Energy and Power Engineering, 2013, 5, 56-62
doi:10.4236/epe.2013.54B011 Published Online July 2013 (http://www.scirp.org/journal/epe)
Low-cost Remote Rain and Stream Data Acquisition
System for Mapping of Potential Micro-Hydro Sites
R. C. Pallugna1, A. B. Cultura1, C. M. Gozon1, N. R. Estoperez2
1Mindanao University of Science and Technology
2Mindanao State University - Iligan Institute of Technology
Received February, 2013
ABSTRACT
The stream and rain data acquisition system presented in this paper makes the mapping of hydro potentials in the region
or of the country econo micall y and practically possible. Moreover, it can also serve as a flood warning system.
Keywords: Stream Data Acquisition; Micro-hydro; Flood Warning System
1. Introduction
Stream flow and rain water information are essential to
the design and operation of micro-hydro power plants.
These are site specific data gathered for a considerable
period of time [1]. According to [2], the Philippines is
one of the countries with an abundant and widely spread
micro hydro sites. Figure 1 shows the map of the mi-
cro-hydro potential of the country and Figure 2 shows
the map of the potential of micro-hydro in Mindanao.
These sites are potential sources of clean electric en-
ergy like micro-hydro for rural and domestic electrifica-
tion. However, most of these sites are not locally as-
sessed and utilized [2]. Part of the problem is the high
cost of gauging instruments, most of which are imported.
This paper proposes the use of locally developed, low-
cost Remote Rain and Stream Data Acquisition System
(RRSDAS) to assess these resources. It is a microcon-
troller based system that employs the use of the tipping
bucket rain gauge and the orifice stream gauging method
for its data acquisition and a GSM module for its com-
munications. Laboratory and field test can be used to
validate the accuracy and reliability of such system. A
block diagram of the system developed is shown in Fig-
ure 3.
2. The Rain and Stream Gauging
2.1. Common Types of Rain Gauges
There are two main types of rain gauges: the non-re-
cording and the recording rain gauges [3]. The most
common of the non-recording type is the Standard rain
gauge (SRG) used for more than a century by the United
States National Water service [4]. The recording type
includes the Optical Rain Gauge which measures rain
rate on the principle that it is proportional to the distur-
bance of done by raindrops on an optical beam. This type
of rain gauge is expensive and used mainly for research
purposes. Another type is the disdrometer. It can measure
the size, velocity, and distribution of rain drops and other
hydrometeors. This is a research oriented device and uses
optical or acoustic technologies. One of the most com-
mon and relatively inexpensive recording types of rain
gauges is the tipping buck et rain gauge. Like the
Figure 1. Micro-hydro potential in the Philippines.

R. C. PALLUGNA ET AL. 57
Figure 2. Micro-hydro potential in Mindanao.
Figure 3. Block diagram of the rain and stream DAS.
SRG, tipping bucket rain gauge has an established his-
tory. Its mechanism is simple. It collects rain through a
funnel into a see-saw like mechanism that tips whenever
a fixed amount of rain volume is collected on one side.
Every time a tip is made, a reed switch is activated and
its signal is recorded as signifying a certain amount of
rainfall. Usually each bucket hold 0.01 inch of rain. Thus
the number of tips multiplied b y the volume per bu cket is
the total amount of rainfall on a certain period of time.
Figure 4 shows the mechanism of a tipping bucket [5]
and Figure 5 a picture of a typical tipping bucket rain
gauge [6].
2.2. Stream Gauging Methods Used in Assessing
Micro-hydro Sites
Literatures on development of micro-hydro resources
usually introduce fairly accurate but inexpensive stream
gauging methods [7-9]. Co mmonly used methods include
the weir method, the float method, the bucket method,
the velocity-area method, and the staff gauge method.
However these methods do not have data logging capaci-
ties and thus, have to be performed repeatedly on the site.
2.3. Microcontroller Technologies
One of the most important developments in computer
and electronics industries is the microcontroller. Micro-
controllers are very small computers, containing a proc-
essor, memory and input/output peripheral, which are
mounted inside a single integrated circuit [10]. For ap-
plication specific conditions, micro controllers have the
advantages of being inexpensive, commonly available,
and easily programmable [11]. For small Data acquisi-
tion systems, microcontrollers are ideally suitable. Even
in developing countries, like the Philippines, microcon-
trollers are readily available. Reference [12] lists the
commonly available microcontrollers in th e coun try.
Figure 4. Tipping bucket rain gauge mechanism.
Figure 5. Typical tipping bucket rain gauge.

R. C. PALLUGNA ET AL.
58
2.4. The Gizduino Microcontroller
The Gizduino microcontrollers are clones of the Arduino
microcontrollers developed by a local company called
eGizmo [12]. These are microcontrollers originally built
for artists and designers but found much use by electron-
ics and robotic hobbyists. Today, even engineers use
them to develop small scale industrial applications. The-
se devices have the advantage of a cheap and available
hardware and open-source software. Moreover, they are
easily programmable and have a lot of available libraries
and support groups. Compared to other microcontrollers
they have very short pr o gramming time .
2.5. The Communication Devices
Aside from microcontrollers, another very important de-
velopment in communication technologies is the GSM
modules. They employ cellular phone technologies which
are very ideal for remote DAS. As compared to other
communication devices, they are relatively cheap, easily
configurable to most microcontrollers, and readily avail-
able. Reference [13] lists the commonly available GSM
modules. The Telit GE 846 QUAD was used in this
study.
2.6. Microcontroller Based DAS
Microcontroller based DAS are commonly used in re-
newable energy systems. Juca [14] summarizes a number
of these systems and its applications. However, most of
the applications involved photovoltaic, biomass, and other
applications but not so much on micro-hydro data acqui-
sition systems. Micro-hydro DAS are exposed to a more
harsh environment.
3. The Development of the Rain and Stream
DAS
The proposed system suggested the use of tipping bucket
rain gauge, the application of the orifice method of stream
flow, the Gizduino microcontroller for data logging, and
the GSM module for communications link.
3.1. The Tipping Bucket Rain Gauge
This study uses the Tipping Bucket Rain gauge because
they are easily developed: the materials are locally avail-
able and easily assembled, and easily interfaced to elec-
tronics. The entire gauge is housed in a plastic container
with a frustum dimension: 12 inches diameter on top, 10
inches diameter at the bottom, and 14 inches high. The
funnel, which is 10 inches in diameter, is made from a
cut top portion of a 16 litters mineral water container
connected to a plastic 4 inch diameter funnel (commer-
cially available). Rain water is collected in the funnel and
dropped to the tipping buckets. The buckets are made of
one piece rectangular aluminum pipe mounted on a gal-
vanized “L” supports and pivoted on a cabinet knob in
two 3 mm bolt as axles. The bucket empties its 2 by 15
milliliters tip on each side into 1.5 inch PVC pipes that
serves to contain the sp lashing of rain water. Each time a
tip is made, a reed switch [15] mounted below the buck-
ets detects it, that is, sense the number of tips of the
buckets and micro-controller acts as counter and recorder.
Furthermore, the information gathered are totaled and
sent through a cellular phone based communication sys-
tem interfaced to it to the researcher’s cellular phone and
computer. Such a system could be battery operated or
solar powered. This system, which is based on low-cost
and locally available electronics, can make the mapping
of micro-hydro re sources aff ord able and practical even in
rural areas. Detailed pictures of the system are shown
in appendix 1.
3.2. The Open Pipe Flow Measurement Method
for Partially Filled Pipe
This study made use of Manning’s equation (1) of dis-
charge for partially filled open pipe given by Bengston
[16]. Figure 6 and Figure 7 illustrates the open pipe
flow measurement method. Due to its simple principle,
this method can also be used in stream gauging of micro
hydro sites, especially for long term site assessment.
Figure 6 illustrates the set up for the open pipe stream
flow measurement method.
Figure 6. An illustration of the Open Pipe stream flow
Measurement method.
Figure 7. For h less than R, (h<R).

R. C. PALLUGNA ET AL. 59
The dischar ge can be given by (1 ) through [16].

2/3 1/2
1.0 h
QAR
n


 s
(1)
where:
Q = the discharge, m3/s
n = 0.009 = Manning roughness Coefficient (Plastic)
Rh = A/P = Hydraulic radius, m
A = cross-sectional area of water in pipe, m2,
which varies with h; most of the time the pipe is not full.
P = R wetted perimeter, m
S = slope of the channe l, m/m
Figure 7 and Figure 8 illustrates that the value of A is
dependent upon h, which may vary from less than r to
greater than r. Equation (2) gives the value for calculat-
ing A. If h is less than r the sign of the radical term is
negative and positive for h greater than r. This means that
if the pipe is more than half filled then the amount of
water above its radius is added [17].
22
0.5() (2)
180
water 2
A
RRhRh






h
(2)
where: R = 2.5 inches = 0.0635 m
The value of h can be determined using an infra-red
sensor mounted on a stilling well. This is shown in Fig-
ure 9. A sharp GP2YOAO2 [18] distance sensor was
used in this study, which can sense distance variation
from 5-120 centimeters from its eyes, with an accuracy
of 5 millimeter and a signal of 0 to 2.5 volts. These sig-
nals are then fed to the micro controller which converts it
directly into Q using (1). Every 6 hours, the microcon-
troller activates the IR sensor and records h an averages
and logs every 4 values of h. In this way a daily value of
Q is acquired.
Figure 8. For greater than R, (h>R).
With the rainfall and stream data a rainfall-runoff rela-
tions can be established. Rainfall and discharge data are
essential to the design and operation of micro-hydro
power plants. The discharge data monitored over a period
of time can be used to form the flow duration curve
which will serve the basis for sizing, design, and opera-
tion of micro hydro sites. Figure 10 shows a typical flow
duration curve [19].
Figure 11 shows the Rain and Stream DAS developed.
It
3.3. Extension of the System Developed to Other
The can
is installed for field testing beside a natural regulation
pond to monitor its rain fall and water level. The white
object on top is the rain gauge. Below it is a solar panel
to supply its power. Below the solar panel is the control
box that housed the microcontroller, battery, solar charger
and other components. The orange PVC pipe serves as a
stilling well. The entire system adopts the Plug-and-play
concept. This means that the entire system can be
mounted easily and quickly.
Methods of Stream Gauging
proposed stream gauging method and system
also be applied to other methods of stream gauging. It
can be applied both to the weir and to the stage level
method. In the weir method, if h is known, the Q can be
determined. In the stage-level method, once the stream
Figure 10. A typical flow duration curve.
Figure 11. Picture of the RRSDAS unde r field test.
Figure 9. The proposed orifice method of stream DAS.

R. C. PALLUGNA ET AL.
60
ra -
4. Results and Discussion
th in a laboratory set up
Table 1 shows the
re rther processed to
ob
ting is known and the stag e-discharge relation is estab
lished then the discharge can be determined for every
value of stag e.
The proposed DAS was tested bo
and in on of the micro-hydro sites in the region. The re-
sults are shown in the next sections,
The Rain field test gauge results.
sult of the r ain gauge dat a loggi ng.
The values of the loggings are fu
tain a graphical relation. This is shown in Figure 12.
Equations (3) and (4) were used to calculate the rainfall
[20].
3
1000 mm
ml ml
mm mm
NxV x
RA  (3)
2
4
mm d
A   (4)
where: e amount of daily rain fall inmillimeters
m) at the month of Feb-
ru
Table 1. Rain gauge data logging.
Rmm = th
N = number of tips per day
Vml = volume of rain per tip (ml)
1000 mm3 /ml = conversion factor
Amm = area of funnel (mm2)
d = diameter of funnel (254 m
It can be seen from Figure 12 th
ary was a rainy month. Reaching up to the maximum
of 9 millimeters of rain.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Height(mm)
Date
AmountofDailyRainful
Figure 12. Graphical display of rainfall loggings.
0.06
0
0.06
0
0.05
0
0.06
0
0.05
0
0.06
0
0.05
0
0.05
0
0.06
0
0.06
0
0.06
0
0.06
0
Series1 0.00.00.00.00.00.00.00.00.00.00.00.0
‐
0.0010
0.0020
0.0030
0.0040
0.0050
0.0060
Discharge
Stage versusDisch argegraph
Figure 13. Stage versus discharge curve using the Open
pipe Flow me thod.
4.1. The Result of the Stream Gauge Tests
The stream gauge was tested in comparison with a veloc-
ity-area method using a standard PRICE TYPE AA (Na-
kaasa model 8154) current meter and the bucket method.
The results are recorded and illustrated in the graphical
result in Figures 13, 14, and 15.
Results indicated the validity and accuracy of the ori-
fice method and system. The average discharge of the
three methods is consistent within three decimal values
of 0.004 cubic meters per second.

R. C. PALLUGNA ET AL. 61
0.06
0
0.06
0
0.05
0
0.06
0
0.05
0
0.06
0
0.05
0
0.05
0
0.06
0
0.06
0
0.06
0
0.06
0
Series1 0.0 0.0 0.00.0 0.0 0.0 0.00.0 0.0 0.0 0.00.0
‐
0.0010
0.0020
0.0030
0.0040
0.0050
0.0060
Discharge
Stageversu sDisc hargegrap h
Figure 13. Stage versus discharge curve using the Open
pipe Flow me thod.
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0.05 0.050.05 0.05 0.050.05 0.05 0.050.05 0.05 0.050.05
StagevsDischar ge Graph
Disch arge
Figure 14. Stage vs discharge graph using the Velocity
method using Current Meter.
- Ar-
ea
0.00000
0.00100
0.00200
0.00300
0.00400
0.00500
0.00600
0.00700
0.00800
1 23 45 6 78 91011121314151617181920
Disch a rgevs.Trialsgraph
Discharge
Figure 15. Discharge versus Trials graph using the Bu
Method.
esented in the graphical
re
three decimal values
d analyzing Rain
and stream Data for assessing of micro-hydro sites and
ydro p ower plants .
flood warning system, turn ing on
alarms whenever a certain amount of rainfall or stage
The remote rain and data acquisition can also be applied
to the weir and sta gauging.
ion System for Micro
of the Micro Hydro
10 November, 2011
,
PTY LTD, Australia
k on How to Develop
y, Philippines, 2009
th Arduino,” O’Reilly Me-
cket [9] DOE, “Manual for Micro-hydropower Development,”
Department of Energ
4.2. The Result of the Stream Gauge Tests
The stream gauge was tested in comparison with a veloc-
ity-area method using a standard PRICE TYPE AA (Na-
kaasa model 8154) current meter and the bucket method.
The results are recorded and repr
sult in Figures 13, 14, and 15.
Results indicated the validity and accuracy of the ori-
fice method and system. The average discharge of the
three methods is consistent within
of 0.004 cubic meters per second.
4.3. The Computer Interface
A computer interface can be used to generate a graphical
display of the results using Microsoft excel. This is a
very convenient way of gathering an
developi ng micro-h
5. Conclusions
Results indicated validity of the low-cost remote rain and
stream data acquisition system developed. Moreover, the
validity of the orifice method of stream flow was verified.
The ability of the DAS to measure the stag e of th e stream
could also be used as a
level is exceeded.
6. Recommendations
ff gauge method of stream
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