Distribution,sources and potential risk of HCH and DDT in soils from a typical alluvial plain of the Yangtze River Delta region,China

Spatial distribution, sources and potential health risks of organochlorine pesticides (OCPs), including hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in surface soils (n = 544) collected from a typical alluvial plain of the Yangtze River Delta region, China, were elucidated. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (<LOD) to 99.0 ng g^?1, dry weight (dw) (mean 3.23 ng g^?1 dw) and <LOD to 600 ng g^?1 dw (mean 88.8 ng g^?1 dw), respectively. Historical applications of HCH and DDT were the major sources of the residue in soils. HCH was mainly distributed in Anthrosols in the southern part of the watershed, while DDT was mainly distributed in Cambosols in the northern part. The 95 % cumulative probability incremental lifetime cancer risks (ILCRs) of different age groups such as children, youths, and adults all exceeded the acceptable risk level of 10^?6 recommended by USEPA for carcinogenic chemicals. The spatial distributions of ∑ILCRs were consistent with concentrations of OCPs in soils, while they were slight different for the different age groups. Adult females had the greatest risk of OCPs in soils, followed by children, while youths had the least risk. The ingestion of OCPs in soils was the more important route of exposure compared with dermal and inhalation exposures. The concentration of OCPs in soils, the particulate emission factor, the fraction of dermal exposure ratio, and the soil ingestion rate were the major contributing variables to total ILCRs according to sensitivity analyses.     

Levels and distribution of heavy metals in atmospheric particular matters over the northern South China Sea

Oceans play a significant role in the cycling of trace metals and persistent organic pollutants. In this study, aerosol samples covering the whole northern South China Sea (SCS) were collected in 2005 and 2007, respectively, for analysis of trace metals and major elements. The levels of trace metals detected ranged from 0.514 to 119 ng/m³ in 2005 and from 0.130 to 24.2 ng/m³ in 2007, respectively. Cu, Zn, and Pb were the three predominant metals with high enrichment factors (>10), indicating the strong anthropogenic inputs. The trace metals over SCS were comparable to the values in suburban and background sites of South China, but generally higher than those over other seas and oceans. Considering the fact that they were influenced by their proximity to source regions and air mass origins, the elevated metals in 2005 were probably attributed to the strong wind and long-range atmospheric transport driven by Asian monsoon.     

Uncertainty assessment of spatial patterns of soil organic carbon density using sequential indicator simulation, a case study of Hebei province, China

The spatial patterns of soil organic carbon (SOC) are closely related to the global climate change. In quantifying the spatial patterns of SOC density, the concept of uncertainty of the SOC density values at unsampled locations is particularly important because such uncertainty can be propagated into the subsequent global climate change modelling and has fundamental impacts on the ultimate results of the model. A total of 361 SOC density data of topsoil (0–20 cm) in Hebei province and sequential indicator simulation (SIS) were applied to perform a conditional stochastic simulation in this study to quantitatively assess the uncertainty of mapping SOC density. The results showed that a great variation exists in the SOC density data. The conditional variance of 500 realizations generated by SIS was larger in mountainous areas of the study area where the SOC density fluctuated the most, and the uncertainty was smaller on the plain area where SOC density was consistently small. Realizations generated by SIS can represent the possible spatial patterns of SOC density without smoothing effect. A set of realizations can be used to explore all possible spatial patterns of SOC density and provide a visual and quantitative measure of the spatial uncertainty of mapping SOC density. With a given threshold of SOC density, SIS can quantitatively assess both local uncertainty and spatial uncertainty of SOC density that is greater the threshold.     

有机固体废物高效腐殖化微生物调控原理与技术

堆肥作为有机固体废物资源化处理处置的方式之一,腐殖化效率低是制约其发展的瓶颈.本文从生物强化调控、微环境调控和调理剂调控3方面,系统梳理了有机固体废物腐殖化微生物调控原理和调控技术,并从基础理论层面和技术研发层面对该领域今后的研究方向进行了展望.指出:生物强化调控技术在腐殖化研究中前景较好;应重点关注腐殖化和矿化过程中...     

软约束机制下的生态预算理论的问题及对策

在分权体制框架下,约束机制软化导致地方政府放大其自利性偏好,在一定程度上成为可持续发展的减项。表现为：在当前政府绩效考核的经济指标压力下扩大自然资源的投入;与资源消耗主体博弈的经济人行为导致不规范的环境资源分配,使环境目标和环境管理目标的实现呈现高成本特征;与中央政府相较的信息优势导致全局性的非理性资源的浪费等。生态预算是ICLEI参照财政预算的程序创建的促进环境资源有效配置和可持续管理的政府工具,其以强可持续发展为目标,采用实物指标度量环境资源在社会经济活动中的实际流量,强调约束支出控制,以保持环境资源全部价值在代内和代际间的平衡。我国在引进生态预算监督制约机制的路径选择及模式设计上,可能会出现因现实文化的惯性、双重代理机制、体制内监督等问题导致的生态预算约束软化,改进方向在于重视环境-经济-社会一体化考核的作用、确定合理的激励方式、由社会审计评价和监督生态预算执行,从而逐步走向制度完善的进程。     

论自然保护区的生态旅游开发

文章认为自然保护区具有典型多样的自然生态系统,适合于开展生态旅游活动.自然保护区实行封闭管理,将保护区的保护与当地社会发展相隔离的做法无法实现真正的保护,生态旅游的开展对自然保护区的保护工作具有积极意义.为了实现自然保护区生态旅游的积极作用,文章提出了确定开发等级、生态规划、容量限制、功能分区、突出保护主题及公平发展等开发原则.     

Changes in soil fertility parameters and the environmental effects in a rapidly developing region of China

An extensive knowledge of the temporal variability of soil fertility parameters and how this variation affects the environment is imperative to a wide range of disciplines within agricultural science for optimal crop production and ecosystem preservation. This paper examines the temporal variability of soil pH, organic matter (OM), cation exchange capacity (CEC), total nitrogen (TN), total phosphorus (TP), available phosphorus (P_Av), and available potassium (K_Av) on Cambosols (Entisols) (n = 179) and Anthrosols (Inceptisols) (n = 95) in Zhangjiagang County, China from 1980 to 2004. Nutrient input was monitored from 1983 to 2004. Annual N fertilizer rates were significantly different during three periods (1983–1989, 1989–1999, 1999–2004), where annual rates increased significantly after 1989 and then decreased after 1999. Annual P fertilizer rates were significantly different during two periods (1983–1993, 1993–2004) where annual rates increased after 1993. No change was found in K fertilizer rates. Soil pH marginally increased by 0.14 units in Cambosols, but significantly decreased by 1.02 units in Anthrosols. OM, CEC, and TN increased in both soil orders an average of 2.15 g kg^?1, 1.6 cmol kg^?1, and 0.21 g kg^?1, respectively. TP decreased in Anthrosols by 70 mg kg^?1, P_Av increased in Cambosols by 4.83 mg kg^?1, and K_Av decreased in Cambosols by 15 mg kg^?1. Fertilizer input rates are causing nutrient imbalances, contributing to acidification in Anthrosols, and decreasing C/N ratios. Nutrient loading of N and deficiency of K is also a potential problem in the area. Efforts should be made to readjust soil nutrient inputs to reach an optimal, sustainable level.     

RETRACTED ARTICLE: Adaptation strategies of farmers to drought in a changing climate in Dingcheng County,Hunan, southern China

Regional Environmental Change -     

基于灾害系统理论的地震灾害链研究——中国汶川“5.12”地震和日本福岛“3.11”地震灾害链对比

重大自然灾害中灾害链对灾情的巨大放大、累加作用,使灾害链研究备受关注。基于灾害系统理论,以中国汶川"5.12"地震灾害和日本福岛"3.11"地震灾害为例进行了地震灾害链梳理和区域对比,并探讨了不同灾害系统下,孕灾环境和承灾体对灾害链致灾成灾的影响。通过构建承灾体脆弱性与灾情累积关系的概念模型,阐述了灾害链对灾情的放大机制。研究表明:汶川地震具有陆地山区灾害链特征,主要灾害链为地震→崩塌/滑坡→(泥石流→)堰塞湖灾害链和地震→结构破坏→设施受损灾害链;日本地震具有海洋岛屿灾害链特征,主要灾害链为地震→海啸→核事故灾害链、地震→(海啸→)结构破坏→火灾/生命线系统损毁灾害链和地震→滑坡/火山/水库溃坝灾害链等;两场地震灾害中灾害链的成因及灾害链对灾情的放大过程差异显著;福岛地震灾害链危害巨大,使灾情在其他相关国家放大。     

基于网格脆弱性曲线的世界小麦旱灾风险评价

旱灾是世界上影响范围最广、造成农业损失最大的自然灾害之一,同时,在全球变化的背景下,旱灾风险呈现加重的趋势。评价农业旱灾风险并进行有效的防范是保障粮食安全的重要措施。借助EPIC模型,假定0.5°网格为均值单元,使用灌溉情景法模拟全球均值网格的小麦旱灾脆弱性曲线。结合历史气象数据评价全球小麦的干旱致灾因子,最后计算了全球小麦因旱灾导致的产量损失风险,并编绘了全球小麦旱灾风险图。结果显示:1中国、俄罗斯、美国/哈斯克斯坦为风险排名前三的国家,归一化后的风险指数分别为0.53、0.22和0.19;2春小麦的旱灾风险要高于冬小麦。在已有的作物旱灾风险评价研究基础上,同时兼顾了脆弱性评价的空间分辨率和表示精度,建立了与风险评价空间分辨率相一致的小麦旱灾脆弱性曲线,从而极大地提升了区域旱灾风险评价,特别是大尺度风险评价的准确度。