This research intends to investigate the relation between cause and effect which influence the water availability and water need, and then to build a formulation as an effort of intervention with high leverage. The object of this research is Batam island that is part of the Riau islands province-Indonesia. This province has been remained as the national strategy area based on the Government Regulation No 26/ 2008 about the spatial plan of national area. The methodology consists of the system dynamics approach that can integrate the complex and persistence system in analyzing water balance. In the system dynamics, the behaviour patterns are generated by the water availability and water need with increasing time and by using the main asumption that every complex system is sourced on the causal structure that is forming the system. The result is as the model of water balance due to the system dynamics generally in Indonesia and especially in Batam island

1. http://www.iaeme.com/IJCIET/index.asp 267 editor@iaeme.com
International Journal of Civil Engineering and Technology (IJCIET)
Volume 9, Issue 12, December 2018, pp. 267–276, Article ID: IJCIET_09_12_031
Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=12
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication Scopus Indexed
MODEL OF WATER BALANCE BASED ON THE
SYSTEM DYNAMICS
Agus Rudyanto
Doctoral Program on the Department of Water Resources, Faculty of Engineering, University
of Brawijaya, Malang, Indonesia
Lily Montarch Limantara, Ussy Andawayanti and Ery Suhartanto
Department of Water Resources, Faculty of Engineering, University of Brawijaya, Malang,
Indonesia
ABSTRACT
This research intends to investigate the relation between cause and effect which
influence the water availability and water need, and then to build a formulation as an
effort of intervention with high leverage. The object of this research is Batam island
that is part of the Riau islands province-Indonesia. This province has been remained
as the national strategy area based on the Government Regulation No 26/ 2008 about
the spatial plan of national area. The methodology consists of the system dynamics
approach that can integrate the complex and persistence system in analyzing water
balance. In the system dynamics, the behaviour patterns are generated by the water
availability and water need with increasing time and by using the main asumption that
every complex system is sourced on the causal structure that is forming the system. The
result is as the model of water balance due to the system dynamics generally in
Indonesia and especially in Batam island.
Keywords: water balance, complex, persistence, causal structure, system dynamics
Cite this Article: Agus Rudyanto, Lily Montarch Limantara, Ussy Andawayanti and
Ery Suhartanto, Model of Water Balance Based on the System Dynamics, International
Journal of Civil Engineering and Technology, 9(12), 2018, pp. 267–276
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=9&IType=12
1. INTRODUCTION
The urgent tasks that are faced by the decision makers and the water resource managers are to
assess and find the effective solutions for the water problems. The conventional systems
approach to problems has been to optimize (Juwono et.al. 2018 and Limantara, 2010), simulate,
or choose an alternative solution based on the trade-offs among the conflicting objectives
(Nandalal and Simonovic, 2003). However, system thinking is evolving into concepts that may
clarify how to approach the complex problems that involve or influence people. The growth of

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population income implies in the growth of food and water demand, however it is also in the
contamination of water bodies (Falkenmark and Molden, 2008; Ludang and Mangkoedihardjo,
2009; Samudro et al., 2011; Samudro et al., 2018). Water resources have a direct relationship
with the systemic approach due to the both of them are systemic and non-linear relation
(Ohlsson and Turton, 1999). A system is mentioned as a set of elements with the connections
among each other. Any system is composed of many sub-systems, each of them is open and
autonomous, directly integrated and interrelated with each environment (Santos, 1982)
System dynamics is an approach for helping the managers meets the challenges of
communicating with stakeholders (Krystyna and Stave, 2003). System dynamics is a policy-
based methodology that assessed the influence of the policy changes on a system. For any
system, the decisions that are made influence the behavior of the system. System dynamics
tries to find out the factors due to the characteristic behavior of the system (Ahmad and Prashar,
2010). The main aim of system dynamics is to better understand the dynamics and complex
systems and suggest the changes in the system dynamics approach decision-making rules for
improving the performance. System dynamics is fundamentally used to understand the policy
decisions and feedbacks (Sharawat et.al, 2014).
Batam Island is part of the Riau islands and has potency of water resources with the
inadequate hydro-climate condition because it does not have groundwater basin. Therefore, all
of the rivers depend on the surface water as well as the rainfall. Besides it, the thin topsoil layer
in Batam Island is needed to be mainly attended in design of area spatial and management of
area/ area conservation. Reservoir is as an artificial water storage that is functioned for holding
water on the rainy season and use it on the dry season. However, the reservoir operation pattern
determines how big the reservoir usage that will be obtained which is as a system unity. The
sub-system of reservoir operation system consists of water availability, water need in
downstream reservoir, hydro electrical power, reservoir physical condition, and the institution
and the aspiration of interest owner. Each of the sub-system is interplaying. The problem that
can be accurately modeled by using the methodology of system dynamics is a dynamic problem
that is changed with time and has the phenomenon structure which at least has a feedback
structure. The system dynamics sees the problem in overall and to understand how the whole
unsure in a system interplaying one another. The aim of this research is to investigate the
relation between cause and effect which influence the water availability and water need, and
then to build a formulation as an effort of intervention with high leverage
2. MATERIALS AND METHODS
Batam-Rempang-Galang (Barelang) where is located in the river area of Batam-Bintan Islands
have been determined by Indonesian Government Decision as the free trade and harbour zone.
To support this xone, there is needed some supporting facilities especially enough fresh water
for fulfilling the society and industrial demands. The supply capacity of fresh water from the
reservoirs in Batam is 5.564 liters per-second (by noted that North Sei Galang is built in 2018).
Thus, there is fresh water deficit in amount of 4.35 litres per-second. Map of the study location
is presented as in the Figure 1.

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Figure 1. Research location in the river area of Riau islands
2.1. System Dynamics
The method of system dynamics has been developed since Joy Forrester introduced at the first
time on 1950 and it is centered in Massachusetts Institute of Technology (MIT), USA
(Mohammad Tasrif, 2015). Regarding to the name, this method is closed knit with the question
about the dynamics tendency of complex systems that are the behavior that is generated by the
system and by the time. The usage of this method is more emphasized on the aims for increasing
the understanding about how the system behavior will be appear from the structure. This
understanding is very important in designing the effective policy.
The system dynamics consists of stock, flow, converter, and connector which is presented
as in the Figure 2. Stock presents how the condition and the accumulation with the resource
such as to present the population growing, irrigation area, etc. Flow presents the action about
how something will be happened that is measured as the rate. Converter is functioned for
accommodating the input and making the output. However, connector presents the relation
between stock and flow as presented in the Figure 2.

4. Agus Rudyanto, Lily Montarch Limantara, Ussy Andawayanti and Ery Suhartanto
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Figure 2. Stock, flow, converter, and connector
2.2. The Steps of System Dynamics Modeling
According to Sterman (1992), the steps that have to be carried out for setting the model of
system dynamics are as follow: 1) To articulating the problem for identifying and analyzing
the problem. This step is carried out by collecting the data; 2) to formulate the dynamic
hypothesis; 3) to formulate the simulation model; 4) to test the model; and 5) to design and
evaluate the policy
3. RESULTS AND DISCUSSION
3.1. The simulation of reservoir operation
On the reservoir simulation or behavior analyses, the reservoir capacity that is needed, can be
analyzed by using the formula of continuity concept as follow (Mcmahon et.al., 2007): St+1 =
St + Qt – Dt ─ ∆Et ─ Lt with the boundary: 0 ≤ St+1 ≤ C and Dt ≤ Kap, where t = time interval
(usually 1 month); St+1 = storage at the end of time interval-t; St = reservoir storage at the
beginning time interval-t; Qt = inflow during the time interval-t; Dt = demand during the time
interval-t; ∆Et = evaporation during the time interval-t; Lt = seepage during the time interval-
t; C = active benefit capacity of reservoir; and Kap = capacity of intake.
In this research, inflow to the 5 reservoirs use the monthly series data of water availability
from 2003 until 2015 that is used recurring in the simulation from 2009 until 2048 with the
assumption that the hydrology condition is continuously recurring in the future. The calibration
of reservoir water level is carried out due to the reservoir water level recording from 2009 until
2015. The calibration is only carried out in 2 reservoirs that are Muka Kuning reservoir and
Duriangkang reservoir due to the data limitation.
3.2. Calibration of reservoir water level
The calibration of Muka Kuning reservoir indicates that the model is good enough in modeling
from 2011 until 2013, however, the model is lower that the data recording out of the year from
2011 until 2013. The calibration result in Duriangkang reservoir indicates that the model is
good enough from 2009 until 2014, however, on 2015 and 2016 the model is higher than the
data recording. The condition of water level in the Muka Kuning and Duriangkang reservoir
are presented as in the Figure 3 and 4,

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Figure 3. Water level of model and data recording in Muka Kuning reservoir
Figure 4. Water level of model and data recording in Duriangkang reservoir
The model structure of 5 reservoirs by using system dynamics is presented in the Figure 5.
The recording data and correlation analyses show the result as follow: the correlation between
recording data (observed data) and model is 0.75 for Muka Kuning reservoir and 0.92 for
Duriangkang reservoir. The difference of water level head between recording data (observed
data) and model is assumed to be happened due to the several things as follow: a) model is pure
due to the analyses result; b) the field recording (observed data) is as the reservoir operation
result in the field that has been affected by human intervention; and c) the model of 5 reservoirs
are integrated among one to another so the operation on one of the reservoirs will affect the
other reservoir water level.
Muka Kuning
Duriangkang
reservoir

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Figure 5. The model structure of 5 reservoirs

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3.3. Water balance analyses
Based on the simulation result, it is known that the fresh water fulfillment in Batam island is
only able to fulfil until the first 10 years, however for the next years has already started the
water deficit. The water supply from 5 reservoirs and the demand for 9 districts is presented as
in the Table 1 and Figure 6, 7, 8.
Tabel 1. Supply from 5 reservoirs and demand for 9 districts in Batam island
Time
Supply
(m3
/s)
Demand
(m3
/s)
Balance
(m3
/s)
Fresh water supply
fulfillment in Batam
island (%)
Jan 1, 2018 2.58 2.58 0.00 100.00
Jan 1, 2019 2.68 2.68 0.00 100.00
Jan 1, 2020 2.79 2.79 0.00 100.00
Jan 1, 2021 2.90 2.90 0.00 100.00
Jan 1, 2022 3.02 3.02 0.00 100.00
Jan 1, 2023 3.13 3.13 0.00 100.00
Jan 1, 2024 3.25 3.25 0.00 100.00
Jan 1, 2025 3.37 3.37 0.00 100.00
Jan 1, 2026 3.49 3.49 0.00 100.00
Jan 1, 2027 3.60 3.60 0.00 100.00
Jan 1, 2028 3.55 3.72 -0.17 95.37
Jan 1, 2029 3.40 3.84 -0.43 88.67
Jan 1, 2030 3.50 4.17 -0.67 83.84
Jan 1, 2031 3.49 4.29 -0.80 81.46
Jan 1, 2032 3.71 4.41 -0.70 84.14
Jan 1, 2033 3.72 4.52 -0.80 82.31
Jan 1, 2034 3.73 4.85 -1.12 76.85
Jan 1, 2035 3.70 4.96 -1.26 74.63
Jan 1, 2036 3.37 5.07 -1.70 66.51
Jan 1, 2037 3.42 5.17 -1.75 66.09
Jan 1, 2038 3.56 5.27 -1.71 67.53
Jan 1, 2039 3.73 5.36 -1.63 69.54
Jan 1, 2040 3.73 5.45 -1.72 68.41
Jan 1, 2041 3.55 5.58 -2.03 63.64
Jan 1, 2042 3.40 5.66 -2.26 60.10
Jan 1, 2043 3.50 5.73 -2.24 60.99
Jan 1, 2044 3.49 5.80 -2.31 60.22
Jan 1, 2045 3.71 5.87 -2.16 63.17
Jan 1, 2046 3.72 5.93 -2.21 62.71
Jan 1, 2047 3.72 5.99 -2.26 62.25

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Figure 6. Supply for 5 reservoirs and demand for 9 districts in Batam island
Figure 7. Service water deficit from 5 reservoir in Batam Island
Figure 8. The percentage of fresh water fulfillment in Batam Island
Based on the simulation result, in further there is formulated and simulated the strategy of
water demand fulfillment increasing in the future by making some efforts.
Jan 1, 2018 Jan 1, 2023 Jan 1, 2028 Jan 1, 2033 Jan 1, 2038 Jan 1, 2043 Jan 1, 2048
3
4
5
6
m³/s
demand
Suplai
Jan 1, 2018 Jan 1, 2023 Jan 1, 2028 Jan 1, 2033 Jan 1, 2038 Jan 1, 2043 Jan 1, 2048
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
m³/s
Balance
Jan 1, 2018 Jan 1, 2023 Jan 1, 2028 Jan 1, 2033 Jan 1, 2038 Jan 1, 2043 Jan 1, 2048
20
40
60
80
100
%
PemenuhanAirBakuPulauBatam

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4. CONCLUSION
Based on the analysis as above, it can be concluded as follow:
1. By using the system dynamics approach, it can give the overall illustration that is
transparent, flexible, and easy to be developed. In addition, it also can show the
counter intuitive case towards a behavior through the model structure analysis and
there is the trade off and leverage point. The many benefits make the system
dynamics approach is fitted to be used in the participate design.
2. The simulation result indicates that the fresh water demand in every district of
Batam island is increasingly increasing in line with the number of population
growth such as the number of district in Batam island have 257,674 population in
2017 with the water demand is 1.12 m3
/s, it is increasing into 658,625 population
in 2017 with the water demand is 3.31 m3
/s.
3. The limitation of water volume and the permanent intake capacity of reservoir such
as the Duriangkang reservoir is in amount of 3.00 m3
/s and Muka Kuning reservoir
is in amount of 0.31 m3
/s, give the result of water availability fulfillment is only
enough until upcoming 10 years that is 2028, however there is deficit water for the
next upcoming years.
REFERENCES
[1] Ahmad S. and Prashar D. Evaluating Municipal Water Conservation Policies Using a
Dynamic Simulation Model, Water Resource Manage, 24,11, 2010, pp. 3371-3395
[2] Falkemark M. and Molden D. Wake Up to Reality of River Basin Closure. International
Journal of Water Resources Development, Vol. 24, 2008, pp. 201-215.
[3] Juwono P.T., Limantara L.M., and Rosiadi F. Optimization of Irrigation Cropping Pattern
by Using Linear Programming, Journal of Water and Land Development, No. 39 (X-XII),
2018, pp. 51-60
[4] Krystyna A. Stave, A System Dynamics Model to Facilitate Public Understanding of Water
Management Options in Las Vegas, Nevada, Journal of Environmental Management,
Vol.67, 2003, pp. 303~313.
[5] Limantara L.M. Optimization of Water Needs at Kepanjen Dam and Sengguruh Dam, East
Java, Indonesia, International Journal of Academic Research, Vol 2(5), 2010, pp, 216-220
[6] Ludang, Y., Mangkoedihardjo, S. Leaf area based transpiration factor for phytopumping of
high organic matter concentration. Journal of Applied Sciences Research, 5(10), 2009,
pp.1416-1420.
[7] Mcmahon T.A., Vogel R.M., Pegram G.G.S., Peel M.C., and Etkin D. Global Streamflows-
Part 2: Reservoir Storage-Yield Performance, Journal of Hydrology, 347, 2007, pp 260-
271.
[8] Nandalal, K.D.W. and Simonovic, S.P. Resolving Conflicts in Water Sharing: A system
approach, Water Resources Research, Vol. 39, 2003, N0. 12, Page of Wes 1-1~Page of
Wes 1-11.
[9] Ohlsson, L. and Turton, A.R. The Turning of Screw: Social Resource Scarcity the Bottle-
Neck in Adaptation to Water Scarcity. London: University of London, 1999. 8p. SOAS
Occasional Paper, 19.
[10] Samudro, H., M. Faqih, E. Sudarma. Green architecture criteria for high-rise building that
serves as a rental office in the city of Surabaya. Journal of Applied Sciences Research 7(5),
2011, pp. 566-571.

10. Agus Rudyanto, Lily Montarch Limantara, Ussy Andawayanti and Ery Suhartanto
http://www.iaeme.com/IJCIET/index.asp 276 editor@iaeme.com
[11] Samudro, G., Syafrudin, Wardana, IW., Samudro, H. and Mangkoedihardjo, S.
Determination of the Specific Energy of Mixed Waste Decomposition in Compost Solid
Phase Microbial Fuel Cells (CSMFCS), International Journal of Civil Engineering and
Technology, 9(11), 2018, pp. 1316–1324.
[12] Santos, M. O Espaço e Os Seus Elementos: Questões de Método. Revista Geografia e
Ensino, v.1, 1982, pp. 19-30
[13] Sharawat, I., Dahiya, R.P., Dahiya, R., and Kumari, S. System Dynamics Approach: A
Novel Water Resource Management Tool, International Journal of Environmental
Research and Development, Vol. 4, 2014, No. 4, pp. 297-302
[14] Sterman J.D. Business Dynamics: Systems Thinking and Modeling for a Complex World.
McGraw Hill Higher Education, 2000..
[15] Tasrif M. Metodologi System Dynamics (Dinamika Sistem) untuk Pemodelan Kebijakan
(Methodology of System Dynamics for Policy Modelling), 2015.