云南地壳生热率分布   总被引：1，自引：3，他引：1       下载免费PDF全文

周真恒  向才英 《地震地质》1996,18(4):443-452

研究地壳岩石放射性生热率的垂向分布，是研究深部热结构的基础。根据深部地震测深资料，利用地震波速与生热率之间的关系，估计了云南地壳生热率的垂向分布。全区上地壳生热率一般为０．８～２．１μＷ／ｍ３，中地壳为０．４～１．２μＷ／ｍ３，下地壳为０．１１～０．５５μＷ／ｍ３  相似文献   

塔里木盆地北缘大地热流测定   总被引：6，自引：1，他引：6       下载免费PDF全文

魏大卫 《地质科学》1992,(1):93-96

1987—1988年,在塔里木盆地北部的库车一轮台地区进行了热流测量,取得了西北地区的首批热流值。研究区在地质上属雅克拉一轮台基岩隆起带,巨厚的中新生界陆相碎屑岩不整合于古生界及前古生界基岩之上。西段雅克拉地区在深约5400m 的不整面之下为下古生界碳酸盐岩,上覆厚仅数十米的侏罗系及厚约5300m 以上的下白垩统一第四系,在侏罗系及下白垩统之间有一沉积间断。  相似文献   

江西省大地热流与铀矿关系的初步研究   总被引：3，自引：0，他引：3  

李学礼  周文斌  张卫民  孙占学 《铀矿地质》1993,(4)

本文根据江西省大地构造、铀矿分布和大地热流实测资料,证明大地热流异常和铀矿均受深大断裂和深部构造变异带的控制,铀矿化能在一定程度上引起热流异常,并据此初步探讨了根据大地热流异常寻找铀矿床的可能性。  相似文献   

Development and sensitivity analysis of a model for assessing stratification and safety of Lake Nyos during artificial degassing     

Martin?SchmidEmail author  Andreas?Lorke  Alfred?Wüest  Michel?Halbwachs  Gregory?Tanyileke 《Ocean Dynamics》2003,53(3):288-301

To prevent the recurrence of a disastrous eruption of carbon dioxide (CO₂) from Lake Nyos, a degassing plan has been set up for the lake. Since there are concerns that the degassing of the lake may reduce the stability of the density stratification, there is an urgent need for a simulation tool to predict the evolution of the lake stratification in different scenarios. This paper describes the development of a numerical model to predict the CO₂ and dissolved solids concentrations, and the temperature structure as well as the stability of the water column of Lake Nyos. The model is tested with profiles of CO₂ concentrations and temperature taken in the years 1986 to 1996. It reproduces well the general mixing patterns observed in the lake. However, the intensity of the mixing tends to be overestimated in the epilimnion and underestimated in the monimolimnion. The overestimation of the mixing depth in the epilimnion is caused either by the parameterization of the k-epsilon model, or by the uncertainty in the calculation of the surface heat fluxes. The simulated mixing depth is highly sensitive to the surface heat fluxes, and errors in the mixing depth propagate from one year to the following. A precise simulation of the mixolimnion deepening therefore requires high accuracy in the meteorological forcing and the parameterization of the heat fluxes. Neither the meteorological data nor the formulae for the calculation of the heat fluxes are available with the necessary precision. Consequently, it will be indispensable to consider different forcing scenarios in the safety analysis in order to obtain robust boundary conditions for safe degassing. The input of temperature and CO₂ to the lake bottom can be adequately simulated for the years 1986 to 1996 with a constant sublacustrine source of 18 l s^–1 with a CO₂ concentration of 0.395 mol l^–1 and a temperature of 26 °C. The results of this study indicate that the model needs to be calibrated with more detailed field data before using it for its final purpose: the prediction of the stability and the safety of Lake Nyos during the degassing process.Responsible Editor: Hans Burchard  相似文献   

上海热浪与健康监测预警系统   总被引：21，自引：0，他引：21       下载免费PDF全文

谈建国  林松伯等 《应用气象学报》2002,13(3):356-363

用1989～1998年上海逐日4次气象观测资料,应用美国特拉华大学的SSC天气分类方法确定逐日天气类型,形成了10年逐日天气类型日历。并通过天气类型与死亡率的对比分析,确定MT+类型是上海地区形成热浪的“侵人型”气团,是具有最高死亡率的天气类型。采用逐步回归方法建立了MT+类型下因受热浪侵袭而超正常死亡数的回归方程。在此基础上建立了上海热浪与健康监测预警系统。通过1999年气象和死亡实况资料检验,系统对热浪及因此引起的死亡具有较好的监测和预警效果。  相似文献   

Mantle heat flow and thermal structure of the northern block of Southern Granulite Terrain, India   总被引：1，自引：0，他引：1  

Ajay Manglik   《Journal of Geodynamics》2006,41(5):510-519

Continental shield regions are normally characterized by low-to-moderate mantle heat flow. Archaean Dharwar craton of the Indian continental shield also follows the similar global pattern. However, some recent studies have inferred significantly higher mantle heat flow for the Proterozoic northern block of Southern Granulite Terrain (SGT) in the immediate vicinity of the Dharwar craton by assuming that the radiogenic elements depleted exposed granulites constitute the 45-km-thick crust. In this study, we use four-layered model of the crustal structure revealed by integrated geophysical studies along a geo-transect in this region to estimate the mantle heat flow. The results indicate that: (i) the mantle heat flow of the northern block of SGT is 17 ± 2 mW/m², supporting the global pattern, and (ii) the lateral variability of 10–12 mW/m² in the surface heat flow within the block is of crustal origin. In terms of temperature, the Moho beneath the eastern Salem–Namakkal region appears to be at 80–100 °C higher temperature than that beneath the western Avinashi region.  相似文献   

云南地热资源及其开发前景   总被引：1，自引：0，他引：1  

殷瑛  王明珠  何绕生 《云南地质》2006,25(1):70-75

云南地热异常多且显著。滇西高温水热活动区是藏滇水热带的南延，滇东断陷盆地中低温水热活动区的形成得益于独特的地质结构，滇西、滇南花岗岩地热系统则主要吸收地层中K^40同位索放射热而成。开发前景极为广阔。  相似文献   

Hydraulic analysis of cell-network treatment wetlands     

Huaguo Wang  James W. Jawitz 《Journal of Hydrology》2006,330(3-4):721-734

When individual cells of a multiple-cell treatment wetland are hydraulically connected, the wetland has a cell-network structure. The hydraulic performance of treatment wetlands is often characterized using tracer residence time distributions (RTDs) measured between the wetland inlet and outlet, such that the wetland is considered as a single hydraulic unit, regardless of the extent of networking between individual internal cells. This work extends the single hydraulic unit approach to enable the specification of moments and RTD parameters for individual cells, or clusters of cells, within the cell-network based on inert tracer tests with injection only at the network inlet. Hydraulic performance is quantified in terms of hydraulic efficiency and travel time dimensionless variance using both the method of moments and RTD modeling. Cell-network analysis was applied to a case study from the Orlando Easterly Wetland (OEW), demonstrating the improvement in hydraulic performance of individual wetland cells following wetland restoration activities. Furthermore, cell-network analysis indicated that the location of water quality sampling station locations within the cell network can significantly affect the accuracy of pollutant removal effectiveness estimation when the individual sample station RTD does not represent the hydraulic unit RTD. At the OEW, it was determined that historical nutrient removal effectiveness estimation may be underestimated for one area and overestimated for another, and recommendations were provided for sample station locations to minimize future performance estimation errors.  相似文献   

Buoyancy and The Sensible Heat Flux Budget Within Dense Canopies   总被引：1，自引：8，他引：1  

D. Cava  G. G. Katul  A. Scrimieri  D. Poggi  A. Cescatti  U. Giostra 《Boundary-Layer Meteorology》2006,118(1):217-240

In contrast to atmospheric surface-layer (ASL) turbulence, a linear relationship between turbulent heat fluxes (F_T) and vertical gradients of mean air temperature within canopies is frustrated by numerous factors, including local variation in heat sources and sinks and large-scale eddy motion whose signature is often linked with the ejection-sweep cycle. Furthermore, how atmospheric stability modifies such a relationship remains poorly understood, especially in stable canopy flows. To date, no explicit model exists for relating F_T to the mean air temperature gradient, buoyancy, and the statistical properties of the ejection-sweep cycle within the canopy volume. Using third-order cumulant expansion methods (CEM) and the heat flux budget equation, a “diagnostic” analytical relationship that links ejections and sweeps and the sensible heat flux for a wide range of atmospheric stability classes is derived. Closure model assumptions that relate scalar dissipation rates with sensible heat flux, and the validity of CEM in linking ejections and sweeps with the triple scalar-velocity correlations, were tested for a mixed hardwood forest in Lavarone, Italy. We showed that when the heat sources (S_T) and F_T have the same sign (i.e. the canopy is heating and sensible heat flux is positive), sweeps dominate the sensible heat flux. Conversely, if S_T and F_T are opposite in sign, standard gradient-diffusion closure model predict that ejections must dominate the sensible heat flux.  相似文献   

人为热源对城市边界层结构影响的数值模拟研究   总被引：30，自引：1，他引：30       下载免费PDF全文

何晓凤  蒋维楣  陈燕  刘罡 《地球物理学报》2007,50(1):74-82

用南京大学多尺度模式系统在不同区域进行了多种人为热源引入方案的研究，结果表明：考虑时空变化的人为热源按比例分别引入到地表能量平衡方程和大气热量守恒方程是将人为热源引入模式的最优方案.人为热通量密度变化的敏感性试验结果发现：人为热源的存在对城市热岛的生成有重要作用.计算结果表明，南京现有的人为热源排放量对该地区的城市热岛贡献率约为296％，若人为热通量密度在现有量值的基础上增大1倍，则其热岛贡献率可达429％；此外，人为热的排放对清晨城市边界层逆温结构有一定程度的破坏作用，能明显升高夜间近地层气温达05～10℃，并能使白天湍流活动的影响范围增大，混合层高度抬高，使夜间城市热岛环流的影响范围扩大.  相似文献