iMOD-SEAWAT for Groundwater in the coastal zone

Gualbert Oude Essink

Deltares & Utrecht University

gualbert.oudeessink@deltares.nl

More information:

freshsalt.deltares.nl

zoetzout.deltares.nl

DSD 2016

Threaths to deltas worldwide:

subsidence, salinisation, depletion, sealing, sea level rise, CC

DSD 2016

1/3 of the world population lives in the

coastal zone

DSD 2016

http://flood.firetree.net

Mississippi, USA

Nederland

Nile delta, Egypt

Mekong delta Bangladesh

Jakarta, Indonesia

Myanmar, Ayeyarwady

Salinisation processes at local scale

Upconing low-lying area

Shallow rainwaterlens

Upconing extraction Salt water intrusion surface water

Salt water intrusion groundwater Inundation saline seawater

DSD 2016

Serious overexploitation aquifers worldwide

20160524 Ara Sul

Murcia, Spanje

Bangkok, Vietnam

3D Regional coastal groundwater model studies

Bangladesh, coastal plain

Modelling:

• variable-density groundwater flow, coupled solute transport

Simulating effects of:

• autonomous processes (change extraction rates)

• sea level rise, changing recharge pattern

• land subsidence

Quantifying:

• hydraulic head

• saline seepage / infiltration

• fresh groundwater resources DSD 2016

Numerical models groundwater coastal zone

DSD 2016

The Netherlands Nile Delta

Central part Bengal Delta

Mekong,

research just

started

Fresh GW Volume

million m3:

NL: ~1000000

Nile: ~450000

Extraction GW

million m3/year:

NL: ~1000

Nile: ~4000

NUS-Deltares project in Singapore Jurong Island Groundwater Modeling and Risk Assessment Study

Monitoring and Modelling

SEAWAT module in iMOD

3D fresh-brackish-salt distribution groundwater

Esther van Baaren & Gualbert Oude Essink, Deltares DSD 2016

iMOD-SEAWAT Jurong Island Singapore

DSD 2016

fresh groundwater

saline groundwater

Fresh water lens 5 years after construction artificial island

W E solid rock

solid rock

saline groundwater

fresh groundwater

N S

Fresh water lens 5 years after construction artificial island

Time (years) after construction island

iMOD-solid module

iMOD-SEAWAT Nile delta

DSD 2016

DEM

SWIBANGLA

Managing Salt Water Impacts in Bangladesh

May 2013 – September 2014

Marta Faneca, Gijs Janssen, Gu Oude Essink, Deltares DSD 2016

iMOD-SEAWAT to build a 3D variable-density grw. model

3D data as input, e.g. boreholes

to build up the subsurface:

aquifers and aquitards

ASCII’S as

input

E.g. surface

elevation

Analysis of the output as ASCIIS and 3D figures and data

sets

DSD 2016

3D modelling area Gent-Terneuzen (BE-NL)

Impacts of dredging, deepening, widening rivers/estuaries

on adjacent groundwater systems

Possible effects:

-saline fluxes to agricultural lands

-increased salinity in root zone

DSD 2016

Questions?

DSD 2016

Gualbert Oude Essink Deltares & Utrecht University gualbert.oudeessink@deltares.nl More information: freshsalt.deltares.nl zoetzout.deltares.nl