Refined conceptualization of TOPMODEL for shallow subsurface flows     

M. Todd Walter  Tammo S. Steenhuis  Vishal K. Mehta  Dominique Thongs  Mark Zion  Elliot Schneiderman 《水文研究》2002,16(10):2041-2046

The TOPMODEL framework was used to derive expressions that account for saturated and unsaturated flow through shallow soil on a hillslope. The resulting equations were the basis for a shallow‐soil TOPMODEL (STOPMODEL). The common TOPMODEL theory implicitly assumes a water table below the entire watershed and this does not conceptually apply to systems hydrologically controlled by shallow interflow of perched groundwater. STOPMODEL provides an approach for extending TOPMODEL's conceptualization to apply to shallow, interflow‐driven watersheds by using soil moisture deficit instead of water table depth as the state variable. Deriving STOPMODEL by using a hydraulic conductivity function that changes exponentially with soil moisture content results in equations that look very similar to those commonly associated with TOPMODEL. This alternative way of conceptualizing TOPMODEL makes the modelling approach available to researchers, planners, and engineers who work in areas where TOPMODEL was previously believed to be unsuited, such as the New York City Watershed in the Catskills region of New York State. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

ME／EXOSAT银道扫描数据的直接解调成像   总被引：5，自引：0，他引：5  

卢方军  李惕碚 《天文学报》1997,38(1):56-66

利用对象重建的直接解调方法，我们对EXOSAT卫星ME探测器银道扫描观测数据进行了重新分析，研究了在以往的分析中难以分辨的几个天区中的分立X射线源．利用Bootstrap方法，我们对成像结果进行了统计误差分析，给出了点源位置和流强的误差．  相似文献   

煤矿排水对枣庄市清凉泉水源地污染作用分析          下载免费PDF全文

姚春梅  姜宏汝  彭燕  罗梅  董玉龙 《山东国土资源》2006,22(5):46-49

近年来,随着枣庄市陶枣矿区煤矿资源的大规模开发,矿坑排水对矿区地下水资源及生态环境产生的负面影响愈发突出,尤其是矿坑水沿地表河流排放途中,通过灰岩“天窗”大量灌入岩溶地下水中,造成地处煤田下游的清凉泉水源地水质遭受明显污染,供水水质难以保证。根据矿坑排水量、水源地水质、开采现状等分析认为,对串层污染进行封堵和控制矿坑水排放渠道是防治水源地污染的有效措施。  相似文献   

凡河元古宙坳拉谷关门山铅锌矿床铅同位素研究     

张国武 《国土资源》1993,(1)

凡河元古宙坳拉谷关门山铅锌矿床及外围铅矿点,矿石中的铅是以正常铅为主,单阶段模式年龄为1807—1995Ma,铅质来源主要是造山带铅,铅源岩为大于2000Ma的太古宙结晶基底。矿石中异常铅具有线性关系,它是由矿石中的正常铅与放射成因铀铅组成的。结合地质观察认为1807—1995Ma是正常铅受到均一化时间,不是成矿时间。该时间大于容矿条带状白云岩的年龄1526—1600Ma。矿体受断裂构造控制,具有穿层性,矿体生成于容矿岩石成岩以后。矿床成因是属后生的。成矿时间(主矿化期)为1400—1500Ma左右,最晚矿化时间为294Ma。矿床成因属元古宙坳拉谷碳酸盐岩密西西比河谷型(MVT)后生铅锌矿床。  相似文献   

Finite integral solution for the point source response of a layered acoustic medium     

M. Tygel  P. Hubral 《Geophysical Journal International》1986,84(3):647-651

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The response of two joined quarter spaces to SH line sources located at the material discontinuity interface   总被引：3，自引：0，他引：3  

Yehuda Ben-Zion 《Geophysical Journal International》1989,98(2):213-222

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关于正确处理对流－弥散方程和渗流方程中源汇项的若干问题     

郭东屏 《地球科学与环境学报》1995,(3)

对流─弥散方程和渗流基本微分方程中的源汇项，分别是决定含水层中任一内点上水质量和溶质质量时变率的重要因素之一。而关于源汇项不适当的乃至是错误的表述，在文献中却不乏其见，其影响之大是显而易见的．本文深入分析了某些表述的不当或错误之处，给出了正确的处理与表述方法。  相似文献   

THE DISCOVERED DEEP BURIED LAKE ICE IN SOURCE REGION OF THE HUANGHE RIVER     

王绍令  李位乾 《中国地理科学(英文版)》1993,3(3):247-254

The 4.45 m-thick pure ice lens have been discovered firstly at depth from 19.81 -24.26 m in the bore No.6, which locates in north bank of the Ngoring Lake. In source region of the Huanghe (Yellow) River, 14C dating, X -ray diffraction, pollen analysis, micropalaeontology, chemical components, environmental isotope 2H, 3H, 18O and freezing point of the ice and water samples from the bore have been tested and microorganism in the ice have been also appraised with microscope. Combined with the research on geomorphy and Quaternary around the lake, the ice lens are determined as a kind of deep-buried lake ice, formed in 35,030-45,209 yr.B.P., and annual mean air temperature was about -10℃ during that time.  相似文献   

浙西北前震旦纪火山岩的Nd、Sr同位素地球化学     

徐步台 《浙江国土资源》1994,(2)

在浙西北双溪坞群和上墅组火山岩系获得较可靠的Sm－Nd同位素年龄的基础上，本文进一步做了Nd、Sr同位素地球化学研究。∈Nd（T）和∈Sr（T）示踪判别了该区前震旦纪火山岩浆源区特征及其物质来源。同时，Nd同位素模式年龄为该区存在更古老基底提供了重要的地质年代信息。  相似文献   

Pervasive granitoid magma transfer through the lower–middle crust during non-coaxial compressional deformation     

W. J. COLLINS  & E. W. SAWYER 《Journal of Metamorphic Geology》1996,14(5):565-579

Granitic magmas migrated through Early Proterozoic middle–lower crust at Mt Hay, central Australia, via a diverse network of narrow structurally controlled channelways, during a period of progressive W–SW-directed thrusting (D1a–D1d). They utilized existing folds, boudins and shear zones, or created new channels by magmatic fracture either parallel to layering or, rarely, in irregular arrays. The magmas rose obliquely, parallel to the plunging (50–60°) regional elongation direction, which was defined by coaxial folds, boudin necks and a strong mineral-elongation lineation. Megacrystic charnockitic magmas migrated through metre-scale conduits during D1a–D1b, but leucosomes were generally restricted to smaller (centimetre-scale) structures that existed throughout the entire deformation history. Thus, D1a/D1b leucosomes were potential feeders of in situ partial melts to the adjacent larger conduits of charnockite magma, thereby providing a pervasive interconnected network that allowed efficient migration of all magma types during the early stages of thrusting. The upper–middle crust of the Anmatjira–Reynolds Range area contains abundant megacrystic granitoid sheets that are of similar age and geochemistry to those at Mt Hay. They are considered to have formed as syntectonic intrusions emplaced during W–SW-directed thrusting, as at Mt Hay, suggesting that granitic magmas formed near the base of the continental crust passed through the mid-lower crustal level (25–30 km) exposed at Mt Hay and accumulated, in batholithic proportions, at shallower crustal levels (12–20 km) such as the Anmatjira–Reynolds Range area. The observations imply that granitoid magmas in the deep crust are capable of pervasive migration through the crust during major compressive, noncoaxial shear deformation. Localization of magmas by sequentially developed, narrow, compressive structures suggests that dilatancy followed successive foliation-forming events, a situation that can occur during steady-state deformation if the effective confining pressures are low, which would be a result of high and possibly variable rates of magma influx. The inferred rapid melt segregation and migration during deformation suggest that large chambers do not form until magma reaches neutral buoyancy in the middle to upper continental crust.  相似文献