The identifiability of parameters in a water quality model of the Biebrza River, Poland   总被引：1，自引：0，他引：1  

Marcel van der Perk  Marc F. P. Bierkens 《Journal of Hydrology》1997,200(1-4):307-322

The identifiability of model parameters of a steady state water quality model of the Biebrza River and the resulting variation in model results was examined by applying the Monte Carlo method which combines calibration, identifiability analysis, uncertainty analysis, and sensitivity analysis. The water quality model simulates the steady state concentration profiles of chloride, phosphate, ammonium, and nitrate as a function of distance along a river. The water quality model with the best combination of parameter values simulates the observed concentrations very well. However, the range of possible modelled concentrations obtained for other more or less equally eligible combinations of parameter values is rather wide. This range in model outcomes reflects possible errors in the model parameters. Discrepancies between the range in model outcomes and the validation data set are only caused by errors in model structure, or (measurement) errors in boundary conditions or input variables. In this sense the validation procedure is a test of model capability, where the effects of calibration errors are filtered out. It is concluded that, despite some slight deviations between model outcome and observations, the model is successful in simulating the spatial pattern of nutrient concentrations in the Biebrza River.  相似文献   

The hydrocarbon generation mechanism and the three-stage type model of hydrocarbon generation for carbonate source rocks   总被引：1，自引：0，他引：1  

Zhaoyun Wang  Keming Cheng 《中国科学D辑(英文版)》1997,40(3):232-238

The diagenetic mechanism and process of carbonate rocks, which is different to that of clastic rocks, decides the existence of different existing state organic matters in carbonate rocks. This has been verified by both the microscopic observation of organic petrology and the analysis of organic geochemistry of many samples. Based on the hydrous pyrolysis simulation experiment of the low-mature carbonate rocks, the contrasting study on the yield and their geochemistry characteristics of different existing state soluble organic matters of a series of various maturity samples shows that the different existing state organic matters make different contributions to hydrocarbon generation during every evolution state. So that, the hydrocarbon generation process of carbonate rocks can be summarized as the following three stages: the first is the direct degradation of biogenic bitumen macromolecules during the immature stage, the second is the thermal degradation of a large amount of kerogen at the mature stage, the last stage is the expulsion or release of inclusion organic matter owing to the increased thermal expansion pressure during the high evolution stage. Part of achievements of the Eighth Five-Year National Science-Technology Key-Task Project “85-102-02-07”.  相似文献   

Converting Radial Distortions Due to Geopotential Models to Geopotential Stokes Coefficients     

Burša  Milan 《Studia Geophysica et Geodaetica》1997,41(4):407-415

A methodology for improving geopotential models has been developed. Theoretical relations have been derived converting coefficients in harmonic expansions for radial distortions due to geopotential models into geopotential Stokes coefficients. Terms of the order of 10 ^–10 in magnitude have been retained.  相似文献   

Main models and distribution patterns of gas reservoirs in large-medium gas fields of China     

Yan Song  Jinxing Dai  Chunsen Dai  Ying Chen  Feng Hong 《中国科学D辑(英文版)》1997,40(1):23-31

Based on characteristics and trap types of gas reservoirs in large and medium gas fields in China, 4 gas reservoir models have been established:(i) structural trap gas reservoir model I, formed earlier than or simutaneously with generating of gases; (ii) structural trap gas reservoir model II, formed later than generating of gases; (iii) fossil weathered residuum gas reservoir model; and (iV) mud diapir abnormal temperature and pressure gas reservoir model. Distribution patterns of large-medium gas fields are described with the concept of “sealed compartment”. It is concluded that the inner-compartment area, marginal area of the compartment and the areas between two overlapped sealed compartments are the most favourable areas for discovering large-medium gas fields. Project supported by the “85–102” Chinese National Key Science and Technology Project.  相似文献   

Evolution model and formation mechanism of bio-thermocatalytic transitional zone gas   总被引：1，自引：0，他引：1  

Wenhui Liu  Yongchang Xu  Jiyang Shi  Huaiyan Lei  Baisheng Zhang 《中国科学D辑(英文版)》1997,40(1):43-53

As a new genetic type of natural gas exploration area, the bio-thermocatalytic transitional zone gas (BTTZG) has been highly stressed by geologists both at home and abroad. Systematic study on the generation mechanism of hydrocarbon at the transitional zone is presented. Based on simulating experiments and geochemistry analysis of the source rock with lower evolution, a hydrocarbon-forming model at the transitional zone has been established. The mechanism is proposed that under the condition of low temperature and pressure combining with extremely active structural stress and clay mineral catalysis, BTTZG is formed by de-group of soluble organic matter and polarized compositions through orthocarbon ion as well as by condensation polymerization of aromatic ring-rich insoluble organic matter. This mechanism controls the formation of BTTZG, and furthermore, BTTZG is the product of superimposition and interaction of all the factors mentioned above.  相似文献   

GPS Ambiguity Resolution: Impact of Time Correlation,Cross-Correlation and Satellite Elevation Dependence     

Teunissen  P.J.G. 《Studia Geophysica et Geodaetica》1997,41(2):181-195

In this contribution we discuss the geometry-free GPS single baseline model and show how the least-squares ambiguities are affected by changes in the stochastic model. We particularly pay attention to the effect of time correlation, cross-correlation and satellite elevation dependence. We also differentiate between the impact on the location of the ambiguity search space and the impact on the size and shape of the search space. The analysis is carried out for both the model in which the ionospheric delays are assumed absent, and for the model in which they are assumed present. The former model is applicable to short baselines only.  相似文献   

三维分块倾斜界面的反演及其应用   总被引：3，自引：0，他引：3       下载免费PDF全文

赖晓玲  郑需要  张先康 《地震工程学报》1997,19(3):63-68

介绍了利用反射波走时反演介质层速度和包含直立断层的三维界面的计算方法．对各层界面利用多个倾斜或平界面方程来描述．给出了数值计算实例．结果表明，反演解与真模型很接近，说明计算方法是有效的．利用该方法处理了唐山地震区的ＰｍＰ反射波资料，获得了该区域莫霍界面的三维分块形态．唐山附近莫霍界面错断与该区域１９７６年唐山地震及一系列余震的发生有密切的联系．  相似文献   

青海湟水盆地活动断裂构造格架激光散斑模拟试验研究          下载免费PDF全文

王赞军  涂德龙  宋晓明  高德禄 《地震工程学报》1997,19(4):84-89

将最新研究的湟水盆地断裂构造格架设置于合理的试验材料之上，进行激光散斑模型模拟试验，取得了断裂活动特征的量化显示结果，并用于评价区域地壳稳定性．  相似文献   

沉降量约束下的黄骅裂谷形成的地球的动力学模式     

杜旭东  漆家福  张一伟  陆春生 《吉林大学学报(地球科学版)》1997,(2)

在计算覆盖整个黄晔裂谷２００口人工井（包括少部分探井）沉降量的基础上，总结本区二种基本沉降曲线模式。统计出热沉降（Ｓｔ）与初始沉降（Ｓｉ）之比为０．６，依此为约束条件与大陆岩石圈伸展的地球动力学正演模式进行对比，与简单剪切模式预测的热沉降与初始沉降之比值及几何效应更接近。进一步证实黄骅裂谷以简单剪切机制形成的地球动力学模式更合理，这与著名的以纯剪模式形成的北海伸展盆地不同  相似文献   

酸性污染物欧拉型输送转化模式的研究   总被引：2，自引：0，他引：2  

高会旺  黄美元 《地球科学进展》1997,12(5):422-427

数值模式是研究酸性污染及其长距离输送特性的一种重要方法。７０年代以来，国内外发展了许多欧拉型的输送转化模式，我国在欧拉型酸性污染物长距离输送模式的研究中也取得了重要进展。主要介绍了国内外的欧拉酸性污染物输送转化模式，并就模式的发展方向进行了讨论。  相似文献