Sediment transport in Swiss torrents

Sediment loads have been measured in six Swiss mountain torrents over several decades. Most of these torrent catchments are situated in the prealpine belt. They have catchment areas of between 0·5 and 1·7 km². Bedslopes at the measuring sites vary between 5 and 17 per cent, and peak discharges up to 12 m³ s⁻¹ have been recorded. Geophone sensors installed in the Erlenbach stream allow bedload transport activity to be monitored and sediment volumes associated with each flood event to be determined. A detailed analysis of the measurements in this stream results in an empirical equation in which the sediment load per flood event is expressed as a function of the effective runoff volume (discharges above the threshold for bedload motion) and of the normalized peak discharge. For the total of 143 investigated flood events in the Erlenbach stream, the deviation of the predicted from the measured value is within a factor of two for more than two-thirds of all events. A distinction can be made between summer and winter events in analysing the bedload transport events. The summer events, mainly caused by thunderstorms, transport comparatively larger sediment loads than the winter events. For the other investigated streams, the periods of the deposited sediment volume surveys cover in general several flood events. An analysis is performed analogous to that for the Erlenbach stream. The sediment loads show a similar dependency on the two factors effective runoff volume and normalized peak discharge. However, the exponents of these factors in the power law expressions differ from stream to stream. A comparison of the investigated stream shows that some of the variation can be explained by considering the bedslope above the measuring site. The inclusion of a bedslope factor is in agreement with laboratory investigations on bedload transport. © 1997 John Wiley & Sons, Ltd.     

东营凹陷北部陡坡带利563区块沙四上亚段砂砾岩扇体沉积特征及沉积模式

东营凹陷北部陡坡带发育的大量砂砾岩扇体在油气勘探与开发中占据重要地位。本文研究针对东营北带利563区块沙四上亚段砂砾岩扇体及其中发育的重力流沉积,通过岩心精细描述,依据岩性、粒度、构造将砂砾岩扇体划分出12种岩相。然后以发育相同水动力条件为单元,依据岩性和沉积机理将岩相在垂向上进行组合,划分8种水动力类型和8种岩相组合类型。再基于砂砾岩沉积的空间分布、尺度大小、接触关系和根据沉积物中泥岩的结构、纹理所细分出的7种泥岩类型所代表的各种环境,定义了5种砂砾岩扇体沉积形态特征：近端厚层砾石沉积、限制性水道沉积、非限制性舌状体沉积、非河道薄层沉积、远端细粒沉积。认为该区砂砾岩扇体为近岸水下扇,包括扇根沟道、沟道间、扇中辫状水道、水道间、扇中前缘、扇端泥6种沉积微相类型并归纳其综合鉴定特征。最终建立本区砂砾岩扇体的沉积过程和沉积模式。     

用水计划与水价对华北工业企业用水的影响--以河北省为例

工业是仅次于农业的用水大户,其用水的规模、方式和效率直接影响着华北地区总的用水需求。在对华北地区工业企业问卷调查的基础上,就影响企业效益的主要因素、用水计划对企业用水的影响、水费占总成本的比例、企业对目前和未来水价的看法、企业对提高水价的意愿、企业应对水价上涨的策略、企业对节水的态度和采取的节水措施等问题进行了分析。结果表明:用水计划对限制企业的用水有明显的作用;提高水价也有明显促进企业节水的效应。并选择了两个万元产值耗水量差别大的典型企业,对其13年来的用水情况进行了分析,验证了用水计划和水价对企业用水行为的影响效果。     

Source rupture model of the 2018 Mw6.7 Iburi,Hokkaido earthquake from joint inversion of strong motion and InSAR observations

The 2018 Mw6.7 Iburi earthquake shocked the eastern Iburi region to the west of the Hidaka Collision Zone in Hokkaido,which is a destructive inland earthquake.We resolved the kinematic rupture process of the event by combining strong motions(SM)and synthetic aperture radar(SAR)images in a joint inversion.The results reveal that the duration of the whole rupture is about 17s,yielding a total seismic moment of 1.4×1019 N·m(Mw=6.7).The main slip area is located at a depth of approximately 24 km with a peak slip of～0.8m above the hypocenter.The comparison with the regional velocity model shows the earthquake was initiated in the upper mantle,while the majority of slips are located in the lower crust,which is an"aseismic"domain in the typical sandwich model.The location of the major slip area is consistent with a high-conductivity volume.We proposed a mechanism of low frictional property(＜0.3)produced by high pore pressure to explain the abnormal high dip angle and centroid depth located in the ductile lower-crust.Aftershocks are distributed in areas where the Coulomb frictional stress increases due to co-seismic displacement with a mechanism conjugating to the mainshock.     

1961-2009 年国际主要粮食价格时间变化特征分析

本文首先介绍了基于国际粮食贸易的国际主要粮食价格测定方法,并用EVIEW 软件对国际主要粮食价格数据进行数据分离,在此基础上,采用谱分析法和数理统计方法分析了1961-2009 国际主要粮食价格的时间特征,总结和分析了国际主要粮食价格变化的趋势性、周期性和波动性特征。结果表明：①国际主要粮食价格趋势性明显,随时间呈现上涨趋势;②在多种因素的影响下,国际主要粮食价格存在着多周期性。③随着全球一体化和粮食金融化趋势的不断加强,国际主要粮食
价格不稳定性也越来越强。本文研究结果对于进一步分析国际粮食价格机制有一定的参考价值。     

轨道交通对其沿线商品住宅价格的影响分析——以北京地铁5号线为例

以北京地铁5 号线为例,研究了地铁沿线两侧2 km范围内,轨道交通对其沿线商品住宅价格的影响程度。① 通过分析商品住宅价格特性和影响因素,建立了轨道交通沿线商品住宅价格的影响因素体系,包括商品住宅项目距最近地铁站的最短路径距离、距市级商服中心距离、周边1 km内公交站点数、中小学及项目容积率、物业类型等10 个因素;② 通过显著性检验,重点中小学、普通中小学、公园3 个变量对商品住宅的价格影响很小,予以剔除后,构建了影响商品住宅价格的多元回归分析模型;③ 将采集到的193 个项目的有效样本进行运算分析,研究结果表明轨道交通对沿线商品住宅价格的影响最大,并随距轨道交通距离的增加,住宅价格呈指数衰减,至2 km以后,对住宅价格影响不显著。针对研究结果,建议地铁沿线土地利用强度和住宅价格确定时,要充分考虑轨道交通的影响。     

基于构造变形约束的川东寒武系膏盐层分布

四川盆地东部广泛沉积一套寒武纪潟湖相的云质膏盐层,盐下的地层及其构造是四川盆地新的油气勘探突破点。该地区高陡构造变形非常复杂,而且钻到该套膏盐层的钻井少,其构造变形特征和分布范围不清,难以落实构造圈闭和优质储集层的分布。通过地震地质综合研究,基于盐构造的构造变形特征和膏盐层的地震响应特征,开展了四川盆地东部寒武系膏盐层的构造变形及分布范围研究。该套膏盐层作为底部滑脱层引发川东形成薄皮构造,发育隔档式褶皱。隔挡式构造模式与寒武系膏盐层的盐构造变形为正相关关系,寒武系膏盐层是该地区构造格局的主控因素,亦是隔档式构造形成的必要条件。利用膏盐岩的岩石力学性质和对构造的控制作用,结合地震反射特征,预测了寒武系膏盐盆在平面上的展布:其西边界沿华蓥山构造边界延伸,向北沿水口厂构造展布直到大巴山前,往南沿川南低陡构造带西边界向南西展布。寒武纪膏盐盆的沉积中心在方斗山沿北东—南西向一线。     

种植孔绿化在福山区下官矿区生态修复中的应用

高陡岩质边坡绿化一直是废弃矿山复绿工程中的难题,该文结合烟台市福山区下官矿区高陡边坡现状,提出种植孔边坡绿化方法,分析研究了种植孔设计方法、植物选择及养护管理办法等,为破损山体高陡边坡绿化进行了有益探索。     

Bedload transport measurements at the Erlenbach stream with geophones and automated basket samplers

In the Erlenbach stream, a pre‐alpine steep channel in Switzerland, sediment transport has been monitored for more than 25 years. Near the confluence with the main valley river, stream flow is monitored and sediment is collected in a retention basin with a capacity of about 2000 m³. The basin is surveyed at regular intervals and after large flood events. In addition, sediment transport has been continuously monitored with piezoelectric bedload impact and geophone sensors since 1986. In 2008–2009, the measuring system in the Erlenbach stream was enhanced by installing an automatic system to obtain bedload samples. Movable metal baskets are mounted on a rail at the downstream wall of the large check dam above the retention basin, and they can be moved automatically into the flow to take bedload transport samples. The wire mesh of the baskets has a spacing of 10 mm to sample all sediment particles coarser than this size (which is about the limiting grain size detected by the geophones). The upgraded measuring system permits to obtain bedload samples over short sampling periods and to measure the grain size distribution of the transported material and its variation over time and with discharge. The analysis of calibration relationships for the geophone measuring system confirms findings from very similar measurements which were performed until 1999 with piezoelectric bedload impact sensors; there is a linear relationship between impulse counts and bedload mass passing over the sensors. Findings from flume experiments are used to discuss the most important factors which affect the calibration of the geophone signal. The bedload transport rates as measured by the moving baskets are among the highest measured in natural streams, with values of the order of several kilograms per meter per second. Copyright © 2012 John Wiley & Sons, Ltd.     

我国“十二五”时期建立碳交易市场的政策思考

基于对国际碳市场的调研和定量分析,建议我国碳市场建设之初,应首先选择电力、钢铁等对碳价格敏感的高排放强度行业进入碳市场;尽早开展跨地区交易,便于有效降低总体减排成本;同时碳排放总量上限的设定应与 “十二五”时期的碳强度下降目标挂钩;并在市场建立之初设定碳价格下限等。