Chinese National Report on Indensity- Frequency - Duration (IFD) for AP FRIEND Phase II
II. DATA AVAILABILITY 2.1 Rainfall Stations
Automatic rain gauge has been widely applied in Indonesia. There are 573 automatic rain gauge stations in total. Table 1 cites the number of automatic rain gauge stations in each province and the average duration year.
Table 1. Automatic Rain Gauge Stations in Indonesia
No. Province Number of Station Average Duration Year
1 Bengkulu 43 4.5
2 D.I. Aceh 19 6.2
3 Sumatera Utara 22 4.5
4 Sumatera Barat 24 7.1
5 Riau 29 5.0
6 Jambi 20 3.5
7 Sumatera Selatan 14 3.6
8 Jawa Barat 78 5.9
9 D.I. Yogyakarta 5 4.0
10 Jawa Tengah 25 9.6
11 Jawa Timur 24 1.8
12 Bali 27 2.9
13 Nusa Tenggara Barat 32 5.4 14 Nusa Tenggara Timur 8 2.0
15 Timor Timur 10 4.3
16 Kalimantan Tengah 17 6.1 17 Kalimantan Timur 19 1.3 18 Kalimantan Barat 2 10.0 19 Kalimantan Selatan 44 2.1
Country Report –Indonesia
Rainfall-recording stations in Indonesia are distributed in main islands of Indonesia such as Sumatera Island, Java Island, Borneo/Kalimantan Island and Sulawesi Island, as well as some rapid developing small islands such as Bali Island, Sumbawa Island and Timor Island. RIWR has collected rainfall data from some prominent sites in Indonesia, displayed in Figure 1.
Figure 1. Sites of Rainfall-recording Stations in Indonesia
Note on Figure 1:
12. Bandung–Ciparay 13. Semarang
Rainfall records, are published by Badan Meteorologi dan Geofisika (BMG), however, must data that are published by BMG consist of daily data. Before 1990 most of the automatic rain gauge recorder are collected and published in the Research Institute for Water Resource (RIWR). Due to regional autonomy, all the hydrological data are collected and managed in the local province. Some of the provinces still send the data to RIWR.
To construct IDF, rainfall data from 27 stations were processed to provide average rainfall depth and intensity for duration of 10 minutes, 15 minutes, 45 minutes, etc.
1 2
Country Report –Indonesia
-69-2.3 Design Storms
Design storms are rainfall events, which are specified by total rainfall and their temporal distribution. A design storm can be calculated from a historical critical storm or by using statistical analysis of historical storms.
The design storm is used to calculate intensity duration frequency (IDF). By having IDF curves, the design flood of a catchment area for various return period can be determined by using rational formulas or other rainfall-runoff models.
2.4 Intensity Duration Frequency (IDF)
The IDF relationships are used in the rational method to determine the average rainfall intensity for a selected time of concentration. The IDF analysis involves the following steps:
• Starting with essentially continuous rainfall data, establish a criterion for identifying independent events.
• Identify a series of rainfall durations to be analyzed, for urban design durations of less than 120 minutes and some times as usual as 10 minutes are desirable.
• For each time (e.g. 15, 30, 60 minutes) scan the events, which have equal or greater durations and identify the largest rainfall for each event.
• Process those data using statistical analysis techniques and establish the best fitting distribution (Pearson III, log Pearson, Gumble, etc)
2.5 Rainfall Intensity Formulas
To get the rainfall intensity, the rainfall data must be developed by the most appropriate method. Some series of calculation were held to find the most suitable approach. The approaches to be considered are using three formulas which are Talbot’s, Sherman’s and Dr. Ichikuro’s formula.
Talbot’s Formula b
t IT a
= + (1) IT is the rainfall intensity for T year return period in t minute rainfall duration,
dimensioning mm/hour. Constant a and b can be described as:
[ ( ) ] ( ) [ ] [ ( ) ] [ ( ) ]
Country Report –Indonesia
-70-Sherman’s Formula
T n
t
I = a (4)
IT is the rainfall intensity for T year return period in t minute rainfall duration, dimensioning mm/hour. Constant a and n can be described as:
( )
Dr. Ichikuro’s Formula
b t IT a
= + (7) IT is the rainfall intensity for T year return period in t minute rainfall duration,
dimensioning mm/hour. Constant a and b can be described as:
[ ] [ ] [ ] [ ]
To find the most appropriate IDF formula, all of the three formulas are applied to three different location characteristics in Indonesia. The first location is Bandung as a city surrounded by many mountains, the second one is Jakarta as a coastal city and the last one is Bali as a representative of small islands. Rainfall data which is used in calculation comes from Cemara Station for Bandung, Halim Perdana Kusuma Station for Jakarta and Ngurah Rai Station for Bali.
Calculation on all locations is held for rainfall intensity in 2-year return period.
Once the comparison result is gained, there will be similar results for other return periods of each location. So, it is assumed to be acceptable to get the most appropriate formula from the calculation for the 2-year return period only. Decision to the most appropriate formula is made by comparing mean deviation of each location’s calculation. The calculation result for each location and formula can be known from Table 2.
Country Report –Indonesia
-71-Table 2. Comparison of IDF Formulas Application in Bandung, Jakarta and Bali for Rainfall in 2-year Return Period
Deviation Mean Deviation
Location Duration (min) Talbot’s Sherman’s Ichikuro’s Talbot’s Sherman’s Ichikuro’s 30 -4.51 12.28 44.42
120 -1.73 4.58 10.83 Bandung
720 0.30 -0.68 -1.72
-0.11 -5.25 22.44 30 1.39 16.61 45.84
120 -0.09 7.36 13.59 Jakarta
720 0.05 -1.29 -1.96
-0.01 -6.13 22.05 30 -0.51 17.72 35.11
120 -5.29 1.52 5.09 Bali
720 1.66 -2.13 -2.75
-0.45 -2.98 26.75
The calculation result shows that Talbot’s formula gives the lowest mean deviation for all of the locations. Therefore, the IDF for those locations is best constructed using Talbot’s formula. Figure 2 to Figure 4 show the IDF curves for each location in various return periods.
Figure 2. IDF Curve of Cemara Station in Bandung
0 50 100 150 200 250 300 350
0 200 400 600 800 1000 1200 1400
Duration (minute)
Intensity (mm/hour)
2-year 5-year 10-year 25-year 50-year 100-year
Figure 3. IDF Curve of Halim Perdana Kusuma Station in Jakarta
Country Report –Indonesia
-72-0 50 100 150 200 250 300
0 200 400 600 800 1000 1200 1400
Duration (minute)
Intensity (mm/hour)
2-year 5-year 10-year 25-year 50-year 100-year
Figure 4. IDF Curve of Ngurah Rai Station in Bali
0 50 100 150 200 250 300 350 400 450
0 100 200 300 400 500 600 700 800
Duration (minute)
Intensity (mm/hour)
2-year 5-year 10-year 25-year 50-year 100-year
Country Report (Presentation) –Indonesia
Agung Bagiawan
Bandung - Indonesia
Indonesia, the South Pacific archipelago with over 17.000 islands is spread over a tropical area extending 90-141 degres east longitude and 6 to 12 degres south latitude. It is with almost two thirds of the area within the Indian and Pacific Oceans between two continents of Asia and Australia. This position of the region causing annual rainfall rauging from 900 mm in the eastern provinces to 6000 mm in the western provinces.
General Information
Rainfall patterns in Indonesia can be divided into three types namely equatorial rainfall, monsoon rainfall and local rainfall. Rainfall in equatorial regions usually has two wet seasons extending from March to May and from September to November. The monsoon rainfall predominantly occurs during the period of October to March and the local rainfall is a reversal pattern of the monsoon type with rainfall occuring between April and September.
All hydrologic methods used for drainage computations require rainfall inputs which may vary according to computational method used. Most common types of rainfall inputs are intensity duration frequency (IDF), design storms and continnous rainfall.
The IDF relationships are used in the rational method to determine the average rainfall intensity for a selected time of concentration. The IDF analysis involves the following steps :
• Starting with essentially continnous rainfall data, establish a criterion for identiflying independent events.
• Identify a series of rainfall durations to be analysed, for urban design durations of less than 120 minutes and some times as usuall as 10 minutes are desirable.
• For each time ( eg. 15, 30, 60 minutes ) scan the events which have equal or greater durations and identify the largest rainfall for each event.
• Process those data using statistical analysis techniques and establish the best fitting distribution ( pearson III, log pearson, gumble, etc )
Rainfall Data
Rainfall records, are published by Badan Meteorology and Geophisica ( BMG ), however, must data that are published by BMG consist of daily data. Before 1990 most of the automatic rain gauge recorder are collected and published in the Research Institute for Water Resource ( RIWR ). Due to regional autonomy, all the hydrological data are collected and managed in the local province. Some of the provinces still send the data to RIWR.
To construct IDF, rainfall data from 27 stations were processed to provide average rainfall depth and intensity for duration of 10 minutes, 15 minutes, 45 minutes, etc
No of Hydrologic Stations (2004)
1. AWLR 411 282 693 2. Peilshaal 202 130 332 3. ARR 310 643 953 4. Manual Raingauge 612 938 1550 5. Climate 151 332 483 Good Need Repair Total
Country Report (Presentation) –Indonesia
RAINFALL RECORDING STATIONS No. of Automatic Raingauge in Indonesia
No. of Station Average Duration
Automatic Raingauge Year
1 Bengkulu 43 4.5
2 Dista Aceh 19 6.2
3 Sumatera Utara 22 4.5
4 Sumatera Barat 24 7.1
5 Riau 29 5.0
6 Jambi 20 3.5
7 Sumatera Selatan 14 3.6
8 Jawa Barat 78 5.9
9 D.I Yogyakarta 5 4.0
10 Jawa Tengah 25 9.6
11 Jawa Timur 24 1.8
12 Bali 27 2.9
13 Nusa Tenggara Barat 32 5.4
14 Nusa Tenggara Timur 8 2.0
15 Timor Timur 10 4.3
16 Kalimantan Tengah 17 6.1
17 Kalimantan Timur 19 1.3
18 Kalimantan Barat 2 10.0
19 Kalimantan Selatan 44 2.1
20 Sulawesi Selatan 26 6.2
21 Sulawesi Tenggara 38 5.4
22 Sulawesi Tengah 9 2.7
23 Sulawesi Utara 16 2.6
24 Maluku 10 3.4
25 Irian Jaya 3 2.7
Province No
573
Talbot’s Formula
IT = rainfall intensity for Tyear return period in tminute duration (mm/hour)
a, b = constants
t = rainfall duration (minute) N = data amount
IT = rainfall intensity for Tyear return period in tminute duration (mm/hour)
a, n= constants
t = rainfall duration (minute) N = data amount T = return period (year)
IT = rainfall intensity for T year return period in t minute duration (mm/hour)
a, b = constants
t = rainfall duration (minute) N = data amount
STATION: HALIM PERDANAKUSUMAH - JAKARTA
0
5 151.64 213.39 243.71 299 363.16 375.52
10 129.5 186.2 216.95 266.75 319.79 336.76
15 112.99 165.15 195.49 240.78 285.68 305.26 30 81.73 123.34 150.76 186.36 216.42 238.37
45 64.02 98.42 122.68 152 174.19 195.52
60 52.62 81.87 103.42 128.34 145.75 165.73
120 30.73 48.96 63.53 79.09 88.17 102.97
180 21.7 34.92 45.85 57.16 63.2 74.69
360 11.53 18.77 24.98 31.2 34.17 40.95
720 5.95 9.75 13.08 16.35 17.81 21.51
INTENSITY DURATION FREQUENCY (MM/JAM) POS HALIM PERDANAKUSUMAH - JAKARTA
Periode Ulang (tahun) T (mnt)
Country Report (Presentation) –Indonesia
IDF STATION: CEMARA - BANDUNG
0
INTENSITY DURATION FREQUENCY (MM/JAM) POS CEMARA - BANDUNG T (mnt)
Periode Ulang (tahun)
TIME ( mnt )
INTENSITY ( mm/hr )
2 years Station : Medan - Sumatera
IDFCurves
TIME ( min )
INTENSITY ( mm/hr )
2 years
INTENSITY ( mm/hr )
TIME ( min ) 2 years
5 years
10 years 20 years
200 Station : Rengat – Sumatera
Country Report (Presentation) –Indonesia
2 years 5 years
10 years
20 years IDF Curves
Station: Pontianak - Kalimantan
TIME (min)
INTENSITY (mm/hr)
0 50 250 200 150 100 300 350
0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255
INTENSITY ( mm/hr )
2 years 5 years
10 years
20 years 100
180
140 160
120
60
40 20
0 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210225 240 255 80
200
IDF Curves Station : M enado - Sulawesi
Country Report (Presentation) –Indonesia
INTENSITY ( mm/hr )
TIME ( min )
Station : Kupang- Nusa Tenggara- Bali
DAS Cimanuk - Wado
--- Predictions ---DAS Brantas - Kediri
--- Predictions
1Bagong - Temon 35 Citanduy - Cirahong
2Bondri - Juwero 36 Citanduy - Karangsari
3Brantas - Kediri 37 Citanduy - Leuwitonjong
4Brantas - Ploso 38 Citanduy - Pataruman
5Brantas - Pundensari 39 Citarum - Nanjung
6Cibuni - Cibungur 40 Citarum - Palumbon
7Cidurian - Kopomaja 41 Citatih - Kebonrandu
8Cidurian - Parigi 42 Ciujung - Kragilan
9Cigulung - Maribaya 43 Ciujung - Rangkasbitung
10 Cijolang - Cikadu 44 Comal - Kecepit
11 Cikadeuen - Cibogo 45 Elo - Mendut
12 Cikapundung - Gandok 46 Grindulu - Gunungsari
13 Cikapundung - Maribaya 47 Jali - Winong
14 Cikarang - Cikarang 48 Kalibaru - Karangdoro
15 Cikawung - Cimei 49 Kupang - Pagerukir
16 Cilangka - Leuwineukteuk 50 Lusi - Mendut
17 Ciletuh - Cipiring 51 Madiun - Nambangan
18 Ciliman - Leuwikopo 52 Pekalen - Condong
19 Ciliman - Munjul 53 Progo - Borobudur
20 Cimandiri - Tegaldatar 54 Progo - Krangan II
21 Cimanuk - Bojongloa 55 Sanen - Sanen
22 Cimanuk - Leuwidaun 56 Serang - Muncar
23 Cimanuk - Leuwigoong 57 Serang - Tongpait
24 Cimanuk - Wado 58 Serayu - Banjarnegara
25 Cimanuk - Warungpeti 59 Serayu - Banyumas
26 Cimayon - Pasirgadung 60 Serayu - Rawalo 27 Cipunegara - Sumurbarang 61 Sewo - Sewoharjo
28 Cirasea - Cengkrong 62 Solo - Babat
29 Cisadane - Batubeulah 63 Solo - Bojonegoro 30 Cisadane - Legokmuncang 64 Solo - Cepu 31 Cisanggarung - Pasuruan 65 Solo - Kauman
32 Cisata - Pasirsereh 66 Solo - Napel
33 Ciseel - Cilisung 67 Tangsi - Susukan
34 Citanduy - Cikawung
DAS DAS
LIST OF STATIONS IN JAVA ISLAND
Actual Data
Distribution
Log Pearson Type III
Weibull Probability
•Frequency of flood can be reduced
•Minimizing of loss
•Optimizing Land use plan
•Depth and duration of flood
•Anticipate inundated area
•Input for Flood Forecasting
•Input for Planning and managing Water
•Resources
•Map of Inundated Areas
•Map of Design Flood for Gauged
& Ungauged Basin
Rainfall Data Questioner Survey Digitized
Land Use,
Map of Inundated Frequency
Analyses
Superimpose of Map
Flood Mapping in Java
Drought Map for Java
•Reduce impact of drought for people
•Planning and Conservation of Water Resources can be Optimized
•Planning of Land Use can be Optimized
•Location of drought
•The Duration and the Amount of Drought
•As an Input for Water Resources Planning
•As an Input for Flood Mitigation
•Set up Priority of drought mitigation
•Maps of Drought from:
- Rainfall point of view - Discharge point of view
Duration of Drought for various Return periods - Consistency Test - Corelation - Double Mass Curve
KetersediaanAvailability of DataData
KetersediaanLimited DataData
< 20 Years KetersediaanPengumpulanAvailable DataCukup DataData
> 20 Years - Consistency Test - Corelation - Double Mass Curve
KetersediaanAvailability of DataData
KetersediaanLimited DataData
< 20 Years KetersediaanPengumpulanAvailable DataCukup DataData
> 20 Years
Country Report (Presentation) –Indonesia
•Clean River
•Reduce O & M budget
•Reduce flood peak and increase water available
Water and Soil Conservation in Bengawan Solo
Water and Soil Conservation
Field Works
Indicator Analyses.
Qmax/Qmin
Water Sampling. Sediment Sampling
Development of Software Analyses of Indicator
Location of Critical Basin
Erosion Map and Critical Basin
Indicator of Critical Catch.
Software for Water Conservation Erosion Map of Critical Catchment
Location of Critical Catchment can be known
The most Dominant Indicator for Critical Catchment
Set up proposal for mitigation of the Critical Catchment
- Do we still have some other Catchments to be published :
Yes : Continue and Edit with new data - good for exchange information
- collaboration among Asia – Pacific members - know the impact of global climate change - add with information about sedimentation No : Change with other Outcome
- joint research - solving problem - exchange expert
Announcement and Call for Papers International Symposium on Ecohydrology
in conjunction with the
13th Regional Steering Committee Meeting for
UNESCO - IHP Southeast Asia and The Pacific
Contribution to IHP-VI Theme 3 Land Habitat Hydrology Focal Area 3.2: Wetlands
and
Cross-Cutting Programme Component: FRIEND (Flow Regimes from International and Experimental Network Data)
Ramada Bintang Bali Resort
Kuta, Bali 21 - 25 November 2005
Sponsored by UNESCO Office, Jakarta
Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT)
Indonesian National Commission to UNESCO (KNIU)
Organized by
Indonesian National Committee for IHP-UNESCO Indonesian Institute of Science - LIPI
Ministry of Public Works - PU
Topics to be discussed are:
1. Ecohydrology, spatial planning, land cover and land use changes
2. Erosion and sedimentation trails 3. Water quality and environmental sanitation 4. Climate variability and ecohydrology 5. Water, culture, and religion 6. Water policy and good governance 7. Best management practices 8. Hydrology and Water Resources
Sunday 20 November Arrival of Participants Welcome Reception Monday 21 November Conference
Conference Dinner Tuesday 22 November Conference Wednesday 23 November Technical Visit – Field Trip Thursday 24 November 13th RSC Meeting
RSC Dinner Friday 25 November 13th RSC Meeting
First Departure Saturday 26 November Second Departure
Schedule
KEY DATES
June 2005 First call for papers Mid of July 2005 Deadline for abstract submission 31 July 2005 Notification of paper acceptance for presentation 30 September 2005 Deadline for full paper submission 20 November 2005 Arrival of participants, welcome party 21- 22 November 2005 International Symposium on Ecohydrology; paper
presentations and poster sessions, cultural evening 23 November 2005 Field trip
24 November 2005 13th Asia Pacific- Regional Steering Committee Meeting and IHP-RSC Dinner.
25 November 2005 13th Asia Pacific- Regional Steering Committee Meeting, APFRIENDS & HTC meetings First Departure
26 November 2005 Second Departures
Country Report –Phillipine