Prospects for Development of an Index of Biotic Integrity for Evaluating Habitat Degradation in Coastal Systems

A multivariate index for assessment of habitat quality and its degradation, the Index of Biotic Integrity (IBI), has been developed for stream fish communities. the extension of the IBI concept to coastal waters is proposed by the development of an estuarine IBI based on macrobenthos and submerged aquatic vegetation. Eleven variables are proposed for inclusion in this index, although further consideration of the appropriateness of several variables is required. It is concluded that development of an IBI for coastal systems is feasible.     

DROUGH TREND IN NORTH CHINA IN RECENT FIFTY YEARS

Inrecentseveralyears ,abnormaldroughtoccursinthepartnorthernofChina .Itex ertssomeinfluenceonChina’snationaleconomyandhasarousedwideattentionfromallwalksoflife .Muchresearchindrought wetindexhasbeendonebothathomeandabroad .Theresultcanbeclassifiedintotwocategories:first,droughtindexdirectlyisdefinedbyprecipitationorothermeteorologicalfactors;second ,droughtindexisidentifiedbycalculatinggainingandlos ingoflocalwaterinaccordancewithequationofwaterbalance ,andsomealsoconsidertheim pactofdrought…     

华北平原地下水重金属山前至滨海空间分布特征与规律

结合华北平原水文地质条件,从山前至滨海选取"保定-沧州"、"石家庄-衡水-德州"两个剖面,通过野外采集地下水样品,分别测定了Fe、Mn、Cu、Zn、Pb、Cd、As、Cr、Se等9种重金属元素含量及其他相关指标。结果表明,调查剖面地下水中出现Fe、Mn、Se、Cr超标现象,其中Fe超标严重。本文首次在区域尺度上对华北平原地下水重金属的空间分布进行了分析,分别阐述了两个剖面地下水重金属的横向与垂向分布特征。总体上,随着地下水埋藏深度的增加,重金属离子总量降低,尤其是对人体有害的重金属元素含量降低显著。通过回归分析对地下水中重金属空间变化规律进行了定量分析,其中Cd、As、Zn、Mn元素含量与空间变量呈现显著相关性。本研究结果可为华北平原地下水质量评价与防控提供一定的依据。     

基于质子转移反应质谱(PTR-MS)对北方冬季大气氨的观测研究

氨是大气中广泛存在的碱性气体,已有的研究表明,氨能够参与包括硫酸/水体系的三元成核过程,进而促进新粒子的形成;同时,氨也是大气二次有机气溶胶（SOA）的重要前体物,对二次有机气溶胶的形成具有不可忽视的影响.了解大气中氨的污染情况,实现对大气中氨的高时间分辨率的在线观测,对于研究大气中氨的时空分布及来源解析,进而加深对气溶胶生成机理及气溶胶在大气辐射平衡与气候变化中作用的认识有重要意义.本研究使用一台自主搭建的质子转移反应质谱仪（PTR-MS）,以丙酮作为反应试剂,由电晕放电离子源产生质子化的丙酮反应试剂离子（（C₃H₆O）_nH⁺）（n=1,2）,与大气中的气态氨及其他碱性气体发生质子转移反应后进行质谱检测.丙酮（C₃H₆O）相较于水（H₂O）和乙醇（C₂H₅OH）,具有更高的质子亲和力（PA=194.1 kcal·mol^-1）,对PA较高的碱基化合物的选择性更好,可减少其他物质对四极杆质谱检测结果的影响.本研究在2017年11月9日—2018年1月10日和2018年11月12日—2019年1月2日华北地区气溶胶生成机理综合研究联合外场观测期间,将PTR-MS部署于山东省德州市平原县气象局观测场内,对大气中的氨气进行实时在线观测.结果表明,两次观测的气态氨平均值分别为（5.89±5.27）ppbv和（2.65±2.41）ppbv,均呈现出一个明显的日变化规律,即上午6：00—7：00出现峰值,随后逐渐下降,在下午大约15：00浓度达到最低值,随后上升.结合正交矩阵因子分解法（Positive Matrix Factorization,PMF）模型对当地近地面大气中氨气进行初步的来源分析,发现当地大气中氨气的来源主要是周边农村在冬季大量使用生物质燃料燃烧取暖造成的生活排放和当地交通源排放.两次冬季观测中当地农村取暖等生活排放分别占到66.0%和55.0%;交通排放在两次观测中分别占到27.0%和36.8%;农田土壤释放、畜牧养殖排放和工业排放等其他来源占比较低,分别是6.2%和7.5%;外部传输来源只占到很少一部分,分别是0.8%和0.7%.2018年的冬季观测相较于2017年,氨气浓度总体出现下降,主要来源还是以当地农村冬季生活和取暖燃烧排放为主,但通过相关政策管控,这一污染来源得到改善.     

南水北调中线工程渡槽的综合防洪风险分析

远距离输水工程沿途往往要跨越众多河系,交叉建筑物极易受到洪水的冲击,这就需要对其防洪风险给出定量的评估。以可靠度理论为基础,根据渠道所穿越的各条河流的水文、气象、地质、工程结构的随机特征给出了引水工程交叉建筑物的综合防洪风险计算方法;并以南水北调中线工程河北省段3座渡槽为例对该方法进行了验证。结果表明:南水北调中线工程河北省段渡槽的综合防洪风险小于万分之一。     

Pulpwood,pesticides, and people. Controlling spruce budworm in northeastern North America

The eastern spruce budworm is a major forest pest over the continental range of the spruce-fir forest ecosystem and its southern ecotonal fringes in Canada and the northeastern United States. The current budworm outbreak illustrates the difficulty of arriving at economically sound and publicly acceptable forest pest control policies. Policies ranging from no use of chemical control to annual widespread crop protection have been adopted. There is no single all-around best policy for spruce budworm control. Chemical spray programs have demonstrably slowed the normal progress of mortality due to budworm, but have not eradicated the pest. Where industry remains heavily dependent on a fully utilized spruce-fir forest, no easy, low-cost solutions to the budworm problem exist. Reliance on spraying will have to be reduced and plans made to utilize higher levels of tree mortality and to manage the forest for lower future vulnerability.     

FRESH GROUND WATER STORED IN AQUIFERS UNDER THE CONTINENTAL SHELF: IMPLICATIONS FROM A DEEP TEST,NANTUCKET ISLAND,MASSACHUSETTS1

ABSTRACT: A deep water-resource and stratigraphic test well near the center of Nantucket Island, about 40 miles (64 km) off the New England Coast, has encountered freshwater at greater depth than predicted by the Ghyben-Herzberg principle. An uppermost lens of fresh-water, which occupies relatively permeable glacial-outwash sand and gravel to a depth of 520 ft. (158 m), is probably in hydrodynamic equilibrium with the present level of the sea and the height of the water table. However, two zones of freshwater between 730-820 ft. (222-250 m) and 900-930 ft. (274-283 m) are anomalously deep. A third zone extending from 1150-1500 ft. (350-457 m) contains slightly salty ground water (2 to 3 parts per thousand dissolved solids). Several explanations are possible, but the most likely is that large areas of the Continental Shelf were exposed to recharge by precipitation during long periods of low sea level in Pleistocene time. After the last retreat of glacial ice, seawater rapidly drowned the shelf around Nantucket Island. Since then, about 8000 years ago, the deep freshwater zones which underlie dense clay layers have not had time to adjust to a new equilibrium. Under similar circumstances freshwater may remain trapped under extensive areas of the Continental Shelf wherever clay confining beds have not permitted saltwater to intrude rapidly to new positions of hydrodynamic equilibrium. The implications are far reaching because all continental shelfs were exposed to similar hydrologic influences during Pleistocene time.     

Energy economy of salmon aquaculture in the Baltic sea

Resource utilization in Atlantic salmon aquaculture in the Baltic Sea was investigated by means of an energy analysis. A comparison was made between cage farming and sea ranching enterprises each with yearly yields of 40 t of Atlantic salmon. A variety of sea ranching options were evaluated, including (a) conventional ranching, (b) ranching employing a delayed release to the sea of young smolts, (c) harvesting salmon both by offshore fishing fleets and as they return to coastal areas, and (d) when offshore fishing is banned, harvesting salmon only as they return to coastal areas where released. Inputs both from natural ecosystems (i.e., fish consumed by ranched salmon while in the sea and raw materials used for producing dry food pellets) and from the economy (i.e., fossil fuels and energy embodied in economic goods and services) were quantified in tonnes for food energy and as direct plus indirect energy cost (embodied energy). The fixed solar energy (estimated as primary production) and the direct and indirect auxiliary energy requirements per unit of fish output were expressed in similar units. Similar quantities of living resources in tonnes per unit of salmon biomass output are required whether the salmon are feeding in the sea or are caged farmed. Cage farming is about 10 times more dependent on auxiliary energies than sea ranching. Sea ranching applying delayed release of smolts is 35–45% more efficient in the use of auxiliary energies than conventional sea ranching and cage farming. Restriction of offshore fishing would make sea ranching 3 to 6.5 times more efficient than cage farming. The fixed solar energy input to Atlantic salmon aquaculture is 4 to 63 times larger than the inputs of auxiliary energy. Thus, cage farming and sea ranching are both heavily dependent on the productivity of natural ecosystems. It is concluded that sustainable development of the aquaculture industry must be founded on ecologically integrated technologies which utilize the free production in marine ecosystems without exhausting or damaging the marine environment.     

沈阳市北部地区风沙危害及防治对策

荒漠化是当今世界严重的环境与社会经济问题。沈阳市北部康平、法库两县均被列为国家防沙、治沙重点县。本文阐述了康平、法库两县风沙危害现状及发展趋势 ,提出了风沙危害的防治对策。     

Influence of releases of I-129 from reprocessing plants on the marine environment of the North Adriatic Sea

Compared to the pre-nuclear era, large amounts of ¹²⁹I have been released to the marine environment, especially as liquid and gaseous discharges from two European reprocessing plants located at Sellafield and La Hague. Their liquid discharges influence Northern Europe and most research was conducted in the area of the North Atlantic Ocean and the Baltic Sea. In this article data on ¹²⁹I content and ¹²⁹I/¹²⁷I ratios observed in the North Adriatic Sea, which is a rather enclosed basin of the Mediterranean Sea, are presented. To the best of our knowledge no data on ¹²⁹I in the Mediterranean Sea have previously been reported. As this area is isolated from direct liquid discharges, the main transport pathway is probably gaseous releases from reprocessing plants. Surface sea water, the marine alga Fucus virsoides, an iodine accumulator, and the Mediterranean mussel Mytilus galloprovincialis collected in 2009 and 2010, and marine sediment collected in 2005 and 2009 were analysed. The ¹²⁹I/¹²⁷I isotopic ratios observed were in the range from 0.8 to 3.0 × 10⁻⁰⁸ for seawater, from 0.06 to 0.35 × 10⁻⁰⁸ for marine sediment, from 0.05 to 0.10 × 10⁻⁰⁸ for F. virsoides and from 0.3 to 0.9 × 10⁻⁰⁸ for M. galloprovincialis.