UTILIZATION OF ARTIFICIAL RAIN GAUGE

FOR HYDROMETEOROLOGICAL STUDY

(FIELD REPORT)

Yustinus Adityawan 1)

1) e-mail : killrockforfun@yahoo.co.idUndergraduate Student of Environmental Geography DepartmentGeography FacultyGadjah Mada UniversityYogyakarta, 2010

ABSTRACT

This research was carried out at Sengkan Village, Sleman Regency, Yogyakarta Special

Province. The taping and measuring of rain event took place during 10 days observation. The

purposes of this research are 1) to know design of simple rain gauge which it is able to record rain

event and 2) to know the correlation between rainfall and rain duration (day and minutes) during

laboratory observation took place.

The methods of this research can be divided into 2 methods. First method is to make

simple rain gauge instrument based the things around us. Rain gauge setting must be counted

aspects, which those can be influent taping and measuring process. Those aspects were existence

of something around the instrument such as vegetation and building, where those can be made

rainfall splash came in into the instrument; and easily to monitoring.

Second method was linear regression, it was used to know the correlation between

rainfall and rain duration during 10 days observation. Based on calculation result of regression

between time duration (day and minute) and rainfall, It wasn’t found any relevance/correlation

between time duration and rainfall.

Key words : Artificial rain gauge, simple rain gauge design, correlation between rainfall and time

duration

1

1. Introduction

Hydrology can be defined as a

science which had relationship with

earth’s water, occuring process,

circulation and distribution, chemistry

and physical behavior, and reaction

with their environment, included the

relevance with organism (International

Glossary of Hydrology, 1974 in

Seyhan, 1977). The role of study

hydrology at ecological life at certain

area has important role. The role of

hydrology at ecological life is as water

supplier for any kind utilization.

Explanation about hydrological

condition at certain area has important

relevance with hydrologic cycles.

Where hydrologic cycles can be

defined as water circulation within

upper, at surface, and below the earth

(Sharp, 2007). One of the components

from hydrologic cycles is rain, which

it becomes source for groundwater and

water surface.

Figure 1. Hydrologic Cycle

(Source : http://www.waterprotection.ca/images/watercycle.jpg)

Rain can be defined as a form

of drop water which it has diameter

more than 0,5 mm or smaller and wide

scattered at certain area (Soewarno,

2000). The process which formed rain

depended a lot of factors, such as wind

direction, coordinate position, and

altitude.

.

2

Taping process and measuring

of rain have important role for

climatological and hydrological

applications at certain area (Habib et

al, 2001; Gómez, 2007; Beek et al,

2010). Taping process and measuring

can be obtained with a lot of

instruments such as remote sensing

(TRMM Precipitation Radar) and rain

gauge. In this paper, author used rain

gauge and manual measurement for

recorded rain. Rain gauge is kind of an

instruments, which it is used by

meteorologist and hydrologist to

gather and measure the amount of

liquid precipitation (solid precipitation

is measured by a snow gauge) over a

set period of time

(http://wikipedia.com, 2010).

Figure 2. Rain Gauge

(Source : Wikipedia.com, 2010)

The development at certain

region had an effects on physical,

social, and ecological aspects. One of

the effects of the development process

was an amount of water required

increasingly for many utilization, like

industrial, agricultural, and household.

The rise of an amount of water

required at certain region must be

balanced with the other of

hydrological branchs, such as

hydrometeorology.

Hydrometeorology is a science

which studies atmosphere and land at

hydrologic cycles, with pressing at the

relevance between both of them

(Nurjani, 2008). Rain is a part of

hydrometeorological branchs, include

3

quantity, time and space distribution.

The taping and measuring of rain need

an expensive instrument which it is

difficult to obtain by local

government, institution, academician,

and society.

At this paper, author is

practicing on measurement and taping

of rain. Rain data was obtained from

simple rain gauge instrument, where it

was made by author. Systematic error

aspects such as velocity and the

direction of wind, evaporation, and

fragment of rain didn’t computable.

The accuracy of space

distribution of rain at certain area

needs a lot of network instrument,

where those need much operation cost

and many instruments to record and

measure rain at certain area.

Therefore, it was needed simple of

rain gauge instrument which it can be

used by a lot of societies in Indonesia.

2. Main Research Questions

The difference of physical

conditions at certain area will be

influenced with social and ecological

aspects. One of physical condition

which has influent to human life is

rain. Taping and measuring processes

of rain were doing during 10 days. It

depended on rain even took place at

these range times. The rain aspects

were observed, those were rainfall,

rain duration, and rain intensity.

Based the explanation on

above, the main research questions of

this paper are 1) How is design of

simple rain gauge instrument, which it

able to record rain event and 2) How is

the correlation between rainfall and

rain duration (day and minutes) during

laboratory observation took place.

3. Objectives

The aims of this paper are 1) to

know design of simple rain gauge

which it is able to record rain event

and 2) to know the correlation between

rainfall and rain duration (day and

minutes) during laboratory

observation took place.

4

4. Methods, Results, and Discussion

4.1. Design of Simple Rain Gauge.

Simple rain gauge can be

useful for a lot of societies in

developing contries like Indonesia,

such as academition, which it useful

for study about climate condition at

certain area; institution and

government which it useful matter for

evaluation of development planning,

where it was considering physical

aspect such hydrometeorological data

or rain data.

Figure 1. The matters of Simple Rain

Gauge

The making process of rain

gauge is simple relatively and it is

easy to apply for various civitas,

which those for expert or still

biginner. The matters of this design of

simple rain gauge easily can be found

around us. Those are :

a. Ex-bottle, like Coca-Cola bottle,

it was used to gather the amount

of liquid precipitation.

b. Glue, it was used to make the

bottom of ex-bottle came to flat

relatively.

c. Paper, it was used to record data.

d. Cutter/Scissors, it was used to

cut ex-bottle.

e. Ruler, to measure the height of

amount of liquid precipitation in

the bottle.

f. Pen or pencil

g. Watch, to know precipitation

duration.

h. Microsoft Exel, to know the

correlation between rainfall and

rain duration.

Figure 2. The bottom of ex-bottle is’nt flat enough to measure the amount of liquid

and to make the bottom of ex-bottle become flat, author use glue.

Rain gauge setting must be

counted aspects, which those can be

influent taping and measuring process.

Those aspects were existence of

something around the instrument such

as vegetation and building, where

those can be made rainfall splash came

in into the instrument; and easy to

measure the instrument.

Sometimes rain data doesn’t

has good quality, it was caused by

systematic and random errors.

Humidity, evaporation, wind (velocity

and direction) are an examples of

systematic error. In this paper,

systematic error wasn’t calculated by

author. Wind is important factor who

has influence to rain quality data.

Because wind data wasn’t available,

so wind didn’t computable.

Rain gauge must accurate,

include a) sputtering of raindrop

mustn’t come in into the bottle, b)

water losses from resovoir by

evaporation must be minimum, c) if

snow, must melt.

Selection place and the type of

rain gauge depend many factors like

reliable data, the type of data, the type

of precipitation, the cost and

treatment, easily to monitoring, and

far away from any disruptions. So

when rain occurred at certain time,

measurement must be done.

Figure 3. Design of Rain Gauge

4.2. The Correlation Between Rainfall, Rain Duration, and Rain Iintensity.

The method was used to know

correlation between rain duration with

rainfall was linear regression. Taping

and measuring processes of

precipitation data include rainfall dan

time duration during precipitation

occured. Microsoft Exel was used for

tabulation data and to know the

regression.

If the value of regression goes

up to 1 or more than 0.5, so it has the

meaning that it has correlation

between rainfall dan rain duration. If

the value of regression less than 0.5,

so it has the meaning that it hasn’t no

correlation between rainfall and rain

duration.

Regression between Height and Observation Days

y = 0.1512x - 6088.2R2 = 0.001

0102030405060708090

3-Sep-10 5-Sep-10 7-Sep-10 9-Sep-10 11-Sep-10

13-Sep-10

15-Sep-10

17-Sep-10

19-Sep-10

Days

Hei

ght (

mm

)

Series1 Linear (Series1)

Figure 4. Regression between time duration (day) and rainfall.

Based on calculation result of

regression between time duration (day

and minute) and rainfall, It wasn’t

found any relevance/correlation

between time duration and rainfall.

Regression between time duration

(day) and rainfall has value as 0.001

and the value of regression between

minute and rainfall is 0.2536.

Regression between Height (mm) and Time Duration (minute)

R2 = 0.2536

y = 0.0837x + 9.9006

0

10

20

30

40

50

60

70

0 50 100 150 200 250 300 350 400

Time Duration (minute)

Hei

ght

Series1 Linear (Series1)

Figure 5. Regression between time duration (minute) and rainfall.

The value percent of rainfall doesn’t depend from time duration of rain

event, but depends on intensity. The greater of rain intesity influences to rainfall.

Time duration becomes not important, but sometimes it becomes important too

depends on situation, place, and another aspects.

5. Conclusions

1. Artificial rain gauge is an easily tool which it can be recorded and

taped rain event, cheap relatively.

2. Design of rain gauge is simple to apply or use for any kind of

society.

3. Based on calculation result of regression between time duration

(day and minute) and rainfall, didn’t find any relevance/correlation

between time duration and rainfall.

4. The value percent of rainfall doesn’t depend from time duration of

rain event, but depends on rain intensity.

6. References

Beek, C.Z.Van de., Leijnse, H., Torfs,

P.J.J.F., and Uijlenhoet,R., 2010,

Climatology of Daily Rainfall

Semivariance In The

Netherlands, Hydrol.Earth

Sysy.Sci.Discuss., 7, 2085-2120.

Gómez, M.R.S., 2007, Spatial And

Temporal Rainfall Gauge Data

Analysis And Validation With

TRMM Microwave Radiometer

Surface Rainfall Retrievals,

Master Thesis, Netherland:

International Institute For Geo-

Information Science And Earth

Observation.

Habib, E., Krajewski, W.F., and

Kruger, A., 2001, Sampling

Errors Of Tipping-Bucket Rain

Gauge Measurements, Journal of

Hydrologic Engineering, pp. 159

- 166.

Nurjani, E., 2008, Manual Book For

Hydrometeorology Lab Work,

Yogyakarta: Hydrology and Air

Quality Lab, Geography Faculty,

UGM.

Sevruk, B., and Lapin, M., 1993,

Precipitation Measurement &

Quality Control, Proc., Int.

Symp. on Precipitation and

Evaporation, Vol. 1, Slovak

Hydrometeorological Institute,

Bratislava, Slovakia.

Seyhan, E., 1977, Fundamentals of

Hydrology, Amsterdam: Instituut

voor Aardwetenschappen, Vrije

Universiteit.

Sharp, J.M., 2007, A Glossary of

Hydrogeological Terms, Texas:

Department of Geological

Sciences, The University of

Texas.

Soewarno, 2000, Hidrologi

Operasional Jilid Satu,

Bandung: PT. Citra Aditya

Bakti.

www.wikipedia.com/ was accessed at

August 26, 2010.

Appendix

Table 1. The result of Taping and Measuring Rain Event

No Day

Time Time Duration Height

(mm)

Volume

(mm3)Start Finish minute second

1 Saturday, Sept 04, 2010 15.36 18.45 189 11340 21 1305.61

2 Sunday, Sept 05, 2010 17.50 19.15 85 5100 12 746.06

3 Monday, Sept 06, 2010 13.30 20.38 248 14880 15 932.58

4 Wednesday, Sept 08, 2010 13.15 19.10 355 21300 48 2984.26

5 Friday, Sept 10, 2010 19.05 19.14 9 540 5 310.86

6 Saturday, Sept 11, 2010 12.55 13.30 35 2100 22 1367.78

Saturday, Sept 11, 2011 21.10 23.55 165 9900 63 3916.84

7 Sunday, Sept 12, 2010 15.31 16.01 30 1800 7 435.20

Sunday, Sept 12, 2010 20.50 21.45 55 3300 4 248.69

8 Thursday, Sept 16, 2010 1.00 4.05 185 11100 23 1429.96

Thursday, Sept 16, 2011 18.00 21.30 210 12600 10 621.72

9 Friday, Sept 17, 2010 13.30 14.05 35 2100 30 1865.16

10 Saturday, Sept 18, 2010 18.48 19.28 40 2400 6 373.03

Total 1641 98460 266 16537.75

Source : Field Measurement, 2010 (during 10 days)