Books in the IHE Delft PhD Thesis Series series

Climate change and development imperatives create additional pressure on water resources and will have severe future impacts on the Nile Delta aquifer. An innovative method for identification of the most representative model has been developed, which is useful for Water-Food Nexus studies.

User interface is one of the most important components for decision support systems since it directly faces to the end users: decision makers and stakeholders. Implementation of modern visualization and interaction techniques can fill the gap between models and information in order to assist the end user to achieve appropriate knowledge. Web-based interactive maps and construction of virtual environments are mainly described in this research. Combining with several case studies, the advantages and disadvantages of 2D and 3D visualization have been revealed.

The challenge of water scarcity as a result of insufficient seasonal rainfall and dry spell occurrences during cropping seasons is compounded by inefficient agricultural practices by smallholder farmers where insignificant soil and water conservation efforts are applied.

In general, groundwater is a preferred source of drinking water because of its convenient availability and its constant and good quality. However this source is vulnerable to contamination by several substances. Acceptable quality limits relative to micropollutant contents in drinking water are becoming increasingly lower and efficient elimination treatment processes are being implemented in order to meet these requirements. Metals contaminants at low concentration are difficult to remove from water. Chemical precipitation and other methods become inefficient when contaminants are present in trace concentrations and the process of adsorption is one of the few alternatives available for such situations. This book describes the adsorption method in the removal of selected heavy metals present as cations (Cd2+, Cu2+ and Pb2+) or oxyanions (Cr(VI) and As(V)) using iron oxide coated sand (IOCS) and granular ferric hydroxide (GFH). The effects of pH, natural organic matter (fulvic acid (FA)) and interfering ions (PO43-, Ca2+) on the adsorption efficiency were also assessed. The sorption reactions that take place at the surface of the adsorbent were also described through the surface complexation modelling for Cd2+, Cu2+ and Pb2+ adsorption. Batch adsorption tests and rapid small scale column tests (RSST) were used as laboratory methods.

This research contributes towards a better understanding of how the concentration of Escherichia coli, Bacillus subtilis spores, and MS2 bacteriophages in contaminated shallow water bodies and on different urban surfaces is affected by the environmental conditions.

Thesis defended 3 July 2015 in front of the PhD committee.

Analysis shows no significant long-term changes of rainfall over Dinder and Rahad basins. Analysis of streamflow response to land use and land cover changes using satellite data and hydrological modelling was performed. The effect of land use and land cover changes on the hydrology of the basins was proven to be true.