汉江中游河谷平原植被指数时空变化及其与沙化土地动态的关联关系

针对沙化土地广泛分布的汉江中游河谷平原区,采用MODIS EVI数据分析2003~2011年区域植被状态时空变化,并据此探讨沙化土地的动态特征。利用时序植被指数统计分析,探讨研究区植被的总体变化规律;分析不同缓冲区植被指数的空间分布格局,反映了区域环境状况的空间差异以及由此而可能产生的土地利用格局的变化;并基于不同距离缓冲区的EVI时空差异对比分析,探讨沙化土地动态与植被变化的关联关系。研究表明,近9 a来汉江中游河谷平原区EVI呈明显上升趋势;随着离河流距离的逐渐增加,每千米范围内各年的年均EVI值均表现出先增大后减小的空间特征,并在距河3 km区域处EVI值达到最大;而EVI的时空差异,则体现了沙化土地的空间分布与动态特征     

太湖沉积物好氧细菌空间分布与氮磷来源及风险

沉积物中氮磷释放到湖水中会加剧湖泊的富营养化,危害生态安全和人类健康.微生物在氮磷转换中不可或缺,准确分析沉积物中氮磷分布特征和来源以及与微生物的关系是湖泊富营养化管控的重要前提.以太湖为研究区,采集30个表层沉积物样品,测定并分析了粒度、pH、有机质（OM）、溶解性有机碳（DOC）、全磷（TP）、全氮（TN）、硝态氮（NO₃^--N）和溶解性有机氮（DON）等指标含量及空间分布特征,同时利用营养琼脂（NA）培养基以平板计数法测定好氧细菌（AB）数量.结合主成分分析（PCA）和Pearson相关分析探究了太湖沉积物和AB空间分布特征和来源.采用综合污染指数法和有机污染指数法研究了太湖沉积物污染特征.结果表明,太湖表层沉积物指标平均值如下：AB为9.25×10⁴ CFU ·g^-1,平均粒径（M_Z）为17.59 μm,pH为7.62,ω（OM）为15.05g ·kg^-1,ω（DOC）为71.60mg ·kg^-1,ω（TP）为598.13mg ·kg^-1,ω（TN）为1113.92 mg ·kg^-1,ω（NO₃^--N）为3.22mg ·kg^-1,ω（DON）为22.60mg ·kg^-1.综合污染指数（FF）显示太湖中的点位13%为中度污染,87%为重度污染.TN除在湖心区、南部湖区和东太湖西部的部分湖区为轻度污染外,其余区域为中重度污染.除竺山湾为重度污染外,太湖中TP整体上为轻中度污染.有机污染指数（OI）表明,太湖沉积物有机污染较轻,主要与有机氮（ON）污染有关.太湖中DOC、DON、TN和OM主要来源于水生植物的影响,TP和AB主要来源于河流外源输入的影响.研究将为湖泊富营养化治理提供理论支撑,也为进一步研究AB去除沉积物中氮磷污染提供新思路.     

外源输入对底泥疏浚新生表层磷恢复及迁移的影响

外源输入对底泥疏浚新生表层磷恢复及迁移转化的影响尚不清楚,阐明该问题对于底泥疏浚实施后流域尺度上的外源控制及管理具有重要的意义.本研究以太湖梅梁湾沉积物为研究对象,采用野外原位模拟疏浚的方法研究在有无外源颗粒物输入条件下,疏浚前后新生泥水界面磷的迁移转化过程,并探讨疏浚对内源磷释放的控制效果.结果表明,疏浚后阻止外源颗粒物输入对沉积物总磷(TP)和总氮(TN)的控制产生着积极的影响;疏浚显著降低了表层沉积物潜在可移动磷的含量,有外源颗粒物输入组潜在可移动态磷(Mobile-P)含量显著高于无外源组,变化的Mobile-P以铁结合态磷(Fe-P)为主,有机磷(Org-P)次之,弱结合态磷(Lb-P)含量较低不足总磷的1‰;实验210d后,有外源颗粒物输入疏浚组间隙水PO_4~(3-)-P浓度低于未疏浚组,无外源疏浚组显著低于未疏浚组(P 0. 05);无外源疏浚组间隙水PO_4~(3-)-P浓度保持着较低的水平,其余组间隙水中PO_4~(3-)-P浓度呈现先增加后减小的趋势,间隙水PO_4~(3-)-P浓度与其对应分层沉积物中Fe-P含量显著正相关;冬春季间沉积物的源-汇功能发生了转变,沉积物对上覆水由汇转变成为源;疏浚措施降低了底泥内源磷释放速率,可有效控制其内源磷释放,阻止外源颗粒物输入对疏浚控制内源磷负荷起到了较好的促进作用.     

Application of China’s National Forest Continuous Inventory Database

The maintenance of a timely, reliable and accurate spatial database on current forest ecosystem conditions and changes is essential to characterize and assess forest resources and support sustainable forest management. Information for such a database can be obtained only through a continuous forest inventory. The National Forest Continuous Inventory (NFCI) is the first level of China’s three-tiered inventory system. The NFCI is administered by the State Forestry Administration; data are acquired by five inventory institutions around the country. Several important components of the database include land type, forest classification and ageclass/ age-group. The NFCI database in China is constructed based on 5-year inventory periods, resulting in some of the data not being timely when reports are issued. To address this problem, a forest growth simulation model has been developed to update the database for years between the periodic inventories. In order to aid in forest plan design and management, a three-dimensional virtual reality system of forest landscapes for selected units in the database (compartment or sub-compartment) has also been developed based on Virtual Reality Modeling Language. In addition, a transparent internet publishing system for a spatial database based on open source WebGIS (UMN Map Server) has been designed and utilized to enhance public understanding and encourage free participation of interested parties in the development, implementation, and planning of sustainable forest management.     

Location set covering for waste resource recycling centers in Taiwan

The efficiency of Taiwan's waste management and resource recycling systems has been well recognized in recent years, but the present model used to locate recycling centers and to assign collection depots to those centers continues to show low efficiency. To address this issue, the study herein suggests implementing a new location-planning and assignment model to reduce the number of existing recycling centers. Such a reduction would reduce the use of land resources. Moreover, the total transportation distance would decrease through the efficient assignment of collection depots to recycling centers. On the basis of results from previous studies, this study proposes a 2-stage location set covering problem-P-median integrated model that obtains exact solutions using heuristic algorithms on the basis of set operations. The results of numerical analyses show that the model introduced in this study is effective in solving the problems stated above as well as in improving the layout of Taiwan's existing recycling centers.     

基于点—轴系统理论的北黄海经济带空间结构研究

选取北黄海经济带作为研究对象,从区域空间角度,基于点—轴理论,重点分析了北黄海经济带的空间结构。结果表明,北黄海经济带的空间发展模式为点—轴渐进逐级开发模式,并具有规模经济效应、集聚与扩散效应、交通协同效应;北黄海经济带依托大连经济发展一级枢纽轴心,沿庄河、东港二级枢纽轴心的两条产业轴延伸,形成一条点—轴式空间发展枢纽轴带,即北黄海经济带。     

Stereoselective toxicity of malathion and its metabolites, malaoxon and isomalathion

In recent years, the stereoselective toxicity of chiral organophosphorus pesticides has received increasing attention from environmental toxicology scientists. In an attempt to explore the stereoselective effects of chiral organophosphorus pesticides on non-target organisms and enzymes, this work investigated the stereoselective toxicity and inhibition of malathion, malaoxon and isomalathion on Daphnia magna and on acid α-naphthyl acetate esterase extracted from wheat flour, respectively. Toxicity differences were observed between the two enantiomers of malathion and malaoxon and among the four stereoisomers of isomalathion in the LC50 values on D. magna and the IC50 values on acid α-naphthyl acetate esterase. Enantiomers with (R)-configuration in all the tested compounds showed higher toxicity to D. magna than their (S)-forms and racemic forms. Racemic malaoxon and isomalathion showed the strongest inhibition on acid α-naphthyl acetate esterase compared to their respective enantiomers and stereoisomers.     

安全评价工作中的几点体会

本人在从事安全评价过程中有几点体会,想与同行进行交流和沟通,希望能够对我们所从事的安全评价工作有一个促进和提升,使每一个从事安全工作的人员真正能够为企业安全生产提供帮助,为安全监督管理部门监管提供技术支撑。也希望能够对刚刚从事安全评价工作的人员有所帮助。     

长株潭城市群核心区土地利用生态风险评价

随着长株潭城市群的快速发展,人类活动导致的土地利用结构及方式改变对生态环境构成了巨大压力。运用G IS和景观生态学方法的土地利用生态风险评价,以长株潭城市群核心区为研究区域,选择湘江岸线为典型样带,建立了基于源与汇景观功能的土地利用生态风险评价指标体系,并构建了评价模型,对生态风险进行了空间分析和综合评价。结果表明,长沙市建成区的土地利用生态风险指数整体最高,株洲和湘潭居次。其中,从城市群建成区向外,风险指数逐渐降低,长沙、株洲、湘潭三市交界处生态风险指数也较低。根据研究区域生态风险状况、变化和分布特征,提出了相应的风险调控策略和管理方法,为实现区域土地利用与生态、社会、经济的可持续发展提供决策依据。     

澜沧江流域梯级水库建设下水体营养盐和叶绿素a的空间分布特征

澜沧江梯级水库群建设对流域水生态环境产生了一定的影响,将流域水体划分为自然河道段和水库段.为了探究梯级水库建设后澜沧江流域不同类型水体氮、磷营养盐和叶绿素a浓度的空间变化规律以及叶绿素a浓度与环境因子之间的关系,于2017年6月对澜沧江流域生态环境进行了调查分析.结果表明,澜沧江水体总氮质量浓度变化范围为0.37~1.22 mg·L^-1,均值为0.70 mg·L^-1;总磷质量浓度变化范围0.01~0.19 mg·L^-1,均值为0.04 mg·L^-1.单因素ANOVA分析表明,总氮空间差异显著,表现为支流段 > 水库段 > 自然河道段;但总磷没有明显的空间差异.澜沧江水库段水体叶绿素a浓度变化范围为2.6~10.2μg·L^-1,均值为5.8μg·L^-1.Pearson相关性分析结果显示,水体叶绿素a浓度与总磷浓度、水温和真光层与混合层之比（Z_eu/Z_mix）等具有显著相关性,其中与Z_eu/Z_mix的相关性最高（R²=0.689,P=0.001）,表明水温分层驱动下的Z_eu/Z_mix是影响澜沧江水库水体中浮游植物生长的关键性指标.