17 documents found

Dissertation

The hydrology of the Sudd : hydrologic investigation and evaluation of...

This dissertation describes the hydrology of the Sudd swamps in southern Sudan, comprising a hydrologic investigation and evaluation of its water balance. The study improves historical interpretations and unveils so far unknown conditions and interdependencies in the swamp and floodplain system, considering...
Dissertation

Nitrate processes investigation for improved ecohydrological modeling at...

The excessive presence of nitrate in predominantly agricultural catchments can result in serious negative impacts on water resources and ecosystems. Ecohydrological models can be used to investigate nitrate dynamics in water and soil and future activities for water quality improvement. The Treene catchment...
Dissertation

Assessing potential impacts of multiple stressors on riverine phytoplankton...

Increasing pressures from both natural disturbance and anthropogenic activities challenge river ecosystem resilience. A better understanding of the ecological balancing of structure under multiple stressors is thus critical for sustainable future as well as human wellbeing. Phytoplankton are one of the...
Dissertation

Assessment of flow and sediment transport in rivers and on floodplains...

Lowland river-floodplain systems are typical interactive ecosystems characterized by low altitude differences, high frequency of flooding, low flow velocity and the exchange of energy and substrate between channel and floodplain. Stream power is recognized as a force of formation and development of the...
Dissertation

Ecohydrologic and hydraulic stream modelling to describe aquatic habitats

Naturnahe Einzugsgebiete, Fließgewässer und die aquatische Vielfalt wurden primär aufgrund der Auswirkungen der industriellen und urbanen Entwicklung sowie der Intensivierung der Landwirtschaft weltweit degeneriert. Diese Veränderungen haben auf verschiedenen Skalen stattgefunden und daher sind Rehabilitationsmaßnahmen...
Dissertation

Socioeconomic contexts for the spatial variations of ecosystem services...

Ecosystem services are strongly underpinned by ecological processes and functions and influenced by socioeconomics in human-environmental systems. As the prerequisites for human well-being, ecosystem services can reflect the interactions of human and environmental systems. Being pervading the process...
Dissertation

A guideline for hydrologically consistent models

Hydrological models are established tools to simulate discharge and hydrological processes of watersheds. Scenario simulations and resource management studies are carried out, assuming that hydrological processes are simulated appropriately. However, several studies revealed that satisfying discharge...
Dissertation

Development and testing of a phytoplankton index of biotic integrity (P-IBI)...

This dissertation developed and tested a phytoplankton index of biotic integrity (P-IBI) to assess the ecological conditions of German lowland rivers, and simulated the daily phytoplankton biomass (as indicated by chlorophyll a) dynamics for the purpose of water quality forecasting and watershed management....
Dissertation

Analyses and quantification of modelling uncertainties in streamflow simulations...

Models are the primary way to predict the values of various system performance indicators in hydrologic researches. The usefulness of any model depends in part on the accuracy and reliability of its output. This PhD thesis presents the development of a methodological framework to analyse the impacts...
Dissertation

Assessing the impact of land use change on hydrology and sediment yield...

This dissertation describes the application of the eco-hydrological model SWAT to a watershed in the Three Gorges Region, which is located in Hubei Province and Chongqing Municipality in Central China. The region is heavily influenced by the construction of the Three Gorges Dam on Yangtze River, which...
Dissertation

Development and application of a non-point sources pollution model for...

This dissertation describes the hydrology and non-point source pollution of the humid, subtropical Xitiaoxi catchment in the south-eastern China and comprises a hydrologic and nutrient dynamics simulation there. The study presents at first an interpretation of hydrological processes influenced by anthropological...
Dissertation

Water quality assessment and management of lowland river catchment

This dissertation describes at first the hydrology and the long-term impact of point and diffuse source pollution on nutrient loads based on the current agricultural practices and sewage disposals in rural lowland catchments. The evaluations of Best Management Practices (BMPs) for water quality improvement...
Dissertation

Regional assessments of selected ecosystem services in northern Germany

The purpose of this study is to gain a better understanding of the land cover distributions, land cover changes and the differences in ecosystem service provisions resulting from distinctive indicators based on various CORINE land cover classes. By analyzing the land cover dynamics and the annual total...
Dissertation

Environmental behaviour of selected herbicides in a lowland catchment in...

In order to gain high production levels and product quality, pesticides are employed for the protection of plants and plant products. By their very nature, however, most pesticides create harmful risks to humans, animals and the environment. As an example for pesticide behaviour in lowland conditions,...
Dissertation

Integrated monitoring, assessment and modeling of nitrogen and phosphorus...

Water pollution caused by nitrogen (N) and phosphorus (P) is originated by diffuse and point sources. The point pollution is linked to wastewater from domestic and industrial sewage, whereas diffuse pollution is mainly from rural areas with agriculture and livestock. The monitoring,...
Dissertation

Model-based quantification of nitrate-nitrogen leaching considering sources...

More precise determination of nitrate-nitrogen losses is still required because of high variations regarding inorganic and/or organic N fertilization, portions of harvest amounts and residues, and associated C and N transformations in soil and plant. The nitrate-nitrogen leaching in agricultural soils...
Dissertation

Water balance of the Aswan High Dam Reservoir

This study aims to discuss the hydrological dimensions of the Aswan High Dam Reservoir. It examines the sedimentation in the reservoir and detects the changes in the storage capacity and the morphology of the AHDR because of sediment deposits. Also, a digital elevation model for the reservoir is generated...