Influence and modelling of urban runoff on the peak flows in rivers.

Surface waters and urban drainage systems are usually studied separately. However there are important interactions between both systems. Urban drainage systems can have an important impact on the surface waters, mainly at combined sewer overflows.

Science-policy interfacing in support of the Water Framework Directive implementation.

Many current water-related RTD projects have established operational links with practitioners, which allow the needs of policy makers to be taken into account. However, RTD results are not easily available to water policy implementers and research scientists may lack insight in the needs of policy makers and implementers (i.e.

Advection-dispersion modelling tools: what about numerical dispersion?

In general the transport of dissolved substances and fine suspended particles is governed by the one-dimensional advection-dispersion equation. In order to model the transport of dissolved substances and fine suspended particles, the advection-dispersion equation is incorporated into commonly used urban drainage modelling tools such as InfoWorks CS (Wallingford Software, United Kingdom) and MOUSE (DHI Software, Denmark). Two examples show the use of InfoWorks CS and MOUSE using standard model settings.

Solids separation efficiency of combined sewer overflows.

The removal of sewer solids at combined sewer overflow locations depends on the flow patterns inside the overflow structure on the one hand and on the sediment characteristics on the other hand. Flow conditions can be described by the residence time distribution; sewer sediments can be characterised by their settling velocity distribution. The combination of both distributions leads to a dimensionless efficiency curve, which gives the removal efficiency as a function of the Hazen number.

Design rules and impact assessment for source control measures based on continuous long-term simulations.

In recent years, more emphasis has been put on source control measures in order to reduce the peak runoff from urban areas during wet weather conditions. This involves the construction of upstream storage and infiltration facilities and rainwater tanks for reuse in households and the revaluation of ditches. Because of the long emptying times of source control facilities, a long antecedent period of rainfall influences the design.