中亚地区气溶胶时空分布及其对云和降水的影响

中亚地区属干旱半干旱气候区,是水资源缺乏最严重的地区之一,也是全球沙尘气溶胶贡献度较大的区域.利用MODIS气溶胶和云资料以及校准后的TRMM降水数据,可从宏观角度分析中亚地区气溶胶、云、降水的时空分布特征,研究气溶胶与云和降水之间的相互影响关系.结果表明:1中亚地区年平均气溶胶光学厚度表现为春季(0~1)夏季(0~0.8)冬季(0~0.42)秋季(0~0.38),2002—2013年间整体呈现增加趋势;冬季COD量值明显高于其他3个季节,12年间整体表现出下降趋势,夏季变化较小,增幅为-0.876%,冬季最大,增幅为-1.713%;云水路径的区域性和季节性变化较为明显,整体处于降低趋势,其中秋季的新疆塔里木盆地变化最为显著,年变化为-6.607%;利用实测降水数据对TRMM月降水数据进行校准处理,可有效提升数据精度,新疆境内夏季降水占年降水量的比重较大,春、秋次之,咸海地区降水量年内分配相对较均匀,季节性差异不明显,中亚干旱区作为一个整体,降水呈现出增加趋势,其中,冬季降水的增加趋势最明显.2气溶胶光学厚度与云光学厚度呈负相关;与云滴粒子有效半径关系复杂,受水汽影响较大,在云层含水量较低的情况下,云滴粒子与气溶胶光学厚度呈负相关,而在云层含水量较高的情况下,二者呈正相关;云水路径随着气溶胶光学厚度的增加而减小,随AOD的变化的敏感程度在秋季最高,冬季最低.3气溶胶和降水关系复杂,整体来看,中亚地区气溶胶抑制降水.     

21世纪初华中地区发展的资源环境基础

作为中国21世纪资源开发的重要场所,华中地区资源环境开发利用将对国家社会经济发展起到举足轻重的作用。对华中地区资源本底特征、人地关系演进状态及发展趋势进行了分析,认 为华中地区拥有较好的资源基础,特别是在水土两大资源的结合方面。但是从现状和未来国家高速工业发展看,未来华中地区自然资源承载负荷将面临较以往更为巨大和更为艰难的挑战。一方面,优越的地理位置使华中地区在国家未来经济发展与资源环境协调过程中的重要地位更为突出,另一方面,当地的人口增长和经济发展同样会对有限的资源基础造成越来越大的压力。因此,区域发展政策应当做出相应调整。     

Simple Model of Dissolved Oxygen Consumption in a Bay within High Organic Loading: An Applied Remediation Tool

San Vicente Bay is a coastal shallow embayment in Central Chile with multiple uses, one of which is receiving wastewater from industrial fisheries, steel mill effluents, and domestic sewage. A simulation model was developed and applied to dissolved oxygen consumption by organic residues released into this embayment. Three compartments were established as function of: depth, circulation and outfall location. The model compartments had different volumes, and their oxygen saturation value was used as baseline. The parameters: (a) BOD₅ of the industrial and urban effluents, (b) oxygen demand by organic sediments, (c) respiration, (d) photosynthesis and (e) re-aeration were included in the model. Iteration results of the model showed severe alterations in Compartment 1, with a decrease of 65% in the oxygen below saturation. Compartment 2 showed a small decline (10%) and compartment 3 did not show apparent changes in oxygen values. Measures recommended for remediation were to decrease the BOD₅ loading by 30% in the affected sector. Iteration of the model for 200 h following recommendations derived from the preceding results produced an increase in saturation of 60% (5 ml O₂ L⁻¹), which suggested an improvement of the environmental conditions.     

Short-term seasonal variability in Be wet deposition in a semiarid ecosystem of central Argentina

The ⁷Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the ⁷Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. ⁷Be activity concentration in rainwater ranged from 0.7 ± 0.3 Bq l⁻¹ to 3.2 ± 0.7 Bq l⁻¹, with a mean value of 1.7 Bq l⁻¹ (sd = 0.53 Bq l⁻¹). No relationship was found between ⁷Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. ⁷Be ground deposition was found to be well correlated with rainfall amount (R = 0.92). For the precipitation events considered, the ⁷Be depositional fluxes ranged from 1.1 to 120 Bq m⁻², with a mean value of 32.7 Bq m⁻² (sd = 29.9 Bq m⁻²). The annual depositional flux was estimated at 1140 ± 120 Bq m⁻² y⁻¹. Assuming the same monthly deposition pattern and that the ⁷Be content in soil decreases only through radioactive decay, the seasonal variation of ⁷Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of ⁷Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes.     

江苏省2014-2016年臭氧污染区域特征分析

分析2014—2016年江苏省O₃污染状况,以及苏北、苏中和苏南3个典型区域O₃年度、季度、日变化和频度占比等分布特征。结果表明,江苏省的O₃空间分布呈现北低南高,2014—2016年的O₃超标占比由18.4%上升至34.9%;2016年苏北、苏中和苏南地区O₃-8h第90百分位数与2014年相比,上升2.7%,21.8%和3.3%;3个区域夏季O₃-8h均值最高,春、秋2季次之,冬季最低;O₃-1h日变化呈单峰状态,最低值出现在06:00—07:00,最高值出现在15:00—16:00;2016年3个地区的O₃频度占比均呈正态分布,主要集中在40~80 μg/m³,所占比例均>15%;苏中和苏南区域2016和2014年相比O₃频率占比的变化幅度较大,苏北地区变化幅度不大。指出,江苏省的O₃污染程度在逐年提高,污染范围从苏南逐渐往中部和北部城市扩大。     

河南省节能环保产业发展对策研究

节能环保产业是跨行业、涵盖面宽的综合性产业,其产业关联度大,带动力强,是国家确定的战略性新兴产业。河南省是新兴工业大省和资源消费大省,经济发展与资源环境承载力之间的矛盾日益突出,发展节能环保产业势在必行。本文分析了河南省节能环保产业的发展现状和存在的突出问题,提出了发展河南省节能环保产业的重点领域和推进路径。     

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM_2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ₁₅PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM₁₀ (Particulate Matter up to 10 μm in size) bounded Σ₁₅PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ₁₅PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones.     

COST SHARING IN TRANSITION: THE CASE OF PLAN 6, CENTRAL ARIZONA PROJECT1

ABSTRACT: In the past, development of Federal water resource projects depended heavily or exclusively on Federal financing of construction costs. However, pressures on the Federal budget, environmental issues, and the notion that there are economic efficiency gains when beneficiaries of Federal water resource projects increase their cost share are causing changes. The case of the Central Arizona Project Plan 6 is a noteworthy example of the transition to more non-Federal participation in water resource development. This is because the non-Federal financing is to be provided for a project already under construction. The negotiation and terms of the Plan 6 financing agreement between the Department of the Interior and multiple interests in Arizona are used as an example of how Federal water project cost sharing is in a state of transition. The negotiation process is described, a financial analysis is provided, and the terms of the agreement and policy issues that were deliberated in the Executive Branch of the Federal Government are discussed.     

Land Conversion for Suburban Housing: A Study of Urbanization Around Warsaw and Olsztyn,Poland

In Poland of the 1990s, urban demand for housing land around city agglomerations increased rapidly. The decreasing profitability of agricultural production also caused farmers to become interested in the sale of agricultural land for nonagricultural purposes, and new land legislation granted them the right to sell their land. Polish counties simultaneously received self-governing status, which allowed them to define the priorities for local development. Counties received additional responsibility for land management and quickly demonstrated strong support for land conversion, which was perceived as a factor of local development. This paper argues that decentralization and the extension of private control over land have led to a loss of rural landscapes in Poland because farmers, county governments, and rural society in general gained from the conversion of agricultural to housing land. Rapid urbanization has significantly reduced the availability of open space around cities and threatened valuable landscapes, for it has occurred in the absence of environmental safeguards. This paper reports findings from research in two counties, located in regions with diverse economic growth rates. Decentralization is particularly problematic if tax regulations and intergovernmental fiscal relations reward local authorities for urbanization but not environmental protection. Note: This version was published online in June 2005 with the cover date of August 2004.