Filtern
Erscheinungsjahr
Dokumenttyp
- Dissertation (45) (entfernen)
Sprache
- Englisch (45) (entfernen)
Schlagworte
- Fernerkundung (10)
- Modellierung (6)
- Remote Sensing (4)
- Biomonitoring (3)
- Deutschland (3)
- Landwirtschaft (3)
- Remote sensing (3)
- remote sensing (3)
- Biogeographie (2)
- Bodenverschmutzung (2)
- Datenassimilation (2)
- Hydrologie (2)
- Landdegradation (2)
- Landsat (2)
- Laptewsee (2)
- Meereis (2)
- Mittelmeerraum (2)
- Monitoring (2)
- Phänologie (2)
- Polynja (2)
- Polynya (2)
- Salamander (2)
- Thailand (2)
- Umweltüberwachung (2)
- Vegetation (2)
- Zeitreihe (2)
- data assimilation (2)
- para-Phenylendiamin (PPD) (2)
- Ökologie (2)
- 15N (1)
- AFLP (1)
- APSIM model (1)
- APSIM-Modell (1)
- Abfall (1)
- Ablagerung (1)
- Abundanz (1)
- Abwasser (1)
- Ah-Rezeptor (1)
- AhR (1)
- Airline (1)
- Alar (1)
- Allozym-Elektrophorese (1)
- Angola (1)
- Antibiotikum (1)
- Anurans (1)
- Aposeris foetida (1)
- Arctic (1)
- Arealgrenzen (1)
- Arktis (1)
- Artificial Neural Network (1)
- Arzneimittel (1)
- Ascaridol (1)
- Australien <Nordost> (1)
- Baumwollpflanze (1)
- Behandlungstechnologien (1)
- Benzo[a]pyrene (1)
- Beweidung (1)
- Bias-Korrektur (1)
- Big Data (1)
- Bildverarbeitung (1)
- Bioakkumulation (1)
- Biogeography (1)
- Bioindication (1)
- Bioindikation (1)
- Biological control (1)
- Biologischer Pflanzenschutz (1)
- Biomasse (1)
- Blattflächenindex (1)
- Bodenaggregate (1)
- Bodenmikrobiologie (1)
- Bodenpilze (1)
- Bodentiere (1)
- Bodenwiderstand (1)
- Brackwasser (1)
- Brutpflege (1)
- CC-Chemokinrezeptor 2 (CCR2) (1)
- CCR2 (1)
- COSMO-CLM (1)
- Carcinogenese (1)
- Carrier-Proteine (1)
- Chain Hotel (1)
- Characteristic (1)
- Chemische Kommunikation (1)
- China (Nordwest) (1)
- Chlorophyll (1)
- Cuvelai Etoscha Becken (1)
- Cuvelai Etosha-basin (1)
- DDT (1)
- Degradation (1)
- Demökologie (1)
- Deposit (1)
- Dispersal (1)
- Dose-response relationship (1)
- Dosis-Wirkungs-Beziehung (1)
- Drift (1)
- Dynamische Modellierung (1)
- E-marketing (1)
- Ecosystem Services (1)
- Ecosystem services (1)
- Ecotoxicology (1)
- Eigenschaft (1)
- Eigenschaften der vorbehandelte Abfälle (1)
- Einzugsgebiet (1)
- Eisbildung (1)
- Eiszeit (1)
- Ellesmere Island (1)
- Endemic Centre (1)
- Endemitenzentren (1)
- Entsalzung (1)
- Environmental Monitoring (1)
- Erbkrankheit (1)
- Erde (1)
- Erzbergbau (1)
- Eugenol (1)
- Europa (1)
- Europe (1)
- Evapotranspiration (1)
- Extremwert (1)
- Extremwertanalyse (1)
- Faunal migration (1)
- Faunenmigration (1)
- Fertilitätsstörung (1)
- Fettsucht (1)
- Feuer (1)
- Fichte (1)
- Fish (1)
- Flechten (1)
- Forst (1)
- Fremdstoffmetabolismus (1)
- Froschlurche (1)
- Functional soil biodiversity (1)
- Fungizid (1)
- Funktionelle Biodiversität (1)
- Gas Chromatography (1)
- Gasaustausch (1)
- Gebirgswald (1)
- Genetik (1)
- Genetische Variabilität (1)
- Geodatenverarbeitung (1)
- Geoinformation Processing (1)
- Geowissenschaften (1)
- Germany (1)
- Getreide (1)
- Glaziale Refugien (1)
- Griechenland (1)
- Grönland (1)
- Habitatfragmentierung (1)
- Hapten (1)
- Haut (1)
- Hautzelle (1)
- Heuschrecken (1)
- Hochmoorgelbling (1)
- Hochwasser (1)
- Hybridisierung (1)
- Hydrodynamik (1)
- Hyperspectral (1)
- Hyperspektraldaten (1)
- Höhle (1)
- Ice production (1)
- Image Processing (1)
- Immunisation (1)
- Immunisierung (1)
- In-vitro-Kultur (1)
- Indonesia (1)
- Indonesien (1)
- Infrarot (1)
- Inhalation (1)
- Inhalation Toxicology (1)
- Insektizid (1)
- Insel-Verdriftungen (1)
- Iran (1)
- Island-drifts (1)
- Isoeugenol (1)
- Kartierung (1)
- Keratiniozyten (1)
- Keratinocytes (1)
- Kieselerden (1)
- Klimamodell (1)
- Klimaänderung (1)
- Konservierende Bodenbearbeitung (1)
- Kontaktdermatitis (1)
- Kosten-Nutzen-Analyse (1)
- LAI (1)
- Lagerung (1)
- Land Degradation (1)
- Landnutzung (1)
- Landsat-8 OLI (1)
- Laptev Sea (1)
- Laptev See (1)
- Leaf Area Index (1)
- Lebenszyklusanalyse (1)
- Leistungsmessung (1)
- Lichens (1)
- Life Cycle Assessment (1)
- Luftverschmutzung (1)
- Lunge (1)
- Luxemburg (1)
- MBA-Technologie (1)
- MBT technology (1)
- MCP-1 (1)
- MODIS (1)
- Mangrove (1)
- Marketing (1)
- Massendaten (1)
- Mechanical and biological treatment (1)
- Mechanisch-biologische Abfallbehandlung (1)
- Mechanisch-biologische Verfahren (1)
- Mechanische Eigenschaft (1)
- Mediterrane Rangelands (1)
- Mediterranean (1)
- Mediterranean Rangelands (1)
- Meteorologie (1)
- Mikrosatelliten (1)
- MoDC (1)
- MoDZ (1)
- Mohrenfalter (1)
- Monozyten-chemotaktische Protein 1 (MCP-1) (1)
- Monte-Carlo simulation (1)
- Monte-Carlo-Simulation (1)
- Moor (1)
- Moose (1)
- Mosses (1)
- Mykotoxin (1)
- N-Acetyltransferase 1 (NAT1) (1)
- N-acetyltransferase 1 (NAT1) (1)
- NOAA AVHRR (1)
- Nervennetz (1)
- Niederschlag (1)
- Nische (1)
- Nitrogen Deposition (1)
- Nordwestchina (1)
- Nutzwertanalyse (1)
- Oberflächenströmung (1)
- Orthoptera (1)
- Ozon (1)
- Ozon-Phytotoxizität (1)
- Ozone flux model (1)
- Ozonflussmodell (1)
- PBMC (1)
- PPD (1)
- Pakistan (1)
- Parapatrie (1)
- Parapatry (1)
- Partnerwahl (1)
- Penman-Monteith equation (1)
- Peru (1)
- Pesticides (1)
- Pestizid-Anwendungen (1)
- Pestizidbelastung (1)
- Pflanzenschutzmitteln (1)
- Pharmazeutika (1)
- Phylogeographie (1)
- Physikalische Eigenschaft (1)
- Plant pathogen repression (1)
- Polargebiete (1)
- Polychlorierte Biphenyle (1)
- Population Ecology (1)
- Populationsgenetik (1)
- Process benchmarking (1)
- Proliferation (1)
- Prozessbenchmarking (1)
- Radar (1)
- Radiometrie (1)
- Randmeer (1)
- Reflectance Modeling (1)
- Reflexionsmodellierung (1)
- Reflexionsspektroskopie (1)
- Regenwurmgang (1)
- Reproduction (1)
- Ressourcen-Konkurrenz (1)
- Rheinland-Pfalz (1)
- Rhizosphäre (1)
- SAR (1)
- Salzgehalt (1)
- Samen (1)
- Satellit (1)
- Schmetterlinge (1)
- Schwermetall (1)
- Schädling (1)
- Sea ice (1)
- Sediment (1)
- Selbstorganisierende Karte (1)
- Self-Organizing Maps (1)
- Sensibilisierung <Immunologie> (1)
- Sexualdimorphismus (1)
- Shifting cultivation (1)
- Sinonatrix (1)
- Solar thermal desalination technique (1)
- Solarthermische Entsalzungstechnologie (1)
- Southern Africa (1)
- Spanien (1)
- Spektrale Emissivität (1)
- Spektroskopie (1)
- Spitzbergen (1)
- Spline (1)
- Stabile Isotope (1)
- Stable Isotopes (1)
- Stickstoffdeposition (1)
- Stomatal conductance (1)
- Stomatäre Leitfähigkeit (1)
- Strategie (1)
- Strategy (1)
- Stress (1)
- Sulfadiazin (1)
- THP-1 (1)
- Taiwan (1)
- Temperatur (1)
- Terpene (1)
- Terrestrisches Laserscanning (1)
- Terrestrisches ükosystem (1)
- Thermales Infrarot (1)
- Thin Sea Ice (1)
- Tourism (1)
- Tourismus (1)
- Touroperator (1)
- Toxikologie (1)
- Toxizität (1)
- Trockengebiet (1)
- Trockenstress Detektion (1)
- Trockenwald (1)
- Tsunami (1)
- Utility analysis (1)
- Vaccination (1)
- Vegetation Index (1)
- Vegetationsindex (1)
- Visualisierung (1)
- Wachstum (1)
- Wachtelweizen (1)
- Waschmittel (1)
- Wassernattern (1)
- Watershed modelling (1)
- Weißklee (1)
- White clover (1)
- Wolke (1)
- Wuchsmodellierung (1)
- Wurzelraum (1)
- Wärmestrahlung (1)
- Xenobiotics (1)
- Zebrabärbling (1)
- Zellzyklus (1)
- Zellzyklus-Regulation (1)
- Zoologie (1)
- abiotic factors (1)
- abiotische Faktoren (1)
- abundance (1)
- acid mine drainage (1)
- actual evapotranspiration (1)
- allozyme electrophoresis (1)
- antibiotic (1)
- ascaridol (1)
- atmospheric pollution (1)
- bias correction (1)
- burrows (1)
- canopy surface resistance (1)
- cave (1)
- cell culture (1)
- cell cycle (1)
- characteristics of pre-treated waste (1)
- chemical communication (1)
- chemometrics (1)
- dendritic cells (1)
- dendritische Zellen (1)
- detergents (1)
- diatomaceous earth (1)
- dispersal (1)
- drylands (1)
- dynamics of mammal population (1)
- ecological niche (1)
- ecology (1)
- entomopathogene Pilze (1)
- entomopathogenic fungi (1)
- epidermal dendritic cells (1)
- epidermale dendritische Zellen (1)
- eugenol (1)
- extreme value analysis (1)
- faunmap database (1)
- floods (1)
- flushing (1)
- forestry (1)
- fungicides (1)
- genetic diversity (1)
- genetische Struktur (1)
- genomic structure (1)
- glacial refugia (1)
- growth modelling (1)
- habitat fragmentation (1)
- heavy metal (1)
- high-resolution (1)
- hochauflösend (1)
- hybridization (1)
- hydraulic modelling (1)
- hydrodynamics (1)
- hyperspectral (1)
- hyperspektral (1)
- imaging spectroscopy (1)
- in vitro (1)
- insecticides (1)
- isoeugenol (1)
- land degradattion (1)
- late quaternary (1)
- lung (1)
- mangrove (1)
- mate choice (1)
- metabolism (1)
- microorganisms (1)
- mircrosatellite (1)
- model evaluation (1)
- model performance (1)
- mutation (1)
- mycotoxin degradation (1)
- northwestern China (1)
- obesity (1)
- para-phenylenediamine (PPD) (1)
- parental care (1)
- peak-over-threshold (1)
- peripheren mononukleären Blutzellen (PBMC) (1)
- pest species (1)
- pesticide application (1)
- pharmaceuticals (1)
- phenology (1)
- phylogeography (1)
- polynomial spline (1)
- population genetics (1)
- pretreated waste (1)
- rain (1)
- resource competition (1)
- rhizosphere (1)
- salamander (1)
- salamanders (1)
- salt (1)
- sexual size dimorphism (1)
- skin (1)
- skin sensitization (1)
- soil contamination (1)
- soil microhabitats (1)
- soil surface resistance (1)
- spectral emissivity (1)
- sulfadiazine (1)
- terrestrial laser scanning (1)
- thermal infrared (1)
- time series (1)
- time series analysis (1)
- toxicity (1)
- uncoupling protein (1)
- vegetation index (1)
- vorbehandelter Abfälle (1)
- wastewater (1)
- water stress detection (1)
- xenobiotic metabolism (1)
- Ästuar (1)
- Ökoeffizienz (1)
- Ökologische Dienstleistungen (1)
- Ökosystemdienstleistung (1)
- ükosystem (1)
Institut
- Raum- und Umweltwissenschaften (45) (entfernen)
This thesis is focused on improving the knowledge on a group of threatened species, the European cave salamanders (genus Hydromantes). There are three main sections gathering studies dealing with different topics: Ecology (first part), Life traits (second part) and Monitoring methodologies (third part). First part starts with the study of the response of Hydromantes to the variation of climatic conditions, analysing 15 different localities throughout a full year (CHAPTER I; published in PEERJ in August 2015). After that, the focus moves on identify which is the operative temperature that these salamander experience, including how their body respond to variation of environmental temperature. This study was conducted using one of the most advanced tool, an infrared thermocamera, which gave the opportunity to perform detailed observation on salamanders body (CHAPTER II; published in JOURNAL OF THERMAL BIOLOGY in June 2016). In the next chapter we use the previous results to analyse the ecological niche of all eight Hydromantes species. The study mostly underlines the mismatch between macro- and microscale analysis of ecological niche, showing a weak conservatism of ecological niches within the evolution of species (CHAPTER III; unpublished manuscript). We then focus only on hybrids, which occur within the natural distribution of mainland species. Here, we analyse if the ecological niche of hybrids shows divergences from those of parental species, thus evaluating the power of hybrids adaptation (CHAPTER IV; unpublished manuscript). Considering that hybrids may represent a potential threat for parental species (in terms of genetic erosion and competition), we produced the first ecological study on an allochthonous mixed population of Hydromantes, analysing population structure, ecological requirements and diet. The interest on this particular population mostly comes by the fact that its members are coming from all three mainland Hydromantes species, and thus it may represent a potential source of new hybrids (CHAPTER V; accepted in AMPHIBIA-REPTILIA in October 2017). The focus than moves on how bioclimatic parameters affect species within their distributional range. Using as model species the microendemic H. flavus, we analyse the relationship between environmental suitability and local abundance of the species, also focusing on all intermediate dynamics which provide useful information on spatial variation of individual fitness (CHAPTER VI; submitted to SCIENTIFIC REPORTS in November 2017). The first part ends with an analysis of the interaction between Hydromantes and Batracobdella algira leeches, the only known ectoparasite for European cave salamanders. Considering that the effect of leeches on their hosts is potentially detrimental, we investigated if these ectoparasites may represent a further threat for Hydromantes (CHAPTER VII; submitted to INTERNATIONAL JOURNAL FOR PARASITOLOGY: PARASITES AND WILDLIFE in November 2017). The second part is related to the reproduction of Hydromantes. In the first study we perform analyses on the breeding behaviour of several females belonging to a single population, identifying differences and similarities occurring in cohorting females (CHAPTER VIII; published in NORTH-WESTERN JOURNAL OF ZOOLOGY in December 2015). In the second study we gather information from all Hydromantes species, analysing size and development of breeding females, and identifying a relationship between breeding time and climatic conditions (CHAPTER IX; submitted to SALAMANDRA in June 2017). In the last part of this thesis, we analyse two potential methods for monitoring Hydromantes populations. In the first study we evaluate the efficiency of the marking method involving Alpha tags (CHAPTER X; published in SALAMANDRA in October 2017). In the second study we focus on evaluating N-mixtures models as a methodology for estimating abundance in wild populations (CHAPTER XI; submitted to BIODIVERSITY & CONSERVATION in October 2017).
Dry tropical forests are facing massive conversion and degradation processes and they are the most endangered forest type worldwide. One of the largest dry forest types are Miombo forests that stretch across the Southern African subcontinent and the proportionally largest part of this type can be found in Angola. The study site of this thesis is located in south-central Angola. The country still suffers from the consequences of the 27 years of civil war (1975-2002) that provides a unique socio-economic setting. The natural characteristics are a representative cross section which proved ideal to study underlying drivers as well as current and retrospective land use change dynamics. The major land change dynamic of the study area is the conversion of Miombo forests to cultivation areas as well as modification of forest areas, i.e. degradation, due to the extraction of natural resources. With future predictions of population growth, climate change and large scale investments, land pressure is expected to further increase. To fully understand the impacts of these dynamics, both, conversion and modification of forest areas were assessed. By using the conceptual framework of ecosystem services, the predominant trade-off between food and timber in the study area was analyzed, including retrospective dynamics and impacts. This approach accounts for products that contribute directly or indirectly to human well-being. For this purpose, data from the Landsat archive since 1989 until 2013 was applied in different study area adapted approaches. The objectives of these approaches were (I) to detect underlying drivers and their temporal and spatial extent of impact, (II) to describe modification and conversion processes that reach from times of armed conflicts over the ceasefire and the post-war period and (III) to provide an assessment of drivers and impacts in a comparative setting. It could be shown that major underlying drivers for the conversion processes are resettlement dynamics as well as the location and quality of streets and settlements. Furthermore, forests that are selectively used for resource extraction have a higher chance of being converted to a field. Drivers of forest degradation are on one hand also strongly connected to settlement and infrastructural structures. But also to a large extent to fire dynamics that occur mostly in more remote and presumably undisturbed forest areas. The loss of woody biomass as well as its slow recovery after the abandonment of fields could be quantified and stands in large contrast to the amount of potentially cultivated food that is necessarily needed. The results of the thesis support the fundamental understanding of drivers and impacts in the study area and can thus contribute to a sustainable resource management.
Water-deficit stress, usually shortened to water- or drought stress, is one of the most critical abiotic stressors limiting plant growth, crop yield and quality concerning food production. Today, agriculture consumes about 80-90% of the global freshwater used by humans and about two thirds are used for crop irrigation. An increasing world population and a predicted rise of 1.0-2.5-°C in the annual mean global temperature as a result of climate change will further increase the demand of water in agriculture. Therefore, one of the most challenging tasks of our generation is to reduce the amount water used per unit yield to satisfy the second UN Sustainable Development Goal and to ensure global food security. Precision agriculture offers new farming methods with the goal to improve the efficiency of crop production by a sustainable use of resources. Plant responses to water stress are complex and co-occur with other environmental stresses under natural conditions. In general, water stress causes plant physiological and biochemical changes that depend on the severity and the duration of the actual plant water deficit. Stomatal closure is one of the first responses to plant water stress causing a decrease in plant transpiration and thus an increase in plant temperature. Prolonged or severe water stress leads to irreversible damage to the photosynthetic machinery and is associated with decreasing chlorophyll content and leaf structural changes (e.g., leaf rolling). Since a crop can already be irreversibly damaged by only mild water deficit, a pre-visual detection of water stress symptoms is essential to avoid yield loss. Remote sensing offers a non-destructive and spatio-temporal method for measuring numerous physiological, biochemical and structural crop characteristics at different scales and thus is one of the key technologies used in precision agriculture. With respect to the detection of plant responses to water stress, the current state-of-the-art hyperspectral remote sensing imaging techniques are based on measurements of thermal infrared emission (TIR; 8-14 -µm), visible, near- and shortwave infrared reflectance (VNIR/SWIR; 0.4-2.5 -µm), and sun-induced fluorescence (SIF; 0.69 and 0.76 -µm). It is, however, still unclear how sensitive these techniques are with respect to water stress detection. Therefore, the overall aim of this dissertation was to provide a comparative assessment of remotely sensed measures from the TIR, SIF, and VNIR/SWIR domains for their ability to detect plant responses to water stress at ground- and airborne level. The main findings of this thesis are: (i) temperature-based indices (e.g., CWSI) were most sensitive for the detection of plant water stress in comparison to reflectance-based VNIR/SWIR indices (e.g., PRI) and SIF at both, ground- and airborne level, (ii) for the first time, spectral emissivity as measured by the new hyperspectral TIR instrument could be used to detect plant water stress at ground level. Based on these findings it can be stated that hyperspectral TIR remote sensing offers great potential for the detection of plant responses to water stress at ground- and airborne level based on both TIR key variables, surface temperature and spectral emissivity. However, the large-scale application of water stress detection based on hyperspectral TIR measures in precision agriculture will be challenged by several problems: (i) missing thresholds of temperature-based indices (e.g., CWSI) for the application in irrigation scheduling, (ii) lack of current TIR satellite missions with suitable spectral and spatial resolution, (iii) lack of appropriate data processing schemes (including atmosphere correction and temperature emissivity separation) for hyperspectral TIR remote sensing at airborne- and satellite level.
This study aims to estimate the cotton yield at the field and regional level via the APSIM/OZCOT crop model, using an optimization-based recalibration approach based on the state variable of the cotton canopy - the leaf area index (LAI), derived from atmospherically corrected Landsat-8 OLI remote sensing images in 2014. First, a local sensitivity and global analysis approach was employed to test the sensitivity of cultivar, soil and agronomic parameters to the dynamics of the LAI. After sensitivity analyses, a series of sensitive parameters were obtained. Then, the APSIM/OZCOT crop model was calibrated by observations over a two-year span (2006-2007) at the Aksu station, combined with these sensitive cultivar parameters and the current understanding of cotton cultivar parameters. Third, the relationship between the observed in-situ LAI and synchronous perpendicular vegetation indices derived from six Landsat-8 OLI images covering the entire growth stage was modelled to generate LAI maps in time and space. Finally, the Particle Swarm Optimization (PSO) and general-purpose optimization approach (based on Nelder-Mead algorithm) were used to recalibrate four sensitive agronomic parameters (row spacing, sowing density per row, irrigation amount and total fertilization) according to the minimization of the root-mean-square deviation (RMSE) between the simulated LAI from the APSIM/OZCOT model and retrieved LAI from Landsat-8 OLI remote sensing images. After the recalibration, the best simulated results compared with observed cotton yield were obtained. The results showed that: (1) FRUDD, FLAI and DDISQ were the major cultivar parameters suitable for calibrating the cotton cultivar. (2) After the calibration, the simulated LAI performed well with an RMSE and mean absolute error (MAE) of 0.45 and 0.33, respectively, in 2006 and 0.46 and 0.41, respectively, in 2007. The coefficient of determination between the observed and simulated LAI was 0.83 and 0.97, respectively, in 2006 and 2007. The Pearson- correlation coefficient was 0.913 and 0.988 in 2006 and 2007, respectively, with a significant positive correlation between the simulated and observed LAI. The difference between the observed and simulated yield was 776.72 kg/ha and 259.98 kg/ha in 2006 and 2007, respectively. (3) Cotton cultivation in 2014 was obtained using three Landsat-8 OLI images - DOY136 (May), DOY 168 (June) and DOY 200 (July) - based on the phenological differences in cotton and other vegetation types. (4) The yield estimation after the assimilation closely approximated the field-observed values, and the coefficient of determination was as high as 0.82, after recalibration of the APSIM/OZCOT model for ten cotton fields. The difference between the observed and assimilated yields for the ten fields ranged from 18.2 to 939.7 kg/ha. The RMSE and MAE between the assimilated and observed yield was 417.5 and 303.1 kg/ha, respectively. These findings provide scientific evidence for the feasibility of coupled remote sensing and APSIM/OZCOT model at the field level. (5) Upscaling from field level to regional level, the assimilation algorithm and scheme are both especially important. Although the PSO method is very efficient, the computational efficiency is also the shortcoming of the assimilation strategy on a regional scale. Comparisons between the PSO and general-purpose optimization method (based on the Nelder-Mead algorithm) were implemented from the RSME, LAI curve and computational time. The general-purpose optimization method (based on the Nelder-Mead algorithm) was used for the regional assimilation between remote sensing and the APSIM/OZCOT model. Meanwhile, the basic unit for regional assimilation was also determined as cotton field rather than pixel. Moreover, the crop growth simulation was also divided into two phases (vegetative growth and reproductive growth) for regional assimilation. (6) The regional assimilation at the vegetative growth stage between the remote sensing derived and APSIM/OZCOT model-simulated LAI was implemented by adjusting two parameters: row spacing and sowing density per row. The results showed that the sowing density of cotton was higher in the southern part than in the northern part of the study area. The spatial pattern of cotton density was also consistent with the reclamation from 2001 to 2013. Cotton fields after early reclamation were mainly located in the southern part while the recent reclamation was located in the northern part. Poor soil quality, lack of irrigation facilities and woodland belts of cotton fields in the northern part caused the low density of cotton. Regarding the row spacing, the northern part was larger than the southern part due to the variation of two agronomic modes from military and private companies. (7) The irrigation and fertilization amount were both used as key parameters to be adjusted for regional assimilation during the reproductive growth period. The result showed that the irrigation per time ranged from 58.14 to 89.99 mm in the study area. The spatial distribution of the irrigation amount is higher in the northern part while lower in southern study area. The application of urea fertilization ranged from 500.35 to 1598.59 kg/ha in the study area. The spatial distribution of fertilization was lower in the northern part and higher in the southern part. More fertilization applied in the southern study area aims to increase the boll weight and number for pursuing higher yields of cotton. The frequency of the RSME during the second assimilation was mainly located in the range of 0.4-0.6 m2/m2. The estimated cotton yield ranged from 1489 to 8895 kg/ha. The spatial distribution of the estimated yield is also higher in the southern part than the northern study area.
In recent decades, the Arctic has been undergoing a wide range of fast environmental changes. The sea ice covering the Arctic Ocean not only reacts rapidly to these changes, but also influences and alters the physical properties of the atmospheric boundary layer and the underlying ocean on various scales. In that regard, polynyas, i.e. regions of open water and thin ice within thernclosed pack ice, play a key role as being regions of enhanced atmosphere-ice-ocean interactions and extensive new ice formation during winter. A precise long-term monitoring and increased efforts to employ long-term and high-resolution satellite data is therefore of high interest for the polar scientific community. The retrieval of thin-ice thickness (TIT) fields from thermal infrared satellite data and atmospheric reanalysis, utilizing a one-dimensional energy balance model, allows for the estimation of the heat loss to the atmosphere and hence, ice-production rates. However, an extended application of this approach is inherently connected with severe challenges that originate predominantly from the disturbing influence of clouds and necessary simplifications in the model set-up, which all need to be carefully considered and compensated for. The presented thesis addresses these challenges and demonstrates the applicability of thermal infrared TIT distributions for a long-term polynya monitoring, as well as an accurate estimation of ice production in Arctic polynyas at a relatively high spatial resolution. Being written in a cumulative style, the thesis is subdivided into three parts that show the consequent evolution and improvement of the TIT retrieval, based on two regional studies (Storfjorden and North Water (NOW) polynya) and a final large-scale, pan-Arctic study. The first study on the Storfjorden polynya, situated in the Svalbard archipelago, represents the first long-term investigation on spatial and temporal polynya characteristics that is solely based on daily TIT fields derived from MODIS thermal infrared satellite data and ECMWF ERA-Interim atmospheric reanalysis data. Typical quantities such as polynya area (POLA), the TIT distribution, frequencies of polynya events as well as the total ice production are derived and compared to previous remote sensing and modeling studies. The study includes a first basic approach that aims for a compensation of cloud-induced gaps in daily TIT composites. This coverage-correction (CC) is a mathematically simple upscaling procedure that depends solely on the daily percentage of available MODIS coverage and yields daily POLA with an error-margin of 5 to 6 %. The NOW polynya in northern Baffin Bay is the main focus region of the second study, which follows two main goals. First, a new statistics-based cloud interpolation scheme (Spatial Feature Reconstruction - SFR) as well as additional cloud-screening procedures are successfully adapted and implemented in the TIT retrieval for usage in Arctic polynya regions. For a 13-yr period, results on polynya characteristics are compared to the CC approach. Furthermore, an investigation on highly variable ice-bridge dynamics in Nares Strait is presented. Second, an analysis of decadal changes of the NOW polynya is carried out, as the additional use of a suite of passive microwave sensors leads to an extended record of 37 consecutive winter seasons, thereby enabling detailed inter-sensor comparisons. In the final study, the SFR-interpolated daily TIT composites are used to infer spatial and temporal characteristics of 17 circumpolar polynya regions in the Arctic for 2002/2003 to 2014/2015. All polynya regions combined cover an average thin-ice area of 226.6 -± 36.1 x 10-³ km-² during winter (November to March) and yield an average total wintertime accumulated ice production of about 1811 -± 293 km-³. Regional differences in derived ice production trends are noticeable. The Laptev Sea on the Siberian shelf is presented as a focus region, as frequently appearing polynyas along the fast-ice edge promote high rates of new ice production. New affirming results on a distinct relation to sea-ice area export rates and hence, the Transpolar Drift, are shown. This new high-resolution pan-Arctic data set can be further utilized and build upon in a variety of atmospheric and oceanographic applications, while still offering room for further improvements such as incorporating high-resolution atmospheric data sets and an optimized lead-detection.
Earth observation (EO) is a prerequisite for sustainable land use management, and the open-data Landsat mission is at the forefront of this development. However, increasing data volumes have led to a "digital-divide", and consequently, it is key to develop methods that account for the most data-intensive processing steps, then used for the generation and provision of analysis-ready, standardized, higher-level (Level 2 and Level 3) baseline products for enhanced uptake in environmental monitoring systems. Accordingly, the overarching research task of this dissertation was to develop such a framework with a special emphasis on the yet under-researched drylands of Southern Africa. A fully automatic and memory-resident radiometric preprocessing streamline (Level 2) was implemented. The method was applied to the complete Angolan, Zambian, Zimbabwean, Botswanan, and Namibian Landsat record, amounting 58,731 images with a total data volume of nearly 15 TB. Cloud/shadow detection capabilities were improved for drylands. An integrated correction of atmospheric, topographic and bidirectional effects was implemented, based on radiative theory with corrections for multiple scatterings, and adjacency effects, as well as including a multilayered toolset for estimating aerosol optical depth over persistent dark targets or by falling back on a spatio-temporal climatology. Topographic and bidirectional effects were reduced with a semi-empirical C-correction and a global set of correction parameters, respectively. Gridding and reprojection were already included to facilitate easy and efficient further processing. The selection of phenologically similar observations is a key monitoring requirement for multi-temporal analyses, and hence, the generation of Level 3 products that realize phenological normalization on the pixel-level was pursued. As a prerequisite, coarse resolution Land Surface Phenology (LSP) was derived in a first step, then spatially refined by fusing it with a small number of Level 2 images. For this purpose, a novel data fusion technique was developed, wherein a focal filter based approach employs multi-scale and source prediction proxies. Phenologically normalized composites (Level 3) were generated by coupling the target day (i.e. the main compositing criterion) to the input LSP. The approach was demonstrated by generating peak, end and minimum of season composites, and by comparing these with static composites (fixed target day). It was shown that the phenological normalization accounts for terrain- and land cover class-induced LSP differences, and the use of Level 2 inputs enables a wide range of monitoring options, among them the detection of within state processes like forest degradation. In summary, the developed preprocessing framework is capable of generating several analysis-ready baseline EO satellite products. These datasets can be used for regional case studies, but may also be directly integrated into more operational monitoring systems " e.g. in support of the Reducing Emissions from Deforestation and Forest Degradation (REDD) incentive. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of Trier University's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.
The development of our society contributed to increased occurrence of emerging substances (pesticides, pharmaceuticals, personal care products, etc.) in wastewater. Because of their potential hazard on ecosystems and humans, Wastewater Treatment Plants (WWTPs) need to adapt to better remove these compounds. Technology or policy development should however comply with sustainable development, e.g. based on Life Cycle Assessment (LCA) metrics. Nevertheless, the reliability or consistency of LCA results can sometimes be debatable. The main objective of this work was to explore how LCA can better support the implementation of innovative wastewater treatment options, in particular including removal benefits. The method was applied to support solutions for pharmaceuticals elimination from wastewater, regarding: (i) UV technology design, (ii) choice of advanced technology and (iii) centralized or decentralized treatment policy. The assessment approach followed by previous authors based on net impacts calculation seemed very promising to consider both environmental effects induced by treatment plant operation and environmental benefits obtained from pollutants removal. It was therefore applied to compare UV configuration types. LCA outcomes were consistent with degradation kinetics analysis. For the comparison of advanced technologies and policy scenarios, the common practice (net impacts based on EDIP method) was compared to other assessments, to better consider elimination benefits. First, USEtox consensus was applied for the avoided (eco)toxicity impacts, in combination with the recent method ReCiPe for generated impacts. Then, an eco-efficiency indicator (EFI) was developed to weigh the treatment efforts (generated impacts based on EDIP and ReCiPe methods) by the average removal efficiency (overcoming (eco)toxicity uncertainty issues). In total, the four types of comparative assessment showed the same trends: (i) ozonation and activated carbon perform better than UV irradiation, and (ii) no clear advantage distinguished between policy scenarios. It cannot be however concluded that advanced treatment of pharmaceuticals is not necessary because other criteria should be considered (risk assessment, bacterial resistance, etc.) and large uncertainties were embedded in calculations. Indeed, a significant part of this work was dedicated to the discussion of uncertainty and limitations of the LCA outcomes. At the inventory level, it was difficult to model technology operation at development stage. For impact assessment, the newly developed characterization factors for pharmaceuticals (eco)toxicity showed large uncertainties, mainly due to the lack of data and quality for toxicity tests. The use of information made available under REACH framework to develop CFs for detergent ingredients tried to cope with this issue but the benefits were limited due to the mismatch of information between REACH and USEtox method. The highlighted uncertainties were treated with sensitivity analyses to understand their effects on LCA results. This research work finally presents perspectives on the use of transparently generated data (technology inventory and (eco)toxicity factors) and further development of EFI indicator. Also, an accent is made on increasing the reliability of LCA outcomes, in particular through the implementation of advanced techniques for uncertainty management. To conclude, innovative technology/product development (e.g. based on circular economy approach) needs the involvement of all types of actors and the support from sustainability metrics.
Besides well-known positive aspects of conservation tillage combined with mulching, a drawback may be the survival of phytopathogenic fungi like Fusarium species on plant residues. This may endanger the health of the following crop by increasing the infection risk for specific plant diseases. In infected plant organs, these pathogens are able to produce mycotoxins like deoxynivalenol (DON). Mycotoxins like DON persist during storage, are heat resistant and of major concern for human and animal health after consumption of contaminated food and feed, respectively. Among fungivorous soil organisms, there are representatives of the soil fauna which are obviously antagonistic to a Fusarium infection and the contamination with mycotoxins. Earthworms (Lumbricus terrestris), collembolans (Folsomia candida) and nematodes (Aphelenchoides saprophilus) provide a wide range of ecosystem services including the stimulation of decomposition processes which may result in the regulation of plant pathogens and the degradation of environmental contaminants. Several investigations under laboratory conditions and in the field were conducted to test the following hypotheses: (1) Fusarium-infected and DON-contaminated wheat straw provides a more attractive food substrate than non-infected control straw (2) the introduced soil fauna reduce the biomass of F. culmorum and the content of DON in infected wheat straw under laboratory and field conditions (3) the species interaction of the introduced soil fauna enhances the degradation of Fusarium biomass and DON concentration in wheat straw; (4) the degradation efficiency of soil fauna is affected by soil texture. The results of the present thesis pointed out that the degradation performance of the introduced soil fauna must be considered as an important contribution to the biological control of plant diseases and environmental pollutants. As in particular L. terrestris revealed to be the driver of the degradation process, earthworms contribute to a sustainable control of fungal pathogens like Fusarium and its mycotoxins in wheat straw, thus reducing the risk of plant diseases and environmental pollution as ecosystem services.
Exposure to fine and ultra-fine environmental particles is still a problem of concern in many industrialized parts of the world and the intensified use of nanotechnology may further increase exposure to small particles. Since many years air pollution is recognized as a critical problem in western countries, which led to rigorous regulation of air quality and the introduction of strict guidelines. However, the upper thresholds for particulates in ambient air recommended by the world health organization are often exceeded several times in newly industrialized countries. Such high levels of air pollution have the potential to induce adverse effects on human health. The response triggered by air pollutants is not limited to local effects of the respiratory system but is often systemic, resulting in endothelial dysfunction or atherosclerotic malady. The link between air pollution and cardiovascular disease is now accepted by the scientific community but the underlying mechanisms responsible for the pro-atherogenic potential still need to be unraveled in detail. Based on the results from in- vivo and in vitro studies the production of reactive oxygen species due to exposure to particles is the most important mechanism to explain the observed adverse effects. However, the doses that were applied in many in vivo and in vitro studies are far beyond the range of what humans are exposed to and there is the need for more realistic exposure studies. Complex in vitro coculture systems may be valuable tools to study particle-induced processes and to extrapolate effects of particles on the lung. One of the objectives of this PhD thesis was the establishment and further improvement of a complex coculture system initially described by Alfaro-Moreno et al. [1]. The system is composed of an alveolar type-II cell line (A549), differentiated macrophage-like cells (THP-1), mast cells (HMC-1) and endothelial cells (EA.hy 926), seeded in a 3D-orientation on a microporous membrane to mimic the cell response of the alveolar surface in vitro in conjunction with native aerosol exposure (VitrocellTM chamber). The tetraculture system was carefully characterized to ensure its performance and repeatability of results. The spatial distribution of the cells in the tetraculture was analyzed by confocal laser scanning microscopy (CLSM), showing a confluent layer of endothelial and epithelial cells on both sides of the Transwellâ„¢. Macrophage-like cells and mast cells can be found on top of the epithelial cells. The latter cells formed colonies under submerged conditions, which disappeared at the air-liquid-interface (ALI). The VitrocellTM aerosol exposure system was not significantly influencing the viability. Using this system, cells were exposed to an aerosol of 50 nm SiO2-Rhodamine nanoparticles (NPs) in PBS. The distribution of the NPs in the tetraculture after exposure was evaluated by CLSM. Fluorescence from internalized particles was detected in CD11b-positive THP-1 cells only. Furthermore, all cell lines were found to be able to respond to xenobiotic model compounds, such as benzo[a]pyrene (B[a]P) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with the upregulation of CYP1 mRNA. With this tetraculture system the response of the endothelial part of the alveolar barrier was studied in- vitro in a still realistic exposure scenario representing the conditions for a polluted situation without direct exposure of endothelial cells. After exposure to diesel exhaust particulate matter (DEPM) the expression of different anti-oxidant target genes and inflammatory genes such as NAD(P)H dehydrogenase quinone 1 (NQO1), superoxide dismutase 1 (SOD1) and heme oxygenase 1 (HMOX1), as well as the nuclear translocation nuclear factor erythroid-derived 2 (Nrf2) was evaluated. In addition, the potential of DEPM to induce the upregulation of CYP1A1 mRNA in the endothelium was analyzed. DEPM exposure led not to an upregulation of the anti-oxidant or inflammatory target genes, but to clear nuclear translocation of Nrf2. The endothelial cells responded to the DEPM treatment also with the upregulation of CYP1A1 mRNA and nuclear translocation of the aryl hydrocarbon receptor (AhR). Overall, DEPM triggered a response in the endothelial cells after indirect exposure of the tetraculture system to low doses of DEPM, underlining the sensitivity of ALI exposure systems. The use of the tetraculture together with the native aerosol exposure equipment may finally lead to a more realistic judgment regarding the hazard of new compounds and/or new nano-scaled materials in the future. For the first time, it was possible to study the response of the endothelial cells of the alveolar barrier in vitro in a realistic exposure scenario avoiding direct exposure of endothelial cells to high amounts of particulates.
Floods are hydrological extremes that have enormous environmental, social and economic consequences.The objective of this thesis was a contribution to the implementation of a processing chain that integrates remote sensing information into hydraulic models. Specifically, the aim was to improve water elevation and discharge simulations by assimilating microwave remote sensing-derived flood information into hydraulic models. The first component of the proposed processing chain is represented by a fully automated flood mapping algorithm that enables the automated, objective, and reliable flood extent extraction from Synthetic Aperture Radar images, providing accurate results in both rural and urban regions. The method operates with minimum data requirements and is efficient in terms of computational time. The map obtained with the developed algorithm is still subject to uncertainties, both introduced by the flood mapping algorithm and inherent in the image itself. In this work, particular attention was given to image uncertainty deriving from speckle. By bootstrapping the original satellite image pixels, several synthetic images were generated and provided as input to the developed flood mapping algorithm. From the analysis performed on the mapping products, speckle uncertainty can be considered as a negligible component of the total uncertainty. In the final step of the proposed processing chain real event water elevations, obtained from satellite observations, were assimilated in a hydraulic model with an adapted version of the Particle Filter, modified to work with non-Gaussian distribution of observations. To deal with model structure error and possibly biased observations, a global and a local weight variant of the Particle Filter were tested. The variant to be preferred depends on the level of confidence that is attributed to the observations or to the model. This study also highlighted the complementarity of remote sensing derived and in-situ data sets. An accurate binary flood map represents an invaluable product for different end users. However, deriving from this binary map additional hydraulic information, such as water elevations, is a way of enhancing the value of the product itself. The derived data can be assimilated into hydraulic models that will fill the gaps where, for technical reasons, Earth Observation data cannot provide information, also enabling a more accurate and reliable prediction of flooded areas.