现代河流沉积物碎屑及矿物组分研究新进展

现代河流沉积物忠实地记录了流域盆地内的母岩、风化、搬运和沉积过程中的化学、物理过程以及人类活动的改造作用,是探索和验证源- 汇系统等理论的重要媒介。本文以全球现代河流砂组分数据库为基础,总结了碎屑组分、重矿物组分在不同大陆的分布特征,探讨了其在物源识别、源区贡献率计算、沉积物产生及搬运过程中气候- 构造等影响因素的评估、对源- 汇系统的研究启示等方面的应用。今后建议加强基于大数据的沉积物组分对气候- 构造- 人类活动的响应、沉积物产生及通量、高时间分辨率的沉积物组分变异性、不同物源定量化方法的差异等方面的研究。     

活动断裂引发的环境地质问题及措施

随着经济的飞速发展和现代化建设的加快，全社会防灾减灾意识的增强，在国土规划、抗震规划及高、深、大型工程项目的建设中，对活动断裂的研究，已成为勘测、设计中的重要课题。本文就影响张家口市城市安全的活动断裂的类型、空间展布、活动特征、引发的环境地质灾害及工程对策等予以阐述，为城市规划提供依据。     

800年来苏北废黄河三角洲的演变模式

根据历史资料、数据和相关研究,结合研究区域背景,分析苏北废黄河三角洲的演变。结果显示,岸线演变在发育阶段和侵蚀阶段分别为向海延伸约90 km和侵蚀后退约22 km,面积相差约800 km2,三角洲地貌演变表现为岸线平直-曲折-平滑-平直的过程。在废三角洲陆海相互作用的基础上,运用演化模式分析三角洲的演变过程。该三角洲演变可以分为7个演变阶段,发育期在径流和潮流作用下以沙洲并陆淤积延伸方式进行,侵蚀期在波浪和潮流作用下以沙洲合并侵蚀后退和淤积外长交替侵蚀的方式。泥沙输运、人类活动和气候变化对废三角洲的演变有重要影响,巨量的来沙是三角洲发育的原因,泥沙平衡被打破是侵蚀的主要原因。发育期中,泥沙输运影响淤积速度和位置,人类活动和气候变化影响黄河河道迁移、输沙量和产沙量;侵蚀期中,泥沙输运影响侵蚀状态,人类活动在一定程度上影响海岸带冲/淤,气候变化将影响三角洲的演变趋势。     

Spatial and Temporal Distribution of Dust‐Bound Trace Metal Elements around Kuhdasht Watershed Area in Iran

Dust, as a source of trace metal elements, affects the health of society. The spatial and temporal concentrations of dust‐bound trace metals (Cd, Pb, Ni, Zn, Cu, and Mn) in Kuhdasht watershed (456 km²), Lorestan Province, Iran, is investigated. Dust is collected using glass traps placed in ten research stations in the region. The spatial and temporal distribution of dust trace metals are plotted using ARC‐GIS. The highest and the lowest concentrations of Zn (9751150 mg kg^?1), Pb (46.352.9 mg kg^?1), and Cd (2.443.30 mg kg^?1) are obtained in winter, of Ni (98110 mg kg^?1) and Cu in autumn (16.053.5 mg kg^?1), and of Mn in summer (385505 mg kg^?1). The spatial concentrations of dust‐bound trace metals indicate all, except Cu, show a decreasing trend from the mountains toward the plains, similar to that of soil and of dust, except for Zn, which shows higher concentrations in dust than in soil. The potential sources of dust‐bound trace metals and their rate of contamination are also investigated using the enrichment and contamination factors. The major sources of Cd and Zn in the dust of watershed are due to anthropogenic activities or from activities outside the borders.     

霍山皖33井水位与"霍山窗"小震活动关系的初步研究

分析了霍山皖33井水位变化与"霍山窗"地震活动的关系:首先采用差分法和从属函数等方法对水位数据进行处理,提取了水位的短期异常,结果表明该井水位异常对霍山以及周边地区的中小地震有较好的反映;其次,通过对该井水位与"霍山窗"小震活动性的对比研究,发现该地区小地震在水位低值时活跃.参考该地区的环境剪应力,我们认为霍山皖33井...     

博斯腾湖水质现状(2010-2011年)及近50年来演变趋势

博斯腾湖(简称博湖)6个采样点周年(2010年6月-2011年6月)水质调查分析表明,博湖水质空间差异明显,但不同样点水质月变化无一致趋势.大湖区西北角水域水质最差;开都河入湖处水质月变化幅度大,水质相对较好;中东部水域水质处于中间水平.小湖区喇嘛湖水质最好,介于Ⅰ-Ⅲ级之间;北闸附近的湖沼湿地,水质差,多为Ⅴ类和劣Ⅴ...     

近50年来内蒙古查干淖尔湖水量变化及其成因分析

内蒙古查干淖尔湖是位于季风边缘区干旱与半干旱过渡带的封闭湖泊,对气候变化响应极为敏感.利用1958-2010年的查干淖尔湖21期遥感影像以及湖泊流域1955-2010年的3个气象站点和1个水文站点的气温、降水、蒸发和径流等数据,分析查干淖尔湖近50余年的湖泊水量、面积/水位波动及其原因.结果表明,近50年来在区域气候暖干化的背景下,查干淖尔湖不断萎缩,流域生态环境退化.1958-2010年湖泊容积以2×106m3/a的速度锐减66.9%(从124.1×106m3降到41.1×106m3),湖泊面积缩小73.3%(从105.3 km2降到28.1 km2),平均缩减速度为1.8 km2/a;流域年均气温上升了2.5℃,年降水量下降了36.6 mm.湖泊水量与流域气温和蒸发量显著负相关.查干淖尔湖分为东西两部分,中间由天然堤坝相连,东湖在水闸的人为控制下水位波动范围不超过1 m.西湖水位波动则相对剧烈,湖面下降7.6 m,于2002年彻底干涸,湖盆裸露,已成为盐尘暴、沙尘暴源地.     

2000-2013年浑善达克沙地植被净初级生产力变化研究

利用卫星遥感资料和地面气象观测资料,基于CASA模型及其他数理方法估算了浑善达克沙地2000-2013年生长季（4-10月）植被净初级生产力（NPP）,并对其时空变化特征进行了分析,讨论了气候因子和人类活动对植被净初级生产力的影响。结果表明： 14年间,研究区生长季的植被净初级生产力呈波动中增加趋势,多年平均NPP为239.8 gC·m^-2·a^-1。整个研究区表现为高NPP值（大于150 gC·m^-2·a^-1）的植被面积在增加,低NPP值（小于150 gC·m^-2·a^-1）的植被面积在减少。在空间分布上,研究区的北部、中部和南部边缘区域的植被NPP增加趋势较明显,而东部和西部部分区域未发生明显的趋势性变化。总体而言,研究区植被净初级生产力变化趋势与降水量的关系更密切,其相关系数达到0.86,是驱动植被NPP年际波动的最直接因素。而与温度呈负相关,相关系数为-0.42。综合考虑气候因素和人类活动对沙地NPP的影响发现,温度降低、种饲料面积、年末牲畜存栏头数和羊的数量的减少是NPP值提高的关键因素。     

Mineralogy and heavy metal content in sediments from Rio Gato,Carelmapu and Cucao,Southern Chile

In southern Chile, with a mild and rainy climate, high levels of heavy metals have been detected in many gold placer deposits. Many of the contaminants pose risks to human life, and consequently damage the trofic chain in this environment. The study zones selected correspond to the handicraft gold-bearing sands of Rio Gato (Los Muermos), Carelmapu and Cucao. These are all located in the X Region of “Los Lagos” in Chile. The type of methodology used in the characterization of the associated mineralization consists of testing each representative sample with a grain size distribution, statistical parameter analysis and a mineralogical analysis, using a binocular magnifying glass, a petrographic microscope, XRD and SEM/EDX. The chemical composition was defined by means of X ray fluorescence and micro-chemical analysis. The results of the study about sediments in southern Chile are presented. The major concentrations of heavy minerals are generally located in areas of dynamic river energy. In the samples, more than 70% of the heavy minerals were distributed among grain sizes corresponding to thin sand with good grain selection (meshes of 0.25–0.06 mm). The main mineral phases present in the analysed samples were gold, zircon, olivine, ilmenite, hornblende, hypersthene, hematite, garnet, chromite, chlorite, augite, amphibolitic-epidote, etc. The main heavy metals found as a result of the study were mercury, lead, cadmium, chrome, tellurium, indium, zinc, cobalt, copper, platinum, gold, etc., and as well some less common elements like cerium, praseodymium, gadolinium, neodymium, samarium and lanthanum. This research work is only a starting point for carrying out a risk probability mapping of heavy metals and the mineralogy of the Cucao, Carelmapu and Rio Gato gold-bearing sands.