印度尼西亚西爪哇低品位金矿柱浸试验     

孙广周  曾茂青  王蓓  王世涛  王德英 《云南地质》2010,29(1):102-104,101

在较佳人浸粒度（-20ram）及适宜的喷淋制度条件下,经5天浸出周期柱浸后,可获得金浸出率91．31％、NaCN耗量142．3g／t的技术经济指标,表明该金矿适合用本堆浸工艺提金。  相似文献   

风暴浪作用下沙质岸滩稳定机制物理模型试验研究     

王俊  尤再进  梁丙臣 《海洋与湖沼》2022,53(4):933-950

近年来风暴潮等海洋灾害日趋频发,沙质海岸侵蚀问题也愈发突出,沙滩稳定防护显得日益重要。为研究风暴浪作用下沙质岸滩稳定机制问题,设计了一系列的水槽试验,对风暴浪作用下沙质岸滩的稳定机制和演变过程进行了录像观察和研究分析。试验中采用图像处理技术,根据水和岸滩床面的像素值差异,对岸滩整体剖面进行实时动态提取;对比和分析了不同入射波高、波周期、水深、岸滩初始坡度以及波高连续变化下沙质岸滩演变过程。试验结果表明,岸滩稳定与岸滩初始坡度和沙坝的发育直接相关,而波参数主要影响岸滩扰动幅度和沙坝以及前滩侵蚀边界的位置变化。当入射波高连续变化时,沙坝迅速响应并向离岸迁移。岸滩变化幅值与入射波能流存在明显正相关关系,波能流越大对岸滩稳定性的危害越大。而水位升高会增强前滩向岸侵蚀风险。此外,在本试验尺度下,前滩以侵蚀为主。当岸滩初始坡度小于稳定坡度且波陡较小时,即Dean参数Ω''较小时,岸滩才发生明显的前滩淤积,这对于试验尺度下岸滩恢复工况研究至关重要。具体来说,当岸滩整体坡度为1:10且前滩坡度达到1:5~1:2.5时,岸滩稳定性最好,岸滩形态最接近最终平衡剖面,岸滩趋于稳定的时间最短。  相似文献   

砾石堤坝和多孔方型鱼礁消浪护滩的试验研究——以北戴河西海滩为例          下载免费PDF全文

杨立鹏  杨少鹏  张芝永  朱金龙  拾兵 《海岸工程》2022,41(3):223-232

本文通过物理模型试验,研究了砾石堤坝、多孔方型鱼礁、堤坝+鱼礁等不同防护措施对岸滩的保护作用。通过测量不同防护措施的波浪透射系数、输沙率、水下坡度角及床面地形变化,并与无防护措施的工况进行对比,结果发现：不同试验条件下堤坝+鱼礁工况的透射系数仅为0.21～0.36,对波浪具有显著的消减作用;同一水位不同防护措施下的输沙率由大变小依次为：堤坝、堤坝+鱼礁、无工程、鱼礁;堤坝迎浪面的水下坡度角随极限波高呈现先增大、后减小的趋势,堤坝工况的水下坡度角约是堤坝+鱼礁工况的2～4倍;对于近岸的地形恢复,堤坝+鱼礁工况的效果比较明显,且对岸滩附近的侵蚀较少。堤坝+鱼礁的防护措施可明显减小波浪的透射系数,增加向岸输沙率,对恢复近岸地形、保护岸滩有显著作用。  相似文献   

Changes in Land Use and Agricultural Production Structure Before and After the Implementation of Grain for Green Program in Western China–Taking Two Typical Counties as Examples   总被引：1，自引：1，他引：0  

ZHOU Ping  WEN An-bang  YAN Dong-chun  SHI Zhong-lin  GUO Jin  JU Zhan-sheng  ZHANG Yi-lan 《山地科学学报》2014,11(2):526-534

Soil erosion becomes a serious environmental problem in the world, especially in western China. An effective management practice called the Grain for Green Program （GGP）, which was launched in 1999, aims to reduce soil and water loss and alleviate the ecological environment problem in western China. Two typical counties in western China, the Zhongxian （in Chongqing Municipality） and Ansai （in Shaanxi Province） were chosen to evaluate the dynamic changes of land use and agricultural production structure before and after the implementation of the Program in this paper. The results showed that the cultivated land area was reduced by 7.08% from 1989 to 2003. The cultivated land per person was decreased by 8.42% during 1999-2003. Moreover, the stability index of the secondary sector of the economy was increased from 0.91 in the period 1990-1999 to 0.94 in the following ten years. In addition, the stability index of tertiary economic sector increased from 0.88 to 0.92 in Zhongxian county. Meanwhile, the cultivated land area was reduced by 15.48% from 1990 to 1999. The soil erosion modulus was decreased by 33.33% from 1999 to 2006. Also, the stability index of secondary and tertiary economic sectors was 0.86 in the period 1998-2002. However, it decreased by 77% during 2002 to 2007 in Ansai County. These results imply that the Grain for Green Program had different impact on the two regions. Several effective strategies of soil and water conservation have been carried out to ameliorate the sustainable development of ecological environment and economy in these two counties of western China.  相似文献   

Damming of large river by debris flow: Dynamic process and particle composition     

Cui Du  Ling-kan Yao  Subhashsagar Shakya  Lun-gui Li  Xiao-dan Sun 《山地科学学报》2014,11(3):634-643

The frequency and extent of debris flows have increased tremendously due to the extreme weather and the Wenchuan earthquake on May 12, 2008. Previous studies focused on the debris flow from gullies damming the mountain streams. In this paper, an equation for the run-out distance of debris flow in the main river is proposed based on the dynamic equation of debris flow at different slopes given by Takahashi. By undertaking field investigations and flume experiments, a new calculation method of the volume of debris flow damming large river is obtained. Using the percolation theory and the renormalization group theory it was deduced that the large particles should comprise more than 50% for forming a stable debris flow dam. Hence, the criteria of damming large river by debris flow is presented in terms of run-out distance and grain composition which was then validated through the event of damming river by debris flow at Gaojia gully, the upper reaches of the Minjiang River, Sichuan, China, on July 3, 2011.  相似文献   

临南洼陷带滩坝砂岩储层分布     

李艳菊 《海洋地质前沿》2014,30(12):25-29

临南洼陷带沙四段滨浅湖滩坝相成因的砂体广泛发育,近年来已成为该区十分重要的勘探后备阵地。但该区火成岩发育,地震资料品质较差,滩坝砂的分布发育不清,不利于勘探部署。在深化研究沙四上亚段古地貌、沉积特征的基础上,运用频谱分解等技术提高地震资料分辩率,综合利用了正演及属性分析等技术,对滩坝砂岩的发育范围进行了预测,取得了良好的效果,为该层系油藏的勘探提供了可靠的依据。  相似文献   

莱州湾东岸三山岛段砂质海岸沉积物运移动力机制   总被引：1，自引：0，他引：1       下载免费PDF全文

刘世昊  丰爱平  杜军  夏东兴  胡维芬  李平 《海洋科学进展》2014,32(3)

通过对三山岛岸段冬夏重复的地形测量和表层沉积物的粒度分析,研究了其地貌特征与地形变化规律、沉积物类型、粒度特征、运移趋势,并探讨了沉积物运移的动力机制。结果表明:该岸段可根据1985黄海高程-1.2m(低潮水位)和-6.5m(闭合深度)平面划分为海滩、水下岸坡和浅海陆架三个地貌单元,各地貌单元表层沉积物分布规律与地形变化特征区别显著。其中水下岸坡和浅海陆架地貌单元主要受潮流作用,海滩地貌单元主要受波浪作用。在西向落潮流和西南向潮余流的作用下,水下岸坡地貌单元发育一个中等规模潮流通道-沙脊沉积系统。表层沉积物以向西运移的趋势为主,少数滞留于西部潮流沙脊处,与地形"东侵西淤"的变化规律相符,这些西向运移的沉积物最终离开研究区,补给莱州浅滩。  相似文献   

数字影像分析技术在海滩环境监测的应用     

胡亚丽  李晶珩  阎子衿  于新生 《海洋科学》2014,38(5):95-99

运用视频监测技术对青岛石老人海滩进行环境变化的监测,将基于高斯混合模型的聚类方法应用于数字影像中进行浒苔目标分割,并计算出浒苔的面积。分析结果表明,该项技术能够对海滩浒苔等海滩环境进行实时的监测,从而避免浒苔在海滩的堆积,对浴场海滩的环境及旅游业的发展都具有重要意义。  相似文献   

新疆赛里木湖的湖滩岩特征、时代及其对 MIS3阶段湖面变化的指示意义   总被引：3，自引：0，他引：3  

徐胜利  吴中海  李跃华  赵希涛  张克旗  马志邦  马丹  田婷婷 《地质力学学报》2014,20(2):174-184

在对西天山赛里木湖盆地进行第四纪地质调查与5万填图基础上,发现沿该湖泊的不同湖岸阶地上都不同程度地发育了可指示湖面变化的湖滩岩。水准测量结果表明,典型的湖滩岩最常见于高出现今湖面7.1~9.4 m和33.4~39.4 m的低、高两级湖积台地上。对湖滩岩样品进行岩石学和矿物学研究进一步揭示,湖滩岩主要由内碎屑、藻团块、陆源碎屑、胶结物和填隙物等构成,胶结物主要为亮晶方解石,夹少量文石,表明赛里木湖周边的湖滩岩为典型的方解石胶结砂屑砾屑岩。湖滩岩样品的U系年代测试结果表明,低、高两级台地上的湖滩岩主要形成于距今24.8±1.5 ka至27.6±1.5 ka和55.4±3.8 ka的晚更新世晚期,大致对应末次冰期间冰阶MIS3阶段早期和末期的相对暖湿气候阶段。湖滩岩及其测年结果指示,赛里木湖最近一期最高湖面出现在距今55.4 ka左右末次间冰阶早期,其后由于气候的干旱化,湖面整体处于逐步下降过程,在相对暖湿期间经历了多次湖面相对稳定期并形成湖滩岩。  相似文献   

Analysis of the Grain Size Properties and Flow Body Classes of the Mud Sand Flow: An Example of Liantanggang Collapsing Hill and Gully in Wuhua County of Guangdong     

Zhang Dalin  Liu Xilin 《地球科学进展》2014,29(7):810-818

Mud sand flow is a kind of solid-liquid two-phase flow formed in collapsing hill and gully basin during rainfall. It is the main way to export erosion product. The discrimination of its fluid type is one of the collapsing hill and gully control theoretical basis. This paper analyzed the basic characteristics of mud sand flow like grain size and so on through fieldwork and sampling. The results show that the density of mud sand flow is between 1.16~1.60 t/m³ and the solids content is between 257.03~960.55 kg/m³, both of which decrease from the upper to the lower channel. The slurry of mud sand flow is composed mainly of silt and clay. As the density increases, the particle size distribution curve transforms from a single peak to the bimodal distribution similar to the weathering crust with no sorting, and the grain size of mud sand flow becomes coarser which shows a well positive linear correlation between the sediment median particle diameter and density of mud sand flow. The comparison during mud sand flow, hyperconcentrated flow and debris flow shows that collapsing hill and gully mud sand flow, which belongs to an intermediate class between hyperconcentrated flow and debris flow, has a closer link with debris flow. Therefore, mud sand flow can be considered as a sub-class of generalized debris flow that may be called as collapsing hill and gully type debris flow.  相似文献