C2) Lowland backwater effects

Tjitske Geertsema

"We investigate backwater effects at the interaction of rivers, upstream of wood and bends and the effects on groundwater"

Practical motivation

Few of the existing strategies towards water retention have been evaluated regarding their functionality and quantified impacts on the regional water system. Backwater effects are present in lowland rivers of all sizes and often increase local flood risk. A better understanding of backwater effects is necessary for water management. In this project, we investigate backwater effects at the interaction of rivers, upstream of wood and bends and the effects on groundwater.

Management phase: Intervention Planning |

Management goals: Flood safety | Hydrological understanding |

(Source: Tjitske Geertsema)

Research Aim

Progress in understanding stream restoration impacts on discharge dynamics requires more knowledge about the potential simultaneous occurrence of discharge waves in a river and its tributaries, and a deeper understanding of response time of surface-subsurface water exchange by looking at:

  • The current practice of stream restoration involves the construction of meander bends and insertion of woody debris, asserting local controls on stream conveyance capacity. Backwater effects resulting from sharp bends and the obstruction by woody debris remain poorly understood to date, and are considered key sources of uncertainty in predicting the effects of stream restoration.
  • Regionally, streams are typically analysed in isolation from the river system in which they debouch, with the risk of simultaneous occurrence of discharge peaks in the river and its tributaries. Within a sub-catchment, ground water variation near restored streams is rarely being analysed as a response to surface water dynamics.

Temporal scale: Daily series | Hourly series | Recent evolution (1-10years) |

Methods

  • Historical records of hourly and daily precipitation and discharge to find out the probability of simultaneous occurrence of discharge peaks in the Meuse River and its tributaries, Dommel and Aa River.
  • Correlation analysis between the occurrence of precipitation events, the discharge peaks and the water level gradient in the River Meuse and its tributaries. We compared these results to analyse the impact of various water retention strategies referring to the less simultaneous occurrence of the precipitation, flood and backwater effects.
  • Hourly water level and discharge time series are collected to analyze the water level effects of woody debris for five streams in the Netherlands.

Data-collection methods: Field survey measurements | Historical approach |

Main progress and next steps

  • Water retention can have significant impact in this case study, because the water retention of at least seven days is required to experience less simultaneous occurrence. Water retention of seven days however provides an additional risk of a new precipitation event within the seven days, which should be retained too.
  • Referring to the backwater effects, the water levels upstream of the woody debris show an increase of tens of centimeters after the insertion of woody debris. We consider the blocking area of the woody debris as the main parameter to indicate the relation of water level gradient and discharge. However, the study is still in progress and aims to indicate the main parameters in the relation between the water level gradient and the discharge.

Study areas

Key study areas: Tributaries Leerinkbeek, Ramsbeek, Tungelroysebeek  and Tongelreep (The Netherlands)

Last modified: 17/06/2018

Main researchers

Tjitske Geertsema

Supervisory team

dr. ir. Ton Hoitink

ton.hoitink@wur.nl

ryan.teuling@wur.nl

Contributing partners

Rijkswaterstaat Ministry of Infrastructure and Water Management

Foundation for Applied Water Research STOWA

Witteveen+Bos Engineering and Consulting

Wageningen University & Research

Utrecht University

NWO Applied and Engineering Sciences

Jump to publications list

Other outputs

Jump to: Abstract |

Abstract

2018

  • Geertsema, T.J., Torfs, P.J.J.F., Teuling, R.J. , Eekhout, J.P.C., Hoitink, A.J.F. (2018). Parametric model of wood-induced backwater in lowland streams. In: Huismans, Y., Berends, K.D., Niesten, I., Mosselman, E (Eds.). The future river: NCR DAYS 2018 Proceedings. Netherland Centre for River Studies publication 42-2018, 8-9 February 2018, Deltares, Delft, pp. 82.

2017

  • K. Kästner, A.J.F. Hoitink, T.J. Geertsema, B. Vermeulen. Do distributaries in a delta plain resemble an ideal estuary? Results from the Kapuas Delta, Indonesia. In: A.J.F. Hoitink, T.V. de Ruijsscher, T.J. Geertsema, B. Makaske, J. Wallinga, J.H.J. Candel, J. Poelman (Eds.), Book of abstracts NCR days 2017, NCR Publication 41-2017, 1-3 February 2017, Wageningen University & Research, pp. 16-17.
  • T.J. Geertsema, P.J.J.F. Torfs, A.J. Teuling, A.J.F. Hoitink. Backwater development by woody debris in streams. In: A.J.F. Hoitink, T.V. de Ruijsscher, T.J. Geertsema, B. Makaske, J. Wallinga, J.H.J. Candel, J. Poelman (Eds.), Book of abstracts NCR days 2017, NCR Publication 41-2017, 1-3 February 2017, Wageningen University & Research, pp. 28-29.
  • T.J. Geertsema, P.J.J.F. Torfs, A.J. Teuling, A.J.F. Hoitink. Backwater development by woody debris. European Geosciences Union (EGU) General Assembly 2017, Geophysical Research Abstracts, Vol. 19, EGU2017-15820,17 – 22 April 2016, Vienna, Austria.

 2016

 2015

Events

15/09/2017

Symposium on River, Coastal and Estuarine Morphodynamics 2017 in Padova (Italy)

View event

All events

Videos

Rivercare floodplain

01/11/2017

View video

All videos

Details

Status
Active
Start
09/2014
End
09/2018
Project group
Project C

Contact details

Tjitske Geertsema

Send a message

Table of contents