Coherence mapping—An automated approach to display goodness-of-correlation between wells in a field     

Harald S. Poelchau 《Mathematical Geosciences》1987,19(8):833-850

Patterns of inter-well correlations in map view can yield insight into the architecture of an area such as a petroleum reservoir. Preferred directions of fluid communications, discontinuities, and structural or depositional “grain” of an area often can be identified. In coherence mapping, large numbers of wells are compared in pairs, using a similarity coefficient. Sliding cross-correlation techniques of sections can be used to adjust for some normal stratigraphic inconsistencies. The calculated parameters are mapped as vector spider plots for each well, or as link-lines between well pairs with line thickness proportional to the strength of correlation. The resulting maps display areas of coherence and lines of discontinuities which can be interpreted according to the geologic style of the region. The method works best for areas with relatively great density of wells and uniform distribution. The database should contain logs digitized over the interval of interest and at least one stratigraphic marker. A pilot study of a carbonate reservoir with some 150 wells provided useful suggestions for reinterpretation of the field in terms of steeply dipping clinoforms of basin margin deposits.  相似文献   

On the formation of the vein-type uranium „Yellow Ores“ from the Schwarzach Area (NE-Bavaria,Germany) and on the behaviour of P,As, V and Se during supergene processes     

Dr. Harald Dill 《International Journal of Earth Sciences》1983,72(3):955-980

Most of the U occurrences situated at the western edge of the Bohemian Massif show in their upper parts secondary U minerals. The immigration (P, V, As and Se) from the country rocks and the ore body, via saprolite and paleosoils into the secondary ore minerals is investigated. The P content is suggested to be closely related to hydromorphic paleosoils. From those intermediate stages it may have been brought into the upper parts of the vein structures. No laterogenic impoverishment in the wall rocks with respect to phosphorus or apatite could be determined. The arsenic distributions is also governed as at other sulfide deposits by underlying sulfides and reducing conditions of a primary hypogene ore zone, whereas vanadium content in U secondary minerals is closely related to the enclosing country rocks. Granites, on account of their low content in mafic minerals, have low V contents in U secondary minerals. Besides the Schwarzach Area, U ore mineralisations from other U occurrences have been investigated. Some of the U deposits are certainly of “per ascensum” origin and their secondary U mineralisation can well be interpreted as having been derived from the underlying primary “black ores”. However, some mineralisations cannot be classified with certainty as being “per ascensum”. They include some properties pointing to “per ascensum” (e. g. sulfide association) as well as characteristics typical for “per descensum” (small depth, large amounts of U-VI minerals). The mode of formation may in some cases be as follows: Variscan or Alpine ore mineralisations of no economic significance may have formed a reducing environment and caused U to be concentrated. Younger redistribution processes influenced by modern tectonics (uplifting) and the fluviatile drainage pattern have taken place and in some cases destroyed the primary deposits or enhanced the ore mineralisation. These processes roughly resemble those described from sandstone — hosted roll front deposits.  相似文献   

A Review of Forest Gap Models   总被引：25，自引：0，他引：25  

Harald Bugmann 《Climatic change》2001,51(3-4):259-305

Forest gap models, initially conceived in 1969 as a special case of individual-tree based models, have become widely popular among forest ecologists for addressing a large number of applied research questions, including the impacts of global change on long-term dynamics of forest structure, biomass, and composition. However, they have been strongly criticized for a number of weaknesses inherent in the original model structure. In this paper, I review the fundamental assumptions underlying forest gap models, the structure of the parent model JABOWA, and examine these criticisms in the context of the many alternative formulations that have been developed over the past 30 years.Four assumptions originally underlie gap models: (1) The forest is abstracted as a composite of many small patches of land, where each can have a different age and successional stage; (2) patches are horizontally homogeneous, i.e., tree position within a patch is not considered; (3) the leaves of each tree are located in an indefinitely thin layer (disk) at the top of the stem; and (4) successional processes are described on each patch separately, i.e., there are no interactions between patches. These simplifications made it possible to consider mixed-species, mixed-age forests, which had been difficult previously mainly because of computing limitations.The structure of JABOWA is analysed in terms of the functional relationships used for formulating the processes of tree establishment, growth, and mortality. It is concluded that JABOWA contains a number of unrealistic assumptions that have not been questioned strongly to date. At the same time, some aspects of JABOWA that were criticized strongly in the past years are internally consistent given the objectives of this specific model.A wide variety of formulations for growth processes, establishment, and mortality factors have been developed in gap models over the past 30 years, and modern gap models include more robust parameterizations of environmental influences on tree growth and population dynamics as compared to JABOWA. Approaches taken in more recent models that led to the relaxation of one or several of the four basic assumptions are discussed. It is found that the original assumptions often have been replaced by alternatives; however, no systematic analysis of the behavioral effects of these conceptual changes has been attempted to date.The feasibility of including more physiological detail (instead of using relatively simple parameterizations) in forest gap models is discussed, and it is concluded that we often lack the data base to implement such approaches for more than a few commercially important tree species. Hence, it is important to find a compromise between using simplistic parameterizations and expanding gap models with physiology-based functions and parameters that are difficult to estimate. While the modeling of tree growth has received a lot of attention over the past years, much less effort has been spent on improving the formulations of tree establishment and mortality, although these processes are likely to be just as sensitive to global change as tree growth itself. Finally, model validation issues are discussed, and it is found that there is no single data source that can reliably be used for evaluating the behavior of forest gap models; instead, I propose a combination of sensitivity analyses, qualitative examinations of process formulations, and quantitative tests of gap models or selected submodels against various kinds of empirical data to evaluate the usefulness of these models for assessing their utility for predicting the impacts of global change on long-term forest dynamics.  相似文献   

Directional properties of alteration CRM in basic igneous rocks     

Harald Walderhaug 《Geophysical Journal International》1992,111(2):335-347

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Comagmatic lamprophyres and diabases on the south coast of Norway     

Dr. Harald Carstens 《Contributions to Mineralogy and Petrology》1959,6(5):299-319

Two lamprophyre-diabase associations on the south coast of Norway are described. The lamprophyres and the diabases contain feldspathic leucocratic segregations in the shape of ocelli, ocellar pipes, sheets, or irregular veins and schheren. The origin of the lamprophyres is considered to be related to the formation of the leucocratic segregations. It is believed that the behaviour of alkaline volatiles under the influence of tensional stress and gravity accounts for the differentiation.  相似文献   

Plastic stress relaxation around solid inclusions in pyrope     

Harald Carstens 《Contributions to Mineralogy and Petrology》1971,32(4):289-294

Misfit between primary (syngenetic) inclusions and pyrope host is usually due to differences in the coefficients of thermal expansion and compressibilities. It is shown that the misfit stresses are relieved by the generation and rearrangement of dislocations. Zones of plastic flow have been recognized around inclusions in pyropes from Bohemian garnet peridotites and in kimberlite pyropes from South Africa and Yakutia. The extent of plastic yield is determined by the history of the pyrope in the ductile regime. Implications for using the piezothermometric method of Rosenfeld and Chase (1961) which is based upon the elastic strain, are discussed.Publications No. 38 in the Norwegian Geotraverse Project.  相似文献   

Entwurf eines topologischen Modells der Wechselwirkungen zwischen Kulturmaßnahmen und Energiehaushalt des Bodens,dargestellt am Beispiel einer Strohmulche     

Dr. Harald Schrödter  Dipl.-Met. Jürgen von Hoyningen-Huene 《Theoretical and Applied Climatology》1971,19(2):183-198

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The lineage structure of quartz crystals     

Harald Carstens 《Contributions to Mineralogy and Petrology》1968,18(4):295-304

Etching and optical methods have been applied to study the lineage structure of quartz crystals from the Swiss Alps. It is shown that lineage boundaries form during growth in crystals of high dislocation density by a rearrangement of dislocations in low angle boundaries. The boundaries usually consist of parallel lines and are supposed to be nearly pure tilt boundaries.  相似文献   

Chemical Mechanism Development: Laboratory Studies and Model Applications     

Harald Geiger  Ian Barnes  Karl H. Becker  Birger Bohn  Theo Brauers  Birgit Donner  Hans-Peter Dorn  Manfred Elend  Carlos M. Freitas Dinis  Dirk Grossmann  Heinz Hass  Holger Hein  Axel Hoffmann  Lars Hoppe  Frank Hülsemann  Dieter Kley  Björn Klotz  Hans G. Libuda  Tobias Maurer  Djuro Mihelcic  Geert K. Moortgat  Romeo Olariu  Peter Neeb  Dirk Poppe  Lars Ruppert  Claudia G. Sauer  Oleg Shestakov  Holger Somnitz  William R. Stockwell  Lars P. Thüner  Andreas Wahner  Peter Wiesen  Friedhelm Zabel  Reinhard Zellner  Cornelius Zetzsch 《Journal of Atmospheric Chemistry》2002,42(1):323-357

Within the German Tropospheric Research Programme (TFS) numerous kinetic and mechanistic studies on the tropospheric reaction/degradation of the following reactants were carried out: oxygenated VOC, aromatic VOC, biogenic VOC, short-lived intermediates, such as alkoxy and alkylperoxy radicals.At the conception of the projects these selected groups were classes of VOC or intermediates for which the atmospheric oxidation mechanisms were either poorly characterised or totally unknown. The motivation for these studies was the attainment of significant improvements in our understanding of the atmospheric chemical oxidation processes of these compounds, particularly with respect to their involvement in photooxidant formation in the troposphere. In the present paper the types of experimental investigations performed and the results obtained within the various projects are briefly summarised. The major achievements are highlighted and discussed in terms of their contribution to improving our understanding of the chemical processes controlling photosmog formation in the troposphere.  相似文献   

Restoration of submerged vegetation in shallow eutrophic lakes – A guideline and state of the art in Germany     

Sabine Hilt  Elisabeth M. Gross  Michael Hupfer  Harald Morscheid  Jens Mhlmann  Arnulf Melzer  Jens Poltz  Stefan Sandrock  Eva-Maria Scharf  Susanne Schneider  Klaus van de Weyer 《Limnologica》2006,36(3):155-171

One of the most serious problems caused by eutrophication of shallow lakes is the disappearance of submerged macrophytes and the switch to a turbid, phytoplankton-dominated state. The reduction of external nutrient loads often does not result in a change back to the macrophyte-dominated state because stabilising mechanisms that cause resilience may delay a response. Additional internal lake restoration measures may therefore be needed to decrease the concentration of total phosphorus and increase water clarity. The re-establishment of submerged macrophytes required for a long-term stability of clear water conditions, however, may still fail, or mass developments of tall-growing species may cause nuisance for recreational use. Both cases are often not taken into account when restoration measures are planned in Germany, and existing schemes to reduce eutrophication consider the topic inadequately. Here we develop a step-by-step guideline to assess the chances of submerged macrophyte re-establishment in shallow lakes. We reviewed and rated the existing literature and case studies with special regard on (1) the impact of different internal lake restoration methods on the development of submerged macrophytes, (2) methods for the assessment of natural re-establishment, (3) requirements and methods for artificial support of submerged macrophyte development and (4) management options of macrophyte species diversity and abundance in Germany. This guideline is intended to help lake managers aiming to restore shallow lakes in Germany to critically asses and predict the potential development of submerged vegetation, taking into account the complex factors and interrelations that determine their occurrence, abundance and diversity.  相似文献