南京河西地区岩土体剪切波速与土层深度的关系

南京河西地区是南京市重点开发的新市区,该区域工程地质条件相似,主要为长江高河漫滩地质地貌单元。本文选取该地区47个典型钻孔的岩土体剪切波速资料,采用三种数学模型进行统计回归分析,运用相关系数R(或测定系数R2)检验Vs—H之间的线性相关关系,并根据计算的SD值选择较优的数学模型。统计结果表明,该地区各类岩土体的Vs—H线性相关关系显著,说明采用上述数学模型进行Vs—H回归是可行的。对两个工程场地进行剪切波速预测,并对场地类别作出划分,检验结果表明,该地区各类岩土体的Vs—H经验关系是可靠的,符合当地岩土特征,在样本深度范围内有足够的工程应用精度,可以应用。     

佛山市南海区降水成分及致酸因子分析

为了解广佛跨界区域佛山市南海区的降水化学组成特征和酸化趋势,于2016年1—12月在南海区采集降水样品,对降水pH、电导率及离子成分进行测定。结果表明:降水pH年均值为5.05,降水的电导率和总离子浓度年均值分别为19.4 μS/cm和6.41 mg/L,南海区2016年的酸雨污染有所改善,但酸雨频率高达63.1%,降水酸化程度仍较高;人为源贡献的N O 3 - 和S O 4 2 - 起主要致酸作用,通过分析S/N发现,N O 3 - 在南海区降水中的致酸作用已超过S O 4 2 - ,成为首要致酸因子。     

The Effects of Ocean Disposal of Sewage Sludge On the Relative Abundance of Benthic Megafauna

Disposal of sewage sludge in the New York Bight Apex (12-Mile Dump Site) ceased at the end of December 1987. Previous efforts to quantify the effects of sludge were hindered by the inability to obtain true replication. the cessation of dumping afforded the opportunity to apply the technique of replication in time, also known as a Before/After, Control/Impact design. Conditionally, this method allows one to separate treatment effects from the natural differences that confound many environmental impact studies. the Environmental Processes Division of the Northeast Fisheries Center, National Marine Fisheries Service sampled the benthic environment of the New York Bight Apex from June 1986 through September 1989 using a sample design based on the technique of replication in time.

Three dominant species (rock crab, Cancer irroratus; little skate; Raja erinacea; and winter flounder, Pseudopleuronectes americanus) and total demersal finfish, collected by otter trawl, showed no statistically significant response to the cessation of disposal. American lobster (Homarus americanus) increased in local abundance, but this result was possibly confounded by a change in fishing effort.     

SYNTHESIS OF FLOW-DURATION CURVES FOR UNREGULATED STREAMS IN NEW HAMPSHIRE1

ABSTRACT: Flow-duration curves are concise pictures of flow variability at a point on a stream, and provide essential information for all water-resource planning. In New Hampshire, useful estimates of flow-duration curves for ungaged points on unregulated streams can be made using only information readily available from contour maps: 1) area of the basin above the point of interest; and 2) either the measured mean basin elevation or the elevations of the highest and lowest points in the basin. Measured or estimated mean basin elevation is then used in regression equations to estimate mean flow QC and the flow exceeded 95% of the time, Q₉₅. QC is assumed to occur at the 27% exceedance frequency. Q₀₂, Q₀₅, and Q₃₀ are estimated as multiples of QC. Equations are provided for calculating 95% confidence intervals for future estimates using the method. The dependence of mean flow on elevation is due to positive vertical precipitation gradients and negative vertical evapotranspiration gradients. The dependence of Q₉₅ on elevation appears to be due largely to the fact that it rains more often, that snowmelt takes longer, and that evapotranspiration is reduced at higher elevations.     

西安市大气颗粒物数浓度分布及典型天气条件特征变化

利用2013年3月到2014年12月期间西安市大气中0.25～32μm颗粒物监测数据和同期气象参数、散射消光系数等数据,分析了大气颗粒物数浓度分布及典型天气条件下变化特征.结果表明:采样期间西安市大气颗粒物平均数浓度为206.27个/cm3, 99%以上为<1μm的颗粒物数.大气颗粒物数浓度冬季最高,其次为秋、夏和春季,分别为267.66、231.31、141.82和135.77个/cm3.四季的数浓度低值均出现在18:00左右,之后数浓度上升,且晚上高于白天,冬季6:00左右达到峰值,夏季的昼夜差最小,秋季最大.春夏秋冬的大气颗粒物数浓度与散射消光系数的Pearson相关系数分别为0.756、0.702、0.411、0.377.大气颗粒物数浓度在沙尘天气发生前、中、后会升高、下降和再下降,霾天气出现前、后会升高和下降;高温干燥天气下,大气颗粒物数浓度相对较低;降雨对大气颗粒物的清除作用明显,但降雨后大气颗粒物数浓度又很快回升.     

酸沉降影响稻米品质的新发现

酸沉降影响了稻米质量和口感.酸雨时空分布从宏观上概括了稻米品质的地理分布.酸雨决定了酶活性相关金属离子的丰缺,继而影响淀粉合成关键酶的活性,最终影响淀粉合成质量.温度变化是表象,降雨pH值变化是条件,酶活性相关金属离子丰缺是根本,实质是酶活性相关金属离子或激活或抑制了支链淀粉合成关键酶的活性.提出了改善粮食作物质量的化控创新技术路线.     

An Environmental Domain Classification of New Zealand and Its Use as a Tool for Biodiversity Management

Abstract:   Successful biodiversity management, including the selection and subsequent management of protected areas, depends in large measure on classifications showing land areas with similar ecosystem character. In contrast to widely used, qualitative land-classification techniques, we used a numerical classification of explicit spatial layers describing aspects of New Zealand's climate and landforms. We chose input variables for their strong functional links with major physiological processes of trees and high statistical correlations with geographic distributions of individual tree species as determined from previous studies. Higher-level divisions of the resulting classification were dominated by macroclimatic variation associated with change in both latitude and orographic protection provided by New Zealand's main mountain ranges, but variation in landform became more important at finer scales of classification. Classification units showed marked variation in the proportional extent of both indigenous vegetation cover and land set aside for conservation purposes. Indigenous ecosystem remnants of the highest priority for increased protection occurred in warm, lowland domains, particularly in drier environments, where both indigenous cover and protected areas are of minimal geographic extent. Such results underline the considerable potential of an environmental classification to provide a landscape context for systematic conservation management, particularly in environments where the natural ecosystem pattern has been severely modified by human activity.     

Concentrations and trends of benzene in ambient air over New York State during 1990–2003

Since 1990s, a systematic program to measure air toxics has been active in New York State with monitors located both in urban and rural areas. In this study we examined the spatial and temporal characteristics of benzene, a known human carcinogen that is emitted by many source categories. The analysis indicates that ambient concentration levels of benzene have decreased by as much as 60% over this period not only in the ozone non-attainment area of New York City that had the reformulated gas (RFG) requirements, but also over the rest of the state as well. Although the rate of decrease appears to have flattened out in recent years, the annual average concentration levels are found to be above the health risk threshold even at the remote location, Whiteface Mountain, suggesting the need for further reductions in benzene emissions.     

北京市丰台区永定河以东浅层地下水水化学演变规律及成因分析

为更好支撑北京市丰台区地下水资源开发利用、污染管控与防治工作,以丰台区永定河以东区域枯水期浅层地下水长序列监测数据为基础,综合运用数理统计、Gibbs图和离子比例分析等方法探究了丰台区地下水水化学演变规律、形成机制及污染来源,结果表明：①研究区现状地下水质量整体较差,地下水中各指标平均浓度自1976年至今呈先升高后降低趋势,Cl^-、SO₄^2-和总硬度（TH）污染范围总体呈扩大趋势,溶解性总固体（TDS）和硝酸盐氮（NO₃^-）污染范围以2005年为拐点呈先扩大后缩小趋势;②各年份地下水中优势阴、阳离子均为HCO₃^-和Ca²⁺,1976年和2021年地下水水化学类型数依次为8和17种,其主要水型依次为HCO₃·SO₄-Ca·Mg·Na（40%）和HCO₃·Cl·SO₄-Ca·Na·Mg（23.88%）,各年份区域范围内与沿地下水流向上地下水水化学类型均呈现复杂化趋势,地下水水文地球化学演变过程中水化学组分受人为活动影响显著;③地下水受岩石风化和蒸发结晶双重作用,且以蒸发作用为主,地下水阳离子交替作用较弱,碳酸盐矿物的溶解为Ca²⁺和Mg²⁺的主要来源;④离子比例分析得出,外源输入的NO₃^-和Cl^-主要来源于农业活动、城市污水,且2005年前农业活动污染影响较大,与研究区历史上大量渗坑、渗井、工业和生活污水灌溉直排关系密切.     

湿地受损遥感识别方法及其在天津滨海新区的应用

城市化进程的加快及对湿地资源的不合理开发利用造成湿地严重受损,开展湿地资源的时空变化监测对于湿地的合理开发和可持续发展具有重要作用。基于多时期土地利用数据和长时间序列的Landsat影像数据,利用马尔科夫转移矩阵和GIS空间分析法分析湿地类型受损状况,利用趋势分析法分析长时间序列和不同阶段的湿地植被、水体和土壤湿度要素受损状况,构建了湿地受损遥感识别方法,综合湿地类型和湿地要素受损状况,分析湿地受损模式,并在天津滨海新区进行案例研究。结果显示:滨海新区湿地类型受损主要分为3个时期(1980s—2000年、2000—2009年、2009—2015年),期间湿地经历了从受损到恢复的过程,1980s—2015年滨海新区湿地面积增加了41.40 km ²;1984—2015年湿地要素均呈退化趋势,植被、水体和土壤显著退化的面积分别为364.66、221.28和253.94 km ²。在不同时间段内,影响湿地面积受损的主导因素不同,3个时期滨海新区湿地受损分别是植被、水体和植被占主要地位。