Defining hydroclimatic regions using daily rainfall characteristics in the southern Appalachian Mountains     

Johnathan W. Sugg  Charles E. Konrad II 《International Journal of Digital Earth》2020,13(7):785-802

ABSTRACT

This paper addresses warm season hydroclimatic variability in the southern Appalachian region of the southeastern U.S., where precipitation can vary as much as 127?mm or more, with maximum seasonal totals exceeding 736?mm in extreme cases. Despite the occurrence of droughts, floods, and their socioecological impacts, hydroclimate variability is still poorly understood. This study characterizes the regional scale variations in the hydroclimate by examining the daily distribution of precipitation patterns in different topographic environments. Parameter-elevation relationships on independent slopes model (PRISM) gridded precipitation estimates are used to identify the location and frequency of different types of rainfall events. Several types of clustering algorithms are used as a regionalization approach to define areas where the precipitation regime exhibits similarities in its frequency of occurrence. The results are compared with internal validation statistics and a visualization is used to assess how well the resulting hydroclimatic regions align with different topographic environments. This study reveals the intricate spatial footprint of dry and wet regimes and demonstrates how clustering applications can be used with gridded climate data to determine where extremes are most likely to develop across mountain catchments.  相似文献   

Varianzspektrumanalyse der Seespiegelschwankungen des Titicaca-Sees (Südamerika)     

Univ.-Prof. Dr. Konrad Cehak  Univ.-Prof. Dr. Albrecht Kessler 《Theoretical and Applied Climatology》1976,24(3):201-208

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Entstehung und Merkmale der Olisthostrome     

Dr. Konrad Görler  Dozent Dr. Klaus -Joachim Reutter 《International Journal of Earth Sciences》1968,57(2):484-514

Zusammenfassung Die Bearbeitung von Olisthostromen des Nord- und Südapennins erbrachte neue Erkenntnisse über ihre Entstehung. Olisthostrome sind das Produkt einer Resedimentation durch submarine Schlammströme. Sie sind als sedimentäre Einheiten in eine normale Schichtfolge eingeschaltet, doch ist ihr Material älter als das der umgebenden Sedimente. Olisthostrome bestehen aus einer tonigen Matrix, in der eckige Gesteinsbruchstücke, die Olistholithe, schlecht eingeregelt liegen. Die primäre Schichtung ging durch den Umlagerungsprozeß verloren. Olisthostrome erreichen Längen (Richtung des Materialtransportes) von 50 km und Breiten bis zu mehreren 100 km. Die bisher bekannte maximale Mächtigkeit beträgt mehr als 2 km. Es besteht ein kontinuierlicher Übergang zwischen den Phänomenen der gravitativen Gleitdecken und der Olisthostrome. Ein Olisthostrom bewegt sich nicht als Ganzes. Es wird durch relativ geringmächtige Schlammströme, die sich vom Beckenrand zum Beckenzentrum bewegen und dabei sedimentieren, allmählich aufgebaut. Im Gegensatz zu der Geschwindigkeit dieser Schlammströme rückt die Stirn eines Olisthostromes nur langsam vor. Die Entstehung größerer Olisthostrome ist an bestimmte lithologische und tektonische Voraussetzungen gebunden, die ihr Auftreten auf Flysch- und Molasse-Becken beschränken. Die Stellung der Olisthostrome innerhalb der Resedimentationserscheinungen und ihre regionale Verbreitung werden diskutiert.

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Geological investigations in the Northern and Southern Apennines yielded some new aspects about the genesis of olisthostromes. Olisthostromes are the result of a resedimentation processus by means of submarine mudstreams. Like other sedimentary bodies they are intercalated in normal stratigraphic sequences, but their material is much older than the overlying and underlying sediments. They consist of an argillaceous matrix in which angular rock fragments, the olistholites, are more or less chaotically distributed. The stratification of the primary series from which the mudstreams originated was almost completely destroyed during the sedimentation processus. With regard to the direction of supply of material the olisthostromes may reach a longitudinal extension of 50 km and a transversal extension of some hundreds of km. The maximum thickness known up to the present exceeds 2 km. There is a close relationship between the phenomena of gravity slide nappes and olisthostromes. An olisthostrome does not move as a whole. It is built up progressively by relatively small mudstreams which flow downslope depositing their material. In contrast to the velocity of the mudstreams the advancing of the front of an olisthostrome is slow. The internal movement of the mudflow is rather laminar than turbulent. The formation of olisthostromes depends on certain lithological and tectonical conditions so that they are predominantly found with the flysch and molasse stages of the orogenetic cycles.

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Résumé L'étude des olisthostromes dans l'Apennin septentrional et méridional a fourni des connaissances nouvelles sur leur génèse. Les olisthostromes sont produits par une resédimentation au moyen de coulées de boue sous-marines. Ils sont intercalés dans les séries stratigraphiques normales comme d'autres membres sédimentaires, mais le matériel dont ils sont composés est plus ancien que les sédiments normaux au-dessus et au-dessous. Ce matériel consiste en une pâte argileuse qui contient des fragments de roche angulaires (ostholithes) distribués presque chaotiquement. La stratification primaire de la série, d'où les coulées de boue provenaient, fut détruite durant le processus de resédimentation. Un olisthostrome peut atteindre par rapport à la direction du mouvement, une extension longitudinale de 50 km et une extension transversale de plusieurs centaines de km. L'épaisseur maximale connue jusqu à présent dépasse 2 km. Entre le phénomène d'une nappe de glissement par gravité et celui d'un olisthostrome il y a toutes les phases de transition, L'olisthostrome ne se meut pas comme un complexe entier. Il se constitue progressivement par des coulées de boue relativement minces qui descendent vers le centre du bassin. Par contraste avec la vitesse de ces coulées qui apportent le matériel, le front d'un olisthostrome ne s'avance que lentement. La naissance des olisthostromes dépend de certaines conditions lithologiques et tectoniques si bien qu'ils sont restreints pour la plupart aux périodes de flysch et de molasse des cycles orogénétiques. Le mouvement interne des coulées est essentiellement laminaire.

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Riassunto Le ricerche eseguite sugli olistostromi dell'Appennino Settentrionale e Meridionale hanno fornito dati nuovi sulla loro genesi. Gli olistostromi possono formarsi solo se sono presenti certe condizioni litologiche e tettoniche. Essi sono limitati, per la maggior parte, ai periodi di sedimentazione del flysch e della molassa nei cicli orogenetici. Il fenomeno delle falde gravitative è strettamente legato a quello degli olistostromi. Un olistostroma non si muove come una massa intera. Colate di fango (frane sottomarine) relativamente sottili scendono dal margine al centro di un bacino sedimentando e accumulando cosi progressivamente l'olistostroma. Al contrario della velocità di queste frane il fronte dell'olistostroma procede solo lentamente nel senso geologico. Il movimento interno delle colate è essenzialmente laminare e solo in parte turbulente. I contatti coi sedimenti al tetto e al letto degli olistostromi sono diversi e permettono di determinarne la polaritá verticale. La imbricazione osservabile nei piccoli olistoliti, può essere un utile mezzo per la determinazione della direzione di apporto del materiale. Vengono discusse le differenze litologiche e genetiche tra olistotromi e altri fenomeni somiglianti.

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Beobachtungen der Böigkeit des Windes in mittleren Turbulenzbereichen     

Univ.-Doz. Dr. Konrad Cehak 《Theoretical and Applied Climatology》1969,17(4):345-356

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Ground-Based and Airborne Measurements of Nonmethane Hydrocarbons in BERLIOZ: Analysis and Selected Results     

J. Winkler  P. Blank  K. Glaser  J. A. G. Gomes  M. Habram  C. Jambert  W. Jaeschke  S. Konrad  R. Kurtenbach  P. Lenschow  J. C. Lörzer  P. E. Perros  M. Pesch  H. J. Prümke  B. Rappenglück  Th. Schmitz  F. Slemr  A. Volz-Thomas  B. Wickert 《Journal of Atmospheric Chemistry》2002,42(1):465-492

During the Berlin Ozone Experiment BERLIOZ in July–August 1998 quasi-continuous measurements ofC₂–C₁₂ nonmethane hydrocarbons (NMHCs) were carried out at 10 sites in and around the city of Berlin using on-line gas-chromatographic systems (GCs) with a temporal resolution of 20–120 minutes. Additional airborne NMHCmeasurements were made using canister sampling on three aircraft and an on-line GC system on a fourth aircraft. The ground based data are analyzed to characterize the different sites and to identify the influence of emissions from Berlin on its surroundings. Benzene mixing ratios at the 4 rural sites were rather low (<0.5 ppbv). Berlin (and the surrounding highway ring) was identified as the main source of anthropogenic NMHCs at Eichstädt and Blossin, whilst other sources were important at the furthermost site Menz. The median toluene/benzene concentration ratio in Berlin was 2.3 ppbv/ppbv, agreeing well with measurements in other German cities. As expected, the ratios at the background sites decreased with increasing distance to Berlin and were usually around one or below. On 20 and 21 July, the three northwesterly sites were situated downwind of Berlin and thus were influenced by its emissions. Considering the distance between the sites and the windspeed, the city plume was observed at reasonable time scales, showing decreasing toluene/benzene ratios of 2.3, 1.6 and 1.3 with increasing distance from Berlin. Isoprene was the only biogenic NMHC measured at BERLIOZ. It was themost abundant compound at the background sites on the hotter days, dominating the local NMHC reactivity with averaged contributions to the total OH loss rate of 51% and 70% at Pabstthum and Blossin, respectively. Emissionratios (relative to CO and to the sum of analysed NMHCs) were derived from airborne measurements. The comparison with an emission inventory suggests traffic-related emissions to be the predominating source of the considered hydrocarbon species. Problems were identified with the emission inventory for propane, ethene and pentanes.  相似文献   

Estrogenic Activity and Volume Fraction of Waste Water Origin in Monitoring Wells Along the Santa Cruz River, Arizona     

David M. Quanrud  Konrad Quast  Otakuye Conroy  Martin M. Karpiscak  Charles P. Gerba  Kevin E. Lansey  Wendell P. Ela  Robert G. Arnold 《Ground Water Monitoring & Remediation》2004,24(2):86-93

The fate of estrogenic activity in waste water effluent was examined during surface transport and incidental recharge along the Santa Cruz River in Pima County, Arizona. Based on measurement of boron isotopes, the fractional contribution of reclaimed water in surface waters and ground water wells proximate to the river was determined for a contemporary sample set. Estrogenic activity decreased by −60% over the 25 mi length of the river below effluent discharge points in Tucson. In ground water samples obtained from monitoring wells that are proximate to the Santa Cruz River, both dissolved organic carbon ( p = 0.0003) and estrogenic activity ( p = 3 × 10⁻⁶) were highly correlated to fractional waste water content. Results indicate that proximate ground water quality is sensitive to incidental recharge of reclaimed water in the Santa Cruz River bed. In a few locations, little attenuation of estrogenic activity was apparent during percolation of effluent in the river channel to well withdrawal points.  相似文献   

Assessment of river habitat in Brandenburg, Germany     

Ulrich Kamp  Rainer Bock  Konrad Hlzl 《Limnologica》2004,34(3):176-186

A habitat assessment of 1,707 km of rivers in the Federal State of Brandenburg, Germany, was undertaken using the desk-based ‘overview method’. This method includes the analysis of different sources such as topographic and thematic maps, reports, remote sensing data, and interviews with authorities. It compares actual habitat conditions with natural conditions, and assesses the human disturbances using a seven-step scale. Results show, that in Brandenburg more than 50% of surveyed river units are heavily (class 5) to totally disturbed (class 7) and only slightly more than 20% are undisturbed (class 1) to little disturbed (class 2). Main human disturbances are canalization, bank stabilizations, flood control, migration barriers, and agricultural and urban development in the floodplain. All survey data and maps are embedded in a geographical information system (GIS) that not only allows future analysis and use in river restoration management by experts, but also serves as information for the public. The river habitat map of Brandenburg is part of the river habitat map of the entire Germany.  相似文献   

Book reviews     

Martin Kaehler  H. Haefner  S. J. Prinsenberg  Pierre Biays  Konrad Murr  W. U. Ehrmann  Gerd Lüttig  Alexander Zaporozec  Peter Schröder  T. Gold  G. R. Lewthwaite  H. Hecklau  Andreas Grotewold  T. H. Elkins  K. Strobach 《GeoJournal》1988,16(3):323-329

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In Memoriam Richard H. Jahns, 1915–1983     

Gordon E. Brown  Konrad B. Krauskopf  Gail A. Mahood  Irwin Remson 《Engineering Geology》1984,20(3):275-277

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Sub-surface precipitation of salts in supercritical seawater   总被引：2，自引：0，他引：2  

Martin Hovland  Tatyana Kuznetsova†  Håkon Rueslåtten‡  Bjørn Kvamme†  Hans Konrad Johnsen¶  Gunnar E. Fladmark§  Andreas Hebach† 《Basin Research》2006,18(2):221-230

Extremely low solubility of typical seawater salts within certain supercritical sections of their pressure–temperature composition space is a proven experimental fact. Its consequences are often referred to as either 'shock crystallization' or 'out-salting'. Our alternative model for the formation of salt deposits hypothesizes that high temperatures and pressures characteristic for the high heat-flow zones of tectonically active basins may bring submarine brines into the out-salting regions and result in the accumulation of geological-scale salt depositions.
To confirm the laboratory observations, molecular-scale simulations (molecular dynamics) have been employed to study structural changes in a model seawater system where temperature increased from ambient to near-critical and supercritical. Fluid properties and phase transition regions extracted from the simulations were then used as input parameters for a reservoir simulator program to model out-salting in a simple hydrothermal geological system. Both numerical simulations and laboratory experiments confirm that supercritical out-salting is a viable process of geological significance for the formation and accumulation of evaporites. We suggest two regions where hydrothermally associated salts may be depositing today: Atlantis II Deep, in the Red Sea, and Lake Asale, Ethiopia.  相似文献