Editors:

Jarosław Kania

Ewa Kmiecik

Andrzej Zuber

University

of Silesia

Press 2010

XXXVIIIIAH Congress

Groundwater Quality Sustainability

Krakow, 12–17 September 2010

Extended Abstracts

abstract id: 129topic: 2

Groundwater and dependent ecosystems

2.3Interactions of surface and ground waters

title: Hydrodynamic interaction between surface water andgroundwater in volcanic aquifer system of Lake Ciseupan,Cimahi, West Java, Indonesia

author(s): Deny PuradimajaApplied Geology Research Division, Institut Teknologi Bandung, Indonesia,denyjp@gc.itb.ac.id

Erwin IrawanApplied Geology Research Division, Institut Teknologi Bandung, Indonesia,erwin@fitb.itb.ac.id

Hendri SilaenFreeport Indonesia, Indonesia, d.erwin.irawan@gmail.com

keywords: groundwater-surface water interaction, volcanic aquifer system of Lake Ciseupan,Cimahi, West Java, Indonesia

Krakow, Poland 2010

INTRODUCTION

The Lake Ciseupan was a sand mining area which excavate sands and stones, that has been started from 1980 to 1990. The remains of the activities are dug holes turned in to man-made lake, with undulating depth and 300 meters in diameter. Such holes are surrounded by hills with a height between 690 to 720 meters above sea level (m a.s.l.) (Figure 1).

Figure 1. The location of Ciseupan Lake, Cimahi, West Java, Indonesia.

The lake water is utilized by the surrounding residential and industries. The volcanic aquifer consists of tuff and volcanic sand as part of Cibeureum formation, underlain by impermeable breccias, and bordered by intrusion at the southern part (Table 1 and Figure 2). Volcanic depos-its are proven to have high productivity, than older sedimentary rocks. The volcanic aquifers are composed of combination between porous and fractured systems.

2. Groundwater and dependent ecosystems

XXXVIII IAH Congress

Table 1. Stratigraphical unit and aquifer productivity of the study area.

Age

Lithological unit

Litologi utama Satuan hidrogeologi

Produktivitas akifer (IWACO, 1991) Silitonga (1973)

Kusumadinata and Hartono

(1981)

Quar

tena

ry

Holocene Lake deposit (Ql) Kosambi Fm. Clay and sand Shallow

aquifer Intermediate

Pleistocene

Sandy Tuff (Qyd)

Yoi-

ung

vol-

can- ics Cibeureum Fm. Sandy Tuff Mid aquifer

High Pumice-Tuff (Qyt) Tufaceous sand

Old volcanic deposit (Qob) Cikapundung Fm. Breccias, lahar, lava Deep aquifer

Andesite (a), Basalt (b) Andesite and basalt

Bed rock

None

Tert

iary

Pliocene Tufaceous Breccia, Lava Sand-stone, Conglomerate (Pb) Breccias Low

Miocene Old sedimentary rock (Cilanang Fm.) Marl None

Figure 2. Aquifer section of the study area.

METHODS

A finite difference modelling with Visual ModFlow was used to identify the hydrodynamic inter-action between surface water and groundwater around the lake. It was built based on surface geological observation, geophysical and hydrochemical measurements (Figure 3).

Figure 3. Aquifer section of the study area.

Desk study (previous

study)

Surface geological

observation

Geophysical measurement

Hydrochemical measurement

Geological model

Simulation

Results

2.3. Interactions of surface and ground waters

Krakow, Poland 2010

The total area modelled is 810,000 m2, 900 m × 900 m.

RESULTS

The result shows that the groundwater flows westward with radial pattern and 0.05 hydraulic gradient (Figure 4 and 5).

Figure 4. Scenarios of groundwater modeling.

Based on the modelling and hydrochemical analysis, showing bicarbonate dominations and small quantities of ammonium, there are similarity between lake water and groundwater. The truncated volcanic aquifer by the previous excavation have exposed the groundwater to fill in all the abandoned openings and have diverted the groundwater flow. Therefore the exploitation of the lake water will convincingly affect the groundwater level at the surrounding areas, as reflected by cone depressions at the settlement area, southern part of the lake. Scenarios of lake

A B

C D

2. Groundwater and dependent ecosystems

XXXVIII IAH Congress

water and groundwater level depletion modelling show that when the lake water drop by 1.3 m, which is equivalent with lake water pumping of 21,000 m3/day, will cause the depletion of groundwater level by 1 m at the nearest well 10 m from the lake.

Figure 5. Scenarios of groundwater modeling cont.

The conceptualization of hydrogeological model at the man-made lake area reveals a complex interaction between lake and groundwater systems, with also considering the layers of volcanic rocks. This research with various scenarios also shows that groundwater flow around a depres-sional form can be in divergent pattern rather than always in convergent. This condition is controlled by the slow dip of volcanic layers.

REFERENCES

Delinom R.M., 2009: Structural Geology Controls on Groundwater Flow: Lembang Fault Case Study, West Java, Indonesia. Hydrogeology Journal, DOI 10.1007/s10040-009-0453-z.

Freeze R.A., dan Cherry J.A., 1979: Groundwater. Prentice Hall.

A

B

C

D

B T S U pemukiman R

R

R

R

2.3. Interactions of surface and ground waters

Krakow, Poland 2010

Irawan D.E., Puradimaja D.J., Notosiswoyo S., Soemintadiredja P., 2009: Hydrogeochemistry of volcanic hydrogeology based on cluster analysis of Mount Ciremai, West Java, Indonesia. Journal of Hydrology 376 (2009), 221–234, doi:10.1016/j.jhydrol.2009.07.033.

IWACO WASECO, 1991: Bandung Groundwater Supplies Report. unpublished report.

Koesoemadinata R.P., Hartono D., 1981: Stratigrafi dan Sedimentasi Daerah Bandung (The Stra-tigraphy and Sedimentation of Bandung Basin). Prosiding Ikatan Ahli Geologi Indonesia (Pro-ceedings of The Annual Meeting of Indonesian Association of Geologist), Bandung.

Liang X., Xie Z., Huang M., 2003: A new parameterization for surface and groundwater interac-tions and its impact on water budgets with the variable infiltration capacity (VIC) land surface model. Journal of Geophysical Research, vol. 108, no. D16, 8613, doi:10.1029/2002JD003090.

Nield S.P., Townley L.R., Barr A.D., 1994: A framework for quantitative analysis of surface water-groundwater interaction: Flow geometry in a vertical section. Water Resource Research, 30(8), pp. 2461–2475.

Puradimaja D.J., 1995: Kajian Atas Hasil-Hasil Penelitian Geologi dan Hidrogeologi dalam Kaitan dengan Deliniasi Geometri Akuifer Cekungan Bandung (Overview of Hydrogeological Setting of Bandung Basin). Prosiding Seminar Air tanah Cekungan Bandung (Proceeding of Seminar on Bandung Basin Groundwater).

Silitonga P.H., 1973: Peta Geologi Lembar Bandung (Geological Map, Bandung Sheet). Pusat Pene-litian dan Pengembangan Geologi (Geological Research and Development Center), Bandung.

Townley L.R., Trefry M.G., 2000: Surface Water–Groundwater Interaction Near Shallow Circular Lakes: Flow Geometry in Three Dimensions. Water Resource Research, 36(4), pp. 935–948.

Woessner W.W., 2000: Stream and Fluvial Plain Ground Water Interactions. Rescaling Hydrogeo-logic Thought, Ground Water, vol. 38, no. 3, pp 423–429.

2. Groundwater and dependent ecosystems

XXXVIII IAH Congress

International Association of Hydrogeologists

AGH University of Science and Technology

2-vol. set + CD

ISSN 0208-6336

ISBN 978-83-226-1979-0