Introduction Methods Preliminary results Closing

Hydrogeological boundaries of stratovolcanoes| Asian Physics Symposium 2015

Irawan, DE., Sumintadireja, P., Darul, A., Agustin, A.,Nurrochman, A., and Puradimaja, DJ.

Institut Teknologi Bandung

Aug 20, 2015 (version1)

Introduction Methods Preliminary results Closing

Introduction

Methods

Preliminary results

Closing

Introduction Methods Preliminary results Closing

Introduction

Introduction Methods Preliminary results Closing

Problem

• Hydrogeological system in volcanic area still has manyquestions, in terms of:

• What is the dominant control to the groundwater flow• The nature of groundwater spring zone• How long is the average residence time in the system

Introduction Methods Preliminary results Closing

Important role of volcanoes

• Water tower for the lowlands• Conservation

Introduction Methods Preliminary results Closing

Location

Introduction Methods Preliminary results Closing

Location2

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Location3

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Location4

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Geological history

Introduction Methods Preliminary results Closing

Methods

Introduction Methods Preliminary results Closing

Tools

• Preliminary results, computer scale,• Using free program: Topodrive and ParticleFlow from

USGS,• It runs on Windows (off course), Mac and Linux.

Introduction Methods Preliminary results Closing

Model specifications

• 2D, finite elements• Boundary condition:

• upper boundary: topography• lower boundary: Tertiary sediments• left and right boundary: no flow

Introduction Methods Preliminary results Closing

Data

• Groundwater spring survey, mainly to identify the springzone:

• Gunung Ciremai: step wise 250 - 650 masl, 750 - 1250 masl,1300 - 1500 masl

• Gunung Karang-Pulasari: 200 - 400 masl• Gunung Gede: 500 - 750 masl

Introduction Methods Preliminary results Closing

Preliminary results

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Flownet

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Flownet2

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Flownet3

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Discussions

• The model still couldn’t mimic the spring zone perfectly,• Another question arise? Which parameter plays dominant

control to the system,• We did some tryouts of sensitivity test.

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Discussions2

Parameter SensitivityDepth to lower boundary HighThickness of the aquifer LowIntercalation layers HighHydraulic properties Low

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Closing

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Future directions

• Hopefully we can develop our own model, based on the realdata,

• It can be the basis of a more quantitative approach topredict spring emergence,

• More tools to support the model: water quality usingmultivariate analysis (cluster, PCA, decision tree)

Introduction Methods Preliminary results Closing

Acknowledgements

• Research funding: ITB• Field team: a group of very dedicated undergrad students

Introduction Methods Preliminary results Closing

Thank you

• This slides are made by R-Markdown syntax usingLATEXbackend

• Slides pdf are available at My Slideshare repo• Codes are available at My Github repo• @dasaptaerwin