoots at feeding sites was assumed to help maximize energy or nutrient intake during their foraging. Conclusions  The difference between microhabitat plots and control plots and between microhabitats and feeding sites uncovered a continuous selection process from the environment via microhabitats to feeding sites. The utilization of old shoots at feeding sites was parallel to the marginal value theorem. The selection and abandonment of foraging patches by giant pandas was an optimal behavioral strategy adapted to their peculiar food with high cellulose and low protein. Recommendations and perspectives  Our results uncovered the importance of multiple scales in habitat selection research. To further understand the process of habitat selection, future research should pay more attention to resolve the question of how to locate foraging patches under dense bamboo forests by the giant panda, which was traditionally considered to have poor eyesight, although our research has answered what type of habitats the giant panda prefers and when to leave.     

安康中心城市饮用水水源地环境现状调查分析及保护措施

根据安康中心城市两个饮用水水源地环境现状调查和水质监测结果,按照国家《地表水环境质量标准》(GB3838-2002),采用比照法进行了环境质量现状评价。同时,针对目前水源地存在的环境问题,提出了法律法规和制度保护措施、组织保障措施、各级水源保护区的工程治理措施,以及相应的生态修复与建设重点工程和管理能力建设重点工程等,对于改善水源地生态环境系统,有效地保证安康市生活饮用水质量和促进区域水资源可持续利用具有一定的指导作用。     

Establishment of control site baseline data for erosion studies using radionuclides: a case study in East Slovenia

The aim of the present study was to establish a reference site and its soil characteristics for use of fallout radionuclides in erosion studies in Slovenia. Prior to this study, no reference site and baseline data existed for Slovenia for this purpose. In the agricultural area of Gori?ko in East Slovenia, an undisturbed forest situated in Šalamenci (46°44’N, 16°7’E), was selected to establish the inventory value of fallout ¹³⁷Cs and to establish a baseline level of multi-elemental fingerprint (major, minor, trace elements including heavy metals) and naturally occurring radionuclides in soils. A total of 20 soil profiles were collected at four 10 cm depth increments for evaluation of baseline level of ¹³⁷Cs inventory. An exponential distribution for ¹³⁷Cs was found and the baseline level inventory was established at 7300 ± 2500 Bq m⁻² with a coefficient of variation of 34%. Of this mean present-day inventory, approximately 45% is due to the Chernobyl contribution.The physical degradation of soils through erosion is linked with biochemical degradation. This study introduces an approach to establishment of the naturally occurring radionuclide and elemental fingerprints baseline levels at a reference site which can provide comparative data to those from neighbouring agricultural fields for assessment of soil redistribution magnitude using fallout radionuclides. In addition, this information will be used to determine the impact of soil erosion processes and agricultural practices on soil quality and redistribution within agricultural landscapes in Slovenia.     

Reserve Design to Maximize Species Persistence

We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based, metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and determining the best of the promising solutions using a multiple-comparison statistical test. We use the strategy to address a problem of allocating limited resources to new and existing reserves. The best reserve design depends on emigration, dispersal mortality, and probabilities of movement between reserves. When movement probabilities are symmetric, the best design is to expand a subset of reserves to equal size to exhaust the habitat budget. When movement probabilities are not symmetric, the best design does not expand reserves to equal size and is strongly affected by movement probabilities and emigration rates. We use commercial simulation software to obtain our results.     

铬渣污染场地修复技术研究进展

铬渣对中国地下水、地表水和土壤造成了严重污染,并对生态环境和人体健康构成了巨大威胁。开展对铬渣污染场地的修复工作已迫在眉睫。在分析铬污染特性的基础上,阐述了国内外最新铬污染场地修复技术研究动态,并概括分析了其不足与未来铬渣污染场地修复技术的发展趋势。     

Signal-transfer modeling for regional assessment of forest responses to environmental changes in the southeastern United States

Stochastic transfer of information in a hierarchy of simulators is offered as a conceptual approach for assessing forest responses to changing climate and air quality across 13 southeastern states of the USA. This assessment approach combines geographic information system and Monte Carlo capabilities with several scales of computer modeling for southern pine species and eastern deciduous forests. Outputs, such as forest production, evapotranspiration and carbon pools, may be compared statistically for alternative equilibrium or transient scenarios providing a statistical basis for decision making in regional assessments. This revised version was published online in July 2006 with corrections to the Cover Date.