The document presents a study on the interaction between groundwater and river water in Tasikmalaya, Indonesia. Water quality measurements from 50 wells along two rivers and 12 river sites were analyzed. The analysis identified two types of water interaction: effluent flow in one river segment and influent flow in the other. Water quality variables like pH, resistivity, and dissolved oxygen showed a clear separation between groundwater and river water. The study provides guidance for further geological modeling of the area to understand water resource management challenges in Tasikmalaya.

1. First draft
Groundwater and River Water Interaction at Ciromban
and Cibeureum Riverbank, Tasikmalaya:
Can We Solve Water Shortage?
Pratama, A., Abdulbari, N ., Nugraha, MI., Prasetio, Y.,
Tulak, GP., Darul, A., and Irawan, DE.
Faculty of Earth Sciences and Technology
Institut Teknologi Bandung
The 5th International Conference on Mathematics and Natural Sciences
Institut Teknologi Bandung, 2-3 November 2014 1

2. Background
• Tasikmalaya is one of the growing city in West Java
Province, which is also suffering from drought.
Currently the source of water is exclusively
supplied by several deep water wells and
groundwater springs at the foot slope of Mount (Mt)
Galunggung.
• The formerly a full agriculture-based area, now
have grown to a industrial and commercial city.
• Local government and water supply company need
to look for alternative source of water. One
alternative is river water: Ciromban and
Cibeureum river.
Photos
First draft
Photos
The 5th International Conference on Mathematics and Natural Sciences
Institut Teknologi Bandung, 2-3 November 2014 2

3. Objective
• This research is a
preliminary study
to identify the
interactions
between
groundwater and
river water based
on water quality.
First draft
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Institut Teknologi Bandung, 2-3 November 2014 3

4. Methods1
First draft
• The dataset was composed of 62 points: 50 points of dug wells
along the riverbank and 12 points of river water measurements.
• We used handheld instruments from Hanna Instrument: water
level detector (WLD), total dissolved solids (TDS) meter for
temperature and TDS measurement, and Dissolved Oxygen (DO)
meter to measure DO concentration.
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Institut Teknologi Bandung, 2-3 November 2014 4

5. Methods2
First draft
• We introduce an statistical analysis to explore the dataset,
consists of: basic exploratory analysis and decision tree.
• Open source and cross-platform software:
• R3.1.1 (R Core Team, 2014) and Rstudio IDE0.98.1028 (RStudio Team, 2014).
• Add-on packages of R:
• graphical plotting using “lattice” (Sarkar, 2008),
• data manipulation with “dplyr” (Wickham and Francois, 2014),
• spatial analysis using “sp” (Roger S. Bivand, 2013), and
• principal component analysis using “pcaMethods” (Stacklies et al.,
2007) and “randomForest” (Liaw and Wiener, 2002a).
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Institut Teknologi Bandung, 2-3 November 2014 5

6. Methods3
First draft
• The principal component analysis (PCA) is a classic multivariate
statistics, used to reduce the size of data dimension. It
succesfully used as tools to analyse hydrogeological nature based
on water quality (Irawan et al., 2014, 2012, 2009).
• The random forest (Breiman, 2001; Hastie et al., 2001; Liaw and
Wiener, 2002) is a variable selection technique.
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Institut Teknologi Bandung, 2-3 November 2014 6

7. First draft
Results1: Two types of water interaction
• Effluent flow in the Cibeureum segment
• Influent flow in the Ciromban river segment
Tunjukkan
alur
sungainya
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Institut Teknologi Bandung, 2-3 November 2014 7

8. First draft
Results2: Water quality pattern
• The close interaction is also
shown by pairs plot.
• High DO and TDS readings due
to mineralization from organic
and non-organic sources and
change of chemical stability.
• A clear separation between
both waters can be drawn from
the multivariate analysis.
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Institut Teknologi Bandung, 2-3 November 2014 8

9. First draft
Results2: Water quality pattern
• Stronger role of some variables than
the others are also detected:
• pH
• Resistivity
• DO
• The strong variables can be used as
tracer.
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Institut Teknologi Bandung, 2-3 November 2014 9

10. Concluding remarks
First draft
• A close interaction occurs between groundwater and river water, as
shown by the water level maps. The close interaction is also shown by
pairs plot.
• Low gradient water flows were identified in the period of dry season
(July-August 2014):
– Effluent flow in the Cibeureum segment
– Influent flow in the Ciromban river segment
• A clear separation between both waters can be drawn from the
multivariate analysis. Stronger role of some variables than the others
are also detected. The strong variables can be used as tracer.
• We recommend that the authority should not use the river water
directly without proper treatment. The pumping of river water should
also be carefully design as it will influence shallow groundwater level.
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Institut Teknologi Bandung, 2-3 November 2014 10

11. Next step
First draft
• This work is part of my final project.
• The result from this paper will be used as a guidance to build a
geological model of the area.
• Breiman, L., Random Forests, in: Machine Learning (Springer, New York, 2001), pp. 5–32.
• Hastie, T., Tibshirani, R., Friedman, J., The Elements of Statistical Learning, Springer Series in Statistics (Springer New York Inc., New York,
NY, USA, 2001).
• Irawan, D.E., Puradimaja, D.J., Notosiswoyo, S., Soemintadiredja, P., "Hydrogeochemistry of volcanic hydrogeology based on cluster analysis of
Mount Ciremai, West Java, Indonesia", J. Hydrol. 376, 221 – 234. doi:http://dx.doi.org/10.1016/j.jhydrol.2009.07.033 (2009).
• Irawan, D.E., Puradimaja, D.J., Silaen, H., Hydrodynamic Relationship between Man-Made Lake and Surrounding Aquifer, Cimahi, Bandung,
Indonesia, Int. Groundw. Eng. Conf. Proceedings (2012).
• Irawan, D.E., Silaen, H., Sumintadireja, P., Lubis, R.F., Brahmantyo, B., Puradimaja, D.J., "Groundwater–surface water interactions of Ciliwung
River streams, segment Bogor–Jakarta, Indonesia", Environ. Earth Sci. 1–8. doi:10.1007/s12665-014-3482-4 (2014).
• Liaw, A., Wiener, M., "Classification and Regression by randomForest", R News 2, 18–22 (2002).
• R Core Team, R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, Vienna, Austria, 2014).
• Roger S. Bivand, V.G.-R., Edzer Pebesma, Applied spatial data analysis with R, Second edition (Springer, New York, 2013).
• RStudio Team, RStudio: An Integrated Development Environment to R (RStudio, Vienna, Austria, 2014).
• Sarkar, D., Lattice: Multivariate Data Visualization with R (Springer, New York, 2008).
• Stacklies, W., Redestig, H., Scholz, M., Walther, D., Selbig, J., "pcaMethods – a Bioconductor package providing PCA methods for incomplete
data", Bioinformatics 23, 1164–1167 (2007).
• Wickham, H., Francois, R., dplyr: A Grammar of Data Manipulation (Springer, New York, 2014).
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Institut Teknologi Bandung, 2-3 November 2014 11

12. Acknowledgement
• We wish to express our gratitude to:
– Dr. Bambang Sunarwan for the sponsorhip.
– Dr. Wouter Buytaert of Imperial College London and Dr. Reik
Donner of PIK Postdam for introducing R to us in 2011.
– Dr. Willem Vervoort University of Sydney for his valuable guidance
and support.
– Prof.Dr. Lambok Hutasoit as Head of Applied Geology Group,
Prof.Dr. Deny Juanda, Prof.Dr. Sudarto Notosiswoyo, Dr. Prihadi
Sumintadireja, and Dr. Suyatno Yuwono who have built a strong
research foundation.
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Institut Teknologi Bandung, 2-3 November 2014 12

13. First draft
Groundwater and River Water Interaction at Ciromban and Cibeureum Riverbank, Tasikmalaya:
Can We Solve Water Shortage?
Pratama, A., Abdulbari, N ., Nugraha, MI., Prasetio, Y., Tulak, GP., Darul, A., and Irawan, DE.
Faculty of Earth Sciences and Technology
Institut Teknologi Bandung
Thank you for your attention
Further questions and comments should be addressed to:
Aditya Pratama : aditya16311209@yahoo.co.id
Dr. Dasapta Erwin Irawan : erwin@gc.itb.ac.id
Twitter : @dasaptaerwin
The resources from this project will be made available online by the end of this
month at:
•ResearchGate: https://www.researchgate.net/profile/Dasapta_Irawan
•Academic.edu: https://itb.academia.edu/dasaptaerwin
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Institut Teknologi Bandung, 2-3 November 2014 13