TY  - JOUR
A1  - Saupe, Gabriele
A1  - Thieme, Siegfried
T1  - Rual areas in the land of Brandenburg - whatïs their future?
Y1  - 1992
ER  - 
TY  - GEN
A1  - Elsenbeer, Helmut
A1  - Cassel, Keith
A1  - Castro, Jorge
T1  - Spatial analysis of soil hydraulic conductivity in a tropical rain forest catchment
N2  - The topography of first-order catchments in a region of western Amazonia was found to exhibit distinctive, recurrent features: a steep, straight lower side slope, a flat or nearly flat terrace at an intermediate elevation between valley floor and interfluve, and an upper side slope connecting interfluve and intermediate terrace. A detailed survey of soil-saturated hydraulic conductivity (K sat)-depth relationships, involving 740 undisturbed soil cores, was conducted in a 0.75-ha first-order catchment. The sampling approach was stratified with respect to the above slope units. Exploratory data analysis suggested fourth-root transformation of batches from the 0–0.1 m depth interval, log transformation of batches from the subsequent 0.1 m depth increments, and the use of robust estimators of location and scale. The K sat of the steep lower side slope decreased from 46 to 0.1 mm/h over the overall sampling depth of 0.4 m. The corresponding decrease was from 46 to 0.1 mm/h on the intermediate terrace, from 335 to 0.01 mm/h on the upper side slope, and from 550 to 0.015 mm/h on the interfluve. A depthwise comparison of these slope units led to the formulation of several hypotheses concerning the link between K sat and topography.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 051 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16979
ER  - 
TY  - GEN
A1  - Elsenbeer, Helmut
A1  - Cassel, Keith
A1  - Tinner, W.
T1  - A daily rainfall erosivity model for Western Amazonia
N2  - Rainfall erosivities as defined by the R factor from the universal soil loss equation were determined for all events during a two-year period at the station La Cuenca in western Amazonia. Three methods based on a power relationship between rainfall amount and erosivity were then applied to estimate event and daily rainfall erosivities from the respective rainfall amounts. A test of the resulting regression equations against an independent data set proved all three methods equally adequate in predicting rainfall erosivity from daily rainfall amount. We recommend the Richardson model for testing in the Amazon Basin, and its use with the coefficient from La Cuenca in western Amazonia.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 050 
KW  - MESOSCALE CONVECTIVE COMPLEXES
KW  - KINETIC-ENERGY
KW  - UNITED-STATES
KW  - EROSION
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16962
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Relations across the boundaries between the old and the new Länder in Germany after reunification : which side makes more profit?
Y1  - 1994
ER  - 
TY  - GEN
A1  - Elsenbeer, Helmut
A1  - Cassel, Keith
A1  - Zuñiga, L.
T1  - Throughfall in the terra firme forest of Western Amazonia
N2  - Throughfall measurements were made under primary terra firme rainforest in the Rio Pichis valley, in the Upper Amazon Basin of Peru. Based on 214 precipitation events over nearly 18 months, throughfall was estimated to be 83.1±8.8% of gross precipitation. Regression analysis of all events revealed that gross precipitation is the only significant explanatory variable; the use of one-burst events does not significantly improve the regression relationship. Gross precipitation is, however, a poor predictor of throughfall for small rainfall events. The two forest structure parameters, canopy capacity, S, and free throughfall coefficient, p, were determined to be 1.3±0.2 mm and 0.32±0.18 mm. Rainfall intensity was found to influence these parameters. New methods which attempt to minimize the influence of meteorologic variables are used to estimate the potential values of these canopy parameters.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 049 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16955
ER  - 
TY  - GEN
A1  - Howald, Markus
A1  - Elsenbeer, Helmut
A1  - Laczko, Endre
A1  - Schlunegger, Urs Peter
T1  - Capillary electrophoresis as a fast and universal tool in soil analysis
N2  - Fast analysis of different species of molecules in soils is investigated by capillary electrophoresis (CE). Several CE techniques for the analysis of inorganic ions and carbohydrates have been tested. With regard to the intents of pedologists and the usually large number of soil analyses a bundle of CE systems is proposed, capable of effecting time-saving soil analyses. Adapted electrolyte systems recently published and new separation systems are described. Examples of the application of these methods to two different soil samples are presented.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 070 
KW  - capillary electrophoresis
KW  - soil analysis
KW  - UV-detection
KW  - inorganic ions
KW  - monosaccharides
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16913
ER  - 
TY  - GEN
A1  - Elsenbeer, Helmut
A1  - Lack, Andreas
A1  - Cassel, Keith
T1  - Chemical fingerprints of hydrological compartments and flow paths at La Cuenca, western Amazonia
N2  - A forested first-order catchment in western Amazonia was monitored for 2 years to determine the chemical fingerprints of precipitation, throughfall, overland flow, pipe flow, soil water, groundwater, and streamflow. We used five tracers (hydrogen, calcium, magnesium, potassium, and silica) to distinguish “fast” flow paths mainly influenced by the biological subsystem from “slow” flow paths in the geochemical subsystem. The former comprise throughfall, overland flow, and pipe flow and are characterized by a high potassium/silica ratio; the latter are represented by soil water and groundwater, which have a low potassium/silica ratio. Soil water and groundwater differ with respect to calcium and magnesium. The groundwater-controlled streamflow chemistry is strongly modified by contributions from fast flow paths during precipitation events. The high potassium/silica ratio of these flow paths suggests that the storm flow response at La Cuenca is dominated by event water.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 047 
KW  - Chemistry of fresh water
KW  - Runoff and streamflow
KW  - Weathering
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16937
ER  - 
TY  - GEN
A1  - Elsenbeer, Helmut
A1  - Lorieri, Daniel
A1  - Bonell, Mike
T1  - Mixing model approaches to estimate storm flow sources in an overland flow-dominated tropical rain forest catchment
N2  - Previous hydrometric studies demonstrated the prevalence of overland flow as a hydrological pathway in the tropical rain forest catchment of South Creek, northeast Queensland. The purpose of this study was to consider this information in a mixing analysis with the aim of identifying sources of, and of estimating their contribution to, storm flow during two events in February 1993. K and acid-neutralizing capacity (ANC) were used as tracers because they provided the best separation of the potential sources, saturation overland flow, soil water from depths of 0.3, 0.6, and 1.2 m, and hillslope groundwater in a two-dimensional mixing plot. It was necessary to distinguish between saturation overland flow, generated at the soil surface and following unchanneled pathways, and overland flow in incised pathways. This latter type of overland flow was a mixture of saturation overland flow (event water) with high concentrations of K and a low ANC, soil water (preevent water) with low concentrations of K and a low ANC, and groundwater (preevent water) with low concentrations of K and a high ANC. The same sources explained the streamwater chemistry during the two events with strongly differing rainfall and antecedent moisture conditions. The contribution of saturation overland flow dominated the storm flow during the first, high-intensity, 178-mm event, while the contribution of soil water reached 50% during peak flow of the second, low-intensity, 44-mm event 5 days later. This latter result is remarkably similar to soil water contributions to storm flow in mountainous forested catchments of the southeastern United States. In terms of event and preevent water the storm flow hydrograph of the high-intensity event is dominated by event water and that of the low-intensity event by preevent water. This study highlights the problems of applying mixing analyses to overland flow-dominated catchments and soil environments with a poorly developed vertical chemical zonation and emphasizes the need for independent hydrometric information for a complete characterization of watershed hydrology and chemistry.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 048 
KW  - SOILWATER END-MEMBERS
KW  - HYDROGRAPH SEPARATION
KW  - STREAMWATER CHEMISTRY
KW  - ACIDIFICATION
KW  - MIXTURE
KW  - TRACERS
KW  - EVENTS
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16948
ER  - 
TY  - JOUR
A1  - Blumenstein, Oswald
T1  - Geoecolocigal problems in the use of morphostructural features in the young moraine area SW Berlin
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Bork, Hans-Rudolf
A1  - Lavee, Hanoch
A1  - Dalchow, Claus
A1  - Bork, Helga
T1  - Development of the western judean desert during the holocene
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Lavee, Hanoch
A1  - Imeson, A.
A1  - Bork, Hans-Rudolf
A1  - Shoshani, M.
A1  - Kutiel, P.
A1  - Benyamin, Yves
A1  - Sarah, P.
T1  - Eco-geomorphic systems along a climatic gradient
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
T1  - Migration and remittances : recent evidence from Kabara Island, Fiji
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Leinweber, Peter
A1  - Blumenstein, Oswald
T1  - Soil organic matter composition in sewage farms soils : investigations by carbon-13 NMR and pyrolysis-field ionization mass spectrometry
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Bork, Hans-Rudolf
A1  - Darchow, Claus
A1  - Schatz, Thomas
A1  - Freilinghaus, Monika
A1  - Höhn, Axel
A1  - Schmidt, R.
T1  - The Soil and Sediment Profile Bäckerweg in the Natural Reserve "Märkische Schweiz", east-Brandenburg, Germany
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Dalchow, Claus
A1  - Bork, Hans-Rudolf
T1  - Landscapes of Northeastern Germany
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - The non agricultural economy of rural post-socialist romania : insights ans perceptions of national, regional ans local institutions and experts
Y1  - 1998
ER  - 
TY  - BOOK
ED  - Heller, Wilfried
T1  - Romania : migration, socio-economic transformation and perspectives of regional development
T3  - Südosteuropa-Studien
Y1  - 1998
SN  - 3-925450-75-0
VL  - 62
PB  - Südosteuropa-Ges
CY  - München
ER  - 
TY  - JOUR
A1  - Mignemi, Salvatore
A1  - Schmidt, Hans-Jürgen
T1  - Classification of multidimensional inflationary models
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Asche, Hartmut
T1  - Mapping and map use in the age of information technology
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Transformation : current importance of the subject, open questions and research deficits
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Experiences and assessments of the transformation from private households point of view
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Introduction : migration, socio-economic transformation and perspectives of regional development in the rural areas of romania ; report on a German - Romanian reseach project
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Migration, socio-economic transformation and perspectives of regional development
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
T1  - Migration and socio-economic transformation in South-East-Europe since 1990 and perspectives of regional development: Romania as an exemple
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Werner, A.
A1  - Bork, Hans-Rudolf
T1  - Integrating diverging orientors : sustainable agriculture ; ecological targets and future land use
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Barsch, Heiner
A1  - Blumenstein, Oswald
A1  - Schubert, Rudolf
T1  - The case of sewage farms south of Berlin
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
T1  - Spatial population mobility as social interaction : A Fijian Island's multi-local village community
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Summary of part I: Objectives and perspectives of the transborder cooperation
Y1  - 1999
ER  - 
TY  - BOOK
ED  - Bronstert, Axel
ED  - Bismuth, Christine
ED  - Menzel, Lucas
T1  - European Conference on Advances in Flood Research : proceedings
T3  - Potsdam-Institut für Klimafolgenforschung: PIK report
Y1  - 2000
VL  - 65
PB  - Potsdam Inst. for Climate Impact Research
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Fritsch, Uta
A1  - Katzenmaier, Daniel
A1  - Bismuth, Christine
T1  - Quantification of the influence of the land-surface and river training on flood discharge of the Rhine Basin
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Krol, Marten S.
A1  - Jaeger, Annekathrin
T1  - WAVES : water availability, vulnerability of ecosystems and society in northeast brazil ; an overview of the interdisciplinary project and integrated modelling
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Blumenstein, Oswald
T1  - Investigation of Environmental Quality and Social Structures in a Mining Area in the North West Province of South Africa
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Fritsch, Uta
A1  - Katzenmaier, Daniel
A1  - Bronstert, Axel
T1  - Land-use and land-cover scenarios for flood risk analysis and river basin management
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Katzenmaier, Daniel
A1  - Fritsch, Uta
A1  - Bronstert, Axel
T1  - Influences of land-use and land-cover changes on storm-runoff generation
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
T1  - The possible impacts of environmental changes on flood formation : relevant processes and model requirements
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Menzel, Lucas
A1  - Bronstert, Axel
A1  - Bürger, Gerd
A1  - Krysanova, Valentina
T1  - Environmental change scenarios and flood responses in the Elbe catchment (Germany)
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Kundzewicz, Zbigniew W.
A1  - Menzel, Lucas
T1  - Achievements and future needs towards improved flood protection in the Oder river basin : results of the EU- expert meeting on the Oder flood in Summer '97
Y1  - 2000
SN  - 0-7923-6451-1, 0-7923-6452-X
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Güntner, Andreas
T1  - A large-scale hydrological model for the semi-arid environment of north-eastern Brazil
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Burkart, Michael
A1  - Itzerott, Sibylle
A1  - Zebisch, Marc
T1  - Classification of vegetation by chronosequences of NDVI from remote sensing and field data : the example of Uvs Nuur basin
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
A1  - Felgentreff, Carsten
T1  - On the study of socio-economic transformation and migration in rural areas of post-socialist countries
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Geldmacher, Karl
A1  - Schaphoff, Sibyll
A1  - Woithe, Franka
A1  - Bork, Hans-Rudolf
T1  - Landscape Development and Land Use in the Pacific Nothwest (USA)
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
T1  - Impact of the 1997 Odra Flood on Flood Protection in Brandenburg (FRG) : the Dyke broke, but the local People's Trust in technical Solutions remained unbroken
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Bárdossy, Andras
A1  - Bronstert, Axel
A1  - Buiteveld, Hendrik
A1  - Disse, Markus
A1  - Fritsch, Uta
A1  - Katzenmaier, Daniel
A1  - Lammersen, Rita
T1  - Influence of the land surface and river training on flood conditions in the Rhine basin
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Niehoff, Daniel
A1  - Bronstert, Axel
T1  - Influences of land-use and land-surface conditions on flood generation : a simulation study
Y1  - 2000
ER  - 
TY  - THES
A1  - Weisheimer, Antje
T1  - Niederfrequente Variabilität großräumiger atmosphärischer Zirkulationsstrukturen in spektralen Modellen niederer Ordnung = Ultra-flow-frequency variability of large scale atmospheric circulation patterns in spectral low-order models
T2  - Berichte zur Polarforschung
Y1  - 2000
SN  - 0176-5027
VL  - 356
PB  - Alfred-Wegener-Inst. für Polar- und Meeresforschung
CY  - Bremen
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
A1  - Heller, Wilfried
A1  - Lindner, Waltraud
A1  - Thieme, Siegfried
A1  - Viehrig, Hans
T1  - Socio-Economic Transformation of East Germany
Y1  - 2000
ER  - 
TY  - BOOK
ED  - Blumenstein, Oswald
ED  - Meiklejohn, I.
ED  - Schachtzabel, Hartmut
T1  - Investigation of environmental quality and social structures in a mining area in the north west province of south africa
T3  - Stoffdynamik in Geosystemen
Y1  - 2001
SN  - 0949-4731
VL  - 5
PB  - Selbstverl. der Arbeitsgruppe Stoffdynamik in Geosystemen
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Helms, Gesa
T1  - Glasgow : the friendly city, the safe city ; an agency orienated enquiry into the practies of place marketing, safety and social inclusion
T3  - Praxis Kultur- und Sozialgeographie
Y1  - 2001
SN  - 3-935024-21-5
SN  - 0934-716x
VL  - 23
PB  - Univ.-Bibliothek Publ.-Stelle
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
T1  - The role of infiltration conditions for storm runoff generation at the hillslope and small catchment scale
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Herzig, Reinhard
T1  - Evaluation of cartographic educational software for children
Y1  - 2001
SN  - 7-5030-1018- 5
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Menzel, Lucas
A1  - Middelkoop, H.
A1  - de Roo, A. P.
A1  - Van Beek, E.
T1  - River basin research and management : integrated modelling and investigation of land-use impacts on the hydrological cycle
Y1  - 2001
ER  - 
TY  - THES
A1  - Müller-Wohlfeil, Dirk-Ingmar
T1  - Model frameworks for the calculation of annual runoff and nitrogen emission from danish catchments
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Güntner, Andreas
A1  - Bronstert, Axel
T1  - Modelling the effects of climate change on water availability in the semi-arid of North-East Brazil
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Krol, Marten S.
A1  - Jaeger, Annekathrin
A1  - Bronstert, Axel
A1  - Krywkow, J.
T1  - The Semi-arid Integrated Model (SIM), a regional integrated model assessing water availability, vulnerability of ecosystems and society in NE-Brazil
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Niehoff, Daniel
A1  - Bronstert, Axel
T1  - Influences of land-use and land-surface conditions on flood generation : a simulation study
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Güntner, Andreas
A1  - Olsson, J.
A1  - Calver, Ann
A1  - Gannon, B.
T1  - Cascade-based disaggregation of continuous rainfall time series : the influence of climate
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
A1  - Felgentreff, Carsten
A1  - Lindner, Waltraud
A1  - Saupe, Gabriele
T1  - Entrepreneurial initiative and regional development : supporting policies in the Land of Brandenburg
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Güntner, Andreas
A1  - Bronstert, Axel
T1  - WAVES - Water availability, vulnerability of ecosystems and society in the northeast of Brazil : sub-project large-scale hydrological modelling
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Asche, Hartmut
A1  - Hermann, Christian
T1  - Thematic cartography
Y1  - 2001
SN  - 0-7506-4996-8
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Socio-economic transformation in rural romania through the eyes of experts : migration and social-demographic issues
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Studies on boundaries : subjects, questions, targets
Y1  - 2001
ER  - 
TY  - BOOK
A1  - Kundzewicz, Zbigniew W.
A1  - Budhakooncharoen, Saisunee
A1  - Bronstert, Axel
A1  - Hoff, Holger
A1  - Lettenmaier, Dennis P.
A1  - Menzel, Lucas
A1  - Schulze, Roland
T1  - Floods and droughts : coping with variability and climate change ; thematic backround paper [for the International Conference on Freshwater 2001, Bonn, 3-7 December 2001]
Y1  - 2001
UR  - http://www.water-2001.de/co_doc/Floods.pdf
PB  - Secretariat of the International Conference on Freshwater
CY  - Bonn
ER  - 
TY  - JOUR
A1  - Blumenstein, Oswald
T1  - First Results of Soil Investigation
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Kundzewicz, Zbigniew W.
A1  - Budhakooncharoen, Saisunee
A1  - Bronstert, Axel
A1  - Hoff, Holger
A1  - Lettenmaier, Dennis P.
A1  - Menzel, Lucas
A1  - Schulze, Roland
T1  - Coping with variability and climate change : floods and droughts
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Blumenstein, Oswald
T1  - Preface
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Blumenstein, Oswald
A1  - Bukowsky, Heinz
A1  - Kraudelt, Heide
A1  - Cerovsky, D.
T1  - First Results of Soil Investigations in a Mining Area of South Africa
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Jessel, Beate
T1  - Turner, M. G., Landscape ecology in theory and practice : pattern and process; New York, Springer, 2001
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Niehoff, Daniel
A1  - Bürger, Gerd
T1  - Effects of climate and land-use change on storm runoff generation : present knowledge and modelling capabilities
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Menzel, Lucas
A1  - Niehoff, Daniel
A1  - Bürger, Gerd
A1  - Bronstert, Axel
T1  - Climate change impacts on river flooding : a modelling study of three meso-scale catchments
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - Spatial development of the economy and spatial mobility in post-socialist Romania
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Niehoff, Daniel
A1  - Fritsch, Uta
A1  - Bronstert, Axel
T1  - Land-use impacts on storm-runoff generation : scenarios of land-use change and simulation of hydrological response in a meso-scale catchment in SW-Germany
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Krol, Marten S.
A1  - Jaeger, Annekathrin
A1  - Güntner, Andreas
T1  - Integrated modelling of climate, water, soil, agricultural and socio-economic processes : a general introduction to the methodology and some exemplary results from the semi-arid Northeast of Brazil
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Szaramowicz, Martin
T1  - Krönert, R. (Hrsg.): Landscape Balance and Landscape Assessment; Berlin, Springer, 2001
BT  - Landscape Balance and Landscape Assessment
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Güntner, Andreas
A1  - Bronstert, Axel
T1  - Process-based modelling of large-scale water availability in a semi-arid environment : process representation and scaling issues
Y1  - 2002
ER  - 
TY  - THES
A1  - Güntner, Andreas
T1  - Large-scale hydrological modelling in the semi-arid north-east of Brazil
N2  - Semi-arid areas are, due to their climatic setting, characterized by small water resources. An increasing water demand as a consequence of population growth and economic development as well as a decreasing water availability in the course of possible climate change may aggravate water scarcity in future, which often exists already for present-day conditions in these areas. Understanding the mechanisms and feedbacks of complex natural and human systems, together with the quantitative assessment of future changes in volume, timing and quality of water resources are a prerequisite for the development of sustainable measures of water management to enhance the adaptive capacity of these regions. For this task, dynamic integrated models, containing a hydrological model as one component, are indispensable tools. The main objective of this study is to develop a hydrological model for the quantification of water availability in view of environmental change over a large geographic domain of semi-arid environments. The study area is the Federal State of Ceará (150 000 km2) in the semi-arid north-east of Brazil. Mean annual precipitation in this area is 850 mm, falling in a rainy season with duration of about five months. Being mainly characterized by crystalline bedrock and shallow soils, surface water provides the largest part of the water supply. The area has recurrently been affected by droughts which caused serious economic losses and social impacts like migration from the rural regions.  The hydrological model Wasa (Model of Water Availability in Semi-Arid Environments) developed in this study is a deterministic, spatially distributed model being composed of conceptual, process-based approaches. Water availability (river discharge, storage volumes in reservoirs, soil moisture) is determined with daily resolution. Sub-basins, grid cells or administrative units (municipalities) can be chosen as spatial target units. The administrative units enable the coupling of Wasa in the framework of an integrated model which contains modules that do not work on the basis of natural spatial units. The target units mentioned above are disaggregated in Wasa into smaller modelling units within a new multi-scale, hierarchical approach. The landscape units defined in this scheme capture in particular the effect of structured variability of terrain, soil and vegetation characteristics along toposequences on soil moisture and runoff generation. Lateral hydrological processes at the hillslope scale, as reinfiltration of surface runoff, being of particular importance in semi-arid environments, can thus be represented also within the large-scale model in a simplified form. Depending on the resolution of available data, small-scale variability is not represented explicitly with geographic reference in Wasa, but by the distribution of sub-scale units and by statistical transition frequencies for lateral fluxes between these units. Further model components of Wasa which respect specific features of semi-arid hydrology are:  (1) A two-layer model for evapotranspiration comprises energy transfer at the soil surface (including soil evaporation), which is of importance in view of the mainly sparse vegetation cover. Additionally, vegetation parameters are differentiated in space and time in dependence on the occurrence of the rainy season.  (2) The infiltration module represents in particular infiltration-excess surface runoff as the dominant runoff component.  (3) For the aggregate description of the water balance of reservoirs that cannot be represented explicitly in the model, a storage approach respecting different reservoirs size classes and their interaction via the river network is applied.  (4) A model for the quantification of water withdrawal by water use in different sectors is coupled to Wasa.  (5) A cascade model for the temporal disaggregation of precipitation time series, adapted to the specific characteristics of tropical convective rainfall, is applied for the generating rainfall time series of higher temporal resolution. All model parameters of Wasa can be derived from physiographic information of the study area. Thus, model calibration is primarily not required. Model applications of Wasa for historical time series generally results in a good model performance when comparing the simulation results of river discharge and reservoir storage volumes with observed data for river basins of various sizes. The mean water balance as well as the high interannual and intra-annual variability is reasonably represented by the model. Limitations of the modelling concept are most markedly seen for sub-basins with a runoff component from deep groundwater bodies of which the dynamics cannot be satisfactorily represented without calibration. Further results of model applications are: (1) Lateral processes of redistribution of runoff and soil moisture at the hillslope scale, in particular reinfiltration of surface runoff, lead to markedly smaller discharge volumes at the basin scale than the simple sum of runoff of the individual sub-areas. Thus, these processes are to be captured also in large-scale models. The different relevance of these processes for different conditions is demonstrated by a larger percentage decrease of discharge volumes in dry as compared to wet years. (2) Precipitation characteristics have a major impact on the hydrological response of semi-arid environments. In particular, underestimated rainfall intensities in the rainfall input due to the rough temporal resolution of the model and due to interpolation effects and, consequently, underestimated runoff volumes have to be compensated in the model. A scaling factor in the infiltration module or the use of disaggregated hourly rainfall data show good results in this respect. The simulation results of Wasa are characterized by large uncertainties. These are, on the one hand, due to uncertainties of the model structure to adequately represent the relevant hydrological processes. On the other hand, they are due to uncertainties of input data and parameters particularly in view of the low data availability. Of major importance is: (1) The uncertainty of rainfall data with regard to their spatial and temporal pattern has, due to the strong non-linear hydrological response, a large impact on the simulation results. (2) The uncertainty of soil parameters is in general of larger importance on model uncertainty than uncertainty of vegetation or topographic parameters. (3) The effect of uncertainty of individual model components or parameters is usually different for years with rainfall volumes being above or below the average, because individual hydrological processes are of different relevance in both cases. Thus, the uncertainty of individual model components or parameters is of different importance for the uncertainty of scenario simulations with increasing or decreasing precipitation trends. (4) The most important factor of uncertainty for scenarios of water availability in the study area is the uncertainty in the results of global climate models on which the regional climate scenarios are based. Both a marked increase or a decrease in precipitation can be assumed for the given data. Results of model simulations for climate scenarios until the year 2050 show that a possible future change in precipitation volumes causes a larger percentage change in runoff volumes by a factor of two to three. In the case of a decreasing precipitation trend, the efficiency of new reservoirs for securing water availability tends to decrease in the study area because of the interaction of the large number of reservoirs in retaining the overall decreasing runoff volumes.
N2  - Semiaride Gebiete sind auf Grund der klimatischen Bedingungen durch geringe Wasserressourcen gekennzeichnet. Ein zukünftig steigender Wasserbedarf in Folge von Bevölkerungswachstum und ökonomischer Entwicklung sowie eine geringere Wasserverfügbarkeit durch mögliche Klimaänderungen können dort zu einer Verschärfung der vielfach schon heute auftretenden Wasserknappheit führen. Das Verständnis der Mechanismen und Wechselwirkungen des komplexen Systems von Mensch und Umwelt sowie die quantitative Bestimmung zukünftiger Veränderungen in der Menge, der zeitlichen Verteilung und der Qualität von Wasserressourcen sind eine grundlegende Voraussetzung für die Entwicklung von nachhaltigen Maßnahmen des Wassermanagements mit dem Ziel einer höheren Anpassungsfähigkeit dieser Regionen gegenüber künftigen Änderungen. Hierzu sind dynamische integrierte Modelle unerlässlich, die als eine Komponente ein hydrologisches Modell beinhalten.  Vorrangiges Ziel dieser Arbeit ist daher die Erstellung eines hydrologischen Modells zur großräumigen Bestimmung der Wasserverfügbarkeit unter sich ändernden Umweltbedingungen in semiariden Gebieten. Als Untersuchungsraum dient der im semiariden tropischen Nordosten Brasiliens gelegene Bundestaat Ceará (150 000 km2). Die mittleren Jahresniederschläge in diesem Gebiet liegen bei 850 mm innerhalb einer etwa fünfmonatigen Regenzeit. Mit vorwiegend kristallinem Grundgebirge und geringmächtigen Böden stellt Oberflächenwasser den größten Teil der Wasserversorgung bereit. Die Region war wiederholt von Dürren betroffen, die zu schweren ökonomischen Schäden und sozialen Folgen wie Migration aus den ländlichen Gebieten geführt haben.  Das hier entwickelte hydrologische Modell Wasa (Model of Water Availability in Semi-Arid Environments) ist ein deterministisches, flächendifferenziertes Modell, das aus konzeptionellen, prozess-basierten Ansätzen aufgebaut ist. Die Wasserverfügbarkeit (Abfluss im Gewässernetz, Speicherung in Stauseen, Bodenfeuchte) wird mit täglicher Auflösung bestimmt. Als räumliche Zieleinheiten können Teileinzugsgebiete, Rasterzellen oder administrative Einheiten (Gemeinden) gewählt werden. Letztere ermöglichen die Kopplung des Modells im Rahmen der integrierten Modellierung mit Modulen, die nicht auf der Basis natürlicher Raumeinheiten arbeiten. Im Rahmen eines neuen skalenübergreifenden, hierarchischen Ansatzes werden in Wasa die genannten Zieleinheiten in kleinere räumliche Modellierungseinheiten unterteilt. Die ausgewiesenen Landschaftseinheiten erfassen insbesondere die strukturierte Variabilität von Gelände-, Boden- und Vegetationseigenschaften entlang von Toposequenzen in ihrem Einfluss auf Bodenfeuchte und Abflussbildung. Laterale hydrologische Prozesse auf kleiner Skala, wie die für semiaride Bedingungen bedeutsame Wiederversickerung von Oberflächenabfluss, können somit auch in der erforderlichen großskaligen Modellanwendung vereinfacht wiedergegeben werden. In Abhängigkeit von der Auflösung der verfügbaren Daten wird in Wasa die kleinskalige Variabilität nicht räumlich explizit sondern über die Verteilung von Flächenanteilen subskaliger Einheiten und über statistische Übergangshäufigkeiten für laterale Flüsse zwischen den Einheiten berücksichtigt. Weitere Modellkomponenten von Wasa, die spezifische Bedingungen semiarider Gebiete berücksichtigen, sind:  (1) Ein Zwei-Schichten-Modell zur Bestimmung der Evapotranspiration berücksichtigt auch den Energieumsatz an der Bodenoberfläche (inklusive Bodenverdunstung), der in Anbetracht der meist lichten Vegetationsbedeckung von Bedeutung ist. Die Vegetationsparameter werden zudem flächen- und zeitdifferenziert in Abhängigkeit vom Auftreten der Regenzeit modifiziert.  (2) Das Infiltrationsmodul bildet insbesondere Oberflächenabfluss durch Infiltrationsüberschuss als dominierender Abflusskomponente ab.  (3) Zur aggregierten Beschreibung der Wasserbilanz von im Modell nicht einzeln erfassbaren Stauseen wird ein Speichermodell unter Berücksichtigung verschiedener Größenklassen und ihrer Interaktion über das Gewässernetz eingesetzt.  (4) Ein Modell zur Bestimmung der Entnahme durch Wassernutzung in verschiedenen Sektoren ist an Wasa gekoppelt.  (5) Ein Kaskadenmodell zur zeitlichen Disaggregierung von Niederschlagszeitreihen, das in dieser Arbeit speziell für tropische konvektive Niederschlagseigenschaften angepasst wird, wird zur Erzeugung höher aufgelöster Niederschlagsdaten verwendet. Alle Modellparameter von Wasa können von physiographischen Gebietsinformationen abgeleitet werden, sodass eine Modellkalibrierung primär nicht erforderlich ist.  Die Modellanwendung von Wasa für historische Zeitreihen ergibt im Allgemeinen eine gute Übereinstimmung der Simulationsergebnisse für Abfluss und Stauseespeichervolumen mit Beobachtungsdaten in unterschiedlich großen Einzugsgebieten. Die mittlere Wasserbilanz sowie die hohe monatliche und jährliche Variabilität wird vom Modell angemessen wiedergegeben. Die Grenzen der Anwendbarkeit des Modell-konzepts zeigen sich am deutlichsten in Teilgebieten mit Abflusskomponenten aus tieferen Grundwasserleitern, deren Dynamik ohne Kalibrierung nicht zufriedenstellend abgebildet werden kann. Die Modellanwendungen zeigen weiterhin: (1) Laterale Prozesse der Umverteilung von Bodenfeuchte und Abfluss auf der Hangskala, vor allem die Wiederversickerung von Oberflächenabfluss, führen auf der Skala von Einzugsgebieten zu deutlich kleineren Abflussvolumen als die einfache Summe der Abflüsse der Teilflächen. Diese Prozesse sollten daher auch in großskaligen Modellen abgebildet werden. Die unterschiedliche Ausprägung dieser Prozesse für unterschiedliche Bedingungen zeigt sich an Hand einer prozentual größeren Verringerung der Abflussvolumen in trockenen im Vergleich zu feuchten Jahren. (2) Die Niederschlagseigenschaften haben einen sehr großen Einfluss auf die hydrologische Reaktion in semiariden Gebieten. Insbesondere die durch die grobe zeitliche Auflösung des Modells und durch Interpolationseffekte unterschätzten Niederschlagsintensitäten in den Eingangsdaten und die daraus folgende Unterschätzung von Abflussvolumen müssen im Modell kompensiert werden. Ein Skalierungsfaktor in der Infiltrationsroutine oder die Verwendung disaggregierter stündlicher Niederschlagsdaten zeigen hier gute Ergebnisse. Die Simulationsergebnisse mit Wasa sind insgesamt durch große Unsicherheiten gekennzeichnet. Diese sind einerseits in Unsicherheiten der Modellstruktur zur adäquaten Beschreibung der relevanten hydrologischen Prozesse begründet, andererseits in Daten- und Parametersunsicherheiten in Anbetracht der geringen Datenverfügbarkeit. Von besonderer Bedeutung ist:  (1) Die Unsicherheit der Niederschlagsdaten in ihrem räumlichen Muster und ihrer zeitlichen Struktur hat wegen der stark nicht-linearen hydrologischen Reaktion einen großen Einfluss auf die Simulationsergebnisse. (2) Die Unsicherheit von Bodenparametern hat im Vergleich zu Vegetationsparametern und topographischen Parametern im Allgemeinen einen größeren Einfluss auf die Modellunsicherheit. (3) Der Effekt der Unsicherheit einzelner Modellkomponenten und -parameter ist für Jahre mit unter- oder überdurchschnittlichen Niederschlagsvolumen zumeist unterschiedlich, da einzelne hydrologische Prozesse dann jeweils unterschiedlich relevant sind. Die Unsicherheit einzelner Modellkomponenten- und parameter hat somit eine unterschiedliche Bedeutung für die Unsicherheit von Szenarienrechnungen mit steigenden oder fallenden Niederschlagstrends. (4) Der bedeutendste Unsicherheitsfaktor für Szenarien der Wasserverfügbarkeit für die Untersuchungsregion ist die Unsicherheit der den regionalen Klimaszenarien zu Grunde liegenden Ergebnisse globaler Klimamodelle. Eine deutliche Zunahme oder Abnahme der Niederschläge bis 2050 kann gemäß den hier vorliegenden Daten für das Untersuchungsgebiet gleichermaßen angenommen werden. Modellsimulationen für Klimaszenarien bis zum Jahr 2050 ergeben, dass eine mögliche zukünftige Veränderung der Niederschlagsmengen zu einer prozentual zwei- bis dreifach größeren Veränderung der Abflussvolumen führt. Im Falle eines Trends von abnehmenden Niederschlagsmengen besteht in der Untersuchungsregion die Tendenz, dass auf Grund der gegenseitigen Beeinflussung der großen Zahl von Stauseen beim Rückhalt der tendenziell abnehmenden Abflussvolumen die Effizienz von neugebauten Stauseen zur Sicherung der Wasserverfügbarkeit zunehmend geringer wird.
KW  - Ceará / Semiarides Gebiet / Wasserreserve / Hydrologie / Mathematisches Modell
KW  - Hydrologie
KW  - Wasserverfügbarkeit
KW  - Klimaänderung
KW  - Niederschlag-Abfluss-Modellierung
KW  - Trockengebiet
KW  - semi-arid
KW  - Unsicherheiten
KW  - Brasilien
KW  - hydrology
KW  - water availability
KW  - climate change
KW  - rainfall-runoff modelling
KW  - drylands
KW  - semi-arid
KW  - uncertainties
KW  - Brazil
Y1  - 2002
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0000511
ER  - 
TY  - THES
A1  - Schaber, Jörg
T1  - Phenology in Germany in the 20th century : methods, analyses and models
N2  - Die Länge der Vegetationsperiode (VP) spielt eine zentrale Rolle für die interannuelle Variation der Kohlenstoffspeicherung terrestrischer Ökosysteme. Die Analyse von Beobachtungsdaten hat gezeigt, dass sich die VP in den letzten Jahrzehnten in den nördlichen Breiten verlängert hat. Dieses Phänomen wurde oft im Zusammenhang mit der globalen Erwärmung diskutiert, da die Phänologie von der Temperatur beeinflusst wird.  Die Analyse der Pflanzenphänologie in Süddeutschland im 20. Jahrhundert zeigte: - Die starke Verfrühung der Frühjahrsphasen in dem Jahrzehnt vor 1999 war kein singuläres Ereignis im 20. Jahrhundert. Schon in früheren Dekaden gab es ähnliche Trends. Es konnten Perioden mit unterschiedlichem Trendverhalten identifiziert werden. - Es gab deutliche Unterschiede in den Trends von frühen und späten Frühjahrsphasen. Die frühen Frühjahrsphasen haben sich stetig verfrüht, mit deutlicher Verfrühung zwischen 1931 und 1948, moderater Verfrühung zwischen 1948 und 1984 und starker Verfrühung zwischen 1984 und 1999. Die späten Frühjahrsphasen hingegen, wechselten ihr Trendverhalten in diesen Perioden von einer Verfrühung zu einer deutlichen Verspätung wieder zu einer starken Verfrühung.  Dieser Unterschied in der Trendentwicklung zwischen frühen und späten Frühjahrsphasen konnte auch für ganz Deutschland in den Perioden 1951 bis 1984 und 1984 bis 1999 beobachtet werden. Der bestimmende Einfluss der Temperatur auf die Frühjahrsphasen und ihr modifizierender Einfluss auf die Herbstphasen konnte bestätigt werden. Es zeigt sich jedoch, dass  - die Phänologie bestimmende Funktionen der Temperatur nicht mit einem globalen jährlichen CO2 Signal korreliert waren, welches als Index für die globale Erwärmung verwendet wurde - ein Index für grossräumige regionale Zirkulationsmuster (NAO-Index) nur zu einem kleinen Teil die beobachtete phänologischen Variabilität erklären konnte.  Das beobachtete unterschiedliche Trendverhalten zwischen frühen und späten Frühjahrsphasen konnte auf die unterschiedliche Entwicklung von März- und Apriltemperaturen zurückgeführt werden. Während sich die Märztemperaturen im Laufe des 20. Jahrhunderts mit einer zunehmenden Variabilität in den letzten 50 Jahren stetig erhöht haben, haben sich die Apriltemperaturen zwischen dem Ende der 1940er und Mitte der 1980er merklich abgekühlt und dann wieder deutlich erwärmt. Es wurde geschlussfolgert, dass die Verfrühungen in der Frühjahrsphänologie in den letzten Dekaden Teile multi-dekadischer Fluktuationen sind, welche sich nach Spezies und relevanter saisonaler Temperatur unterscheiden. Aufgrund dieser Fluktuationen konnte kein Zusammenhang mit einem globalen Erwärmungsignal gefunden werden. Im Durchschnitt haben sich alle betrachteten Frühjahrsphasen zwischen 1951 und 1999 in Naturräumen in Deutschland zwischen 5 und 20 Tagen verfrüht. Ein starker Unterschied in der Verfrühung zwischen frühen und späten Frühjahrsphasen liegt an deren erwähntem unterschiedlichen Verhalten. Die Blattverfärbung hat sich zwischen 1951 und 1999 für alle Spezies verspätet, aber nach 1984 im Durchschnitt verfrüht. Die VP hat sich in Deutschland zwischen 1951 und 1999 um ca. 10 Tage verlängert. Es ist hauptsächlich die Änderung in den Frühjahrphasen, die zu einer Änderung in der potentiell absorbierten Strahlung (PAS) führt. Darüber hinaus sind es die späten Frühjahrsphasen, die pro Tag Verfrühung stärker profitieren, da die zusätzlichen Tage länger undwärmer sind als dies für die frühen Phasen der Fall ist. Um die relative Änderung in PAS im Vergleich der Spezies abzuschätzen, müssen allerdings auch die Veränderungen in den Herbstphasen berücksichtigt werden. Der deutliche Unterschied zwischen frühen und späten Frühjahrsphasen konnte durch die Anwendung einer neuen Methode zur Konstruktion von Zeitreihen herausgearbeitet werden. Der neue methodische Ansatz erlaubte die Ableitung verlässlicher 100-jähriger Zeitreihen und die Konstruktion von lokalen kombinierten Zeitreihen, welche die Datenverfügbarkeit für die Modellentwicklung erhöhten. Ausser analysierten Protokollierungsfehlern wurden mikroklimatische, genetische und Beobachtereinflüsse als Quellen von Unsicherheit in phänologischen Daten identifiziert. Phänologischen Beobachtungen eines Ortes können schätzungsweise 24 Tage um das parametrische Mittel schwanken.Dies unterstützt die 30-Tage Regel für die Detektion von Ausreissern. Neue Phänologiemodelle, die den Blattaustrieb aus täglichen Temperaturreihen simulieren, wurden entwickelt. Diese Modelle basieren auf einfachen Interaktionen zwischen aktivierenden und hemmenden Substanzen, welche die Entwicklungsstadien einer Pflanze bestimmen. Im Allgemeinen konnten die neuen Modelle die Beobachtungsdaten besser simulieren als die klassischen Modelle.  Weitere Hauptresultate waren: - Der Bias der klassischen Modelle, d.h. Überschätzung von frühen und Unterschätzung von späten Beobachtungen, konnte reduziert, aber nicht vollständig eliminiert werden. - Die besten Modellvarianten für verschiedene Spezies wiesen darauf hin, dass für die späten Frühjahrsphasen die Tageslänge eine wichtigere Rolle spielt als für die frühen Phasen. - Die Vernalisation spielte gegenüber den Temperaturen kurz vor dem Blattaustrieb nur eine untergeordnete Rolle.
N2  - The length of the vegetation period (VP) plays a central role for the interannual variation of carbon fixation of terrestrial ecosystems. Observational data analysis has indicated that the length of the VP has increased in the last decades in the northern latitudes mainly due to an advancement of bud burst (BB). This phenomenon has been widely discussed in the context of Global Warming because phenology is correlated to temperatures.   Analyzing the patterns of spring phenology over the last century in Southern Germany provided two main findings: - The strong advancement of spring phases especially in the decade before 1999 is not a singular event in the course of the 20th century. Similar trends were also observed in earlier decades. Distinct periods of varying trend behavior for important spring phases could be distinguished. - Marked differences in trend behavior between the early and late spring phases were detected. Early spring phases changed as regards the magnitude of their negative trends from strong negative trends between 1931 and 1948 to moderate negative trends between 1948 and 1984 and back to strong negative trends between 1984 and 1999. Late spring phases showed a different behavior. Negative trends between 1931 and 1948 are followed by marked positive trends between 1948 and 1984 and then strong negative trends between 1984 and 1999. This marked difference in trend development between early and late spring phases was also found all over Germany for the two periods 1951 to 1984 and 1984 to 1999.  The dominating influence of temperature on spring phenology and its modifying effect on autumn phenology was confirmed in this thesis. However, - temperature functions determining spring phenology were not significantly correlated with a global annual CO2 signal which was taken as a proxy for a Global Warming pattern. - an index for large scale regional circulation patterns (NAO index) could only to a small part explain the observed phenological variability in spring.  The observed different trend behavior of early and late spring phases is explained by the differing behavior of mean March and April temperatures. Mean March temperatures have increased on average over the 20th century accompanied by an increasing variation in the last 50 years. April temperatures, however, decreased between the end of the 1940s and the mid-1980s, followed by a marked warming after the mid-1980s.  It can be concluded that the advancement of spring phenology in recent decades are part of multi-decadal fluctuations over the 20th century that vary with the species and the relevant seasonal temperatures. Because of these fluctuations a correlation with an observed Global Warming signal could not be found. On average all investigated spring phases advanced between 5 and 20 days between 1951 and 1999 for all Natural Regions in Germany. A marked difference be! tween late and early spring phases is due to the above mentioned differing behavior before and after the mid-1980s. Leaf coloring (LC) was delayed between 1951 and 1984 for all tree species. However, after 1984 LC was advanced. Length of the VP increased between 1951 and 1999 for all considered tree species by an average of ten days throughout Germany. It is predominately the change in spring phases which contributes to a change in the potentially absorbed radiation. Additionally, it is the late spring species that are relatively more favored by an advanced BB because they can additionally exploit longer days and higher temperatures per day advancement. To assess the relative change in potentially absorbed radiation among species, changes in both spring and autumn phenology have to be considered as well as where these changes are located in the year. For the detection of the marked difference between early and late spring phenology a new time series construction method was developed. This method allowed the derivation of reliable time series that spanned over 100 years and the construction of locally combined time series increasing the available data for model development. Apart from analyzed protocolling errors, microclimatic site influences, genetic variation and the observers were identified as sources of uncertainty of phenological observational data. It was concluded that 99% of all phenological observations at a certain site will vary within approximately 24 days around the parametric mean. This supports to the proposed 30-day rule to detect outliers.  New phenology models that predict local BB from daily temperature time series were developed. These models were based on simple interactions between inhibitory and promotory agents that are assumed to control the developmental status of a plant. Apart from the fact that, in general, the new models fitted and predicted the observations better than classical models, the main modeling results were:  - The bias of the classical models, i.e. overestimation of early observations and underestimation of late observations, could be reduced but not completely removed.  - The different favored model structures for each species indicated that for the late spring phases photoperiod played a more dominant role than for early spring phases.  - Chilling only plays a subordinate role for spring BB compared to temperatures directly preceding BB.
KW  - Phänologie
KW  - kombinierte Zeitreihen
KW  - Physiologie-basierte Modelle
KW  - Unsicherheit
KW  - Variabilität
KW  - Ausreisser
KW  - Trends
KW  - Naturräume
KW  - Trendwendepunkte
KW  - Fag
KW  - phenology
KW  - combined time series
KW  - physiology-based models
KW  - uncertainty
KW  - variability
KW  - outliers
KW  - trends
KW  - Natural Regions
KW  - trend turning points
KW  - Fagus syl
Y1  - 2002
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0000532
ER  - 
TY  - JOUR
A1  - Heller, Wilfried
T1  - European border cities in the process of radial change-new urban forms in the transition from national isolation to transnational networks
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Menzel, Lucas
T1  - Advances in Flood Research
Y1  - 2002
ER  - 
TY  - THES
A1  - Grimm, Volker
T1  - Bottom-up Simulation Modelling in Ecology : Strategies and Examples
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
T1  - Floods and climate change : interactions and impacts
Y1  - 2003
SN  - 0272-4332
ER  - 
TY  - BOOK
ED  - Heller, Wilfried
ED  - Felgentreff, Carsten
ED  - Lindner, Waltraud
T1  - The socio-economic transformation of rural areas in Russia and Moldova
T3  - Praxis Kultur- und Sozialgeographie
Y1  - 2003
SN  - 0934-716X
VL  - 28
PB  - Univ.-Bibl., Publ.-Stelle
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Jessel, Beate
A1  - Lahmer, Werner
A1  - Itzerott, Sibylle
A1  - Pfützner, Bernhard
T1  - Management in the Havel river basin : building up decision tools for spatial planning
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Günter, A.
A1  - Bronstert, Axel
T1  - Large-scale hydrological modelling of a semi-arid environment : model development, validation and application
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Bronstert, Axel
A1  - Bardossy, Andras
T1  - Uncertainty of runoff modelling at the hillslope scale due to temporal variations of rainfall intensity
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Krol, Marten S.
A1  - Jaeger, Annekathrin
A1  - Bronstert, Axel
T1  - Integrated modelling of climate change impacts in northeastern brazil
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Jessel, Beate
T1  - Helming, K. (Hrsg.), Sustainable Development of Multifunctional Landscapes; Berlin, Springer, 2003
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Rößling, Holger
T1  - Landscape ecology and environmental planning and assessment on a local and regional level
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Kühling, Matthias
A1  - Gzik, Axel
A1  - Schneider, Ingo
A1  - Tschochner, Bernd
T1  - Heavy metal contamination of soils in a mining area in South Africa and its impact on some biotic systems
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Felgentreff, Carsten
T1  - Post-Disaster Situations as "Windows of Opportunity"? Post-Flood Perceptions and Changes in the German Odra River Region after the 1997 Flood
Y1  - 2003
UR  - http://die-erde.de/2003-2Felgentreff.pdf
ER  - 
TY  - JOUR
A1  - Herzig, Reinhard
A1  - Jarausch, Helga
T1  - Development of Cartographic and Spatial Comprehension by Children : an Investigation about Barbara Petchenik Childrens Map Competition
N2  - The Barbara Petchenik Award was created by the International Cartographic Association in 1993. The aims of the competition are to promote childrens creative representation of the world, to enhance their cartographic awareness and to make them more conscious of their environment. Every two years a lot of children from all over the world take part in this competition. The national committee for organizing the competition in Germany collected and archieved all of the german entries since 1993. The evaluation of the childrens maps takes place continuous and get an insight into the cartogaphic and spatial comprehension of the children. The favourite subjects of the paintings depend on the age of children and current occurrences during the time of making the maps (map as document of the times). Designing an own map requires a good knowledge of cartographic rules. Therefor especially the creation of thematic maps shows very clear the stage of development of childrens cartographic education and spatial ideas. The connection of their selected subjects with the map design is very different. Either the most imaginative created subject in a way of a picture or the exact cartographic design comes to the fore. In some cases were noticed a very good combination between figurative and cartographic expression with a high harmony of a recognizable message and cartographic content. A development of cartographic and spatial comprehension in general can be seen, but the childrens maps waver between reality and fantasy.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Flögel, W.-A,
A1  - Märker, Michael
A1  - Moretti, S.
A1  - Rodolfi, G.
T1  - Integrating GIS, Remote Sensing, Ground Trouthing and Modelling Approaches for Regional Erosion Classification of semiarid catchments in South Africa and Swaziland
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Reineking, Björn
A1  - Schröder-Esselbach, Boris
T1  - Computer-intensive methods in the analysis of species-habitat relationships
Y1  - 2003
UR  - http://brandenburg.geoecology.uni-potsdam.de/users/schroeder/download/publications/ reineking_schroeder_aktheorie2003.pdf
ER  - 
TY  - JOUR
A1  - Rudner, Michael
A1  - Schröder-Esselbach, Boris
A1  - Biedermann, Robert
A1  - Müller, Mark
T1  - Habitat modelling in GIMOLUS - webGIS-based e-learning modules using logistic regression to assess species- habitat relationships
Y1  - 2003
UR  - http://brandenburg.geoecology.uni-potsdam.de/users/schroeder/download/publications/ rudner_schroeder_biedermann_mueller_agit2003.pdf
ER  - 
TY  - JOUR
A1  - Sidorchuk, A.
A1  - Märker, Michael
A1  - Moretti, S.
A1  - Rodolfi, G.
T1  - Gully erosion modelling and landscape response in the Mbuluzi River catchment of Swaziland
Y1  - 2003
SN  - 0341-8162
ER  - 
TY  - JOUR
A1  - Ochschild, V.
A1  - Staudenbrausch, H.
A1  - Märker, Michael
T1  - Detection of different land degradation stages in semi-arid grassland areas in Souhtern Africa
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Märker, Michael
A1  - Sidorchuk, A.
T1  - Assessment of gully erosion process dynamics for water resources management in a semiarid catchment of Swaziland, Southern Africa
Y1  - 2003
SN  - 1-901502-22-8
ER  - 
TY  - BOOK
A1  - Chen, Rui
A1  - Liu, Jiaqi
A1  - Niu, Wenyuan
A1  - Deng, Xiangzheng
A1  - Mu, Guijin
A1  - Wagner, Mayke
A1  - Geldmacher, Karl
T1  - Critical controlling of PRED system of oasis ecology in the arid region of central Asia : a case study of Keriya River Valley oases, Xinjiang
T3  - Ecosystems dynamics, ecosystem-society interactions, and remote sensing applications for semi-arid and arid land
N2  - Oases is a special ecosystem formed in arid climate and hungriness environment, in which resident, water and soil are the principal factor and exchanges of materials, energy and information are the main functional characteristics. The oases regions in central Asia are not only the basilic cradle of civilization of human beings, but also the important strategic places in world growing awareness of the potential benefits. We choose Keriya River Basin oases in south of Xinjiang as a case to study critical controlling of Oases Evolution, Based on the theories and methods used for environmental geology, physical geography, land resource research, and oases ecology. This study try to indicate the essential factors driving the oases ecosystem and the interactional dynamic mechanism in different scales and levels, confirm the optimal equilibrium aggregate of harmonious development between Population, Resources, Environment and Development, and establish the critical controlling pattern of sustainable development. We advance the indicator system to research the evolution of the PRED System of oases in Keriya River valley oases, in basis of the information derived from the field investigation and local materials. According to inquisitional result based on technical support of Geographic Information System (GIS) and Remote Sense (RS), the comparisons and analyses are carried out in land use at the upper reaches, vegetation change in the middle reaches, and desertification at the lower reaches, which narrates the regulations of Keriya River Valley oases land cover dynamic change. The main land cover types represent distinct characteristics of the local place. On the basis of field survey and statistical data, we use ARCINFO software to preprocess these data and the 2 TM satellite images. Through analyzing these images resulting from post- classification compare, we sums up the concrete quantificational dynamic distributed data of 13 land types covering a span of 15 years and regulation of the local ecological environment system. It finally points out that the trend of Keriya River Valley oases desertification expansion is mainly related to two important reasons: impact of natural environment and impact of human activities.
T2  - 24 - 27 October 2002, Hangzhou, China
Y1  - 2003
UR  - 1960 = doi:10.1117/12.466176
SN  - 0-8194-4676-9
VL  - 4890
PB  - SPIE
CY  - Bellingham, Wash.
ER  - 
TY  - JOUR
A1  - Pfister, L.
A1  - Kwadijk, J.
A1  - Musy, A.
A1  - Bronstert, Axel
A1  - Hoffmann, L.
T1  - Climate change, land use change and run-off prediction in the Rhine-Meuse basins
N2  - As a consequence of increasing winter rainfall totals and intensities over the second half of the 20th century, signs of increased flooding probability in many areas of the Rhine and Meuse basins have been documented. These changes affecting rainfall characteristics are most evidently due to an increase in westerly atmospheric circulation types. Land use changes, particularly urbanization, can have significant local effects in small basins (headwaters) with respect to flooding, especially during heavy local rainstorms, but no evidence exists that land use change has had significant effects on peak flows in the rivers Rhine and Meuse. For the 21st century, most global circulation models suggest higher winter rainfall totals. Most hydrological simulations of the Rhine-Meuse river basins suggest an increased flooding probability, with a progressive shift of the Rhine from a 'rain-fed/meltwater' river into a mainly 'rain-fed' river. A very limited effect of changes in land use on the discharge regime seems to exist for the main branches of the Meuse and Rhine rivers. For mesoscale basins, future changes in peak flows depend on the changes in the variability of extreme precipitations in combination with land use changes. Copyright (C) 2004 John Wiley Sons, Ltd
Y1  - 2003
SN  - 1535-1459
ER  - 
TY  - THES
A1  - Thonicke, Kirsten
T1  - Fire disturbance and vegetation dynamics : analysis and models
N2  - Untersuchungen zur Rolle natürlicher Störungen in der Vegetation bzw. in Ökosystemen zeigen, dass natürliche Störungen ein essentielles und intrinsisches Element in Ökosystemen darstellen, substanziell zur Vitalität und strukturellen Diversität der Ökosysteme beitragen und Stoffkreisläufe sowohl auf dem lokalen als auch auf dem globalen Niveau beeinflussen. Feuer als Grasland-, Busch- oder Waldbrand ist ein besonderes Störungsagens, da es sowohl durch biotische als auch abiotische Umweltfaktoren verursacht wird. Es beeinflusst biogeochemische Kreisläufe und spielt für die chemische Zusammensetzung der Atmosphäre durch Freisetzung klimarelevanter Spurengase und Aerosole aus der Verbrennung von Biomasse eine bedeutende Rolle. Dies wird auch durch die Emission von ca. 3.9 Gt Kohlenstoff pro Jahr unterstrichen, was einen großen Anteil am globalen Gesamtaufkommen ausmacht.  Ein kombiniertes Modell, das die Effekte und Rückkopplungen zwischen Feuer und Vegetation beschreibt, wurde erforderlich, als Änderungen in den Feuerregimes als Folge von Änderungen in der Landnutzung und dem Landmanagement festgestellt wurden. Diese Notwendigkeit wurde noch durch die Erkenntnis unterstrichen, daß die Menge verbrennender Biomasse als ein bedeutender Kohlenstoffluß sowohl die chemische Zusammensetzung der Atmosphäre und das Klima, aber auch die Vegetationsdynamik selbst beeinflusst. Die bereits existierenden Modellansätze reichen hier jedoch nicht aus, um entsprechende Untersuchungen durchzuführen. Als eine Schlussfolgerung daraus wurde eine optimale Menge von Faktoren gefunden, die das Auftreten und die Ausbreitung des Feuers, sowie deren ökosystemare Effekte ausreichend beschreiben. Ein solches Modell sollte die Merkmale beobachteter Feuerregime simulieren können und Analysen der Interaktionen zwischen Feuer und Vegetationsdynamik unterstützen, um auch Ursachen für bestimmte Änderungen in den Feuerregimes herausfinden zu können. Insbesondere die dynamischen Verknüpfungen zwischen Vegetation, Klima und Feuerprozessen sind von Bedeutung, um dynamische Rückkopplungen und Effekte einzelner, veränderter Umweltfaktoren zu analysieren. Dadurch ergab sich die Notwendigkeit, neue Feuermodelle zu entwickeln, die die genannten Untersuchungen erlauben und das Verständnis der Rolle des Feuer in der globalen Ökologie verbessern.  Als Schlussfolgerung der Dissertation wird festgestellt, dass Feuchtebedingungen, ihre Andauer über die Zeit (Länge der Feuersaison) und die Streumenge die wichtigsten Komponenten darstellen, die die Verteilung der Feuerregime global beschreiben. Werden Zeitreihen einzelner Regionen simuliert, sollten besondere Entzündungsquellen, brandkritische Klimabedingungen und die Bestandesstruktur als zusätzliche Determinanten berücksichtigt werden. Die Bestandesstruktur verändert das Niveau des Auftretens und der Ausbreitung von Feuer, beeinflusst jedoch weniger dessen interannuelle Variabilität. Das es wichtig ist, die vollständige Wirkungskette wichtiger Feuerprozesse und deren Verknüpfungen mit der Vegetationsdynamik zu berücksichtigen, wird besonders unter Klimaänderungsbedingungen deutlich. Eine länger werdende, vom Klima abhängige Feuersaison bedeutet nicht automatisch eine im gleichen Maße anwachsende Menge verbrannter Biomasse. Sie kann durch Änderungen in der Produktivität der Vegetation gepuffert oder beschleunigt werden. Sowohl durch Änderungen der Bestandesstruktur als auch durch eine erhöhte Produktivität der Vegetation können Änderungen der Feuereigenschaften noch weiter intensiviert werden und zu noch höheren, feuerbezogenen Emissionen führen.
N2  - Studies of the role of disturbance in vegetation or ecosystems showed that disturbances are an essential and intrinsic element of ecosystems that contribute substantially to ecosystem health, to structural diversity of ecosystems and to nutrient cycling at the local as well as global level. Fire as a grassland, bush or forest fire is a special disturbance agent, since it is caused by biotic as well abiotic environmental factors. Fire affects biogeochemical cycles and plays an important role in atmospheric chemistry by releasing climate-sensitive trace gases and aerosols, and thus in the global carbon cycle by releasing approximately 3.9 Gt C p.a. through biomass burning.   A combined model to describe effects and feedbacks between fire and vegetation became relevant as changes in fire regimes due to land use and land management were observed and the global dimension of biomass burnt as an important carbon flux to the atmosphere, its influence on atmospheric chemistry and climate as well as vegetation dynamics were emphasized. The existing modelling approaches would not allow these investigations. As a consequence, an optimal set of variables that best describes fire occurrence, fire spread and its effects in ecosystems had to be defined, which can simulate observed fire regimes and help to analyse interactions between fire and vegetation dynamics as well as to allude to the reasons behind changing fire regimes. Especially, dynamic links between vegetation, climate and fire processes are required to analyse dynamic feedbacks and effects of changes of single environmental factors. This led us to the point, where new fire models had to be developed that would allow the investigations, mentioned above, and could help to improve our understanding of the role of fire in global ecology.   In conclusion of the thesis, one can state that moisture conditions, its persistence over time and fuel load are the important components that describe global fire pattern. If time series of a particular region are to be reproduced, specific ignition sources, fire-critical climate conditions and vegetation composition become additional determinants. Vegetation composition changes the level of fire occurrence and spread, but has limited impact on the inter-annual variability of fire. The importance to consider the full range of major fire processes and links to vegetation dynamics become apparent under climate change conditions. Increases in climate-dependent length of fire season does not automatically imply increases in biomass burnt, it can be buffered or accelerated by changes in vegetation productivity. Changes in vegetation composition as well as enhanced vegetation productivity can intensify changes in fire and lead to even more fire-related emissions.  --- Anmerkung: Die Autorin ist Trägerin des von der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam vergebenen Michelson-Preises für die beste Promotion des Jahres 2002/2003.
KW  - Waldbrand
KW  - Feuerregime
KW  - Vegetationsdynamik
KW  - natürliche Störungen
KW  - Waldbrandmodellierung
KW  - Klimaänderung
KW  - forest fires
KW  - fire regimes
KW  - vegetation dynamics
KW  - natural disturbances
KW  - fire modelling
KW  - climate change
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0000713
ER  - 
TY  - BOOK
A1  - Alexeev, Alexandr Ivanovich
A1  - Savoskul, Maria Sergeevna
A1  - Simagin, Yuriy Alexeevich
A1  - Shabalina, Natalia Vladimirovna
A1  - Porosenkov, Yuriy Vasilevich
A1  - Didenko, Olga Valerievna
A1  - Krupko, Anatoliy Emanuilovich
A1  - Rudzkiy, Viktor Valentinovich
A1  - Prazdnikova, Nadezda Nikolaevna
A1  - Lyssenkova, Soya Valerianovna
A1  - Matei, Constantin Gheorghe
A1  - Hachi, Mihai Gheorghe
A1  - Sainsus, Valerii Anton
ED  - Heller, Wilfried
ED  - Felgentreff, Carsten
ED  - Lindner, Waltraud
T1  - The socio-economic transformation of rural areas in Russia and Moldava
T3  - Praxis Kultur- und Sozialgeographie | PKS - 28 
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-53092
SN  - 978-3-935024-79-2
SN  - 0934-716X
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  -