| dc.description.abstract | Due to climate change the Netherlands will have longer periods of droughts, and more extreme
precipitation events during both summer and winter. It’s in society interest to secure crop yield, ensure
healthy water quality, prevent damage in urban areas and make the management cost-effective. “Smart”
water management could contribute to uniform, transparent and efficient management decisions. Water
board Hollandse Delta (WSHD) has set up a project called “New Control of the Water System, technical
automation (NBWS-TA)” in which WSHD aims to set-up regional control systems (RCS’s), which will be
implemented into a SCADA-system (Supervisory Control and Data Acquisition). SCADA displays all assets
connected to a PLC (Programmable Logic Controller). A RCS forms a set of rules that determines how
multiple assets should be controlled during a certain situation. WSHD has the prospective to incorporate
this into a Decision Support System (DSS) in which external data input is integrated. This thesis aims to
develop RCS’s for the Eendragt polder by answering the following research question; How can the control
of assets in the polder “De Eendragt” be integrated to have a water system that is adaptive to changing
meteorological conditions?
Firstly, the water management philosophy at WSHD has been explained. Secondly, the best practices of
Smart water management have been evaluated. Thirdly, the management scenarios during regular
circumstances, prolonged drought and periods of intense rainfall have been described and the
corresponding management strategies have been explained. Fourthly, the effectiveness of the rainfall
management strategy has been evaluated. Lastly, possible corresponding algorithms have been proposed.
WSHD must mitigate climate extremes and ensure clean and enough water in the polder.
Waterverordening “Zuid Holland” describes the maximal allowed increase in water level during an intense
rainfall event. During regular circumstances, no intense rainfall events or prolonged droughts or
exceptional events occur. During a prolonged drought, the water level drops further than the maximal
allowed drop in water level. A rainfall event is considered intense if the maximal drainage capacity of 17
mm/day is exceeded. Currently, each scenario has a corresponding management strategy.
Before implementing a DSS, there must be a clear aim, it is a supportive system, reflecting reality. Local
characteristics, initial state, type of rainfall event affects the impact of a rainfall event. In a DSS the
uncertainty of a rainfall event can be diminished by postponing the decision, performing high frequent
calculations, obtaining meteorological advice, high-quality data input, and data validation. The robustness
of the water system affects the goals, which influences the input parameters. More data points offer an
extra backup. Indirect values help to determine signal values.
During regular circumstances and a prolonged drought multiple (conflicting) interests should be
incorporated and prioritized by WSHD. The heterogeneityof the Eendragt polder and seasonal variability
makes it undesirable to design a management strategy based on land-use type. Therefore, only the “Equal
filling degree” strategy and “Risk informed management” strategy focusing on mitigating an intense rainfall
event have been elaborated further. Whereas the Equal filling degree strategy incorporates an equal filling
degree in all sub-polders, the Risk informed management strategy classifies the sub-polders into
vulnerability levels.
The management strategy Equal filling degree resulted in a more even water distribution and less
inundation. This strategy is most effective if all weirs are automated and can reach a 100% filling degree.
The results of the Risk informed management strategy were largely in alignment with the previous
strategy. This could be caused by a too high rainfall intensity, or the chosen filling degrees could have an
effect. The given algorithms can be specified and argued later according to the wishes of WSHD. In a DSS
these algorithms could be expanded further by also utilizing external data input.
It can therefore be concluded that Smart water management offers great potential in the support for
transparent, well-reasoned decisions. WSHD is still in the orienting phase. A clear prioritization of
management goals and interests is needed, this could be achieved by conducting additional interviews or
brainstorming sessions. Future research is needed to evaluate the potential of the Risk informed
management strategy. This could be done by elaborating the vulnerability levels and chosen filling degrees
in further detail. Although the SOBEK simulations consisted of several constrains, it provided valuable
insights in the change in water levels when applying multiple management strategies. | |
