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Perennial energy crops (PECs) are increasingly used as feedstock to produce energy in an environmental friendly way. Compared to traditional conversion strategies like thermal use, sophisticated technologies such as biomethanation defined different re-quirements of the feedstock. Whereas the first concept relies on dry, woody mate-rial, biomethanation requires a moist feedstock. Thus, over time, the spectrum of species used as PECs has widened. Moreover, harvest dates were adjusted to pro-vide the feedstock at suitable moisture contents. It is well known that perennial, lignocellulose- based energy crops, compared to annual, sugar- and starch- based ones, offer ecological advantages such as, inter alia, improving biodiversity in landscape, protecting soil against erosion, and protecting groundwater from nutrient inputs. However, one of the main arguments for PEC cultivation was their undemanding nature concerning external inputs. With respect to the broader spectrum of PEC spe-cies and changed harvest dates, the question arises whether the concept of PECs being low- input energy crops is still valid. This also implies the question of suitable grow-ing conditions and sustainable management. The aims of this opinion paper were to classify different PECs according to their life- form strategy, compare nutrient exports when harvested in different maturation stages, and to discuss the results in the context of sustainable PEC cultivation on marginal land. This study revealed that nutrient exports with yield biomass of PECs harvested in green state are in the same range than those of annual energy crops and therewith several times higher than those of PECs harvested in brown state or of woody short rotation coppices. Thus, PECs can-not universally be claimed as low- input energy crops. These results also imply the consequences of cultivation of PECs on marginal land. Finally, the question has to be raised whether the term PECs should prospectively be better specified in written and spoken words.
In der vorliegenden Arbeit wurden die Einsatzmöglichkeiten von Carbon Footprints in Großküchen untersucht. Dabei wurden sowohl methodische Aspekte und Herausforderungen ihrer Erhebung untersucht als auch mögliche Kennzeichnungsformate (Label) evaluiert.
Zunächst wurde am Beispiel Hochschulgastronomie eine vollständige Carbon Footprint Studie nach DIN 14067 für sechs exemplarische Gerichte (PCF) sowie angelehnt an DIN 14064 für den Mensabetrieb (CCF) durchgeführt. Es zeigte sich, dass die gewichteten durchschnittlichen Emissionen pro Teller, unter Einbezug der verwendeten Rohstoffe und des Energiebedarfs, 1,8 kg CO2eq pro Teller betragen (Mgew=1,78 kg CO2eq; [0,22-3,36]). Zur Vereinfachung des Erhebungsprozesses wurden anknüpfend an diese Ergebnisse Pauschalisierungsansätze zur vereinfachten Emissionsallokation im Gastrosektor evaluiert und in Form eines appgestützten Berechnungstools umgesetzt. Es konnte verifiziert werden, dass der Energiebedarf und die daraus resultierenden Emissionen unabhängig von der Beschaffenheit der Gerichte auf die Anzahl produzierter Gerichte alloziert werden können und die Ausgabewerte dennoch hinreichend belastbar sind (Abweichung <10 %).
In dieser Studie konnte gezeigt werden, dass am untersuchten Standort Skaleneffekte hinsichtlich der Anzahl produzierter Gerichte und Strombedarf pro Gericht auftreten. Beide Faktoren korrelieren stark negativ miteinander (r=-.78; p<.05). Zur Verifikation der Ergebnisse wurde eine Datenabfrage unter allen deutschen Studierendenwerken (N=57) hinsichtlich des Energiebedarfs und der Produktionsmengen in Hochschulmensen durchgeführt. Aus den Daten von 42 Standorten konnten für das Jahr 2018 prognostizierte Gesamtemissionen in Höhe von 174.275 Tonnen CO2eq, verursacht durch etwa 98 Millionen verkaufte Gerichte, ermittelt werden. Im Gegensatz zur durchgeführten Standort-Studie konnten die Skaleneffekte, d.h. sinkender Strombedarf pro Teller bei steigender Produktionszahl, bei der deutschlandweiten Datenerhebung statistisch nicht nachgewiesen werden
(r=-.29; p=.074).
Im Anschluss wurden mögliche Label-Formate für Carbon Footprints evaluiert, indem vier vorbereitete Label unterschiedlicher Beschaffenheit (absolute Zahlen, einordnend, vergleichend und wertend) in sechs Fokusgruppen mit insgesamt 17 Teilnehmer:innen im Alter zwischen 20 und 31 Jahren (M=25,12; SD=3,31) diskutiert wurden. Im Ergebnis zeigte sich, dass bei den Teilnehmer:innen ein breiter Wunsch nach der Ausweisung absoluter Zahlen bestand. Zur besseren Einordnung sollte ein Label zudem einordnende Elemente enthalten. Wertende Label in Form von Ampelsymbolen oder Smileys mit unterschiedlichen Emotionen wurden überwiegend abgelehnt. Ableitend aus den Erkenntnissen konnten zwei synthetisierende Label-Vorschläge entwickelt werden.
The nonhydrostatic regional climate model CCLM was used for a long-term hindcast run (2002–2016) for the Weddell Sea region with resolutions of 15 and 5 km and two different turbulence parametrizations. CCLM was nested in ERA-Interim data and used in forecast mode (suite of consecutive 30 h long simulations with 6 h spin-up). We prescribed the sea ice concentration from satellite data and used a thermodynamic sea ice model. The performance of the model was evaluated in terms of temperature and wind using data from Antarctic stations, automatic weather stations (AWSs), an operational forecast model and reanalyses data, and lidar wind profiles. For the reference run we found a warm bias for the near-surface temperature over the Antarctic Plateau. This bias was removed in the second run by adjusting the turbulence parametrization, which results in a more realistic representation of the surface inversion over the plateau but resulted in a negative bias for some coastal regions. A comparison with measurements over the sea ice of the Weddell Sea by three AWS buoys for 1 year showed small biases for temperature around ±1 K and for wind speed of 1 m s−1. Comparisons of radio soundings showed a model bias around 0 and a RMSE of 1–2 K for temperature and 3–4 m s−1 for wind speed. The comparison of CCLM simulations at resolutions down to 1 km with wind data from Doppler lidar measurements during December 2015 and January 2016 yielded almost no bias in wind speed and a RMSE of ca. 2 m s−1. Overall CCLM shows a good representation of temperature and wind for the Weddell Sea region. Based on these encouraging results, CCLM at high resolution will be used for the investigation of the regional climate in the Antarctic and atmosphere–ice–ocean interactions processes in a forthcoming study.
Das Policy Paper ‚Handlungsbedarfe für die Raumentwicklung der Großregion aus Sicht der Forschung‘ fasst wesentliche Erkenntnisse von Forscher*innen des UniGR-Center for Border Studies in fünf für die Großregion relevanten Bereichen (Demographie und Migration, Verkehr, Beschäftigung und wirtschaftliche Entwicklung, Energielandschaften, Grenzüberschreitende Governance) zusammen und formuliert Handlungsoptionen für die Planungspraxis und politische Entscheidungsträger*innen. Darüber hinaus thematisiert es den Wissensaus-tausch zwischen Forschung und Politik.
Soils in forest ecosystems bear a high potential as carbon (C) sinks in the mitigation of climate change. The amount and characteristics of soil organic matter (SOM) are driven by inputs, transformation, degradation and stabilization of organic substances. While tree species fuel the C cycle by producing aboveground and belowground litter, soil microorganisms are crucial for litter degradation as well as the formation and stabilization of SOM. Nonetheless, our knowledge about the tree species effect on the SOM status is limited, inconsistent and blurred. The investigation of tree species effects on SOM is challenging because in long-established forest ecosystems the spatial distribution of tree species is a result of the interplay of environmental factors including climate, geomorphology and soil chemistry. Moreover, tree distribution can further vary with forest successional stage and silvicultural management. Since these factors also directly affect the soil C-status, it is difficult to identify a pure “tree species effect” on the SOM status at regular forested sites. It therefore remains unclear in how far tree species-specific litter with different quality influences the microbial driven turnover and formation of SOM.
Tree species effects on SOM and related soil microbial properties were investigated by examining soil profiles (comprising organic forest floor horizons and mineral soil layers) in different forest stands at the recultivated spoil heap ‘Sophienhöhe’ located at the lignite open-cast mine Hambach near Jülich, Germany. The afforested sites comprised monocultural stands of Douglas fir (Pseudotsuga menziesii), black pine (Pinus nigra), European beech (Fagus sylvatica) and red oak (Quercus rubra) as well as a mixed deciduous stand site planted mainly with hornbeam (Carpinus betulus), lime (Tilia cordata) and common oak (Quercus robur) that were grown for 35 years under identical soil and geomorphological conditions. Because the parent material used for site recultivation was free from organic matter or coal material, the SOM accumulation is entirely the result of in situ soil development due to the impact of tree species.
The first study revealed that tree species had a significant effect on soil organic carbon (SOC) stocks, stoichiometric patterns of C, nitrogen (N), sulfur (S), hydrogen (H) and oxygen (O) as well as the microbial biomass carbon (MBC) content in the forest floor and the top mineral soil layers (0-5 cm, 5-10 cm, 10-30 cm). In general, forest floor SOC stocks were significantly higher at coniferous forest stands compared to deciduous tree species, whereas in mineral soil layers the differences were smaller. Thus, the impact of tree species decreased with increasing soil depth. By investigating the linkage of the natural abundance of 13C and 15N in the soil depth gradients with C:N and O:C stoichiometry, the second study showed that differences in SOC stocks and SOM quality resulted from a tree species-dependent turnover of SOM. Significantly higher turnover of organic matter in soils under deciduous tree species depended to 46 % on the quality of litterfall and root inputs (N content, C:N, O:C ratio), and on the initial isotopic signatures of litterfall. Hence, SOM composition and turnover also depends on additional – presumably microbially driven – factors. The subsequent results of the third study revealed that differences in SOM composition and related soil microbial properties were linked to different microbial communities. Phospholipid fatty acid (PLFA) patterns in the soil profiles indicated that the supply and availability of C and nutrient-rich substrates drive the distribution of fungi, Gram-positive (G+) bacteria and Gram-negative (G−) bacteria between tree species and along the soil depth gradients. The fourth study investigated the molecular composition of extractable soil microbial biomass-derived (SMB) and SOM-derived compounds by electrospray ionization Fourier transformation ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). This was complemented by the analysis of nine monosaccharides representing microbial or plant origin. Microbially derived compounds substantially contributed to SOM and the contribution increased with soil depth. The supply of tree species-specific substrates resulted in different chemical composition of SMB with largest differences between deciduous and coniferous stands. At the same time, microorganisms contributed to SOM resulting in a strong similarity in the composition of SOM and SMB.
Overall, the complex interplay of tree species-specific litter inputs and the ability, activity and efficiency of the associated soil fauna and microbial community in metabolizing the organic substrates leads to significant differences in the amount, distribution, quality and consequently, the stability of SOM. These findings are useful for a targeted cultivation of tree species to optimize soil C sequestration and other forest ecosystems services.
Erlebnisgenese im Tourismus
(2021)
Das Thema des Erlebnisses steht bereits seit langem im Fokus von Anbietern von Dienstleistungen. Dies gilt insbesondere für den Tourismus, einer Branche, deren Produkte zu einem signifikanten Teil aus solchen bestehen. Entsprechend der Prominenz des Themas, vor allem in den Bereichen touristischer Produktentwicklung und Marketing, ist dieses bereits breit in der Forschung diskutiert worden.
Trotz ausgiebiger Publikationsaktivitäten ist der tatsächliche Wissensstand in diesem Thema dennoch auffällig gering. Ein wichtiges Problem liegt darin begründet, dass die Terminologie im Bereich von Erlebnissen noch nicht allgemein akzeptiert und scharf abgegrenzt ist. So muss zwischen Erlebnissen und Erfahrungen unterschieden werden. Erstere treten während des Prozesses der Wahrnehmung einer touristischen Dienstleistung auf und bilden die Basis für Erfahrungen, welche prägend hinsichtlich der Wahrnehmung wirken und im Gesamtkontext der Reise betrachtet werden. Dieser Unterscheidung wird nicht nur in der englischsprachigen Literatur, in der beide Begriffe mit dem Begriff Experience beschrieben werden, sondern auch in der deutschsprachigen Literatur zumeist zu wenig Rechnung getragen, was dazu führt, dass häufig zu Erlebnissen publiziert wird, obwohl eigentlich Erfahrungen beschrieben werden. Problematisch ist dies vor allem, weil damit ein Phänomen untersucht wird, dessen Basis nahezu gänzlich unbekannt ist. Wichtige Fragen, welche zum Verständnis von Erlebnissen und damit auch von Erfahrungen bleiben unbeantwortet:
1) Welche Faktoren werden in der Genese von Erlebnissen wirksam?
2) Wie wirken diese zusammen?
3) Wie wird die Stärke eines Erlebnisses determiniert?
4) Wie werden Erlebnisse stark genug um den Konsum einer touristischen Dienstleistung zu prägen und damit gegebenenfalls zu Erfahrungen zu werden?
In der vorliegenden Arbeit wurden diese Fragen beantwortet, womit ein erster Schritt in Richtung der Füllung einer für die Tourismuswissenschaft nicht unbedeutenden Forschungslücke gelungen ist.
Um Erlebnisse, den Prozess der Genese dieser und deren Bewertung durch den Gast verstehen zu können, wurde ein triangulierter, zweistufiger Forschungsprozess ersonnen und in einem naturtouristischen Setting im Nationalpark Vorpommersche Boddenlandschaft zur Anwendung gebracht. Es handelt sich dabei um einen Mixed-Methods-Ansatz:
1) Induktive-qualitative Studie auf Basis der Grounded Theory
a. Ziel: Identifikation von Wirkkomponenten und deren Zusammenspiel und Generierung eines Modells
b. Methoden: Verdeckte Beobachtung und narrative Interviews
c. Ergebnisse: Modelle der Genese punktueller Erlebnisse und prägender Erlebnisse
2) Deduktive-quantitative Studie
a. Ziel: Überprüfung und Konkretisierung der in 1) generierten Modelle
b. Methoden: Fragebogengestützte, quantitative Befragung und Auswertung mittels multivariater Verfahren
c. Ergebnisse: Zusammenfassung der beiden Modelle zu einem finalen Modell der Erlebnis- und Erfahrungsgenese
Das Ergebnis des Vorgehens ist ein empirisch erarbeitetes und validiertes, detailliertes Modell der Genese von Erlebnissen und der Bewertung dieser durch den Erlebenden in Bezug auf deren Fähigkeit zu Erfahrungen zu werden.
Neben der Aufarbeitung und Konkretisierung dieses Prozesses konnte zusätzlich die in viele Richtungen diskutierte Bedeutung von Erwartungen und Produktzufriedenheit mit Blick auf die Bewertung von Erlebnissen geklärt werden. So konnte empirisch nachgewiesen werden, dass Erlebnisse, die auf Überraschungen, dem Unerwarteten, basierten besonders resistent gegenüber Störfaktoren waren und positive Erlebnisse zwar durchaus im Zusammenhang mit Produktzufriedenheit stehen aber sich vor allem durch eine zumindest temporär gesteigerte Lebenszufriedenheit manifestieren. Damit konnte das Hauptkriterium für die Bewertung von Erlebnissen mit Blick auf ihre Tauglichkeit zu Erfahrungen identifiziert werden.
Für die weitere Forschung kann die vorliegende Arbeit mit dem finalen Modell der Erlebnis- und Erfahrungsgenese einen soliden Ausgangspunkt bilden. So bieten zahlreiche Faktoren im Modell die Möglichkeit zur weiteren Forschung. Auch sollten die Ergebnisse in weiteren touristischen Kontexten überprüft werden.
Für die touristische Praxis kann die vorliegende Arbeit zahlreiche Hinweise geben. So bedeutet die Generierung von Erlebnissen im touristischen Kontext mehr als nur die Erfüllung von Erwartungen. Die widerstandsfähigsten Erlebnisse sind jene, die den Gast zu überraschen vermögen. Ein qualitativ hochwertiges, den Gast zufriedenstellendes Produkt ist dabei nicht mehr als ein Basisfaktor. Wirklich erfolgreich ist ein erlebnisbasierender Ansatz nur dann, wenn dieser es vermag die Lebenszufriedenheit des Gastes zu steigern.
Grundlage der Arbeit stellten zwei Arbeitshypothesen dar, die es zu überprüfen galt. Die beiden Arbeitshypothesen wurden aufgrund einer Beobachtung eines Phänomens im Freiland formuliert, da bei scheinbar unterschiedlich starkem Reblausbesatzes im Boden kein direkter Zusammenhang zu einer schädigenden Wirkung dieses Stressphänomens (Reblausbefall) hergestellt werden konnte. Im Gegenteil traten die schädigenden Wirkungen des Reblausbefalls in Form von Rückgangserscheinungen eher in Rebflächen auf, die einer mangelhaften Bewirtschaftung oder Bestandsführung unterlagen. Zur Klärung dieses Phänomens wurden daher die beiden (A., B.) folgenden Hypothesen aufgestellt, die es zu überprüfen galt:
A.: Die in mit Unterlagsrebsorten der Kreuzung V. berlandieri x V. riparia zu beobachtenden Rückgangserscheinungen in Rebanlagen mit Reblausvorkommen werden nicht allein durch die Saugtätigkeit der Reblaus an den Rebwurzeln verursacht; eine direkte Korrelation zwischen Reblausdichte und Ausmaß der Rückgangserscheinungen an infizierten Reben besteht nicht. B.: Das Ausmaß möglicher Rückgangserscheinungen ist abhängig von der Bewirtschaftung des Rebbestands, wobei der Bodenbewirtschaftung eine maßgebliche Rolle zukommt.
Um diese Hypothesen zu überprüfen wurde ableitend von den Zielen der Arbeit ein Reblausbonitursystem zur Erfassung der Reblausabudanz im Freiland im Boden erarbeitet. Die besonderen Schwierigkeiten bei der Erfassung des Reblausbefalls im Boden aufgrund des stark variierenden Wurzelsystems der Rebe und dem ebenfalls stark schwankenden Reblausbefalls an der Wurzel der Rebe wurde mit dem Reblausbonitursystem (Grabungen) Rechnung getragen, sodass ein valides System zur Beurteilung des Reblausbefalls auch im jahreszeitlichen Verlauf erstellt worden konnte. Damit wurde ein Reblausbonitursystem geschaffen, das auch in praktischer Anwendung durchführbar ist und somit mit seiner höheren möglichen Replikationsrate bei der Probenentnahme dem stark variierenden Charakter des Reblausbefalls im Boden Rechnung trägt.
Um Rückgangserscheinungen in einem Weinberg nachhaltig analysieren zu können, wurde ein Wuchsbonitursystem evaluiert. Dieses System beurteilt alle Reben einer Rebfläche innerhalb eines einfachen für den Menschen kognitiv sehr gut verarbeitenden Bewertungssystem zum Wuchs der Reben. Damit ist eine Erfassung einer sehr großen Datenmenge zur Beurteilung des Wuchses auf einem Rebfeld möglich. Die Korrelation des mit dem System ermittelten Wuchses zu vielen Leistungsparametern der Rebe und den Gegebenheiten auf den Versuchsflächen zeigt die hohe Validität des Wuchsbonitursystems auf. Auch konnten Wuchsunterschiede in sehr differierenden Versuchsfeldern mit dieser Methode deutlich belegt werden. Damit wurde deutlich, dass mit dieser Wuchsboniturmethode die Rückgangserscheinungen in einer Rebfläche erkannt und analysiert werden konnten. Somit konnten mit den beiden Instrumenten der Wuchs- und Reblausbonitur die beiden Arbeitshypothesen dahingehend belegt werden, dass unter Verwendung der Unterlagensorten der Kreuzungskombination V. berlandieri x V. riparia kein Zusammenhang zwischen der Reblausdichte im Boden und Rückgangserscheinungen der Rebe vorliegen. Darüber hinaus konnte belegt werden, dass in Erweiterung dieser Erkenntnis das Ausmaß der Rückganserscheinungen bei Reben maßgeblich von der Art der Bewirtschaftung abhängt und somit deutlich abzutrennen ist vom Einfluss des Reblausbefalls. Vor allem konnte durch die vorliegende Arbeit unter Einbeziehung des Wuchsbonitursystems eine Methode erarbeitet werden, die in Zukunft bei der Beurteilung von Fernerkundungsdaten ein nützliches Instrument darstellt, um die wirklichen Gegebenheiten hinsichtlich des Wuchses der Reben auf Weinbergsflächen mit den berechneten Werten zu Wuchsindizes zu korrelieren.
Aufgrund oftmals erhöhter Arsen- und Schwermetallgehalte in den Oberböden von Auen ist eine Verwertung von Auenböden, zum Beispiel im Rahmen von Renaturierungsmaßnahmen, oftmals schwierig, da keine auenspezifische Bewertungsgrundlage für dieser Stoffgehalte vorliegt.
Am Beispiel der Lippeaue erfolgte auf Grundlage abgeleiteter Haupteinflussfaktoren für die Konzentration von Arsen- und Schwermetallen in den Oberböden die Ableitung von Hintergrundgehalten. Die Metall- und Schwermetallgehalte in den Oberböden der Lippeaue lagen i. d. R. erwartungsgemäß oberhalb der in der Praxis verwendeten Einstufungswerte (z. B. Vorsorgewerte der BBodSchV, Hintergrundwerte von NRW), die sich allerdings auf Standorte außerhalb der Aue beziehen.
Anhand von gewonnen Daten aus Projektarbeiten im Zuge der Umsetzung der EU-Wasserrahmenrichtlinie (z. B. bodenkundliche und ingenieurgeologische Profilaufnahme, bodenmechanische Laborversuche) und ergänzend durchgeführter Untersuchungen, wie z. B. Bodentypenkartierung und mineralogische Untersuchungen, erfolgte eine detaillierte Standortcharakterisierung der Böden in der Lippeaue.
Auf Basis der abgeleiteten Hintergrundgehalte wurden unter Berücksichtigung der ermittelten Bodenkennwerte und Einflussgrößen auenspezifische Einbauregeln abgeleitet. Mit dem Ziel einer praktikablen Anwendbarkeit wurde eine auf die wesentlichen Kenngrößen reduzierte Bewertungsmatrix erarbeitet. Bei geplanten baulichen Eingriffen in den Boden kann nun mit den lippeauenspezifischen Einbauwerten für Arsen und Schwermetalle anhand konventioneller Parameter für jeden Standort ermittelt werden, ob besonders günstige oder ungünstige Bedingungen für einen potenziellen Wiedereinbau vorliegen. Die abgeleiteten Hintergrundgehalte und Einbauwerte verstehen sich dabei als – auf Basis der aktuellen Datenlage abgeleitete – Handlungsempfehlung und Orientierung zur Bewertung von Böden im Hinblick auf einen gebietsübergreifenden Wiedereinbau in der Lippeaue.
This working paper examines the concept of metabolism and its potential as a critical analytical lens to study the contemporary city from a political perspective. The paper illustrates how the metabolism concept has been used historically, both as a metaphor to describe the technological, social, political and economic dimensions of human-environment relations, and as a concrete analytical tool to quantify and better understand how flows of matter and energy shape the territorial and spatial configurations of cityscapes. Drawing on the example of the urban water metabolism of the Greater Accra Metropolitan Area (GAMA), it is argued that contemporary approaches to metabolic analysis should be extended in two ways to increase the integrative potential of the urban water metabolism concept. On the one hand, the paper demonstrates that a political ecology approach is particularly well-suited to illuminate the contested production of urban environments and move beyond a narrow technical, managerial and state- centric focus in research on urban metabolic relations. On the other hand, the paper advocates for an approach to metabolic analysis that views the urban environment not simply as a relatively static exteriority that is produced by dynamic flows of matter, energy and information, but rather as a dynamic, nested and co-evolutionary network of complex biosocial and material relations, which in itself shapes how various metabolisms interact across scales. The paper then concludes by briefly discussing how a combination of metabolic analysis and political ecology research can inform urban water governance. In sum, the paper emphasizes the need for metabolic analysis to remain open to a plurality of different knowledge forms and perspectives, and to remain attentive to the inherently political nature of material and technological phenomena in order to allow for mutually beneficial exchanges between various scholarly communities.
The impacts of intense urbanization and associated urban land-use change along coastlines is vast and unprecedented. Several coasts of the world have been be subjected to human-induced coastal changes and it is imperative to monitor, assess and quantify them. This paper provides the state-of-the-art discourses on the changing dynamics of urban land-use driven by the forces of urbanization. Drawing on extant literature mainly from Web of Science and Google scholar, the status quo of the spatio-temporal dynamics of urbanization and urban change processes were explored with specific focus on global, Africa, Ghana and an actual case of Accra coast. Findings show whilst urbanization continues to increase exponentially, urban land also continue to change markedly. Current trends and patterns shows that changing urban dynamics exhibit are distinctly different from that of the past. Particularly, the rate, magnitude, geographic location, urban forms and functions are changing. In the specific case of Accra coast, there is general trend of urbanization moving outwards, i.e. from the core city centre towards the peripheral areas. Additionally, spatial urban pattern is dominated by urban sprawl, characterized by the cyclical process of diffusion and coalescence. The processes of urbanization are further exacerbated within coastal areas with a new and unique spatial urban form, “tourism urbanization” emerging. This new urban form is largely driven by rapid expansion of tourist infrastructure, developing at the instance of government policy to develop coastal tourism. In addition, the coastal conurbation of Accra-Tema is a powerful hub for industrial and commercial activities, which is drawing huge “humanline” to- wards the coastline. The literature illustrates that contemporary approaches and conceptualizations for urbanization and urban land-use change analysis be extended particularly from the mere focus on statistical classifications of cities in different size categories. With the urban fringe spreading outwardly, it should be kept in mind that new forms of urban settlements are emerging along with varying sizes. Considering the multiple scales, magnitude and rates involved as well as the geospatial patterns of urban change processes, experimental case studies that include coastal cities, Peri-urban fringes and interconnections with rural areas across a range of urbanization processes is essential and very urgent.
The main socio-ecological pressures in five wetlands in the Greater Accra Region were first identified and then summarized by reviewing the relevant literature. As a second step, fieldwork in the region was carried out in 2016 to further examine the pressures identified in the literature. Most research on the wetlands in Ghana was published around the year 2000. Yet, similar socio-ecological pressures persist today. Based on both, fieldwork observations and the literature review, these pressures were ranked using the IUCN pressures system analysis framework. It is suggested that further research needs to proceed with uncovering how trade-offs between ecosystem and quality of life can be defined.
In a first step, this paper analyses the emergence of the UN Sustainable Development Goals (SDGs) as new global development framework with regard to key actors, social learning cycles, innovation platforms, fundamental policy changes and transition dynamics towards sustainability. In a second step, it traces the convolution of social, political and environmental dimensions, social power relations and governance paradigms embedded in the drafting process and final framework of the water related SDG 6. This research concludes that the SDGs induced important paradigm and policy changes in addition to rearranging existing power relations.
Stakeholder Mapping
(2016)
This report presents the results of a stakeholder mapping exercise carried out in the WaterPower project. The mapping was conducted for the following main research areas of the project: water supply, land use planning and management, wetland management and climate change adaptation/disaster risk reduction. The report gives an overview of the stakeholders that play a role in these respective areas and identifies those who have concomitant responsibilities in different sectors. It represents the first step towards further involvement of stakeholders in the WaterPower project.
In the first overview lecture, we take a look at conceptualizations of water – from the hydrological cycle to socio-political perspectives on water. During the 20th century, water management developed from traditional uses and local industrial schemes to the “hydraulic paradigm” and finally, to the concept of modern water governance at the turn of the millennium. We will raise the question of whether there has truly been a paradigm shift from the natural, science based hydraulic paradigm to water governance and how dual- isms of culture/society and nature are still being reproduced. With this in mind, we will also take an introductory look at the much talked about global water crisis.
GIS – what can and what can’t it say about social relations in adaptation to urban flood risk?
(2017)
Urban flooding cannot be avoided entirely and in all areas, particularly in coastal cities. Therefore adaptation to the growing risk is necessary. Geographical Information Systems (GIS) based knowledge on risk informs location-based approach to adaptation to climate risk. It allows managing city- wide coordination of adaptation measures, reducing adverse impacts of local strategies on neighbouring areas to the minimum. Quantitative assessments dominate GIS applications in flood risk management, for instance to demonstrate the distribution of people and assets in a flood prone area. Qualitative, participatory approaches to GIS are on the rise but have not been applied in the context of flooding yet. The overarching research question of this working paper is: what can GIS, and what can it not say about relationships / social relations in adaptation to urban flood risk? The use of GIS in risk mapping has exposed environmental injustices. Applications of GIS further allow model- ling future flood risk in function of demographic and land use changes, and combining it with decision support systems (DSS). While such GIS applications provide invaluable information for urban planners steering adaptation they however fall short on revealing the social relations that shape individual and household adaptation decisions. The relevance of networked social relations in adaptation to flood risk has been demonstrated in case studies, and extensively in the literature on organizational learning and adaptation to change. The purpose of this literature review is to identify the type of social relations that shape adaptive capacities towards urban flood risk which can- not be identified in a conventional GIS application.
Understanding the mechanisms that shape access to the fisheries ecosystem service in Tsokomey, Accra
(2019)
Questions of access to ecosystem services remain largely unaddressed. Yet, in the coming decades, addressing access to services and securing them for livelihoods and well-being of people will likely gain importance, especially to guide according policies at the local scale. Through a qualitative approach, this paper addresses the mechanisms that shape access to the fisheries eco- system service in Accra, Ghana. The analysis uses a framework that focuses on access to land, tools and technology, knowledge and information, capital and credit, as well as labor. This research reveals how access is organized across the different categories of this framework and how people’s well-being is shaped. Moreover, it helps to further our understanding of what regulates the access to ecosystem services and how to address future shocks and capacity in terms of production of ecosystem services.
The rate and range of ongoing changes in social and ecological systems and particularly the global environmental degradation illustrates the need of holistic and sustainable approaches for the governance of natural resources to ensure their well-functioning for future generations (Rockström et al. 2009). The narrative of common pool resources system such as SES of small-scale fisheries, reports world-wide of stock collapse, environmental degradation and overexploitation (Cinner et al. 2013). In order to understand the complexity of system interactions in those resource systems, the consideration of local scale specific phenomena is of great relevance (Ostrom 2007b). The focus of this thesis consequently is the social-ecological system of a small scale fishery in a heavily urbanised coastal wetland on the fringes of Ghana ́s capital Accra. With the theoretical foundation of the social-ecological system (SES) theory (Folke et al. 2004; Berkes et al. 2003; G. S. Cumming 2011) and the social-ecological system framework (SESF) by Ostrom (2007a) and McGinnis & Ostrom (2014) as analytical tool, the study ex- amines the role of the fishers as focal actor group and the governance system based on traditional ecological knowledge (TEK) (Berkes et al. 2003). While the common narrative of system collapse is partly confirmed for the focal system, also contradicting findings about the diversity of the actor group, their sustainable and responsible exploitation of the deltas resources have been found, that rather illustrate the fishers as potential cooperation partners for the development of sustainable governance strategies (see Hollup 2000) than simply as bur- den to the system. However, the results also show that in order to achieve sustainable outcomes in the focal SES, so far unsuccessful top-down governance efforts have to work cooperatively with the fishers to challenge the multiple threats to the system from external perturbation and internal changes, in the long run.
As in many other cities of the Global South, in Accra and its Greater Metropolitan Area (GAMA) water provision for drinking, domestic and productive uses is coproduced by multiple provisioning and delivery modalities. This paper contributes to the overall understanding of sociospatial conditions of urban water (in)security in GAMA. By looking at the geography of infrastructure and inequalities in water access, it seeks to identify patterns of uneven access to water. The first part provides an overview of urban water supply in GAMA, focusing on water infrastructure and the perspective of water providers. In the second part, households’ access strategies are discussed by combining both quantitative and qualitative perspectives. The paper brings together literature research and empirical material collected during fieldwork in the Ghanaian capital city.
This literature review was conducted to identify important wetlands in the Greater Accra Region and to illustrate dominant research trends, prevailing perspectives and corresponding research gaps. Six wetlands systems were identified as most significant lagoon systems, namely the Densu Delta, Sakumo, Muni-Pomadze, Keta, Korle and Songor Lagoons. Research foci for each of the respective wetlands were extrapolated and summarized in a category system. The frequency of different categories illustrates that natural science’s perspectives dominate, as most of Accra’s lagoons have been studied with regard to their ecological, physical and chemical properties. The development of research interest over time and focus on ecological baseline conditions are related to the designation of Ramsar Sites and orientation of national policies towards environmental protection. A research gap was identified, as studies link their findings to human activities but neglect the connection between governance variables and environmental developments. It is suggested to expand the natural science’s perspective on Accra’s wetlands to account for social and political aspects in order to develop a holistic and more sustainable management strategy.
This paper provides an overview of five major shifts in urban water supply governance in relation to changing paradigms in the water sector as a whole and in water-related research: i) the municipal hydraulic paradigm in the Global North; ii) its travel to cities in the Global South; iii) the shift from government to governance; iv) the (private) utility model and v) its contestation. The articulation of each shift in the Ghanaian context is described from the creation of the first water supply system during colonial time to the recent contestation against private corporate sector participation. Current challenges are outlined together with new pathways for researching urban water governance. The paper is based on a literature review conducted in 2015 and serves as a background study for further research within the WaterPower project.
This working paper outlines analytical pathways that could contribute to deepening the understanding of water inequalities in cities of the Global South. It brings together the status quo of research on water inequalities in Accra, the capital of Ghana, and studies on Environmental Justice. In doing so, it argues for the need to analytically distinguish between the terms ‘(in)equality’ and ‘(in)justice’. Studying everyday water practices and per- spectives on water (in)justice of different stakeholders would be a suitable entry point for an in-depth ethnographic study that analytically separates water inequalities and water injustices but considers their interlinkages. The working paper is based on a literature review conducted in 2015 in the scope of the WaterPower project.
Both water scarcity and flood risk are increasingly turning into safety concerns for many urban dwellers and, consequently, become increasingly politicised. This development involves a reconfiguration of the academic land- scape around urban risk, vulnerability and adaptation to climate change research. This paper is a literature assessment of concepts on disaster risk, vulnerability and adaptation and their applicability to the context of studying water in an African city. An overview on water-related risk in African cities is presented and concepts and respective disciplinary backgrounds reviewed. Recent debates that have emerged from the application of risk, vulnerability and adaptation concepts in research and policy practice are presented. Finally the applicability of these concepts as well as the relevance and implications of recent debates for studying water in African cities is discussed. ‘Riskscape’ is proposed as a conceptual frame for close and integrated analysis of water related risk in an African city.
Global food security poses large challenges to a fast changing human society and has been a key topic for scientists, agriculturist, and policy makers in the 21st century. The United Nation predicts a total world population of 9.15 billion in 2050 and defines the provision of food security as the second major point in the UN Sustainable Development Goals. As the capacities of both, land and water resources, are finite and locally heavily overused, reducing agriculture’s environmental impact while meeting an increasing demand for food of a constantly growing population is one of the greatest challenges of our century. Therefore, a multifaceted solution is required, including approaches using geospatial data to optimize agricultural food production.
The availability of precise and up-to-date information on vegetation parameters is mandatory to fulfill the requirements of agricultural applications. Direct field measurements of such vegetation parameters are expensive and time-consuming. On the contrary, remote sensing offers a variety of techniques for a cost-effective and non-destructive retrieval of vegetation parameters. Although not widely used, hyperspectral thermal infrared (TIR) remote sensing has demonstrated being a valuable addition to existing remote sensing techniques for the retrieval of vegetation parameters.
This thesis examined the potential of TIR imaging spectroscopy as an important contribution to the growing need of food security. The main scientific question dealt with the extraction of vegetation parameters from imaging TIR spectroscopy. To this end, two studies impressively demonstrated the ability of extracting vegetation related parameters from leaf emissivity spectra: (i) the discrimination of eight plant species based on their emissivity spectra and (ii) the detection of drought stress in potato plants using temperature measures and emissivity spectra.
The datasets used in these studies were collected using the Telops Hyper-Cam LW, a novel imaging spectrometer. Since this FTIR spectrometer presents some particularities, special attention was paid on the development of dedicated experimental data acquisition setups and on data processing chains. The latter include data preprocessing and the development of algorithms for extracting precise surface temperatures, reproducible emissivity spectra and, in the end, vegetation parameters.
The spectrometer’s versatility allows the collection of airborne imaging spectroscopy datasets. Since the general availability of airborne TIR spectrometers is limited, the preprocessing and
data extraction methods are underexplored compared to reflective remote sensing. This counts especially for atmospheric correction (AC) and temperature and emissivity separation (TES) algorithms. Therefore, we implemented a powerful simulation environment for the development of preprocessing algorithms for airborne hyperspectral TIR image data. This simulation tool is designed in a modular way and includes the image data acquisition and processing chain from surface temperature and emissivity to the final at-sensor radiance data. It includes a series of available algorithms for TES, AC as well as combined AC and TES approaches. Using this simulator, one of the most promising algorithms for the preprocessing of airborne TIR data – ARTEMISS – was significantly optimized. The retrieval error of the atmospheric water vapor during the atmospheric characterization was reduced. As a result, this improvement in atmospheric characterization accuracy enhanced the subsequent retrieval of surface temperatures and surface emissivities intensely.
Although, the potential of hyperspectral TIR applications in ecology, agriculture, and biodiversity has been impressively demonstrated, a serious contribution to a global provision of food security requires the retrieval of vegetation related parameters with global coverage, high spatial resolution and at high revisit frequencies.
Emerging from the findings in this thesis, the spectral configuration of a spaceborne TIR spectrometer concept was developed. The sensors spectral configuration aims at the retrieval of precise land surface temperatures and land surface emissivity spectra. Complemented with additional characteristics, i.e. short revisit times and a high spatial resolution, this sensor potentially allows the retrieval of valuable vegetation parameters needed for agricultural optimizations. The technical feasibility of such a sensor concept underlines the potential contribution to the multifaceted solution required for achieving the challenging goal of guaranteeing global food security in a world of increasing population.
In conclusion, thermal remote sensing and more precisely hyperspectral thermal remote sensing has been presented as a valuable technique for a variety of applications contributing to the final goal of a global food security.
Finding behavioral parameterization for a 1-D water balance model by multi-criteria evaluation
(2019)
Evapotranspiration is often estimated by numerical simulation. However, to produce accurate simulations, these models usually require on-site measurements for parameterization or calibration. We have to make sure that the model realistically reproduces both, the temporal patterns of soil moisture and evapotranspiration. In this study, we combine three sources of information: (i) measurements of sap velocities; (ii) soil moisture; and (iii) expert knowledge on local runoff generation and water balance to define constraints for a “behavioral” forest stand water balance model. Aiming for a behavioral model, we adjusted soil moisture at saturation, bulk resistance parameters and the parameters of the water retention curve (WRC). We found that the shape of the WRC influences substantially the behavior of the simulation model. Here, only one model realization could be referred to as “behavioral”. All other realizations failed for a least one of our evaluation criteria: Not only transpiration and soil moisture are simulated consistently with our observations, but also total water balance and runoff generation processes. The introduction of a multi-criteria evaluation scheme for the detection of unrealistic outputs made it possible to identify a well performing parameter set. Our findings indicate that measurement of different fluxes and state variables instead of just one and expert knowledge concerning runoff generation facilitate the parameterization of a hydrological model.
Because EU water quality policy can result in infrastructure creation or adaptation at the local level across member states, compliance cases are worth examining critically from a sustainable spatial planning perspective. In this study, the 2000 EU Water Framework Directive’s (WFD) reach to local implementation efforts in average towns and cities is shown through the case study of nonconforming household wastewater infrastructure in the German state of Rhineland Palatinate. Seeing wastewater as a socio-technical infrastructure, we ask how the WFD implementation can be understood in the context of local infrastructure development, sustainability, and spatial planning concepts. In particular, this study examines what compliance meant for the centralization or decentralization of local wastewater infrastructure systems—and the sustainability implications for cities
from those choices.
Background: Increasing exposure to engineered inorganic nanoparticles takes actually place in both terrestric and aquatic ecosystems worldwide. Although we already know harmful effects of AgNP on the soil bacterial community, information about the impact of the factors functionalization, concentration, exposure time, and soil texture on the AgNP effect expression are still rare. Hence, in this study, three soils of different grain size were exposed for up to 90 days to bare and functionalized AgNP in concentrations ranging from 0.01 to 1.00 mg/kg soil dry weight. Effects on soil microbial community were quantified by various biological parameters, including 16S rRNA gene, photometric, and fluorescence analyses.
Results: Multivariate data analysis revealed significant effects of AgNP exposure for all factors and factor combinations investigated. Analysis of individual factors (silver species, concentration, exposure time, soil texture) in the unifactorial ANOVA explained the largest part of the variance compared to the error variance. In depth analysis of factor combinations revealed even better explanation of variance. For the biological parameters assessed in this study, the matching of soil texture and silver species, and the matching of soil texture and exposure time were the two most relevant factor combinations. The factor AgNP concentration contributed to a lower extent to the effect expression compared to silver species, exposure time and physico–chemical composition of soil.
Conclusions: The factors functionalization, concentration, exposure time, and soil texture significantly impacted the effect expression of AgNP on the soil microbial community. Especially long-term exposure scenarios are strongly needed for the reliable environmental impact assessment of AgNP exposure in various soil types.
Der vorliegende Artikel beschreibt die klimatische Situation des Naturparks Saar-Hunsrück. Neben der Einordnung der Region in die großskalige klimatische Zirkulation werden die wesentlichen Klimaelemente beschrieben. Da sich die Klimaelemente mit zunehmender Höhe verändern, bestimmt im unteren Saartal, im Saar-Nahe-Bergland und Hunsrück mit Osburger Hochwald, Schwarzwälder Hochwald und Idarwald die Höhenlage entscheidend die räumliche Struktur der einzelnen Klimaelemente. Die Niederschlagsverteilung zeigt deutlich den Luveffekt in den westlichen Teilen des Naturparks und die Abnahme der Niederschlagshöhen in nordöstlicher Richtung. Die räumlichen Muster der mittleren und maximalen Lufttemperatur folgen der Topographie, während Minimalwerte der Temperatur ein weniger differenziertes Bild zeigen. In den tiefer gelegenen Regionen des Naturparks treten 4-7 Hitzetage in langjährigen Mittel auf, in den Hochlagen des Hunsrücks werden nur noch 1-3 Tage / Jahr beobachtet. Oberhalb der 600 m-Höhenlinie ergeben sich im Mittel 110-130 Frosttage im Jahr, im südwestlichen Teil des Naturparks geht die Zahl auf 50 Tage / Jahr zurück. Die mittlere Anzahl der Tage mit Schneedecke liegt, bezogen auf das Areal des Naturparks, insgesamt zwischen 10 und 90 Tagen pro Jahr. Ihre Veränderung infolge des regionalen Klimawandels zeigt eine Abnahme zwischen 3-15 Tagen pro Jahr zwischen den Zeiträumen 1961-1990 und 1981-2010. Die aktuelle Sonnenscheindauer beträgt im westlichen Teil des Naturparks im Mittel 1500-1600 Sonnenscheinstunden pro Jahr, im südöstlichen Teil werden bis 1600 Stunden pro Jahr erreicht.
In the present study a non-motion-stabilized scanning Doppler lidar was operated on board of RV Polarstern in the Arctic (June 2014) and Antarctic (December 2015– January 2016). This is the first time that such a system measured on an icebreaker in the Antarctic. A method for a motion correction of the data in the post-processing is presented.
The wind calculation is based on vertical azimuth display (VAD) scans with eight directions that pass a quality control. Additionally a method for an empirical signal-tonoise ratio (SNR) threshold is presented, which can be calculated for individual measurement set-ups. Lidar wind profiles are compared to total of about 120 radiosonde profiles and also to wind measurements of the ship.
The performance of the lidar measurements in comparison with radio soundings generally shows small root mean square deviation (bias) for wind speed of around 1ms-1(0.1ms-1) and for wind direction of around 10 (1). The post-processing of the non-motion-stabilized data shows comparably high quality to studies with motion-stabilized systems.
Two case studies show that a flexible change in SNR threshold can be beneficial for special situations. Further the studies reveal that short-lived low-level jets in the atmospheric boundary layer can be captured by lidar measurements with a high temporal resolution in contrast to routine radio soundings. The present study shows that a non-motionstabilized Doppler lidar can be operated successfully on an
icebreaker. It presents a processing chain including quality control tests and error quantification, which is useful for further measurement campaigns.
Species can show strong variation of local abundance across their ranges. Recent analyses suggested that variation in abundance can be related to environmental suitability, as the highest abundances are often observed in populations living in the most suitable areas. However, there is limited information on the mechanisms through which variation in environmental suitability determines abundance. We analysed populations of the microendemic salamander Hydromantes flavus, and tested several hypotheses on potential relationships linking environmental suitability to population parameters. For multiple populations across the whole species range, we assessed suitability using species distribution models, and measured density, activity level, food intake and body condition index. In high-suitability sites, the density of salamanders was up to 30-times higher than in the least suitable ones. Variation in activity levels and population performance can explain such variation of abundance. In high-suitability sites, salamanders were active close to the surface, and showed a low frequency of empty stomachs. Furthermore, when taking into account seasonal variation, body condition was better in the most suitable sites. Our results show that the strong relationship between environmental suitability and population abundance can be mediated by the variation of parameters strongly linked to individual performance and fitness.
The changing views on the evolutionary relationships of extant Salamandridae (Amphibia: Urodela)
(2018)
The phylogenetic relationships among members of the family Salamandridae have been repeatedly investigated over the last 90 years, with changing character and taxon sampling. We review the changing composition and the phylogenetic position of salamandrid genera and species groups and add a new phylogeny based exclusively on sequences of nuclear genes. Salamandrina often changed its position depending on the characters used. It was included several times in a clade together with the primitive newts (Echinotriton, Pleurodeles, Tylototriton) due to their seemingly ancestral morphology. The latter were often inferred as a monophyletic clade. Respective monophyly was almost consistently established in all molecular studies for true salamanders (Chioglossa, Lyciasalamandra, Mertensiella, Salamandra), modern Asian newts (Cynops, Laotriton, Pachytriton, Paramesotriton) and modern New World newts (Notophthalmus, Taricha). Reciprocal non-monophyly has been established through molecular studies for the European mountain newts (Calotriton, Euproctus) and the modern European newts (Ichthyosaura, Lissotriton, Neurergus, Ommatotriton, Triturus) since Calotriton was identified as the sister lineage of Triturus. In pre-molecular studies, their respective monophyly had almost always been assumed, mainly because a complex courtship behaviour shared by their respective members. Our nuclear tree is nearly identical to a mito-genomic tree, with all but one node being highly supported. The major difference concerns the position of Calotriton, which is no longer nested within the modern European newts. This has implications for the evolution of courtship behaviour of European newts. Within modern European newts, Ichthyosaura and Lissotriton changed their position compared to the mito-genomic tree. Previous molecular trees based on seemingly large nuclear data sets, but analysed together with mitochondrial data, did not reveal monophyly of modern European newts since taxon sampling and nuclear gene coverage was too poor to obtain conclusive results. We therefore conclude that mitochondrial and nuclear data should be analysed on their own.
Reptiles belong to a taxonomic group characterized by increasing worldwide population declines. However, it has not been until comparatively recent years that public interest in these taxa has increased, and conservation measures are starting to show results. While many factors contribute to these declines, environmental pollution, especially in form of pesticides, has seen a strong increase in the last few decades, and is nowadays considered a main driver for reptile diversity loss. In light of the above, and given that reptiles are extremely underrepresented in ecotoxicological studies regarding the effects of plant protection products, this thesis aims at studying the impacts of pesticide exposure in reptiles, by using the Common wall lizard (Podarcis muralis) as model species. In a first approach, I evaluated the risk of pesticide exposure for reptile species within the European Union, as a means to detect species with above average exposure probabilities and to detect especially sensitive reptile orders. While helpful to detect species at risk, a risk evaluation is only the first step towards addressing this problem. It is thus indispensable to identify effects of pesticide exposure in wildlife. For this, the use of enzymatic biomarkers has become a popular method to study sub-individual responses, and gain information regarding the mode of action of chemicals. However, current methodologies are very invasive. Thus, in a second step, I explored the use of buccal swabs as a minimally invasive method to detect changes in enzymatic biomarker activity in reptiles, as an indicator for pesticide uptake and effects at the sub-individual level. Finally, the last part of this thesis focuses on field data regarding pesticide exposure and its effects on reptile wildlife. Here, a method to determine pesticide residues in food items of the Common wall lizard was established, as a means to generate data for future dietary risk assessments. Subsequently, a field study was conducted with the aim to describe actual effects of pesticide exposure on reptile populations at different levels.