北京平原地区VS30估算模型适用性研究

本文使用基于钻孔测井数据的3类模型,即常速度外推模型、速度梯度模型、双深度参数外推模型,通过对北京地区460个深度超过30m的钻孔剪切波速资料进行分析,详细探究了V_S30估算模型在本研究区的适用性。研究结果表明双深度参数外推模型在估算V_S30上准确度很高,其不需要大量的数据进行回归分析,且不具有区域独立性,可以为全球包括北京地区场地类别划分提供依据,进而在震害快速评估中用于确定场地影响,是一种值得推广的估算模型。     

Non-point source pollution in Indian agriculture: Estimation of nitrogen losses from rice crop using remote sensing and GIS

The paper presents a detailed understanding of nitrogenous fertilizer use in Indian agriculture and estimation of seasonal nitrogen loosses from rice crop in Indo-Gangetic plain region, the ‘food bowl’ of the Indian sub-continent. An integrated methodology was developed for quantification of different forms of nitrogen losses from rice crop using remote sensing derived inputs, field data of fertilizer application, collateral data of soil and rainfall and nitrogen loss coefficients derived from published nitrogen dynamics studies. The spatial patterns of nitrogen losses in autumn or ‘kharif’ and spring or ‘rabi’ season rice at 1 × 1 km grid were generated using image processing and GIS. The nitrogen losses through leaching in form of urea-N, ammonium-N (NH₄-N) and nitrate-N (NO₃-N) are dominant over ammonia volatilization loss. The study results indicate that nitrogen loss through leaching in kharif and rabi rice is of the order of 34.9% and 39.8% of the applied nitrogenous fertilizer in the Indo-Gangetic plain region. This study provides a significant insight to the role of nitrogenous fertilizer as a major non-point source pollutant from agriculture.     

盾构辅助常压开仓技术在南宁地铁隧道中的应用

盾构开仓是盾构隧道施工中难以避免的一道工序,结合南宁地铁四号线总部基地站-飞龙路站区间隧道的盾构开仓实践经验,介绍了素桩加降水这一辅助常压开仓技术在南宁地铁隧道中成功应用的实例。在介绍工程应用背景的基础上,详细叙述了辅助开仓方法中素桩及降水施工的技术要点,可为南宁地区盾构开仓方案选择提供指导,也可为类似条件下盾构开仓方案的选择提供借鉴。     

基于高分影像的松嫩低平原地区生态环境问题解析——以黑龙江省肇源县为例

基于高分辨率卫星影像数据,利用遥感、GIS技术获取黑龙江省肇源县内自然资源与生态地质环境各因子分布现状数据,其中：耕地2 541.75 km²、林地161.88 km²、草地349.00 km²、河流128.05 km²、湖泊215.80 km²、沼泽109.17 km²、其他水域84.65 km²、建设用地191.25 km²、未利用地329.94 km²;湿地1 334.54 km²、荒漠化土地775.47 km²。利用地类覆盖率、人均占有量以及景观指数（破碎度指数、平均斑块分形指数、分形维数、多样性指数、均匀度指数）量化分析后,得出两类生态地质环境因子中湿地资源尤其是自然湿地受人类活动干扰程度较大、荒漠化土地受人类活动干扰程度较小的结论。并选取老山村等典型地区进行了多期次遥感动态监测及野外核查,揭示了松嫩低平原典型地区目前存在的湿地退化、土地荒漠化等生态地质环境问题。     

An endemic freshwater mussel species from the Orontes River basin in Turkey and Syria represents duck mussel’s intraspecific lineage: Implications for conservation

Amik Lake or, historically, Lake of Antioch, was a large freshwater body in the lower Orontes River basin (Hatay Province, Turkey) that was drained in the 1940s–1970s. Several endemic animal species were described from this lake, including the freshwater mussel Anodonta pseudodopsis Locard, 1883 (Bivalvia: Unionidae) characterized by a large rounded shell covered by a peculiar yellow or yellowish-brown periostracum. Molecular analyses of topotypes of this nominal taxon collected from the former lake’s tributaries in the Amik Plain indicate that it is an intra-specific lineage of the widespread Anodonta anatina (Linnaeus, 1758) based on the mitochondrial COI and 16S rRNA, and the nuclear 28S rRNA gene fragments. Geometric morphometric analyses using the lectotype and topotypes of Anodonta pseudodopsis support our DNA-based hypothesis on the status of this nominal taxon. A new synonymy is provided as follows: Anodonta anatina = Anodonta pseudodopsis syn. nov. The syntype of Anodonta pseudodopsis SMF 5129 “See von Antiochia” (Senckenberg Research Institute and Natural History Museum, Frankfurt, Germany) is designated here to be the lectotype of this nominal taxon. Finally, we conclude that Anodonta anatina range covers the Orontes River basin in Turkey and Syria and the Nahr al-Kabir al-Shamali River in the Latakia Governorate of Syria. This intraspecific lineage of Anodonta anatina and other freshwater mussels of the Middle East are highly threatened due to multiple anthropogenic impacts and must be a focus of international conservation efforts. The Karasu River in eastern Turkey hosts viable populations of all freshwater mussel species of the Orontes’s fauna and can be considered one of the most important water bodies for the conservation of these imperiled animals in the region.     

江苏海岸带盐沼潮滩在小尺度下的沉积变化过程

在小尺度范围内,潮滩沉积的研究一般都是基于几个站位或断面进行短时日的调查和监测来获取数据,或多或少地存在数据的连续性不足等问题。基于此,本文在潮滩地貌典型的江苏平原海岸选取了约160 000 m²的盐沼潮滩作为研究对象,在多年的野外连续观测下,分析了人类围垦活动对盐沼潮滩沉积过程及变化的影响。结果表明：人类围垦活动（如堤坝建设等）对潮滩沉积和盐沼植被覆盖的变化有重要影响。围垦堤坝修建之前,研究区向陆一侧为盐沼植物（现为养殖池）,向海一侧为光滩,岸线形态比较平直。在2006年围垦堤坝修建后,研究区变为“凹岸”型的人工岸线,沉积环境变得更有利于泥沙的淤积。根据2007-2012年对滩面高程的野外观测,在风暴潮的影响下,潮滩最大淤积率高达23 cm/a。盐沼植被在泥沙快速淤积的基础上不断发育生长,盐沼植物覆盖面积不断扩张。同时外部的沙嘴也在不断增长,潮汐风浪侵蚀携带沙嘴外部泥沙进入盐沼滩地,盐沼植物在泥沙的覆盖下,出现萎缩退化,覆盖面积减少,但是对潮滩上的泥沙而言还是不断堆积增厚。柱状样岩芯的粒度垂向剖面特征也记录了盐沼潮滩沉积环境的变化。小尺度下盐沼潮滩沉积表现出的阶段性变化规律,揭示出合理的围垦活动有利于堤坝前的潮滩淤积和盐沼植被的扩张。     

天绘一号卫星影像的平原绿化提取方法

平原绿化是我国平原地区森林植被的主体,为生态环境建设提供了有力保障。但平原绿化分布零散,斑块面积小,不易被准确提取。本文以河南省封丘县为例,利用天绘一号卫星影像面向对象分类技术提取了平原绿化。在面向对象分类过程中,针对不同平原绿化信息选取不同的分割尺度和参数,建立影像对象的分割层次结构,确保农田林网、通道防护林、四旁防护林等平原绿化信息能够被准确分割。分类时通过构建隶属度函数,利用层与层之间的关系,子类继承父类的分类特征,在此基础上增加自己的特征,建立分类规则集,逐层提取绿化信息。本文共获取封丘县平原绿化面积152.51 km²,其中,农田林网36.09 km²,通道防护林21.29 km²,四旁防护林71.56 km²,片林23.57 km²。利用验证点数据,对分类结果进行精度评价,总体分类精度为93.50%,Kappa系数达到0.92。     

基于生态需水的石羊河北部平原生态保障技术研究

针对石羊河流域日益严峻的生态环境问题,选择干旱区生态需水计算为切入点,以变异理论为基础,利用Mann-Kendall非参数检验的方法确定石羊河北部平原区地下水位恢复的目标年,用生态功能区划方法划分生态功能区,利用达西定律、阿维里扬诺夫公式计算了地下水恢复及生态目标条件下的生态需水量,并提出了相应的生态保障措施. 结果表明：石羊河北部平原区划分为5个生态功能亚区及16个三级区,地下水位恢复的目标年份为1977年,地下水恢复到1977年的生态需水量为 55.95×10⁸~74.10×10⁸ m³,2015年和2020年生态目标条件下的生态需水分别为1.66×10⁸ m³和1.80×10⁸ m³. 考虑到地下水恢复的缓慢性和现实性,建议优先考虑设定目标条件下的植被正常生长生态需水,其次通过继续压缩人均耕地面积和灌溉定额的方式保证地下水恢复.     

A Siltation Simulation and Desiltation Measurement Study Downstream of the Suzhou Creek Sluice, China

The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition.     

潍北平原土壤盐渍化现状及成因分析

通过环境地质调查及易溶盐测试,根据相关标准确定了潍北平原土壤盐渍化程度,并从地层、气象、地貌、水文地质、卤水开采等方面系统的分析了潍北土壤盐渍化形成原因,为当地土壤盐渍化防治提供了参考依据。