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基于随机森林的火山岩岩性测井识别——以准噶尔盆地滴西地区石炭系为例
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作者 尚亚洲 张兆辉 +3 位作者 许多年 赵雯雯 陈华勇 韩海波 《物探与化探》 CAS 2024年第4期1025-1036,共12页
火山岩岩性的准确识别是火山岩油气藏高效勘探开发的重要基础工作。火山岩储层岩性种类多、纵向多期叠置、横向相变快,致使交会图版法对火山岩储层岩性的识别准确率较低。本文在利用网格搜索和正交试验法确定模型最优参数组合基础上,量... 火山岩岩性的准确识别是火山岩油气藏高效勘探开发的重要基础工作。火山岩储层岩性种类多、纵向多期叠置、横向相变快,致使交会图版法对火山岩储层岩性的识别准确率较低。本文在利用网格搜索和正交试验法确定模型最优参数组合基础上,量化评价了常规测井曲线对火山岩岩性的检测能力,将自然伽马、补偿中子、声波时差和地层电阻率作为岩性指示因子,采用随机森林方法建立了准噶尔盆地滴西井区石炭系火山岩岩性的智能识别模型。通过识别研究区5口取心井累计870 m钻井取心段的岩性,识别结果与岩石薄片鉴定结果的符合率达到76.67%,与钻井取心描述结果的符合率高达85.98%,取得了良好的识别效果,为该地区火山岩油气藏的精细评价奠定了基础。 展开更多
关键词 随机森林 岩性识别 火山岩 机器学习
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关于铷的独立矿物 被引量:10
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作者 赵振华 陈华勇 韩金生 《地球化学》 CAS CSCD 北大核心 2020年第6期690-693,共4页
虽然自然界铷(Rb)的独立矿物非常罕见,但至今已有3种Rb的独立矿物获国际矿物学协会新矿物命名及分类委员会(IMA-CNMNC)批准,分别为铷微斜长石(RbAlSi_(3)O_(8))、铷拉曼石(RbB_(5)O_(8)·4H_(2)O)和沃罗申石(Rb(LiAl_(1.5)□_(0.5))... 虽然自然界铷(Rb)的独立矿物非常罕见,但至今已有3种Rb的独立矿物获国际矿物学协会新矿物命名及分类委员会(IMA-CNMNC)批准,分别为铷微斜长石(RbAlSi_(3)O_(8))、铷拉曼石(RbB_(5)O_(8)·4H_(2)O)和沃罗申石(Rb(LiAl_(1.5)□_(0.5))[Al_(0.5)Si_(3.5)O_(10)]F_(2))。它们均产于稀有金属伟晶岩中,在战略性金属Rb矿资源的科学研究、勘查开发中应予以关注。 展开更多
关键词 铷独立矿物 稀有金属伟晶岩
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高寒小流域措普沟山洪风险分析 被引量:2
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作者 陈华勇 蒋良文 +3 位作者 游勇 王科 张广泽 王涛 《长江科学院院报》 CSCD 北大核心 2020年第10期171-176,共6页
已有山洪泥石流灾害的风险评估主要针对暴雨或者冰川融水激发条件下的风险评估,而当高寒山区流域源头存在冰湖发育时,如何考虑冰湖对下游铁路、公路等线性工程影响的研究并不多见。以巴塘县措普沟及其支沟上游绒伊措冰湖为例,在分析冰... 已有山洪泥石流灾害的风险评估主要针对暴雨或者冰川融水激发条件下的风险评估,而当高寒山区流域源头存在冰湖发育时,如何考虑冰湖对下游铁路、公路等线性工程影响的研究并不多见。以巴塘县措普沟及其支沟上游绒伊措冰湖为例,在分析冰湖孕灾环境背景的基础上,通过遥感解译和详细的野外调查,获得了绒伊措冰湖几何参数与沟道断面特征参数;结合坝体结构与物质组成特征,分析了坝体结构的稳定性;依据措普流域水文计算成果,评估了山洪对拟建铁路的影响。研究表明:绒伊措冰湖坝体由坚硬的花岗岩组成,坝体完整性好,在不考虑高烈度地震等极端条件下,绒伊措冰湖坝体稳定性较好,发生溃决的可能性较小,绒伊措冰湖对下游拟建铁路的影响小;在考虑P=1%设计频率暴雨与冰川融水情景下,措普流域山洪洪峰流量为448 m^3/s,桥位所处断面的平均流速2.75 m/s,水深4.62 m,与铁路梁底的高差为53.89 m,对铁路线路安全不构成威胁。 展开更多
关键词 绒伊措冰湖 坝体稳定性 洪水灾害 风险分析 流速 水深
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地壳浅部(低温-低压条件下)卤水-安山质火山岩作用实验研究及其地质意义 被引量:1
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作者 李建平 陈华勇 +1 位作者 张婷 张世涛 《地球化学》 CAS CSCD 北大核心 2019年第5期468-482,共15页
水岩作用是影响地球岩石圈层质量平衡的重要过程,控制着围岩和流体中元素的迁移、重新分配以及物质组成的演化。本研究通过实验手段模拟地壳浅部(低温-低压条件下)火山围岩与含碱卤水的相互作用,来揭示围岩元素迁移、碱交代蚀变过程和... 水岩作用是影响地球岩石圈层质量平衡的重要过程,控制着围岩和流体中元素的迁移、重新分配以及物质组成的演化。本研究通过实验手段模拟地壳浅部(低温-低压条件下)火山围岩与含碱卤水的相互作用,来揭示围岩元素迁移、碱交代蚀变过程和流体的成矿潜力。实验结果显示,不同pH条件下产物具有不同的碱交代蚀变特征,碱性条件有利于岩石样品同时发生钾化和钠化蚀变,但前者占据主导,而酸性条件下则仅发生钾化蚀变。产物中主元素和成矿元素,如Cu、Fe、Zn、Mn和LREE等发生明显淋滤,该过程受温度和流体pH影响明显。随温度上升产物淋滤程度明显增强,相同温度不同pH条件下产物淋滤程度虽然处于同一数量级,但酸性条件下淋滤程度更加明显。实验结果表明,地壳浅部高温酸性卤水与(安山质)火山围岩作用,有利于形成富含Fe、Cu、Zn和Mn等元素的含矿流体,而低温碱性流体有利于富集和迁移LREE。本实验为揭示地壳浅部火山围岩与卤水的作用过程和元素迁移、富集机制,以及判断流体成矿潜力提供了有效证据。 展开更多
关键词 地壳浅部 火山围岩 富碱卤水 元素淋滤 成矿指示
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基于科研实践的医学生创新思维培养模式探索 被引量:3
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作者 陈华勇 许东元 《教育教学论坛》 2019年第47期113-114,共2页
以230名医学大学生为研究对象,初步探索基于科研实践的创新思维培养模式:课堂教育中非逻辑思维的渗透、参与课外科研竞赛活动、再进入科研项目的实际操作。研究发现,这种模式效果显著,具有可行性。
关键词 创新思维 科学研究 实践 培养 模式
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鄂东南铜绿山大型铜铁金矿床成矿岩体年代学、地球化学特征及成矿意义 被引量:24
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作者 张世涛 陈华勇 +6 位作者 韩金生 张宇 初高彬 魏克涛 赵逸君 程佳敏 田京 《地球化学》 CAS CSCD 北大核心 2018年第3期240-256,共17页
通过详细的野外地质调查及室内岩相学观察,在鄂东南铜绿山矿区新发现的深部矿体中厘定出两类中酸性侵入岩与夕卡岩矿化密切相关,分别为石英二长闪长岩和石英二长闪长玢岩,两者在岩相上呈过渡关系。锆石LA-ICP-MS U-Pb定年表明,两者形成... 通过详细的野外地质调查及室内岩相学观察,在鄂东南铜绿山矿区新发现的深部矿体中厘定出两类中酸性侵入岩与夕卡岩矿化密切相关,分别为石英二长闪长岩和石英二长闪长玢岩,两者在岩相上呈过渡关系。锆石LA-ICP-MS U-Pb定年表明,两者形成时代基本一致,锆石^(206)Pb/^(238)U加权平均年龄分别为(141.0±0.8)Ma和(141.3±1.1)Ma,属长江中下游地区早白垩世构造岩浆活动的产物。两类岩浆岩都具有高硅(SiO_2>63%)、富碱(K_2O+Na_2O=7.38%~8.22%)、富铝(Al_2O_3>15%)和准铝质等特征,属I型高钾钙碱性花岗岩系列。在微量元素组成上,两者都具有高Sr和贫重稀土元素(Y和Yb)等特征,显示出埃达克质岩的地球化学属性,可能是富集地幔源区的碱性玄武质岩浆混染下地壳物质经同化混染分离结晶(AFC)过程形成。此外,两类岩浆岩都富含角闪石、磁铁矿和榍石,且锆石微量元素Ce^(4+)/Ce^(3+)比值较高(347~1231),指示岩浆形成源区为高氧逸度和富水环境,有利于铜铁金等成矿元素在岩浆熔体中富集。 展开更多
关键词 锆石U-Pb定年 地球化学 埃达克质岩 铜绿山铜铁金矿床 鄂东南矿集区
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考虑浆体黏度的泥石流流速计算方法 被引量:4
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作者 王喜安 陈剑刚 +2 位作者 陈华勇 Nirdesh Nepal 王飞 《长江科学院院报》 CSCD 北大核心 2020年第4期56-61,共6页
泥石流浆体黏度通过影响泥石流内、外部的阻力特征影响泥石流的糙率系数,泥石流糙率系数与浆体黏度之间的关系还没有基于观测数据的定量表述。通过对云南东川蒋家沟泥石流观测资料的分析,研究泥石流糙率系数与浆体黏度之间的关系,并通... 泥石流浆体黏度通过影响泥石流内、外部的阻力特征影响泥石流的糙率系数,泥石流糙率系数与浆体黏度之间的关系还没有基于观测数据的定量表述。通过对云南东川蒋家沟泥石流观测资料的分析,研究泥石流糙率系数与浆体黏度之间的关系,并通过回归分析得到考虑浆体黏度的泥石流糙率系数计算公式,最后基于此构建了考虑浆体黏度的泥石流流速计算公式。结果表明,随着泥石流浆体黏度的增加,泥石流糙率系数逐渐增加,浆体黏度在宏观上表现为增阻作用,考虑浆体黏度的泥石流流速计算公式改进了现有公式在计算浆体黏度较高的泥石流流速中的不足。研究结果可为进一步研究浆体黏度对泥石流运动阻力的影响提供参考,也为工程实践中的流速计算和增阻消能设计提供新的思路。 展开更多
关键词 泥石流 流速 浆体黏度 曼宁糙率系数 蒋家沟
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湖北铜绿山夕卡岩型铜铁金矿床深部矿体地球化学勘查方法有效性分析 被引量:6
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作者 李莎莎 陈华勇 +6 位作者 张世涛 孙四权 金尚刚 魏克涛 刘冬勤 程佳敏 许高 《地球化学》 CAS CSCD 北大核心 2020年第2期205-217,共13页
铜绿山夕卡岩型铜铁金矿床是目前中国最大的夕卡岩型铜多金属矿床之一。近年来,岩石原生晕地球化学勘查结合构造和碳酸盐围岩-岩体接触界面延伸方向进行深部隐伏矿体预测取得了成功,新发现的ⅩⅢ号矿体显著增加了矿床资源量。从平面上... 铜绿山夕卡岩型铜铁金矿床是目前中国最大的夕卡岩型铜多金属矿床之一。近年来,岩石原生晕地球化学勘查结合构造和碳酸盐围岩-岩体接触界面延伸方向进行深部隐伏矿体预测取得了成功,新发现的ⅩⅢ号矿体显著增加了矿床资源量。从平面上、剖面上分别对岩石原生晕地球化学和短波红外光谱(SWIR)勘查的找矿预测结果进行对比研究发现,(1)岩石原生晕地球化学勘查在平面上通过指示元素异常套合进行隐伏矿体预测的效果比较明显。指示元素异常的出现与元素的亲铜性、亲硫性、迁移性等特征有关,同时也受热液蚀变作用的影响;在剖面上,岩石原生晕地球化学分析显示大部分元素仅富集在矿体位置,与夕卡岩型矿床中成矿热液的流动严格受接触界面控制的规律相一致,除I之外的元素在剖面上对找矿预测的指示作用并不显著。(2)SWIR结果在平面和剖面上均显示绿泥石的Fe-OH从围岩→接触带/矿化中心呈明显的低值→高值变化规律,平面上能较为精确地进行矿体定位,在垂向距离矿化中心约400 m处进入有效预测范围,显示SWIR勘查在隐伏矿体找矿预测方面具有较好的发展潜力。 展开更多
关键词 地球化学勘查 短波红外光谱 原生晕 有效性对比 铜绿山铜铁金矿床 湖北省
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堰塞坝溃决过程中孔隙水压力变化规律 被引量:2
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作者 李霄 陈华勇 +1 位作者 阮合春 俞昀晗 《科学技术与工程》 北大核心 2022年第34期15304-15311,共8页
为研究堰塞坝坝体内部孔隙水压力对坝体的溃决发展过程的影响,通过水槽模型试验,在分析堰塞坝溃决过程的基础上,研究了堰塞坝溃决过程中孔隙水压力的变化过程。研究成果表明:根据溃口演化特征,可将堰塞坝的溃决过程分为3个阶段:坡面侵... 为研究堰塞坝坝体内部孔隙水压力对坝体的溃决发展过程的影响,通过水槽模型试验,在分析堰塞坝溃决过程的基础上,研究了堰塞坝溃决过程中孔隙水压力的变化过程。研究成果表明:根据溃口演化特征,可将堰塞坝的溃决过程分为3个阶段:坡面侵蚀阶段(Ⅰ)、溯源陡坎侵蚀阶段(Ⅱ)、粗化再平衡阶段(Ⅲ),其中,阶段Ⅱ发展最为剧烈;堰塞坝溃决过程中各测点孔隙水压力的变化过程均呈现先增后减的变化趋势,并存在明显的滞后现象;左右两侧的孔隙水压力呈“左小右大”的变化趋势,二者差值随溃口发展速率的加快而增加;上游孔隙水压力较下游明显增大,敏感程度也更高;蓄水期孔压可采用饱和非稳定二维渗流微分方程进行求解,整体变化趋势与实际值相符合,孔压增长速率呈先缓后陡趋势,最大孔压差绝对值为0.09 kPa。 展开更多
关键词 堰塞坝 溃决过程 孔隙水压力 变化规律
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基于新样本的滑坡坝溃决洪峰流量预测模型修正与对比 被引量:3
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作者 阮合春 陈华勇 +2 位作者 李霄 俞昀晗 李鑫 《科学技术与工程》 北大核心 2022年第20期8606-8615,共10页
受极端天气(强降雨)及高烈度地震的影响,高山峡谷区常发生滑坡堵江事件,形成具有明显“多漫顶,短寿命”特征的堰塞坝。堰塞坝溃决后,将形成具有强大破坏力的溃决洪水。溃决洪峰流量作为一个重要的水力参数,直接决定了下游灾害的影响程... 受极端天气(强降雨)及高烈度地震的影响,高山峡谷区常发生滑坡堵江事件,形成具有明显“多漫顶,短寿命”特征的堰塞坝。堰塞坝溃决后,将形成具有强大破坏力的溃决洪水。溃决洪峰流量作为一个重要的水力参数,直接决定了下游灾害的影响程度。广泛收集了来自全球具有完整资料记载的67例滑坡坝溃决案例,扩充了已有的滑坡坝数据库,增加了数据样本区间,进而基于新数据库对已有滑坡坝溃决洪峰流量的参数预测模型进行了修正,并采用均方根误差(root mean square error,RMSE)和相关系数R 2两个度量指标对比分析了各模型的预测效果,最后采用2018年在西藏江达县与四川省白玉县交界处发生的两次(10月10日和11月3日各一次)白格滑坡堰塞坝溃决事件对修正后的模型进行应用并对比。结果表明:修正模型的整体计算效果较修正前均有不同程度的提升,适用范围更广,但大部分模型因选取指标单一,未全面考虑水土耦合作用下复杂溃坝问题中的关键影响因子;经对比,Costa(1985)坝高H_(d)单参数模型(修正后RMSE和R 2分别为61231.95 m^(3)/s、0.0746)的计算自效果较差,建议优先选用Peng M模型(修正后RMSE和R 2分别为6070.52 m^(3)/s、0.9909)进行滑坡坝的溃决洪峰流量计算,其他模型可作为参考使用;该结论与白格堰塞湖溃决案例应用对比结果一致。研究成果可为滑坡坝的防灾减灾和应急抢险提供重要的理论依据。 展开更多
关键词 滑坡坝 洪峰流量 预测模型 模型修正 白格堰塞湖
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广东玉水铜多金属矿床岩浆活动对永梅坳陷带构造演化的约束:来自花岗斑岩和辉绿岩锆石年龄的证据 被引量:1
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作者 李莎莎 陈华勇 +2 位作者 彭永新 汪礼明 罗志荣 《地球化学》 CAS CSCD 北大核心 2019年第4期313-324,共12页
众所周知,矿床是地球动力学研究的有效探针。广东省梅州玉水铜铅锌多金属矿床是以产出特富铜铅锌矿石、易采和经济价值高等为特点的中型矿床,前人对该矿床的研究主要集中于矿床成因上,但对矿区分布的花岗斑岩和辉绿岩岩脉及其所指示的... 众所周知,矿床是地球动力学研究的有效探针。广东省梅州玉水铜铅锌多金属矿床是以产出特富铜铅锌矿石、易采和经济价值高等为特点的中型矿床,前人对该矿床的研究主要集中于矿床成因上,但对矿区分布的花岗斑岩和辉绿岩岩脉及其所指示的构造意义缺乏关注。本文在前人研究的基础上,运用激光剥蚀-电感耦合等离子质谱仪(LA-ICP-MS)对矿区内脉状花岗斑岩和辉绿岩进行锆石U-Pb定年,获得花岗斑岩206Pb/238U协和年龄为(128.4±1.0)Ma(MSWD=2.6,n=26);辉绿岩锆石年龄范围分别为1776~1114Ma、533~437Ma、282~255Ma、226~209Ma、186~154Ma、141~125Ma和87~56Ma。结合锆石成因、野外辉绿岩切穿花岗斑岩和黄铜矿脉的关系,认为辉绿岩的结晶年龄为(59.3±2.5)Ma(n=13,MSWD=3.1),形成于晚古新世,其动力学背景为陆缘拉张环境。辉绿岩中继承锆石年龄表明玉水矿区深部不仅存在新元古代的基底物质,还经历了中晚侏罗世、白垩世的中酸性岩浆活动和早古近世的基性岩浆活动,这些岩浆活动与华南地区晚中生代以来发育的多期地壳拉张活动相耦合。本研究也为中国东南部存在50~60Ma地壳拉张事件提供了新的年龄证据。 展开更多
关键词 辉绿岩 花岗斑岩 锆石 LA-ICP-MSU-Pb定年 玉水铜矿
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冰崩涌浪作用下的冰湖溃决过程试验研究
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作者 阮合春 陈华勇 +4 位作者 陈晓清 赵万玉 陈剑刚 李霄 俞昀晗 《科学技术与工程》 北大核心 2023年第29期12391-12398,共8页
冰崩涌浪是导致冰湖溃决的一个主要的诱发因素之一。通过水槽模型试验,研究了在冰崩涌浪作用下,不同坝体颗粒级配、坝高、下游坝坡坡度对冰碛坝溃决过程的影响,揭示了涌浪对溃决过程的影响机制,并得到了冰碛坝溃决的临界条件。结果表明... 冰崩涌浪是导致冰湖溃决的一个主要的诱发因素之一。通过水槽模型试验,研究了在冰崩涌浪作用下,不同坝体颗粒级配、坝高、下游坝坡坡度对冰碛坝溃决过程的影响,揭示了涌浪对溃决过程的影响机制,并得到了冰碛坝溃决的临界条件。结果表明:冰碛坝存在漫顶溃决、坝坡失稳、管涌破坏3种溃决模式;根据冰崩涌浪对坝体的侵蚀效应,结合溃口的纵向演化过程,将冰碛坝的溃决过程划分为涌浪侵蚀阶段(阶段Ⅰ)、库区小扰动溢流侵蚀阶段(阶段Ⅱ);涌浪过坝后的强水动力条件增加了坝体的侵蚀率,当溃口贯通后,涌浪已基本消散,溃决过程转为正常的溢流溃决,并且涌浪向坝体提供了高频瞬时荷载,削减了坝体稳定性;从动力学的角度提出了冰碛坝临界溃决条件的判定方法;冰湖溃决洪峰流量与坝高和下游坝坡呈现正相关,与坝体中值粒径D_(50)呈现负相关关系。 展开更多
关键词 冰崩涌浪 冰湖溃决 冰碛坝 洪峰流量 溃决过程
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Landslide inventory and susceptibility assessment using multiple statistical approaches along the Karakoram highway,northern Pakistan 被引量:6
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作者 Mian Luqman HUSSAIN Muhammad SHAFIQUE +2 位作者 Alam Sher BACHA chen Xiao-qing chen hua-yong 《Journal of Mountain Science》 SCIE CSCD 2021年第3期583-598,共16页
China-Pakistan Economic Corridor(CPEC)is a framework of regional connectivity,which will not only benefit China and Pakistan but will have positive impact on Iran,Afghanistan,India,Central Asian Republic,and the regio... China-Pakistan Economic Corridor(CPEC)is a framework of regional connectivity,which will not only benefit China and Pakistan but will have positive impact on Iran,Afghanistan,India,Central Asian Republic,and the region.The surrounding area in CPEC is prone to frequent disruption by geological hazards mainly landslides in northern Pakistan.Comprehensive landslide inventory and susceptibility assessment are rarely available to utilize for landslide mitigation strategies.This study aims to utilize the high-resolution satellite images to develop a comprehensive landslide inventory and subsequently develop landslide susceptibility maps using multiple techniques.The very high-resolution(VHR)satellite images are utilized to develop a landslide inventory using the visual image classification techniques,historic records and field observations.A total of 1632 landslides are mapped in the area.Four statistical models i.e.,frequency ratio,artificial neural network,weights of evidence and logistic regression were used for landslide susceptibility modeling by comparing the landslide inventory with the topographic parameters,geological features,drainage and road network.The developed landslides susceptibility maps were verified using the area under curve(AUC)method.The prediction power of the model was assessed by the prediction rate curve.The success rate curves show 93%,92.8%,92.7%and 87.4%accuracy of susceptibility maps for frequency ratio,artificial neural network,weights of evidence and logistic regression,respectively.The developed landslide inventory and susceptibility maps can be used for land use planning and landslide mitigation strategies. 展开更多
关键词 LANDSLIDES Inventory map Susceptibility assessment Northern Pakistan CPEC
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Effects of spillway types on debris flow trajectory and scour behind a sabo dam 被引量:5
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作者 chen hua-yong CUI Peng +1 位作者 chen Jian-gang TANG Jin-bo 《Journal of Mountain Science》 SCIE CSCD 2016年第2期203-212,共10页
Debris flows are one of the common natural hazards in mountainous areas.They often cause devastating damage to the lives and property of local people.The sabo dam construction along a debris flow valley is considered ... Debris flows are one of the common natural hazards in mountainous areas.They often cause devastating damage to the lives and property of local people.The sabo dam construction along a debris flow valley is considered to be a useful method for hazard mitigation.Previous work has concentrated on the different types of sabo dams such as close-type sabo dam,open-type sabo dam.However,little attention has been paid to the spillway structure of sabo dam.In the paper,a new type of spillway structure with lateral contraction was proposed.Debris flow patterns under four different spillway structures were investigated.The projection theory was employed to predict trajectory of debris flow out from the spillway and to estimate the incident angle and terminal velocity before it plunged into the scour hole behind the sabo dam.The results indicated that the estimated data were in good agreement with the experimental ones.The discrepancy between the estimated and experimental values of main parameters remained below 21.82%(relative error).Additionally,the effects of debris flow scales under different spillway structures were considered to study the scour law.Although the debris flow pattern and scour law behind the sabo dam under different operating conditions was analyzed in this paper,further study on the scour mechanism andthe maximum scour depth estimation based on scour theory is still required in the future. 展开更多
关键词 Debris Flow SPILLWAY Sabo dam Flow trajectory VELOCITY SCOUR
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Effects of river flow velocity on the formation of landslide dams 被引量:4
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作者 chen Kun-Ting chen Xiao-Qing +2 位作者 HU Gui-Sheng KUO Yu-Shu chen hua-yong 《Journal of Mountain Science》 SCIE CSCD 2019年第11期2502-2518,共17页
Natural dams are formed when landslides are triggered by heavy rainfall during extreme weather events in the mountainous areas of Taiwan.During landslide debris movement,two processes occur simultaneously:the movement... Natural dams are formed when landslides are triggered by heavy rainfall during extreme weather events in the mountainous areas of Taiwan.During landslide debris movement,two processes occur simultaneously:the movement of landslide debris from a slope onto the riverbed and the erosion of the debris under the action of high-velocity river flow.When the rate of landslide deposition in a river channel is higher than the rate of landslide debris erosion by the river flow,the landslide forms a natural dam by blocking the river channel.In this study,the effects of the rates of river flow erosion and landslide deposition(termed the erosive capacity and depositional capacity,respectively)on the formation of natural dams are quantified using a physics-based approach and are tested using a scaled physical model.We define a dimensionless velocity index vde as the ratio between the depositional capacity of landslide debris(vd)and the erosive capacity of water flow(ve).The experimental test results show that a landslide dam forms when landslide debris moves at high velocity into a river channel where the river-flow velocity is low,that is,the dimensionless velocity index vde>54.Landslide debris will not have sufficient depositional capacity to block stream flow when the dimensionless velocity index vde<47.The depositional capacity of a landslide can be determined from the slope angle and the friction of the sliding surface,while the erosive capacity of a dam can be determined using river flow velocity and rainfall conditions.The methodology described in this paper was applied to seven landslide dams that formed in Taiwan on 8 August 2009 during Typhoon Morakot,the Tangjiashan landslide dam case,and the Yingxiu-Wolong highway K24 landslide case.The dimensionless velocity index presented in this paper can be used before a rainstorm event occurs to determine if the formation of a landslide dam is possible. 展开更多
关键词 Natural DAM LANDSLIDE DEPOSITIONAL capacity of LANDSLIDE DEBRIS EROSIVE capacity of water FLOWS
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Characteristics and interpretation of the seismic signal of a field-scale landslide dam failure experiment 被引量:5
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作者 YAN Yan CUI Peng +3 位作者 chen Su-chin chen Xiao-qing chen hua-yong CHIEN Yi-liang 《Journal of Mountain Science》 SCIE CSCD 2017年第2期219-236,共18页
Outburst floods caused by breaches of landslide dams may cause serious damages and loss of lives in downstream areas; for this reason the study of the dynamic of the process is of particular interest for hazard and ri... Outburst floods caused by breaches of landslide dams may cause serious damages and loss of lives in downstream areas; for this reason the study of the dynamic of the process is of particular interest for hazard and risk assessment. In this paper we report a field-scale landslide dam failure experiment conducted in Nantou County, in the central of Taiwan.The seismic signal generated during the dam failure was monitored using a broadband seismometer and the signal was used to study the dam failure process.We used the short-time Fourier transform(STFT) to obtain the time–frequency characteristics of the signal and analyzed the correlation between the power spectrum density(PSD) of the signal and the water level. The results indicate that the seismic signal generated during the process consisted of three components: a low-frequency band(0–1.5 Hz), an intermediate-frequency band(1.5–10 Hz) and a highfrequency band(10–45 Hz). We obtained the characteristics of each frequency band and the variations of the signal in various stages of the landslide dam failure process. We determined the cause for the signal changes in each frequency band and its relationship with the dam failure process. The PSD sediment flux estimation model was used to interpret the causes of variations in the signal energy before the dam failure and the clockwise hysteresis during the failure. Our results show that the seismic signal reflects the physical characteristics of the landslide dam failure process. The method and equipment used in this study may be used to monitor landslide dams and providing early warnings for dam failures. 展开更多
关键词 Landslide dam Dam failure process Field-scale experiment Seismic signal
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Coseismic landslide sediment increased by the“9.5”Luding earthquake,Sichuan,China 被引量:4
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作者 XIONG Jiang chen hua-yong +3 位作者 ZENG Lu SU Feng-huan GONG Ling-feng TANG chen-xiao 《Journal of Mountain Science》 SCIE CSCD 2023年第3期624-636,共13页
The"9.5"Luding earthquake(Ms 6.8),which occurred on September 5,2022,has triggered thousands of landslides,and caused coseismic landslide sediment in the mountain basin to increase significantly.After the Lu... The"9.5"Luding earthquake(Ms 6.8),which occurred on September 5,2022,has triggered thousands of landslides,and caused coseismic landslide sediment in the mountain basin to increase significantly.After the Luding earthquake,landslide sediment may continue to divert to channels,and increase the activity of debris flows.Importantly,the formation of debris flows can pose a major threat to infrastructure,lives and property.To better understand the landslide sediment that increased by the"9.5"Luding earthquake and its impact on the activity of debris flows,we mapped the coseismic landslide database using satellite images.A total of9142 landslides with an area of 49.51 km^(2),covering4.81%of the whole basin,were triggered by the Luding earthquake.The coseismic landslides induced by this earthquake are dominated by shallow landslides and are densely distributed in the combined zone of the Xianshuihe fault and the Daduhe fault.Approximately 333.31×10^(6)m^(3)(error:111.43×10^(6)m^(3)/-70.73×10^(6)m^(3))of coseismic landslide sediments were induced by the earthquake in the epicenter,and the landslide materials were concentrated downstream of the basins.In addition.more than 13986.45×10^(4)m^(3)(error:4675.67×10^(4)m^(3)/-2967.92×10^(4)m^(3))of landslide sediment may supply for debris flow occurrence.Simultaneously,the small basins that are distributed near Moxi,Detuo and the junction of the Xianshuihe fault and Daduhe fault are more susceptible to debris flows when rainstorms hit these regions.Therefore,prevention and mitigation measures,early warning,and land use planning should be adopted in advance in these regions.However,from the perspectives of landslide scale and the degree of landslide-channel coupling,the activity or active intensity of debris flows in the Luding earthquake area may be lower than that in the epicenter area of the 2008 Wenchuan earthquake. 展开更多
关键词 Luding earthquake Landslide sediment Debris flow activity Remote sensing image
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Characteristics of viscous debris flow in a drainage channel with an energy dissipation structure 被引量:4
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作者 chen Jian-gang chen Xiao-qing +1 位作者 chen hua-yong ZHAO Wan-yu 《Journal of Mountain Science》 SCIE CSCD 2016年第2期223-233,共11页
A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental... A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental studies were performed to determine the characteristics of viscous debris flow in a drainage channel of this type with a slope of 15%.The velocity and depth of the viscous debris flow were measured,processed,and subsequently used to characterize the viscous debris flow in the drainage channel.Observations of this experiment showed that the surface of the viscous debris flow in a smooth drainage channel was smoother than that of a similar debris flow passing through the energy dissipation section in a channel of the new type studied here.However,the flow patterns in the two types of channels were similar at other points.These experimental results show that the depth of the viscous debris flow downstream of the energy dissipation structure increased gradually with the length of the energy dissipation structure.In addition,in the smooth channel,the viscous debris-flow velocity downstream of the energy dissipation structure decreased gradually with the length of the energy dissipation structure.Furthermore,theviscous debris-flow depth and velocity were slightly affected by variations in the width of the energy dissipation structure when the channel slope was 15%.Finally,the energy dissipation ratio increased gradually as the length and width of the energy dissipation structure increased;the maximum energy dissipation ratio observed was 62.9%(where B = 0.6m and L/w = 6.0). 展开更多
关键词 Debris flow Drainage channel Energy dissipation structure Geological disaster
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Geomorphic and tectonic controls of landslides induced by the 2022 Luding earthquake 被引量:2
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作者 ZHAO Bo HU Kai-heng +7 位作者 YANG Zong-ji LIU Qiao ZOU Qiang chen hua-yong ZHANG Bo ZHANG Wei-feng ZHU Lei SU Li-jun 《Journal of Mountain Science》 SCIE CSCD 2022年第12期3323-3345,共23页
On 05 September 2022,an Ms 6.8(Mw 6.6)earthquake occurred in Luding County,Sichuan Province,China,with the epicenter at 29.59°N,102.08°E and a focal depth of approximately 16.0km.Combining field investigatio... On 05 September 2022,an Ms 6.8(Mw 6.6)earthquake occurred in Luding County,Sichuan Province,China,with the epicenter at 29.59°N,102.08°E and a focal depth of approximately 16.0km.Combining field investigations,high-resolution satellite images and multiple datatpes characterizing the seismogenic structure,topography and geology,this study attempts to discuss the influence of geomorphic and tectonic indexes on landslide distribution.The results show that the 2022 Luding earthquake with seismogenic fault at the Moxi fault,was a sinistral strike-slip event that triggered at least 4528landslides over an area of~2000 km2.These landslides span a total area of 28.1 km^(2),and the western section of the seismogenic fault,which serves as the active wall area,is characterized by a higher landslide concentration,especially in the Wandong Basin.The seismogenic fault and lithology influence the regional distribution of landslides,and more landslides occurred closer to the seismogenic fault and in the controlling lithologies of granite and dolomite.Local topography influences the landslide occurrence position on the slope;the eastern section is prone to form landslides in the lower gorge section,and the western section is prone to form landslides in the upper-top section of the gorge.For coseismic landslides in the eastern Baryan Har block,the eastern boundary(Longmenshan fault),where the earthquakes are characterized by thrusts with slight dextral strike-slip movement,could be the primary landslide-prone area;the southern boundary,the Moxi fault and the southern segment of the Xianshuihe fault,with more intensive strikeslip movement,may be the secondary landsideprone area;and the northern boundary is the tertiary landside-prone area.Additionally,the current landslide inventory may be underestimated although this underestimation has limited influence on the results. 展开更多
关键词 LANDSLIDES Luding earthquake Spatial distribution Geomorphic index Tectonic index
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Self-adaptively inpainting gaps between electrical image pads according to the image fabric 被引量:2
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作者 Zhang Zhao-hui Deng Jing +1 位作者 chen hua-yong Yu Hong-guo 《Applied Geophysics》 SCIE CSCD 2020年第5期823-833,903,904,共13页
Images created from measurements made by wireline microresistivity imaging tools have longitudinal gaps when the well circumference exceeds the total width of the pad-mounted electrode arrays.The gap size depends on t... Images created from measurements made by wireline microresistivity imaging tools have longitudinal gaps when the well circumference exceeds the total width of the pad-mounted electrode arrays.The gap size depends on the tool design and borehole size,and the null data in these gaps negatively aff ect the quantitative evaluation of reservoirs.Images with linear and texture features obtained from microresistivity image logs have distinct dual fabric features because of logging principles and various geological phenomena.Linear image features usually include phenomena such as fractures,bedding,and unconformities.Contrarily,texture-based image features usually indicate phenomena such as vugs and rock matrices.According to the characteristics of this fabric-based binary image structure and guided by the practice of geological interpretation,an adaptive inpainting method for the blank gaps in microresistivity image logs is proposed.For images with linear features,a sinusoidal tracking inpainting algorithm based on an evaluation of the validity and continuity of pixel sets is used.Contrarily,the most similar target transplantation algorithm is applied to texture-based images.The results obtained for measured electrical imaging data showed that the full borehole image obtained by the proposed method,whether it was a linear structural image refl ecting fracture and bedding or texture-based image refl ecting the matrix and pore of rock,had substantially good inpainting quality with enhanced visual connectivity.The proposed method was eff ective for inpainting electrical image logs with large gaps and high angle fractures with high heterogeneity.Moreover,ladder and block artifacts were rare,and the inpainting marks were not obvious.In addition,detailed full borehole images obtained by the proposed method will provide an essential basis for interpreting geological phenomena and reservoir parameters. 展开更多
关键词 electrical image logging binary structure image inpainting self-adaptively fabric guiding
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