Stand 2012 12 31 (GAIA 1997&2004 Leider Rausgefallen!)
Stand 2012_12_31 (GAIA 1997&2004 leider rausgefallen!)
Published items in each year (sum: 19 in 22 years = 0.86/year; from 1995: 15/17 = 0.88/year)
Citations in each year (sum: 210/180[wsc])
VR / 1.0
PT / J
AU / Sietz, D
Choque, SEM
Ludeke, MKB
AF / Sietz, Diana
Mamani Choque, Sabino Edgar
Luedeke, Matthias K. B.
TI / Typical patterns of smallholder vulnerability to weather extremes with regard to food security in the Peruvian Altiplano
SO / REGIONAL ENVIRONMENTAL CHANGE
AB / Smallholder livelihoods in the Peruvian Altiplano are frequently threatened by weather extremes, including droughts, frosts and heavy rainfall. Given the persistence of significant undernourishment despite regional development efforts, we propose a cluster approach to evaluate smallholders' vulnerability to weather extremes with regard to food security. We applied this approach to 268 smallholder households using information from two existing regional assessments and from our own household survey. The cluster analysis revealed four vulnerability patterns that depict typical combinations of household attributes, including their harvest failure risk, agricultural resources, education level and non-agricultural income. We validated the identified vulnerability patterns by demonstrating the correlation between them and an independently reported damage: the purchase of food and fodder resulting from exposure to weather extremes. The vulnerability patterns were then ranked according to the different amounts of purchase. A second validation aspect accounted for independently reported mechanisms explaining smallholders' sensitivity and adaptive capacity. Based on the similarities among the households, our study contributes to the understanding of vulnerability beyond individual cases. In particular, the validation strengthens the credibility and suitability of our findings for decision-making pertaining to the reduction of vulnerability.
SN / 1436-3798
PD / SEP
PY / 2012
VL / 12
IS / 3
BP / 489
EP / 505
DI / 10.1007/s10113-011-0246-5
UT / WOS:000307534400007
ER
PT / J
AU / Kit, O
Ludeke, M
Reckien, D
AF / Kit, Oleksandr
Luedeke, Matthias
Reckien, Diana
TI / Texture-based identification of urban slums in Hyderabad, India using remote sensing data
SO / APPLIED GEOGRAPHY
AB / This paper outlines a methodology to identify informal settlements out of high resolution satellite imagery using the concept of lacunarity. Principal component analysis and line detection algorithms were applied alternatively to obtain a high resolution binary representation of the city of Hyderabad, India and used to calculate lacunarity values over a 60 x 60 m grid. A number of ground truthing areas were used to classify the resulting datasets and to identify lacunarity ranges which are typical for settlement types that combine high density housing and small dwelling size - features characteristic for urban slums in India. It was discovered that the line detection algorithm is advantageous over principal component analysis in providing suitable binary datasets for lacunarity analysis as it is less sensitive to spectral variability within mosaicked imagery. The resulting slum location map constitutes an efficient tool in identifying particularly overcrowded areas of the city and can be used as a reliable source in vulnerability and resilience assessments at a later stage. The proposed methodology allows for rapid analysis and comparison of multi-temporal data and can be applied on many developing urban agglomerations around the world. (C) 2011 Elsevier Ltd. All rights reserved.
SN / 0143-6228
PD / MAR
PY / 2012
VL / 32
IS / 2
BP / 660
EP / 667
DI / 10.1016/j.apgeog.2011.07.016
UT / WOS:000298362400043
ER
PT / J
AU / Reckien, D
Eisenack, K
Ludeke, MKB
AF / Reckien, Diana
Eisenack, Klaus
Luedeke, Matthias K. B.
TI / Land Consumption by Urban Sprawl-A New Approach to Deduce Urban Development Scenarios from Actors' Preferences
SO / ENVIRONMENTAL MODELING & ASSESSMENT
AB / A new modelling approach to urban sprawl dynamics is introduced which allows representing qualitative knowledge on relations between moving actor populations and properties of locations. The results of this Qualitative Attractiveness Migration (QuAM) Model are scenario-like sets of possible future developments of the urban system, much in contrast to quantitative forecasts gained by traditional modelling approaches. QuAM models allow for the interaction between internal dynamics and external influences. The application of the new approach is exemplified by the case of urban sprawl in Leipzig since 1990. It was possible to reproduce the observed qualitative development and to calculate future scenarios. The scenario runs project a new wave of middle class driven residential sprawl and suggest implications for sprawl reducing policy interventions.
SN / 1420-2026
PD / OCT
PY / 2011
VL / 16
IS / 5
BP / 465
EP / 477
DI / 10.1007/s10666-011-9254-6
UT / WOS:000294459800004
ER
PT / J
AU / Sietz, D
Ludeke, MKB
Walther, C
AF / Sietz, Diana
Luedeke, Matthias K. B.
Walther, Carsten
TI / Categorisation of typical vulnerability patterns in global drylands
SO / GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS
AB / Drylands display specific vulnerability-creating mechanisms which threaten ecosystems and human well-being. The upscaling of successful interventions to reduce vulnerability arises as an important, but challenging aim, since drylands are not homogenous. To support this aim, we present the first attempt to categorise dryland vulnerability at a global scale and sub-national resolution. The categorisation yields typical patterns of dryland vulnerability and their policy implications according to similarities among the socio-ecological systems. Based on a compilation of prevalent vulnerability-creating mechanisms, we quantitatively indicate the most important dimensions including poverty, water stress, soil degradation, natural agro-constraints and isolation. A cluster analysis reveals a set of seven typical vulnerability patterns showing distinct indicator combinations. These results are validated by case studies reflecting the cluster-specific mechanisms and their spatial distribution. Based on these patterns, we deduce thematic and spatial entry points for reducing dryland vulnerability. Our findings could contribute new insights into allocating the limited funds available for dryland development and support related monitoring efforts based on the manageable number of key indicators. (C) 2010 Elsevier Ltd. All rights reserved.
SN / 0959-3780
PD / MAY
PY / 2011
VL / 21
IS / 2
SI / SI
BP / 431
EP / 440
DI / 10.1016/j.gloenvcha.2010.11.005
UT / WOS:000292177500016
ER
PT / J
AU / Reckien, D
Ewald, M
Edenhofer, O
Ludeke, MKB
AF / Reckien, Diana
Ewald, Maren
Edenhofer, Ottmar
Luedeke, Matthias K. B.
TI / What parameters influence the spatial variations in CO2 emissions from road traffic in Berlin? Implications for urban planning to reduce anthropogenic CO2 emissions
SO / URBAN STUDIES
AB / The aim of this paper is to find major influencing factors of CO2 emissions from road traffic in urban areas. The approach of the study involved a statistical analysis on the basis of the formerly 23 urban districts of the German capital of Berlin. Correlation and regression analyses of empirical data from the settlement structure, the traffic structure and income have found that the number of jobs per district and the share of the well-off population can best describe the CO2 emissions from traffic in Berlin. Also the number of residents, the total built area, the number of cars and the amount of traffic area are positively related to the dependent variable. Therefore, the possibilities to reduce CO2 emissions from road traffic for urban planners seem limited: a restriction of space dedicated to traffic and a change of transport means for commuting represent leverage points, according to the analysis. The other significant indicators are less able to be influenced by local and regional decision-makers-an alteration in the means of mobility to less CO2 emitting alternatives is needed if CO2 emissions from road traffic are extensively to be decreased.
SN / 0042-0980
PD / FEB
PY / 2007
VL / 44
IS / 2
BP / 339
EP / 355
DI / 10.1080/00420980601136588
UT / WOS:000244276000007
ER
PT / J
AU / Sietz, D
Untied, B
Walkenhorst, O
Ludeke, MKB
Mertins, G
Petschel-Held, G
Schellnhuber, HJ
AF / Sietz, D
Untied, B
Walkenhorst, O
Ludeke, MKB
Mertins, G
Petschel-Held, G
Schellnhuber, HJ
TI / Smallholder agriculture in Northeast Brazil: assessing heterogeneous human-environmental dynamics
SO / REGIONAL ENVIRONMENTAL CHANGE
AB / A qualitative model of smallholder agriculture with a few core variables and two allocation rules for labour and investment in agricultural resources was developed to cover spatial heterogeneity in Northeast Brazil. This region is characterised by large natural and socio-economic variance, recurrent droughts and widespread rural poverty. The resulting system dynamics essentially consists of a cycle of four qualitative states, each depicting a typical pattern of trends in smallholder agriculture. Municipal statistical data were used to identify the spatial distribution of these patterns for the 1990s and the internal transition likelihood between subsequent states. Additionally the influence of external perturbations like droughts and producer price shocks on the smallholder system was investigated.
RI / Schellnhuber, Hans Joachim / B-2607-2012
SN / 1436-3798
PD / JUN
PY / 2006
VL / 6
IS / 3
BP / 132
EP / 146
DI / 10.1007/s10113-005-0010-9
UT / WOS:000238382000002
ER
PT / J
AU / Moldenhauer, O
Ludeke, MKB
AF / Moldenhauer, O
Ludeke, MKB
TI / Climate sensitivity of global terrestrial net primary production (NPP) calculated using the reduced-form model NNN
SO / CLIMATE RESEARCH
AB / In order to assess the potential impact of climate change on terrestrial equilibrium net primary production (NPP), information about the sensitivity of terrestrial NPP to climate change is needed. A novel approach to the definition of climate sensitivity is introduced; it does not depend on specific (and uncertain) scenarios, but rather describes the worst-case climate sensitivity of NPP, as measured by the magnitude of the gradient of NPP, as a function of the climate variables. The metric in climate space necessary for the determination of the gradient is calculated using the existing spatial variation of the climate variables as a measure of the potential for climate change, taking into account the unchanging determinants of the climate-latitude and altitude. The current correlations between the climate variables are preserved using principal component analysis. The resulting map of global NPP sensitivity shows especially high values, e.g. in the US Midwest, southern Africa, Australia, western Kazakhstan, the Maghreb and Spain, The sensitivity is aggregated to the country level, excluding the effects of the very insensitive deserts, in order to make these results applicable for policy analysis. The reduced-form model 'NNN' predicts annual terrestrial NPP of potential natural vegetation in equilibrium on the basis of a climatology including monthly values for temperature, precipitation and light. The very short computing time of this model is a prerequisite for the above-described multidimensional sensitivity study. To construct NNN, the average of the global NPP results of 7 advanced climatology-driven functional vegetation models was used to obtain a 'best guess' NPP field at a 0.5degrees x 0.5degrees spatial resolution. With the underlying climatology (36 values for monthly mean temperature, precipitation and light intensity per grid element), 62 483 points of an R-36 --> R-1 mapping are defined, A subset of these was used to train a neural network yielding a good reproduction of the spatial pattern with a mean absolute error of 0.026 kg C m(-2) yr(-1), which is significantly less than the mean uncertainty of the NPP average (mean absolute deviation: 0.097 kg C m(-2) yr(-1)). Furthermore, it is shown that the simple model calculates moisture-limited regions correctly, indicating that functional properties of the original models are reproduced, We hope with the NNN to make a contribution to other research which needs a very fast reduced-form NPP model. The NNN model is accessible in FORTRAN or as a C-subprogram available at:
SN / 0936-577X
PD / MAY 23
PY / 2002
VL / 21
IS / 1
BP / 43
EP / 57
DI / 10.3354/cr021043
UT / WOS:000177521400003
ER
PT / J
AU / CasselGintz, MA
Ludeke, MKB
PetschelHeld, G
Reusswig, F
Plochl, M
Lammel, G
Schellnhuber, HJ
AF / CasselGintz, MA
Ludeke, MKB
PetschelHeld, G
Reusswig, F
Plochl, M
Lammel, G
Schellnhuber, HJ
TI / Fuzzy logic based global assessment of the marginality of agricultural land use
SO / CLIMATE RESEARCH
AB / In order to assess the agricultural potential of regions and to evaluate the risk of environmental degradation due to agriculture, we define a marginality index for agricultural land use which is based on available global data sets and takes into account various environmental conditions, Influencing factors taken into consideration are the general climatic conditions for plant growth, the soil fertility, the soil moisture availability, the precipitation uncertainty and the erosion risk due to the steepness of slopes. Comparison of our marginality index with present global assessments of agricultural land use shows that about 30% of agricultural land currently in use can be identified as marginal, in other words as having a disposition towards overuse and potential environmental degradation. The validity of our approach is strengthened by the fact that agriculturally used areas identified as marginal are described as vulnerable in the literature. The risk of degradation with a further intensification of agriculture on existing crop land and the potential for the cultivation of previously unused land can be identified using our fuzzy logic technique.
RI / Schellnhuber, Hans Joachim / B-2607-2012
SN / 0936-577X
PD / MAY 8
PY / 1997
VL / 8
IS / 2
BP / 135
EP / 150
DI / 10.3354/cr008135
UT / WOS:A1997XH99000005
ER
PT / J
AU / Kohlmaier, GH
Badeck, FW
Otto, RD
Hager, C
Donges, S
Kindermann, J
Wurth, G
Lang, T
Jakel, U
Nadler, A
Ramge, P
Klaudius, A
Habermehl, S
Ludeke, MKB
AF / Kohlmaier, GH
Badeck, FW
Otto, RD
Hager, C
Donges, S
Kindermann, J
Wurth, G
Lang, T
Jakel, U
Nadler, A
Ramge, P
Klaudius, A
Habermehl, S
Ludeke, MKB
TI / The Frankfurt Biosphere Model: A global process-oriented model of seasonal and long-term CO2 exchange between terrestrial ecosystems and the atmosphere .2. Global results for potential vegetation in an assumed equilibrium state
SO / CLIMATE RESEARCH
AB / Regional variability and seasonal courses of atmospheric CO2 provide important clues to the understanding of the carbon exchange fluxes which determine the global carbon budget. We apply the Frankfurt Biosphere Model (FBM) to all 32 vegetation types of a modified global Matthews' vegetation map, simulating seasonal carbon exchange fluxes of the terrestrial ecosystems and their geographical variability on a global scale. For each 0.5 degrees by 0.5 degrees grid element the model calculates gross photosynthesis of the canopy and autotrophic respiration on an hourly time step, and heterotrophic respiration as well as the model-compartment sizes and LAI (leaf area index) on a daily time step. The driving variables temperature, irradiation, and soil moisture are derived from the Cramer and Leemans database. Soil moisture is calculated by an improved bucket model in which the soil properties given by the FAO soil map are combined with the rooting depth of different vegetation types to deduce the available water capacity and the permanent wilting point. Based on mean estimates of ecological variables [e.g. net primary production (NPP), biomass and soil carbon] and a characteristic seasonal climate, the free parameters of each vegetation type are calibrated. With these parameters, taking the climate variation within the vegetation types into account, the seasonal courses of NPP are calculated, summing up to a global annual integral of 50.3 Gt C yr(-1). The results are presented in the form of a world map showing the annual NPP and a table with monthly values of NPP averaged over 5 degrees latitude belts. The latter results are graphically displayed not only for NPP but also for heterotrophic respiration and the resulting seasonal net ecosystem production. Since the FBM keeps track of the seasonal development of leaf biomass, the corresponding seasonal LAI is examined for each grid element. The calculated leaf emergence dales are in good agreement with observations from phenological gardens as well as with NDVI (normalized difference vegitation index) derived phenology.
RI / Badeck, Franz / C-6722-2008
SN / 0936-577X
PD / MAR 27
PY / 1997
VL / 8
IS / 1
BP / 61
EP / 87
DI / 10.3354/cr008061
UT / WOS:A1997WZ14500005
ER
PT / J
AU / Ludeke, MKB
Ramge, PH
Kohlmaier, GH
AF / Ludeke, MKB
Ramge, PH
Kohlmaier, GH
TI / The use of satellite NDVI data for the validation of global vegetation phenology models: Application to the Frankfurt Biosphere Model
SO / ECOLOGICAL MODELLING
AB / An algorithm based on a three-spline function fitted to measured NDVI courses (normalized difference vegetation index) was developed to analyze a given NDVI annual course with respect to leaf shooting and leaf abscission times of deciduous vegetation. in contrast to algorithms which are based on modified second derivatives of the NDVI time course to detect shooting or abscission, the proposed algorithm takes into account the whole annual time course and is therefore less sensitive to noise in the NDVI-signal. In the present study this algorithm was used to validate the phenology results for the deciduous vegetation of a global equilibrium run of the prognostic Frankfurt Biosphere Model (FBM, spatial resolution 0.5 degrees x 0.5 degrees) driven by a climatology which represents a mean seasonality of the driving variables. The mean value of the area-weighted frequency distribution of the difference between the shooting date deduced from NDVI and the shooting date calculated by the FBM for the deciduous vegetation types is -4 days, indicating that in the global mean the FBM predicts leaf shooting less than one week too late. A 75% fraction of the area under consideration shows predicted shooting dates lying within a range of +/- 30 days compared to the satellite-derived dates. The distribution has its maximum at a difference of 0 days (i.e. the FBM exactly fits the NDVI deduced shooting day for these areas). This result supports the general assumption that at least in global scale models phenology can be successfully deduced from carbon flux balance considerations.
SN / 0304-3800
PD / NOV 15
PY / 1996
VL / 91
IS / 1-3
BP / 255
EP / 270
DI / 10.1016/0304-3800(95)00192-1
UT / WOS:A1996VL66400018
ER
PT / J
AU / Schlamadinger, B
Spitzer, J
Kohlmaier, GH
Ludeke, M
AF / Schlamadinger, B
Spitzer, J
Kohlmaier, GH
Ludeke, M
TI / Carbon balance of bioenergy from logging residues (vol 8, pg 221, 1995)
SO / BIOMASS & BIOENERGY
SN / 0961-9534
PY / 1996
VL / 11
IS / 6
BP / 499
EP / 499
UT / WOS:A1996WA60400008
ER
PT / J
AU / KOHLMAIER, GH
HAGER, C
NADLER, A
WURTH, G
LUDEKE, MKB
AF / KOHLMAIER, GH
HAGER, C
NADLER, A
WURTH, G
LUDEKE, MKB
TI / GLOBAL CARBON DYNAMICS OF HIGHER LATITUDE FORESTS DURING AN ANTICIPATED CLIMATE-CHANGE - ECOPHYSIOLOGICAL VERSUS BIOME-MIGRATION VIEW
SO / WATER AIR AND SOIL POLLUTION
CT / International-Boreal-Forest-Research-Association Conference on Boreal Forests and Global Change
CY / SEP 25-30, 1994
CL / SASKATOON, CANADA
SP / Int Boreal Forest Res Assoc
AB / The response of the vegetation and soils of the higher latitude forests and tundra ecosystems to an anticipated climate change is investigated using two alternative approaches to calculate the resulting change in the total carbon content (TCC) of the vegetation and the soils: On the one hand a BGC (bio-geochemical-cycle) model, in this case the FBM (Frankfurt Biosphere Model), where the ecosystem response is entirely due to the ecophysiological response of the vegetation and the ecological response of the soils. On the other hand a biome or ''rule-based'' model, in this case the BIOME model, which allows for the determination of the occurrence of a specific biome type from a given climatic situation assuming equilibrium conditions. Within the FBM prognosis net primary production and TCC are reduced both for needle leaved and broad leaved forests if the CO2-fertilisation effect is not taken into account. When the CO2-fertilisation effect is taken into consideration NPP, standing biomass and soil carbon are increased in a future greenhouse climate. Although there is a considerable shift of the biomes in response to the greenhouse climate within the BIOME approach, the TCC in the investigated northern biomes stayed more or less constant. This is due to a decrease in biomass in the southern regions of today's temperate forests compensating the biomass increase by the northward shift of the taiga border.