A patch hierarchy approach to modeling surface and subsurface hydrology in complex flood‐plain environments

Geomorphology interacts with surface‐ and ground‐water hydrology across multiple spatial scales. Nonetheless, hydrologic and hydrogeologic models are most commonly implemented at a single spatial scale. Using an existing hydrogeologic computer model, we implemented a simple hierarchical approach to modeling surface‐ and ground‐water hydrology in a complex geomorphic setting. We parameterized the model to simulate ground‐ and surface‐water ?ow patterns through a hierarchical, three‐dimensional, quantitative representation of an anabranched montane alluvial ?ood plain (the Nyack Flood Plain, Middle Fork Flathead River, Montana, USA). Comparison of model results to ?eld data showed that the model provided reasonable representations of spatial patterns of aquifer recharge and discharge, temporal patterns of ?ood‐water storage on the ?ood plain, and rates of ground‐water movement from the main river channel into a large lateral spring channel on the ?ood plain, and water table elevation in the alluvial aquifer. These results suggest that a hierarchical approach to modeling ground‐ and surface‐water hydrology can reproduce realistic patterns of surface‐ and ground‐water ?ux on alluvial ?ood plains, and therefore should provide an excellent ‘quantitative laboratory’ for studying complex interactions between geomorphology and hydrology at and across multiple spatial scales. Copyright © 2004 John Wiley & Sons, Ltd.     

~(40)Ar/~(39)Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

TheNW-SEstrikingXianshuihefaultzoneslicesthesoutheasternTibetanPlateauandconnectssoutheastwardwiththeAnninghe-Zemuhe-Xiaojiangfaultzone,whichformahuge,activesinistralstrike-slipfaultzone(fig.1).ThisfaultzoneisanimportantseismicfaultineastTibet[1-5].EarthquakegeologystudiesandoffsetpatternsofyounggeologicalfeatureshaveshownthatlateQuaternarysinistralsliprateoftheXianshuihefaultzonereaches13mm/a[1,2].TheXianshuhefaultzoneconsistsoftwomainbranches,theDaofufaultbranchinthewestandtheXianshuih…     

The Rotational Structure along the Eastern Segment of the Altyn Tagh Fault and Its Implications in Dynamics

As a result of the left-lateral strike-slipping of the Altyn Tagh fault in Neotectonic period, a contra-rotational structure, namely the Zhaobishan vortex structure, has developed at the juncture of the main Altyn Tagh fault and the northern fringe fault of the Qilian Mountains.Preliminary analysis on the deformation and evolution of the Zhaobishan vortex structure. In combination with the previous data, suggests that the tectonic transform between the Altyn Tagh fault and the northern fringe fault of the Qilian Mountains attributes to the deformation of the rotational structure. The existence of a series of rotational structures along the Altyn Tagh fault and on the northeastern edge of the Qinghai-Xizang(Tibet) plateau indicate that as the substance in the northern Qinghal-Xizang (Tibet) plateau moves clockwise around the eastern tectonic knot of the Himalayas, rotational structures become the principal mode on the northern marginal zone of the Plateau of transforming and absorbing tectonic deformation.     

陕西略阳铧厂沟金矿床地质与矿床类型

铧厂沟金矿床位于勉略缝合带中泥盆系三河口群郭镇岩组中。含矿与容矿岩系为泥盆系三河口群郭镇岩组中的细碧岩和结晶灰岩。主控矿构造为寨子湾韧-脆性剪切构造带。围岩蚀变包括退化蚀变和矿化蚀变。在矿区内产出南北两条矿化带，矿石类型为蚀变细碧岩型、黄铁绢英片岩型和石英脉型。主要的金属矿物为黄铁矿和黄铜矿，金矿物是自然金。韧脆性剪切构造叠加和岩石强烈变形、彻底退化蚀变以及后期含矿热液交代与充填是主要的成矿作用，属于火山-沉积岩系中的类卡林型金矿床。     

内蒙古铜矿床区域成矿特征初步研究

近年来，随着内蒙古周边地区铜矿的地质找矿不断取得重大突破，以及内蒙古铜矿勘查取得的一系列重要新进展，在内蒙古开展铜矿地质勘查工作已引起国内外地质学家的关注。笔者经综合研究地质构造、铜矿勘查及有关地球化学等新信息后，均显示出巨大的铜矿找矿潜力。从内蒙古自治区铜矿勘查史以及与邻区对比研究人手，研究总结了全区铜矿床及铜异常空间分布特征，划分出3个铜成矿区(带)，并进一步划分出铜矿床或异常密集区，初步提出了寻找大型及超大型铜矿床的找矿方向。     

塔里木河南岸地下淡水资源分布特征及成因分析--以哈得4油田水源地为例

塔里木河南岸地下水资源，卡要为受塔里水河控制的具有高矿化背景的地下水，在塔里木河洪水的淡化影响下，形成了一定范围的地下水淡化带．这种淡化水对油田供水具有战略意义，在一定程度上制约着油田建设的发展．通过对塔埋木河南岸地下淡水资源的分布特征与成因分析．为塔河南岸地下淡水资源的合理开发与利用指明了方向．     

二连盆地可地浸砂岩型铀成矿的再认识

笔者从铀成矿条件入手 ,分析了二连盆地在基底演化期、含矿建造形成期以及后生改造成矿期各阶段对可地浸砂岩型铀矿的控制作用 ,认为二连盆地在含矿建造形成期是由众多分割性强的 ,构造演化和沉积变迁自成体系 ,并具有多物源、近物源特点的小凹陷所组成。同时 ,综合其他控制砂岩型铀矿的因素 ,确定了二连盆地是以发育潜水 层间氧化带砂岩型铀矿为其主要成矿类型 ,且矿床规模以中、小型为主 ,具有成群成带产出的特点。     

水质大涡模拟数学模型研究

建立了基于弱可压缩流基础上的水质大涡模拟数学模型及污染物质扩散系数与平均运动的关系。数值计算采用有限体积法和预测校正法,固壁边界条件采用"部分滑移条件"。并应用该模型对重庆嘉陵江、长江两江交汇段的流场,污染物质浓度分布进行了计算,计算结果与实测值比较吻合。研究表明,横向扩散与流动状态有关,当支流流量相对较小时,横向扩散较弱,形成岸边污染带,当支流流量相对较大时,横向扩散较强,污染带向江心移动。     

包气带中温度变化对水分分布影响的实验研究

笔者在高180cm、宽50cm的砂槽中,做了温度对水分运移影响的模拟试验。试验结果表明,在包气带一定深度以下,孔隙相对封闭,孔隙内液态水与气态水处于动态平衡,相对湿度接近或达到饱和状态。在此条件下,砂柱内温度场的任何微小变化都会导致孔隙系统内的水分发生蒸发或凝结。当包气带内温度场发生变化时,气态水在温度梯度作用下,向最低温度界面运移,蒸发或是凝结取决于最低温度界面的性质。在不发生聚集的开放性界面上出现蒸散,消耗包气带内水分。在聚集性封闭界面上则出现凝结,使包气带内水分增加。在温度场控制下,包气带中气态水凝结或蒸发是水分运移的另一重要形式,它在一定程度上决定着水分的分布状态,尤其在温差巨大的地区,这种作用显得十分重要。     

石岭沟-拐道沟铜-铅-锌多金属成矿带成矿地质条件分析

成矿带位于北秦岭北部晚元古代-早古生代裂谷带南缘的变质火山岩区，受油房-皇台断裂的次级分支断裂及燕山-印支期的侵入岩体及次火山岩脉的联合控制，成矿地质条件与甘肃白银厂铜-铅-锌矿田相类似，成矿带内地表已发现多条铜-铅-锌矿(化蚀变)体，找矿潜力较大，只要进一步深入开展工作，有望找到与白银厂铜-铅-锌矿田相类似的大型一超大型铜-铅-锌多金属矿床。