Assessing soil salinity using WorldView-2 multispectral images in Timpaki,Crete, Greece

Salinization is one of the major soil degradation threats occurring worldwide. This study evaluates the feasibility of operational surface soil salinity mapping based on state-of-the-art Earth Observation (EO) products captured by sensors on-board WorldView-2 (WV2) and Landsat 8 satellites. The proposed methods are tested in Timpaki, south-central Crete,Greece, where brackish water irrigation puts soil health at risk of soil salinization. In all cases, EO products are calibrated against soil samples collected from bare soil locations. Results indicate a moderate correlation of observed EC_e values with the investigated remote sensing parameters. Regarding sensitivity to saline soil, the yellow band displays higher values. Comparison between methods used in the literature shows that those developed specifically for soil salinity, and especially index S5, perform better. The proposed ‘detection index’ and 3D PCA transformation methodology perform reasonably well in detecting areas with high EC_e values and provide a simple and effective operational alternative for saline topsoil detection and mapping.     

Investigating the effect of ballasting by CaCO3 in Emiliania huxleyi, II: Decomposition of particulate organic matter

The quantitative relationship between organic carbon and mineral contents of particles sinking below 1800 m in the ocean indicates that organisms with mineral shells such as coccolithophores are of special importance for transporting carbon into the deep sea. Several hypotheses about the mechanism behind this relationship between minerals and organic matter have been raised, such as mineral protection of organic matter or enhanced sinking rates through ballast addition. We examined organic matter decomposition of calcifying and non-calcifying Emiliania huxleyi cultures in an experiment that allowed aggregation and settling in rotating tanks. Biogenic components such as particulate carbon, particulate nitrogen, particulate volume, pigments, transparent exopolymer particles (TEP), and particulate amino acids in suspended particles and aggregates were followed over a period of 30 d. The overall pattern of decrease in organic matter, the amount of recalcitrant organic matter left after 30 d, and the compositional changes within particulate organic matter indicated that cells without a shell are more subject to loss than calcified cells. It is suggested that biogenic calcite helps in the preservation of particulate organic matter (POM) by offering structural support for organic molecules. Over the course of the experiment, half the particulate organic carbon in both calcifying and non-calcifying cultures was partitioned into aggregates and remained so until the end of the experiment. The partial protection of particulate organic matter from solubilization by biominerals and by aggregation that was observed in our experiment may help explain the robustness of the relationship between organic and mineral matter fluxes in the deep ocean.     

一种新的基于PCA变换多源遥感影像像素级融合方法

在多源遥感影像融合中,基于传统PCA变换的多源遥感影像融合的光谱分辨率受到较大影响。提出了一种新的基于PCA变换的多源遥感影像像素级融合方法,通过在传统PCA变换融合算法基础上引入小波变换融合,保留了多波段遥感图像光谱特性的有用信息,进一步提高融合后遥感影像的效果。给出实验的融合结果,并与传统PCA变换方法进行对比,证明了该方法的有效性。     

三峡库区地质灾害防减灾战略关键问题

三峡库区地质灾害防治已成为目前中国地质灾害防治的主战场。论文主要分析三峡库区地质灾害防治工作中面临的主要问题及防、减灾战略实施中的一系列关键问题。先概要介绍了库区地质灾害种类繁多、量大面广、日趋严重的现状;然后从库区人为诱发地质灾害愈演愈烈的状况、地质灾害基础调查工作在广度与深度方面的不足、地质灾害防治资金投入有限等方面对目前该区地质灾害防治面临的主要问题进行了研究;其后重点从库区地质灾害防治总体规划的形成历程与实施、地质灾害的科学管理制度的建立与多体系管理体制的理顺、地质灾害的预测预报研究与成果转化及库区地质灾害全面监测预警体系的建立、治理地质灾害采用的整治与利用相结合的技术措施等方面,深入分析了实施库区地质灾害防、减灾战略的一些关键问题。结论认为,呈日趋严重之势的库区地质灾害,难以在水库最终建成蓄水之前实施全面治理,防、减灾战略的关键是要尽快实施库区地质灾害总体防治规划,并且在总体防治规划的指导下,在科学的地质灾害管理制度及顺畅的管理体制下,开展库区地质灾害预测预报工作及全面实施监测预警。同时实施重点整治与土地利用相结合的治灾技术路线。     

应用多光谱ASTER数据对ETM遥感异常的定性判别研究——以东昆仑五龙沟为例

文中讨论了新的找矿参数——蚀变遥感异常的地质基础和光谱前提,在矿床地质学和蚀变矿物光谱参数特征的基础上,编制了一张用于遥感异常提取及对其地质解释的表格。ETM遥感异常提取技术已在全国推广,ASTER数据可以在三个方面对已推广的ETM起到重要的补充作用：1.利用短波红外增设的波段,对某些矿致异常区分其矿化（矿床）类型;2.利用增设的热红外波段区分某些岩性;3.可有助于解决ETM因第7波段太宽而产生的许多疑难问题。本文以东昆仑五龙沟为例讨论了ASTER对于解决ETM遥感异常性质判别困难方面的作用。     

海洋生境刀鲚菌群PCR-DGGE指纹图谱构建及分析

为了分析海洋生境刀鲚(Coilia nasus)体内及生长环境菌群结构,作者采用免培养16S r DNA的PCR-DGGE指纹图谱技术,对刀鲚鳃、肠道壁、肠道内容物及水体环境中的菌群结构进行了对比分析。结果表明:变性梯度为35%~55%、浓度为8%的聚丙烯酰胺凝胶,150V 60℃下电泳10 h,DGGE带谱的分离效果较好;刀鲚鳃、肠道壁、肠道内容物及水体样品指纹图谱上分别显示出24、19、14和29条信号强度不同的条带;相同样品重复组细菌结构相似度在80%以上,差异不显著;不同样品之间,刀鲚鳃与海水聚为一支,具有较高的相似度为52%,肠壁与肠内容物相似度为41%。样品菌群主要以未培养菌为主,主要包括变形菌、放线菌和厚壁菌。本文首次成功构建海洋生境刀鲚菌群16S r DNA的PCR-DGGE指纹图谱。     

Preliminary Interlaboratory Trial for ISO/DIS 12010: Determination of Short Chain Polychlorinated Alkanes (SCCP) in Water

A first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality – determination of short chain polychlorinated alkanes (SCCP) in water – method using GC/MS and electron capture negative ionisation (ECNI). The task was to determine the sum of short chain polychlorinated n‐alkanes with carbon chain lengths of C₁₀–C₁₃ and a chlorine content between 49 and 67% in water by GC‐ECNI‐MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 µg/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010.     

Using principal component analysis in the investigation of groundwater hydrochemistry of Upper Jezireh Basin,Syria

Principal component analysis (PCA) was applied to hydrochemical and isotopic data of 34 groundwater samples. This allowed the reduction of 20 variables to four significant PCs that explain 81.9% of the total variance; F1 (47.1%) explains the groundwater mineralization, whereas F2 (17%) shows isotopic enrichment and nitrate pollution. Based on an iso-factor scores map of F1, three water zones were delineated: Zone A (F1 < ?1), with fresh groundwater from the unconfined aquifer; Zone B (1 > F1 > ?1), with moderate mineralization from the confined–unconfined aquifer boundary; and Zone C (F1 > 1), with the most mineralized hot water from the confined aquifer. The iso-factor scores map of F2 delineates positive values representing samples from the unconfined aquifer, with freshwater and nitrate contamination associated with stable isotope enrichment, whereas negative values represent samples from the confined aquifer. The results clearly demonstrate the usefulness of PCA in groundwater hydrochemistry investigations.     

我国几种常见润滑油的指纹分析

采用气相色谱／质谱方法（GC／MS）对7种常见润滑油中的生物标志化合物（正构烷烃、姥鲛烷、植烷、甾烷、萜烷、多环芳烃）进行定性分析,并基于其生物标志化舍物指纹信息进行了多元统计分析。结果表明,润滑油的气相色谱图中不可分辨的混合物（UCM）具有明显优势;润滑油中含有丰富的甾、萜烷类稠环生物标志化合物,仅含有非常少量的饱和...