广东海岸湿地退化现状及保护对策

介绍广东省类型多样的海岸湿地,分析海岸湿地退化现状及其原因,有针对性地提出了海岸湿地保护与可持续利用的对策.     

化学药剂灭杀棘豆技术研究与试验示范

棘豆的大面积滋生繁衍是草地退化的一个重要标志,对草原畜牧业发展构成了重大危害。文章通过自配制除草剂——"灭棘豆"对棘豆杀灭效果的试验研究得出结论:"灭棘豆"的最佳推广用药量为1 350~1 650 mL·hm^-2,喷药最佳时间是在棘豆盛花期。它灭除棘豆死亡率达92%以上,对草原可食牧草和环境无害。"灭棘豆"可以作为一种经济有效且适宜大面积灭除棘豆的除草剂而大面积推广。     

基于ETM+影像的草地退化评价模型研究——以西藏自治区那曲县为例

在实地调查和样方测定基础上,选用建群种植株高度、草地植被盖度和草地生物量作为草地退化地面评价体系中的单一评价指标,并通过加权综合三个单一评价指标,构建草地退化地面综合评价指标;在分析退化草地光谱特征的基础上,从ETM+影像的波段数据中派生出草地退化的遥感评价指标。通过相关分析的方法,选出最能反映草地退化趋势、最适于用于线性拟合的地面评价指标（地面综合评价指标）和遥感评价指标（TM4/TM5）,采用线性回归技术构建草地退化遥感评价模型,并通过计算确定系数（R2）、均方根差（RMSE）和相对误差对模型精度做出评价。确定主要草地类型的不同退化等级标准,完成草地退化图的编制。通过分析草地退化地面评价指标与遥感评价指标之间的关系,探讨了西藏北部草地退化的遥感评价模型,为科学、快速评价草地退化提供一种新思路。     

城市污水与海水混合过程中有机污染物的转移

以３种不同混合体系模拟研究了城市污水与海水混合过程中有机污染物的转移。在“污水颗粒物－过滤海水”体系中，颗粒态有机物有一定的释放，释放率约在０．０２－０．０４ｄ－１之间。释放过程可用交换平衡动力学模式描述。在“天然海水－过滤污水”和“海水－污水”给 体系中，未发现有机污染和有明显的吸附或释放。在这３种混合体系中均发现化学耗氧量（ＣＯＤ）的降解现象，降解过程符合一级动力学方程，降解速率常数在０．０４     

羽毛复合氨基酸钙配合物降解有机磷农药的研究

有机磷农药在我国农作物生产中已被广泛应用,但常因使用不当造成作物产品中残留超标。采用硫酸水解羽毛制取复合氨基酸,并与碳酸钙反应制得复合氨基酸钙配合物,该配合物可以通过水解有机磷农药中的磷酸酯键降低作物中的农药残留。将配合物分别喷施已施有机磷农药的茶叶、黄瓜和西红柿,5d后采摘茶叶鲜叶,按绿茶加工工艺进行处理,测定其毒死蜱含量,毒死蜱的残留量减少了75.80%;喷施配合物次日采摘黄瓜和西红柿样品,并测定其毒死蜱与乐果的残留量,黄瓜中毒死蜱残留量为空白对照的70.75%,乐果完全降解;西红柿中毒死蜱残留量为空白对照的71.33%,乐果的残留量为67.79%。     

渤海湾中化学需氧量(COD)扩散、降解过程研究

对渤海湾中水质因子化学需氧量(COD)的随流输移扩散和生物化学过程进行了研究。在对有机污染物的生化降解过程进行试验研究的基础上,建立了模拟浅水、缓坡海湾有机物(COD)迁移转化规律的水质模型,并应用实测资料结果对水质模型进行了验证。     

Improvement of kerogen structural interpretations based on oxidation products isolated from aqueous solutions

A detailed investigation of kerogen oxidation products remaining in aqueous solutions after the usual isolation of degradation products by extraction with ether or precipitation, was carried out for the first time in kerogen structural studies. Three shale samples were investigated: Green River shale (type I kerogen), Toarcian shale, Paris Basin (type II), and Mannville shale, Canada (type III). The yields of acids from aqueous solutions were noticeable: 12.98, 15.32 and 22.32%, respectively, based on initial kerogens. Qualitative and quantitative capillary GC/MS analysis showed that the ratios of different kinds of identified acids depended much on the type of precursor kerogen. Some of the acids identified in aqueous solutions have not been found earlier among the degradation products of the same kerogen samples, or were obtained in different ranges and yields. Consequently, slight modifications were suggested of the image on the nature of various types of kerogens based on examination of ether-soluble acids only. Namely, slightly higher proportions of aromatic and alkane-polycarboxylic acids in the total oxidation products of both type I and type II kerogens indicated larger participation of aromatic and alicyclic and/or heterocyclic structures in these two kerogens. On the other hand, for type III Mannville shale kerogen, a somewhat larger share of aliphatic type structures was demonstrated.     

Knowledge generation using satellite earth observations to support sustainable development goals (SDG): A use case on Land degradation

Land degradation is a critical issue globally requiring immediate actions for protecting biodiversity and associated services provided by ecosystems that are supporting human quality of life. The latest Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services Landmark Assessment Report highlighted that human activities are considerably degrading land and threating the well-being of approximately 3.2 billion people.In order to reduce and ideally reverse this prevailing situation, national capacities should be strengthened to enable effective assessments and mapping of their degraded lands as recommended by the United Nations Sustainable Development Goals (SDGs). The indicator 15.3.1 (“proportion of land that is degraded over total land area”) requires regular data production by countries to inform and assess it through space and time. Earth Observations (EO) can play an important role both for generating the indicator in countries where it is missing, as well complementing or enhancing national official data sources.In response to this issue, this paper presents an innovative, scalable and flexible approach to monitor land degradation at various scales (e.g., national, regional, global) using various components of the Global Earth Observation System of Systems (GEOSS) platform to leverage EO resources for informing SDG 15.3.1. The proposed approach follows the Data-Information-Knowledge pattern using the Trends.Earth model (http://trends.earth) and various data sources to generate the indicator. It also implements additional components for model execution and orchestration, knowledge management, and visualization.The proposed approach has been successfully applied at global, regional and national scales and advances the vision of (1) establishing data analytics platforms that can potentially support countries to discover, access and use the necessary datasets to assess land degradation; and (2) developing new capacities to effectively and efficiently use EO-based resources.     

唐古拉山南麓多年冻土退化与嵩草草甸变化的关系

测定了分布于唐古拉山南木麓两道河－聂荣高地多年冻土岛和冻土退化后，季节冻土区的两种嵩草草甸群落中各物种的重要值以及群落生态优势度，物种多样性，结合冻土环境对比分析得出，诸多物种重要值发生了明显变化，物种多样性，生态优势度有所增高，这是该区独特的生境特征所导致，另外，草场的特性也发生了改变，应引起畜牧生产者的关注。     

Sediment non-linearity and attenuation of seismic waves: a study of accelerograms from Lefkas, western Greece

We investigate the dependence of the S-wave high-frequency spectral-decay parameter, κ (“kappa”) — a measure of wave attenuation — on ground-motion amplitude. 21 three-component accelerograms from two adjacent sediment sites in the town of Lefkas, western Greece, are used, representing 17 earthquakes with magnitudes M_w 4.7–7.0 and hypocentral distances 12–93 km. Recorded peak horizontal ground accelerations (PGA) and velocities (PGV) are 22–540 cm/s² and 1.3–54.5 cm/s.Fourier amplitude spectra are computed for S-wave windows, and the frequency range is visually determined where the high-frequency spectral decay can be approximated by a straight line on the linear-log plot; its slope (and hence κ) is computed by linear regression. κ is found to depend on hypocentral distance as κ=0.108+0.058R (r=0.518).As PGV increases from 1.3 to 54.5 cm/s, κ₀ (κ at 0 km, characterising inelastic attenuation in the site's subsurface geology) varies between 0.060 and 0.160 s. κ₀ is found to correlate very strongly with log MGA (r=0.645) (MGA — mean horizontal acceleration in the S-wave window) but also with log PGA (r=0.447) and log PGV (r=0.627). We attribute this behaviour to sediment non-linearity (shear-modulus degradation), resulting in the decrease of the site's dominant-resonance frequency (from about 3.5 to 2.4 Hz) and leading to the increase of κ₀. Our results imply that at sediment sites, an important contribution to κ comes from wave attenuation (damping) in the softest sediments and show that κ₀ is amplitude dependent, thus being a measure of sediment non-linearity.