Part 16 Hydrological Analysis for Masang-2 HEPP Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
PART 16 HYDROLOGICAL ANALYSIS FOR MASANG-2 HEPP
16.1 METEOROLOGY AND HYDROLOGY
Meteorological Records and Hydrological Records are collected from Meteorological Climatological and Geophysical Agency (Badan Meteorologi Klimatologi dan Geofisika: BMKG), Research Institute for Water Resources Development under Ministry of Public Works (Pusat Penelitian dan Pengembangan Sumber Daya Air: PUSAIR, formerly DPMA), and engineering reports on various hydropower development projects. The location map of the stations is shown in Figure 1. The availability of data is summarized in Figure 2 and Figure 3. The catchment area of Masang-2 HEPP intake weir site is shown in Figure 4.
16.1.1 METEOROLOGICAL DATA
Climatic data such as air temperature, relative humidity, wind velocity, sunshine duration have been observed at the Tabing-Padang station, which is collected from BMKG. Pan-evaporation has been observed at the Lubuk Sikaping and the Tanjung Pati stations. Pan-evaporation data is collected from Masang-3 HEPP report.
The variation of principal climatic data at the Tabing-Padang station, the Tanjung Pati station and the Lubuk Sikaping station is shown in Figure 5.
(1) Air Temperature
Table 1 shows the monthly mean air temperature at the Tabing-Padang station. The average monthly mean air temperature at the Tabing-Padang station in the period of 1971 to 2002 is summarized below.
Unit: ℃ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 26.3 26.2 26.4 26.5 26.6 26.3 25.9 25.7 25.7 25.8 25.7 26.0 26.1
As seen, the mean annual air temperature at the Tabing-Padang station is 26.1ºC on an average. There is a slight seasonal change ranging 25.7ºC in August or September to 26.6ºC in May.
(2) Relative Humidity
Table 2 shows the monthly mean relative humidity at the Tabing-Padang station. The average monthly relative humidity at the Tabing-Padang station in the period of 1971 to
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2002 is summarized below.
Unit: % Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 81.1 81.3 82.4 83.0 82.6 81.4 81.6 82.2 82.2 83.9 84.6 83.1 82.5
As well as the monthly pattern of mean air temperature, there is no significant change of relative humidity throughout the year. The annual mean relative humidity in the period of 1971-2002 at the Tabing-Padang station is 82.5 % and there is a slight seasonal change ranging from 81.1% in January to 84.6 % in November.
(3) Sunshine Duration
Table 3 shows the monthly mean sunshine duration at the Tabing-Padang station. The average monthly mean sunshine duration at the Tabing-Padang station in the period of 1971 to 2002 is summarized below.
Unit: % Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 53.1 57.4 53.3 55.3 59.5 61.7 60.9 55.4 42.9 41.7 40.4 50.7 52.7
As seen, the mean annual sunshine duration at the Tabing-Padang station is 52.7 % on an average. The maximum duration of 61.7 % and the minimum one of 40.4 % occur in June and November, respectively. Sunshine duration generally decreases with an increase of rainfall. The highest sunshine duration therefore occurs in June in the dry season.
(4) Wind Velocity
Table 4 shows the monthly mean wind velocity at the Tabing-Padang station. The average monthly mean wind velocity at the Tabing-Padang station in the period of 1971 to 2002 is summarized below.
Unit: m/sec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 1.3 1.3 1.3 1.1 1.0 0.9 1.1 1.0 1.1 1.1 1.1 1.1 1.1
Mean annual wind velocity at the Tabing-Padang station is 1.1 m/sec ranging from 0.9m/sec in June and 1.3 m/sec in January, February or March. The wind velocity records collected from Masang-3 HEPP reports in the period of 1971 to 1989 are around 1 m/sec, but the others collected from BMKG in the period of 1990 to 2002 are around 0.1 m/sec.
(5) Evaporation
Pan evaporation records are available at the Lubuk Sikaping station and the Tanjung Pati station. The pan evaporation records at both stations are summarized on monthly basis as shown in Table 5. The average monthly mean pan evaporation at the Lubuk Sikaping and the Tanjung Pati stations is summarized below.
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Station Name: Lubuk Sukaping (1979-1985) Unit: mm/day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 4.8 4.4 4.3 3.9 3.7 4.1 4.1 4.2 3.6 3.6 3.9 4.1 4.1
Station Name: Tanjung Pati (1975-1985) Unit: mm/day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 3.3 4.1 3.5 3.6 3.6 3.5 3.6 3.9 3.6 4.1 3.1 3.5 3.6
The ruling factors of pan evaporation may be air temperature and relative humidity, namely evaporation rate varies season to season following to mainly the variation of humidity. As seen in the above table, the seasonal variation of pan evaporation is generally small throughout the year, because there is no great seasonal variation of relative humidity.
16.1.2 RAINFALL DATA
There are 13 rainfall gauging stations in and around the Masang River basin. The location map of these stations is shown in Figure 1. Also the data availability at these stations is shown in Figure 2.
The rainfall gauging stations are operated and maintained under BMKG. Monthly rainfall records are collected in Masang-3 HEPP and HPPS2, besides daily rainfall records are collected from BMKG in this study.
PLN formerly had own hydrological observation network (PLN-LMK Observation Network). Currently most of these stations have broken down, after regional office of PLN took responsibility for maintenance which the central office of PLN had taken.
(1) Monthly Rainfall Data
The monthly mean rainfall records are collected at 13 stations as presented in Table 6 to Table 18.
The monthly distributions of mean annual rainfall are illustrated below.
Maninjau: 3,199 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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Limau Purut: 3,491 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Padang Panjang: 3,760 mm (1969-2002) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Bukit Tinggi: 2,021 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Baso: 2,012 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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Padang Mangatas: 2,045 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Payakumbuh: 2,181 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Koto Tinggi: 2,638 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Suliki: 2,440 mm (1969-2007) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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Kota Baharu: 2,828 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Bonjol: 4,613 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Jambak: 3,797 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lubuk Sikaping: 3,760 mm (1969-1993) 600 500 400 300 200 Rainfall(mm) 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
As seen above, the annual mean rainfall at these stations ranges from 2,000 mm to 4,600 mm per year. It might be said that there exists little seasonality in the Masang River basin receiving rainfalls throughout the year.
(2) Hourly Rainfall Records
Hourly rainfall records are available at the Gunung Melintang, Maninjau, Sungai Talang
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Barat, Solok Bio-Bio, Muara Paiti, Patir, Puar Datar and Halaban Dua rainfall gauging stations. The location map of the stations is illustrated in Figure 6.
Hourly rainfall records are collected to determine the rainfall pattern for the flood analysis. Hourly rainfall records of more than 50 mm were selected for estimating the characteristics of relatively heavy rainfall. The list of selected hourly rainfall records are enumerated in Table 19 and illustrated in Figure 7.
The accumulated hourly rainfall curves are constructed as shown in Figure 7. From these curves, the following findings on storm rainfall characteristics are drawn.
z The duration of storm rainfall is less than 6 hours.
z Most of the total amount of rainfall occurs in antecedent 3 hours.
16.1.3 RUNOFF RECORDS
(1) Water Level Gauging Station (AWLR Station)
Only one water level gauging station has been installed in the Masang River basin. The station name is the Sipisang AWLR station located in the north of Palembayan town. The catchment area of the station is described as 458 km2 in the records from 1975 to 1992, and as 436.4 km2 in the records from 1993to 2008. On this study, the catchment area of the station is measured as 475km2 based on 1:50,000 scale map. Besides, the catchment area of Masang-2 HEPP intake weir site is measured as 443km2.
The Sipisang AWLR station is operated by the regional office of the River Bureau under the Ministry of Public Works (Balai Pengendalian Sumber Daya Air: BPSDA).
(2) Runoff Records
The daily runoff records are collected from PUSAIR in Bandung and the daily water level records are collected from BPSDA in Bukit Tinggi. The daily runoff records are available from 1975 to 2008 except in 1988, 1989, 1994, 2002, 2003 and 2004. The monthly mean runoff at the Sipisang AWLR station is presented in Table 20. The daily hydrographs are illustrated in Figure 8 to Figure 14, and the daily water level graphs are illustrated in Figure 15 to Figure 16.
The average monthly mean runoff in the period of 1975-2008 is summarized below.
Station Name: Sipisang (1975-2008) Unit: m3/s Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 22.4 20.0 21.6 23.8 22.5 18.7 16.8 18.1 20.6 21.4 27.7 29.2 21.9
As seen, the annual mean runoff at the Sipisang AWLR station is 21.9m3/s or 1,455mm in
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terms of the annual runoff depth, which is computed by dividing the annual accumulated runoff volume by the catchment area of the gauging station.
16.1.4 LOWFLOW ANALYSIS
(1) General Approach
The continuous long-term runoff data for a time period of more than 20 years at the proposed intake weir site is normally required for evaluating an optimum development scale of the project through power output computation. Further, it is highly expected that the runoff data should be of high accuracy because measurement on economic viability of project is highly dependent on the reliability of available runoff records.
On the Masang-2 HEPP, daily runoff records are required because the type of hydropower development scheme is runoff type.
As described in the previous chapter, the daily runoff records are available from 1975 to 2008 except in 1988, 1989, 1994, 2002, 2003 and 2004. Furthermore, the remaining observation years still include data-missing periods. Therefore, it is necessary to supplement the runoff records at the Sipisang station by infilling of missing data.
On the other hand, the monthly basin mean rainfall at the Sipisang station can be estimated for the period between 1973 and 1993. Thus the runoff data at the Sipisang station can be supplemented and expanded for the period of 1973 to 1993 by constructing a rainfall-runoff simulation model.
Along this line, the Tank Model Method is applied in this study as a rainfall-runoff model, the model parameters of which are calibrated by using rainfall and runoff records available in the period of 1982 to 1986.
Firstly, the reliability of the available runoff records at the Sipisang station for using calibration is evaluated by means of runoff coefficient and annual rainfall loss. Then lowflow analysis by the Tank Model Method is carried out to simulate 21-year long-term monthly runoff data at the Sipisang station.
Finally the daily runoff data at the Masang-2 intake weir site is estimated with 14-year simulated monthly data and 7-year observed daily data.
The outline of lowflow analysis is described below.
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(2) Estimation of Missing Data
The observed rainfall records at all of the selected stations include several data interruptions. For the purpose of supplementing the missing rainfall records, the simple regression analysis on the monthly basis are carried out among the selected stations. Missing data at a station is supplemented by another station with linear regression equation which has the highest correlation coefficient. The number of data and correlation coefficient and slopes of linear regression equation is tabulated in Table 21.
(3) Test of Consistency of Rainfall Records
The method of testing rainfall records for consistency is the double-mass curve technique. Double-mass analysis tests the consistency of the record at a station by comparing its accumulated annual or seasonal precipitation with the concurrent accumulated values of mean precipitation for a group of surrounding stations.
The corrected rainfall is determined by the following equation.
PCX = PX ×(M C / M a )
where, PCX : Corrected rainfall at any time period at station x (mm)
PX : Original recorded rainfall at any time period at station x (mm)
M C : Corrected slope of the double-mass curve
M a : Original slope of the double-mass curve
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The double-mass curves are presented in Figure 17. As seen, the monthly rainfall records at the following stations are adjusted for the following periods.
Maninjau Station: 1979 to 1993
Suliki Station: 1988 to 1993
(4) Estimation of Basin Mean Rainfall at the Sipisang AWLR Station
The basin mean rainfall at the Sipisang AWLR station is estimated by applying the Thiessen Method using the corrected data. The records of selected rainfall gauging stations are divided in two periods considering data availability.
Case1 (1973 to 1986): Maninjau, Koto Tinggi, Suliki
Case2 (1987 to 1993): Koto Tinggi, Suliki, Jambak
The tables below show the computed Thiessen coefficients for estimating basin mean rainfall at the the Sipisang AWLR station. Thiessen polygon is illustrated in Figure 18.
Case1 (1973-1986) Maninjau Koto Tinggi Suliki 0.67 0.23 0.10
Case2 (1987 to 1993) Koto Tinggi Suliki Jambak 0.74 0.21 0.05
The estimated monthly basin mean rainfall at the Sipisang AWLR station is presented in Table 22. The estimated annual basin mean rainfall is 2,507mm.
(5) Evaluation of Runoff Records at the Sipisang AWLR Station
The Sipisang AWLR station is selected as a key stream gauge station for predicting the long-term runoff at the proposed Masang-2 intake weir site, because it is the only gauge located in the Masang River. The evaluated period of runoff records is determined to be 5 years from 1982 to 1986, because both rainfall and runoff records are available in this period for calibration of Tank Model parameters.
1) Relationship between Annual Basin Mean Rainfall and Annual Runoff Depth at the Sipisang AWLR Station
The annual basin mean rainfall at the Sipisang AWLR station is estimated for the period of 1982 to 1986. On the other hand, the annual runoff depth of Masang River at the Sipisang station is computed by dividing the annual runoff volume by its drainage area of 475 km2 for the same period as above.
The established relationship between annual basin mean rainfall and annual runoff depth at
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the Sipisang station is as follows. Besides, the relationship is plotted in Figure 19.
Annual Rainfall Annual Runoff Annual Rainfall Runoff Year (mm) Depth Loss Coefficient 1976 2,207 1,375 832 0.62 1982 2,430 1,253 1,176 0.52 1983 2,314 1,233 1,081 0.53 1984 3,339 1,318 2,022 0.39 1985 2,615 1,449 1,165 0.55 1986 3,029 1,450 1,579 0.48 1991 3,030 1,326 1,704 0.44 1993 3,027 2,101 925 0.69 Average 2,749 1,438 1,311 0.53
The difference between the annual basin mean rainfall and annual runoff depth is the so-called evapotranspiration loss or annual rainfall loss.
The annual rainfall loss is analyzed for major rivers in Sumatra in HPPS2 as presented in Table 23 and illustrated in Figure 20. It is therefore found that the annual rainfall loss normally falls in a range of 700 to 1,500 mm a year which varies according to altitude, natural vegetation, seasonal distribution of rainfall, etc.
As seen above, the rainfall loss at the Sipisang station varies from 800mm to 2,000mm. From the hydrological point of view, the rainfall loss usually varies in a small range. Therefore it is estimated that rainfall data or runoff data has some errors. The basin mean rainfall is adjusted based on the following consideration.
z The annual runoff depth is likely to be constant rather than the basin mean rainfall, with small variations of 1,200 to 1,500 mm. The observed record in 1993 is eliminated because it might contain errors due to malfunctioning of water level recorder.
z Maninjau, Koto Tinggi, Suliki, Jambak rainfall gauging stations which are used for estimating basin mean rainfall are located outside the Masang River basin. This fact implies that the estimated basin mean rainfall might inevitably contain some error to some extent.
The estimated annual basin mean rainfall in 1976, 1984 and 1991 are thus adjusted such that the annual rainfall loss becomes 1,251mm, which corresponds to the mean annual rainfall loss in 1982, 1983, 1985 and 1986.
The adjusted relationship between annual basin mean rainfall and annual runoff depth at the Sipisang station is given below.
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Annual Rainfall Annual Runoff Annual Rainfall Runoff Year (mm) Depth Loss Coefficient 1976 2,626 1,375 1,251 0.52 1982 2,430 1,253 1,176 0.52 1983 2,314 1,233 1,081 0.53 1984 2,568 1,318 1,251 0.51 1985 2,615 1,449 1,165 0.55 1986 3,029 1,450 1,579 0.48 1991 2,577 1,326 1,251 0.51 1993 - - - - Average 2,594 1,343 1,251 0.52
2) Double Mass Curve Analysis
Based on the adjusted annual basin mean rainfall and annual runoff depth at the Sipisang station, the double mass curve is constructed as given below.
10,000
1991
1986 ff Depth (mm) ff Depth 1985 5,000 1984
1983
1982 Accumulated Runo
1976 - - 5,000 10,000 15,000 20,000 Accumulated Basin Mean Rainfall (mm)
As shown above, the annual basin mean rainfall and annual runoff depth are plotted on a straight line, satisfactorily showing the hydrological consistency ready for Tank model analysis to be discussed in the next section.
(6) Tank Model
1) Concept of Tank Model Method
The Tank Model simulation method is widely applied for estimating river runoff from rainfall data. The Tank Model Method has been successfully applied for low-flow analysis in various water resources development projects in Indonesia.
Basic concept of Tank Model
The basic idea of Tank Model is very simple. Consider a tank having a hole at the bottom and another hole at the side as illustrated below.
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When the tank is filled with water, the water will be released from the holes as shown in the above. In the tank model simulation, it is considered that the water released from the side hole corresponds to runoff from a stream, and the water from the bottom hole goes into the ground water zone.
The depth of water released from a hole is given by the following tank equation.
Q = α × H
where, Q : Runoff depth of released water (mm) α : Coefficient of hole H : Water depth above the hole (mm)
Applied Tank Model
For the purpose of natural runoff simulation, four by four (4×4) tanks combined in series are used as shown in Figure 21.
The top tank receives the rainfall as inflow to the tank, while the tanks below get the supply from the bottom holes of the tank directory above. The aggregated outflow from all the side holes of the tanks constitutes the inflow in the river course.
To effectively trace dry conditions in the basin, several modifications are made on the basic model. The model is firstly facilitated with a structure to simulate the moisture content in the top tank. This sub-model is composed of two moisture-bearing zones, which contain moisture up to the capacities of saturation. Between the two zones, the water transfers as expressed below.
T 2 = TC(XP / PS − XS / SS)
where, T 2 : Transfer of moisture between primary and secondary zones (if positive, transfer occurs from primary to secondary, and vice versa) TC : Constant
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XP : Primary soil moisture depth PS : Primary soil moisture capacity XS : Secondary soil moisture depth SS : Secondary soil moisture capacity
When the primary soil moisture is not saturated and there is free water in lower tanks, the water goes up by capillary action so as to fill the primary soil moisture with the transfer speed T1 as given below.
T1 =TB(1− XP / PS)
where, T1 : Transfer of the water from lower tank with capillary action TB : Constant
There are many tank model parameters such as hole coefficients of each tank, and height of side holes of each tank. These parameters cannot be determined mathematically. Therefore, these parameters are subject to determination through trial-and-error calculations comparing the calculated runoff with the actually observed runoff.
2) Input Data for Calibration Model
The applied model and simulation condition for calibration are given below. The period for calibration set from 1982 to 1986 because there are continuously rainfall records and runoff records.
Number of Tanks 4×4 Calculation Time Interval 1 month Calculation Period 1982 to 1986 Observed Runoff at Sipisang Station 1982 to 1986 Basin Mean Rainfall at Sipisang Station 1982 to 1986 Monthly Average Evaporation at Lubuk Sikaping 1979 to 1985
The pan evaporation record at the Lubuk Sikaping station is applied. The pan coefficient of 0.7 is applied for estimating evapotranspiration in the basin. The average monthly pan evaporation is given below.
Station Name: Lubuk Sukaping (1979-1985) Unit: mm/day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean 4.8 4.4 4.3 3.9 3.7 4.1 4.1 4.2 3.6 3.6 3.9 4.1 4.1
3) Calibration Results
Through several trial-and-error calculations, the best coincidence between the simulated and observed runoff at the Sipisang station is obtained under the tank parameters as follows.
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Hole Coefficient Height of Hole (mm) βα1α2H1H2 Tank-1 0.300 0.350 0.350 15.0 30.0 Tank-2 0.050 0.070 0.000 5.0 0.0 Tank-3 0.010 0.030 0.000 2.0 0.0 Tank-4 0.001 0.006 0.000 0.0 0.0
Both observed and simulated hydrographs are shown in Figure 22. These hydrographs show that the simulated runoff satisfactorily represents the observed low-flow-season runoff.
Furthermore, the consistency of the simulated runoff is examined by the comparison of flow duration curves constructed on the basis of the observed and simulated runoff. The flow duration curve for the runoff is drawn by arranging the discharges in descending order and assigning probabilities to each discharge, as illustrated in Figure 23.
Both flow duration curves coincide with each other, especially in the lowflow period. The error of the estimated runoff over 40 % in probability varies between 0.4 % and 4.2 %.
In addition to the above, the rainfall-runoff relationship of the simulated runoff is examined compared with the observed runoff as summarized below.
Annual Annual Runoff Depth Annual Rainfall Loss Rainfall (mm) (mm) Runoff Coefficient Year (mm) Observed Simulated Observed Simulated Observed Simulated 1982 2,430 1,254 1,203 1,177 1,227 0.52 0.50 1983 2,314 1,233 1,143 1,081 1,171 0.53 0.49 1984 2,635 1,314 1,241 1,321 1,395 0.50 0.47 1985 2,615 1,449 1,400 1,166 1,215 0.55 0.54 1986 3,029 1,450 1,697 1,579 1,332 0.48 0.56 Average 2,605 1,340 1,337 1,265 1,268 0.52 0.51
As seen above, the average runoff coefficient and rainfall loss of the simulated runoff are derived to be 0.51 and 1,268 mm, respectively. On the other hand, hydrological indices of the observed runoff at the Sipisang station are 0.52 and 1,265 mm. These derived hydrological indices are judged to be in the hydrologically reasonable range.
(6) Prediction of the Long-Term Runoff at the Sipisang AWLR Station
The tank model with the calibrated parameters in the above is applied to generate the monthly runoff at the Sipisang station dating back to the period of 1973 to 1993 by use of the estimated monthly basin mean rainfall. The simulation results are summarized in Figure 24.
The rainfall-runoff relationship of simulated runoff is summarized below.
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Annual Annual Runoff Depth Annual Rainfall Loss Runoff Coefficient Year Rainfall (mm) (mm) (mm) Observed Simulated Observed Simulated Observed Simulated 1973 2,213 - 1,188 - 1,025 - 0.54 1974 2,622 - 1,255 - 1,367 - 0.48 1975 1,882 - 990 - 893 - 0.53 1976 2,208 1,371 848 836 1,360 0.62 0.38 1977 2,215 - 1,010 - 1,205 - 0.46 1978 2,203 - 1,071 - 1,132 - 0.49 1979 2,061 - 866 - 1,195 - 0.42 1980 2,252 - 919 - 1,333 - 0.41 1981 2,797 - 1,403 - 1,395 - 0.50 1982 2,430 1,254 1,377 1,177 1,053 0.52 0.57 1983 2,314 1,233 1,159 1,081 1,155 0.53 0.50 1984 2,635 1,314 1,245 1,321 1,390 0.50 0.47 1985 2,615 1,449 1,401 1,166 1,214 0.55 0.54 1986 3,029 1,450 1,697 1,579 1,332 0.48 0.56 1987 2,674 - 1,410 - 1,264 - 0.53 1988 2,231 - 1,292 - 939 - 0.58 1989 2,122 - 963 - 1,159 - 0.45 1990 2,516 - 1,184 - 1,333 - 0.47 1991 3,030 1,326 1,538 1,704 1,492 0.44 0.51 1992 2,874 - 1,821 - 1,053 - 0.63 1993 3,027 - 1,646 - 1,381 - 0.54 Average 2,474 - 1,251 - 1,222 - 0.50
As seen in the table, the average runoff coefficient and rainfall loss of the simulated runoff are derived to be 0.50 and 1,222 mm, respectively. These hydrological indices are judged to be within the hydrological reasonable range.
The monthly runoff data for the flow duration curve is consisted of 7-year observed monthly runoff in 1976, 1982 to 1986 and 1991, and of 14-year simulated monthly runoff in remaining period from 1773 to 1993. The flow duration curve for the 21-year runoff is drawn by arranging the discharges in descending order and assigning probabilities to each discharge. The flow duration curve of the observed and simulated runoff is shown in Figure 25.
(7) Daily Flow Duration Curve
For Masang-2 HEPP, daily runoff data is required for power output computation because the type of scheme is runoff type. Nevertheless, it is difficult to collect long-term daily rainfall and runoff data in Masang River basin and the monthly runoff records are supplemented and extended with Tank Model method. So the combination of daily observed runoff and simulated monthly runoff is used for setting the daily flow duration curve. The value of simulated monthly runoff data is regarded as simulated daily runoff in same amount.
The condition of data is summarized below.
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Time Interval Daily Observed Daily Runoff 1976, 1982 to 1986, 1991 Simulated Monthly Runoff 1973 to 1975, 1977 to 1981, 1987 to 1990, 1992, 1993
(8) Long-Term Runoff at the Masang-2 Intake Weir Site
The long-term daily runoff at Masang-2 intake weir site for 21 years in the period of 1973 to 1993 is estimated from the predicted long-term daily runoff at the Sipisang station by using the following equation. The flow duration curve as shown in Figure 26, is drawn by arranging the discharges in descending order and assigning probabilities to each discharge.
QD = QW × (AD / AW )
3 where, QD : Runoff at Masang-2 intake weir site (m /sec) 3 QW : Runoff at Sipisang AWLR station (m /sec) 2 AD : Catchment area at Masang-2 intake weir site (=443km ) 2 AW : Catchment area at Sipisang AWLR station (=475km )
(9) Water Level Observation and Discharge Measurement
The field investigation of 3 month water level observation and 30 times discharge measurement was carried out from 2010 October 6th to 2011 January 7th by the sub-contractor. Location of the observation is at the Masang-2 intake weir site (St.1) and the Sipisang AWLR station (St.2). The location map of observation is shown in Figure 27. H-Q rating curve is established on the basis of observed water level and discharge, and hydrograph is established on the basis of observed water level and H-Q rating curve. Hydrograph is illustrated in Figure 28 and H-Q plot is shown in Figure 29.
Consequently, the average water level is 0.75m and the average runoff is 23.85 m3/s calculated with H-Q rating curve. The Equation of H-Q rating curve is given below.
Q = 36.55× (H + 0.06)2
where, Q : Runoff (m3/sec) H : Water level (m)
The observed average runoff is about 15% of probability on the duration curve shown in Figure 26.
16.1.5 FLOOD ANALYSIS
(1) General Approach
Flood analysis is carried out to estimate the probable floods with various return periods as well as the probable maximum flood (PMF) at the Masang-2 intake weir site which are
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basically required for design of spillway and diversion facilities, and determination of dam height.
For estimating the probable floods, the unit hydrograph method is applied, which synthesizes the various probable runoff hydrographs from the probable basin mean rainfalls based on the relationship between unit of basin mean rainfall and its runoff, that is the so-called unit hydrograph. It is generally agreed that the unit hydrograph method is applied for catchment areas less than 3,000 km2.
In this study, the Soil Conservation Service (SCS) unit hydrograph, which is empirically developed in USA Department of the Interior is used, because no hourly flood hydrograph is available at the Sipisang AWLR station to construct the unit hydrograph.
The general approach of flood analysis is outlined below.
(2) Rainfall Analysis
1) Depth-Area-Duration (DAD) Analysis
DAD analysis is carried out to examine the following relationships.
z Relationship between rainfall depth and duration (DD Analysis)
z Relationship between rainfall depth and area (DA Analysis)
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a) Depth-Duration (DD) Analysis
Generally, heavy rainfall occurs intensively in a short duration and sporadically in a limited area. Figure 7 shows the accumulated hourly rainfall curves of selected rain storms at the stations located around the Masang River basin. Hourly rainfall records exceeding 50 mm within 12 hours were selected for estimating the hourly rainfall hyetograph of heavy storm rainfall which might cause flood.
The rainfall duration of selected 63-storm rainfall is arranged as histogram in Figure 30. Among the storm rainfalls bigger than 50mm, 6-hour of rainfall duration covers 63% of all. Besides, 6-hour of rainfall duration covers 80% of all among the storm rainfalls bigger than 100mm. So, the design rainfall duration time is estimated as 6-hour, which represents the characteristics of the storm rainfalls in Masang River basin.
40 of selected 63-storm rainfall have smaller duration time than 6-hours. The average of the 40 storm rainfalls is estimated as the design rainfall pattern. The accumulated hourly rainfall curves and the design rainfall curve are presented in Figure 31.
The design distribution of hourly rainfall is shown below.
Time (hour) 0 1 2 3456 Cumulative Rainfall Depth 0% 47% 78% 87% 95% 99% 100% Incremental Rainfall Depth 0% 47% 31% 9% 8% 4% 1%
b) Depth-Area (DA) Analysis
Generally, heavy rainfall occurs intensively in a short duration and sporadically in a limited area. Therefore the average depth of storm rainfall (basin mean rainfall) is likely to be smaller than the point depth of storm rainfall.
In general, relation between point rainfall depth and average area is expressed by an exponential equation given by the following equation.
n Pb = P0 × exp[−kA ]
where, Pb : Average rainfall depth over an area A (mm)
P0 : Maximum point rainfall at the storm center (mm) A : Area in question (km2) k,n : Constants for a given area
The above equation is the so-called Horton’s Equation. Constants k and n usually vary according to the given rainfall duration such as 1 hour, 6 hours, 12 hours, 1 day, etc. These constants are to be obtained through rainfall analysis based on the isohyetal maps of various major rain storms occurred in the river basin in question. However, the exact determination
of P0 is practically impossible, because it is very unlikely that the rain storm center
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coincides with a rainfall gauging station.
To estimate the basin mean rainfall from the point rainfall, the area reduction factor showing the ratio of basin mean rainfall to point rainfall is introduced as expressed below.
Pb = f a × P0
where, Pb : Basin mean rainfall (mm)
P0 : Point rainfall (mm)
f a : Area reduction factor
If the Horton’s equation is applied, the area reduction factor under the given rainfall duration is given by the following equation.
n f a = exp[−kA ]
However the available rain storm records in the Masang River basin are insufficient for reliable determination of the area reduction factor. The preliminary estimation of the design area reduction factor is carried out based on the following three approaches.
Firstly, the area reduction factor is estimated as 0.63 under the catchment area of 443 km2 for the Masang-2 intake weir site by applying the Horton’s equation assuming that constants of k and n are 0.1 and 0.25, respectively. These constants have been widely and empirically applied in tropical rain forest area.
A 443 (km2) k0.1 n0.25 fa 0.63
Secondly, the estimated design area reduction factors are examined in several other projects. The following design area reduction factors are based on the rainfall analysis using the observed rain storm records.
Catchment Area Area Reduction Project Name (km2) Factor Besai HEPP (D/D in 1990) 415 0.50 Malea HEPP (F/S in 1984) 1,463 0.45 Tampur-1 HEPP (F/S in 1984) 2,000 0.40 Musi HEPP (F/S in 1984) 586 0.50 Cibuni-3 (F/S in 1984) 1,000 0.41 Masang-3 HEPP (Pre F/S in 1999) 993 0.50
Thirdly, the relation between the daily point rainfall and the daily basin mean rainfall around the Masang River basin is analyzed to estimate the area reduction factor of the river basin. The selected rainfall stations are the Payakumbuh and Maninjau stations. A basin mean
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rainfall derives from an arithmetic average of an annual maximum daily rainfall of a target station and daily rainfall of another station at the same day. The average of ratios between basin mean rainfalls and annual maximum daily rainfalls of target stations is estimated as the area reduction factor. The list of rainfall is presented in Table 24 and plotted on Figure 32.
Usually, it is considered that the rainfall intensity in hyetal areas increases with the depth of point rainfall. However, the area reduction factor showing the ratio of area rainfall to the maximum point rainfall varies from 0.5 to 0.8 for the area rainfall amount. Further, the area reduction factor does not always increase with the enlargement of the point rainfall. On the other hand, the design area reduction factors examined in several hydropower projects varies from 0.4 to 0.5.
In due consideration above, the design area reduction factor is conservatively determined to be 0.50.
2) Probable Point Rainfall
Out of the available rainfall records around the Masang River basin, the annual maximum 1-day rainfall records are available at the Payakumbuh rainfall gauging station as presented in Table 25. As seen in this table, the rainfall records at the Payakumbuh station have recording periods between 1951 and 1993 with some interruptions in recording.
The probable point rainfalls at the station with several return periods are estimated through frequency analysis using the Gumbel and Log Normal distributions as summarized below. The estimated frequency curves of probable daily rainfall at these stations are also presented in Figure 33.
Return Period Probable Point Rainfall (mm) Average (years) Gumbel LN 400 263 319 291 200 242 281 261 150 233 266 249 100 220 245 233 80 213 235 224 50 199 213 206 30 183 190 186 20 170 173 171 10 148 145 146 5 125 119 122 3 106 100 103 2908587
The probable point rainfall is estimated as the average of the probable rainfalls by the Gumbel and Log Normal distributions, because the estimated frequency curves by the Gumbel and Log Normal distributions have similar shapes.
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3) Probable Maximum Precipitation (PMP)
Generally three (3) approaches are used for estimating the probable maximum precipitation (PMP) as follows.
¾ Meteorological (theoretical) approach in consideration of the upper physical limit of moisture source
¾ Statistical approach which is empirically developed by Dr. Hershfield from the rainfall records in the United States of America
¾ Historical approach by examining the historical maximum one over occurred in the area of interest
The available basic climatological data such as dew point, humidity, wind velocity in Masang-2 catchment area for the first meteorological approach are insufficient for the time being. Further, no historical rain storm records are also so far available.
Therefore, PMP is estimated by the simple statistical Hershfield method using a series of the annual maximum daily rainfall records. This method is widely applied in the basin where rainfall records are available but other basic climatological records are hardly obtainable.
The Hershfield’s equation is expressed as follows.
X m = X n + K m × Sn
where, X m : Extreme value of 24-hour rainfall (PMP) (mm)
X n : Adjusted mean annual maximum rainfall (mm)
K m : Statistical coefficient
Sn : Adjusted standard deviation of a series of annual maximum rainfall
As seen in the above equation, PMP in question is assumed to be given as the adjusted mean
annual maximum rainfall in question plus the Km times the standard deviation of a series of annual maximum rainfall in question.
The PMP is estimated by applying a series of annual maximum rainfall in the Masang river basin. The calculation process is as follows.
Computation of Statistical Parameters
The mean annual maximum rainfall (Xn) and its standard deviation (Sn) are calculated to be 96.1 mm and 47.1 mm, respectively.
Concurrently with the above, Xn-m and Sn-m are estimated at 91.6 mm and 38.2 mm, which are computed after excluding the maximum rainfall in the series of rainfall data. These statistical
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parameters are used for several adjustment necessary computing Xn and Sn.
Adjustment of Xn and Sn for Maximum Observed Event
The adjustment factors of Xn (fx1) and Sn (fs1) for the maximum observed rainfall shall be obtained from the Hershfield’s adjustment curves as shown in Figure 34 and Figure 35.
Applying the values of Xn, Xn-m, Sn and Sn-m, adjustment factors are obtained 97 % for fx1 and
89 % for fs1, respectively.
Adjustment of Xn and Sn for Sample Size
The adjustment factors of Xn (fx2) and Sn (fs2) for the length of record shall be obtained from the adjustment curves as presented in Figure 36.
The obtained factors of fx2 and fs2 are 100.5 % and 101.6 %, respectively.
Statistical Coefficient Km
The statistical coefficient Km shall be obtained from the empirical Km curves as presented in
Figure 37. Applying the mean annual maximum rainfall at the Payakumbuh station (Xn) is 96.1 mm, the Km value is obtained to be 15.5.
Adjustment for Fixed Observational Time Intervals
Rainfall observation has been carried out on the daily basis at the Payakumbuh station. Since the recorded daily rainfall is computed based on the single fixed observation time interval (say 8 a.m to 8 p.m), the PMP value yielded by the statistical procedure should be increased
multiplying by the adjustment factor (fo).
The adjustment factor curve is presented by Dr. Hersfield as shown in Figure 38. Applying
that the number of observation units is equal to 1, the fo value is obtained to be 113 %.
Computation of PMP at the Payakumbuh Station
The adjustment mean annual maximum rainfall (Xn) is finally given as follows.
X n = f X 1 × f X 2 ×X n
In addition, the adjusted standard deviation of a series of annual maximum rainfall (Sn) is given as follows.
Sn = fS1 × fS 2 × Sn
The unadjusted point PMP (Xm) is computed as follows.
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X m = X n + Km × Sn
Finally, the point PMP is adjusted using the adjustment factor fo as follows.
PMP = fO × X m
The computation process of the point PMP is summarized in Table 26. As seen, the point PMP at the Payakumbuh station is estimated to be 852 mm.
4) Basin Mean Rainfall
Applying the design area reduction factor of 0.5, the probable basin mean 1-day rainfalls with various return periods as well as PMP at the Masang-2 intake weir site are estimated as follows.
Return Period Probable Rainfall (years) (mm) PMP 426 400 146 200 131 150 125 100 117 80 112 50 103 30 93 20 86 10 73 561 352 244
(3) Hydrograph Analysis
1) Unit hydrograph
Since no flood hydrographs are available for the present flood analysis, the unit hydrograph is developed by means of the SCS (Soil Conservation Service) synthetic hydrograph method. The SCS method was developed by analyzing a large number of basins with varying geographic locations. Unit hydrographs were evaluated for a large number of actual watersheds and then made dimensionless by dividing all discharge ordinates by the peak discharge and the time ordinates by the time to peak. An average of these dimensionless unit hydrographs was computed.
a) SCS Unit Hydrograph
The SCS unit hydrograph is derived from the flood concentration time and unit basin rainfall. The unit hydrograph is constructed for a unit rainfall of 1 mm.
The peak discharge of the unit hydrograph is calculated as follows.
JICA Project for the Master Plan Study of 16-24 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
q p = 0.208AQ /t p
3 where, q p : Peak discharge (m /sec) A : Basin area (km2) Q : Total volume of the unit hydrograph (=1mm)
t p : Time to peak (hours)
SCS has determined that the time to peak ( t p ) and rainfall duration ( D ) are related to time
of concentration (tc ) as follows.
t p = 2×tc /3
D = 0.133tc
b) Flood Concentration Time
The flood concentration time is defined as the time of travel from the most remote point in the catchment to the forecast point. The flood concentration time can be estimated by the formula of Kirpich as follows.
0.77 −0.385 tc = 3.97 × L × S
where, tc : Flood concentration time (min) L : Maximum length of travel of water (km) S : Average slope (=H/L, where H is the difference in elevation between the remotest point in the basin and the outlet)
c) SCS Unit Hydrograph Calculation
With a maximum length of travel ( L ) of 49km, the concentration time ( tc ) was found to be 2 about 6.2 hours. With a catchment area ( A ) of 443 km , the peak flow ( q p ) is found to be 22.3 m3/sec/mm. The average slope of the Masang River is illustrated in Figure 39. The SCS unit hydrograph for the Masang River basin is shown in Figure 40.
A 443 km2 Q1mm L 49.156 km
tc 6.2 hours 3 qp 22.3 m /s/mm t p 4.1 hours
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2) Probable Flood Hydrograph at Masang-2 Intake Weir Site
The probable flood hydrographs including PMF at the Masang-2 intake weir site are derived by convolution of the probable basin mean rainfall, PMP with the design rainfall hyetograph and the unit hydrograph.
The base flow is determined to be 14 (m3/s) from the average rainy-season discharge records at the Sipisang AWLR station, and the rainfall loss is assumed to be 47 %. The daily hydrograph is shown in Figure 41, and the rainfall loss is presented in Table 28.
The computed probable flood hydrographs as well as PMF are presented in Table 29 and shown in Figure 42.
The probable design flood discharges with various return periods together with PMF are collected from various hydropower projects in Sumatra as presented in Table 30.
3) Creager’s Coefficient for Probable Floods at Masang-2 Intake Weir Site
Creager’s coefficient for probable flood is computed by the following equations.
a Qp = (46× 0.02832) × C × (0.3861× A)
a = 0.894(0.3861× A)−0.048
3 where, Q p : Peak discharge of probable flood (m /sec) C : Creager’s coefficient A : Catchment area (km2)
The Creager’s coefficients corresponding to the various return periods and PMF for the Masang-2 HEPP are enumerated in the table below.
TQC (year) (m3/s) PMF 4344 92 400 1493 32 200 1341 28 150 1280 27 100 1198 25 80 1152 24 50 1061 22 30 959 20 20 883 19 10 756 16 5 634 13 3 537 11 2 456 10
Figure 43 and Figure 44 shows the relationship between probable flood peak discharges with return periods of 2, 20, 100, 200 years as well as PMF and catchment area for the Masang-2
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HEPP and other water resources development projects in the whole Sumatra. The Creager’s curves are illustrated using the Creager’s coefficients of the Masang-2 intake weir site calculated in above. The probable floods at the Masang-2 HEPP are well plotted in reasonable range of design floods in Sumatra.
4) Probable Floods at the Masang-2 Regulating Pond Site
The time of concentration (tc ) at the Masang-2 Regulating Pond is calculated as 0.17 hour with the same method as the Masang-2 intake weir site. Probable floods at the Masang-2 Regulating Pond are estimated with the Creager’s coefficients of the Masang-2 intake weir site, because short time interval rainfall records like 10-minutes do not exist in Masang River basin. The catchment area of the Masang-2 intake weir site is illustrated in Figure 46.
A1km2 L1.3km t c 0.17 hours
The results of flood analysis are estimated as follows.
Intake Pond TQCQ (year) (m3/s) (m3/s) PMF 4344 92 49.1 400 1493 32 16.9 200 1341 28 15.2 150 1280 27 14.5 100 1198 25 13.5 80 1152 24 13.0 50 1061 22 12.0 30 959 20 10.8 20 883 19 10.0 10 756 16 8.6 5 634 13 7.2 3 537 11 6.1 2 456 10 5.2
5) Probable Floods at the Masang-2 Power House Site
The Alahanpanjang River and the Masang River join together at the upstream of the Masang-2 Power House site. At the power house site, probable floods seem to be controlled by floods from the Masang River, because the catchment area of the Alahanpanjang River basin is smaller than the Masang River basin. So, Probable floods at the Masang-2 power house site are estimated with the Creager’s coefficients of the Masang-2 intake weir site as same as the regulating pond. The catchment area of the power house site is 919.5km2, illustrated in Figure 47.
The results of flood analysis are estimated as follows.
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Intake PH TQCQ (year) (m3/s) (m3/s) PMF 4344 92 6281.3 400 1493 32 2158.8 200 1341 28 1939.1 150 1280 27 1850.9 100 1198 25 1732.3 80 1152 24 1665.8 50 1061 22 1534.2 30 959 20 1386.7 20 883 19 1276.8 10 756 16 1093.2 5 634 13 916.8 3 537 11 776.5 2 456 10 659.4
(4) Water Level Observation and Discharge Measurement
As mentioned in the chapter of lowflow analysis, the field investigation of 3 month water level observation and 30 times discharge measurement was carried out from 2010 October 6th to 2011 January 7th by the sub-contractor.
Consequently, the maximum water level is 2.01m and the maximum runoff is 156.61 m3/s calculated with H-Q rating curve in extrapolation. The Equation of H-Q rating curve is given below.
Q = 36.55× (H + 0.06)2
where, Q : Runoff (m3/sec) H : Water level (m)
16.1.6 SEDIMENT ANALYSIS
(1) General
Sedimentation analysis is preliminarily carried out to estimate the denudation rate in the Masang River basin. The sedimentation load is herein predicted based on the estimated runoff and the sediment discharge rating curve at the intake weir site. The rating curve is established based on the in-situ sampling records obtained through the field investigation conducted in the course of the study. The field investigation was carried out at the Masang-2 intake weir site and Sipisang AWLR station.
The sediment transport in the Masang River is judged to be higher than other rivers in the Sumatra. The denudation rate showing the expected average annual erosion rate in a river basin is generally influenced by the topography (soil condition, river gradient), deforestation of the land in the basin, rainfall intensity, etc.
In addition, the design denudation rates adopted in other water resources or hydropower JICA Project for the Master Plan Study of 16-28 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
development projects in Sumatra are collected for comparison purposes.
(2) Suspended Load Sampling
A total of thirty (30) suspended load samplings were carried out at the intake weir site where discharge measurements were taken. The samples were taken to a laboratory for further analysis. The sieve analysis results of samples are shown in Figure 48.
(3) Suspended Load Rating Curve
The laboratory analysis results of the samples show the total suspended sediment concentration which is the combination of both dissolved and undissolved sediment. The total suspended load is found from the following formula.
QS = 0.0864× C × QW
where, QS : Suspended load (ton/day) C : Total suspended sediment concentration (mg/L) 3 QW : Flow discharge (m /s)
The suspended load calculations using the above formula are presented in Table 31. Several results are considered unreliable because they show very low concentration or very high concentration. Therefore these unreliable results will not be used in the determination of the suspended load rating curve. The values of Qs are plotted against their respective Qw values to determine the suspended load rating curve. On the basis of the estimated sediment discharge at the intake weir site, the suspended load rating curve is established as shown in Figure 49. The rating curve equation is given below.
1.7812 QS = 5.4615×QW
If the flow discharge Qw is known, the suspended load sediment Qs can be estimated.
(4) Total Sediment Load
The annual suspended load sediment yield is simulated by applying the above rating curve to the simulated daily runoff at the intake weir site. The catchment area of the Masang-2 intake weir site is 443km2.
Substituting runoff data, the average annual suspended load sediment at the intake weir site is estimated at 369,749 ton.
The density of sediment in appearance can be calculated by the following equation.
γ ′ = (1−V ) ×γ
where, γ ′ : Density of sediment (ton/m3)
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V : Void ratio of sediment γ : Unit weight of sediment (=2.65ton/m3)
Assuming a void ratio of 60 % in sedimentation, the density of sediment is found to be 1.06 ton/m3. Hence, the annual suspended load sediment is estimated at 348,820 m3.
The sediment load transport into an intake weir generally consists of suspended load and bed load. It is generally accepted that it might be difficult to accurately measure the bed load in a natural river. Usually, the rate of bed load transport is empirically estimated at 10 to 30 % of the total suspended load. The rate of bed load transport is estimated as 10% of the total suspended load, because 10% is usually applied in Indonesia.
Consequently, the mean annual sediment inflow volume into the Masang-2 intake weir is estimated to be 383,702 m3, which is equivalent to a denudation rate of 0.87 mm per year.
For comparison purpose, design denudation rates of various schemes around the project site are presented in the following table.
Project Name Project Stage Province Catchment Area Denudation Rate (km2) (mm/year) Masang-3 Pre-F/S W. Sumatra 993 0.50 Bt. Tonggar W. Sumatra 320 0.45 Bt. Bayang-1 Pre-F/S W. Sumatra 84 0.70 Bt. Bayang-2 Pre-F/S W. Sumatra 36 0.70 Kotapanjang D/D Riau 3,337 0.50 Kampar River Basin F/S Jambi - 0.50 Upper Indragiri River Basin Jambi - 0.59 Middle Indragiri River Basin Jambi - 0.53 Merangin-2 D/D Jambi 1,309 0.34 Merangin-5 Pre-F/S Jambi 2,597 0.70 Lake Kerinci Jambi 1,053 0.72 Source: Masang-3 HEPP, 1999.
As seen in the above table, the design denudation rates vary from 0.34 to 0.72 mm/year. The assumed denudation rate of 0.87 mm/year at the Masang-2 intake weir site might not be in the appropriate range.
Referring to the geology report in this study, there is place of gravel pit in the upstream of Masang River, and gravel extraction is seems to be carried out frequently. The samples of suspended load might be influenced by the gravel extraction. The gravel extraction might not be continuously carried out, so the design denudation rate of the Masang-2 intake weir should be estimated without influence of the gravel extraction in upstream. Nevertheless, it is difficult to estimate the volume of sediment yield from the gravel pit.
The grain size distributions of the samples are consists of mainly fine size grain smaller than 0.1mm, of which falling velocity is slow. It is estimated that the fine size grain has small influence to the sedimentation in the intake weir.
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Consequently, the design denudation rate of the Masang-2 intake weir is estimated as 0.5mm/year which is the middle of design denudation rates in other projects. The design annual sediment inflow volume into the Masang-2 intake weir is estimated to be 221,500m3/year.
16.1.7 WATER QUALITY ANALYSIS
Water quality is important because it is linked to the availability of water for various uses. Specifically, for the Masang-2 HEPP it is important for the well being of hydraulic machinery, other equipment and hydraulic structures used in the project.
The laboratory test for water quality was carried out through the field investigation under the current study to identify the content of various chemical elements contained in the water in the Masang River. Water sampling is carried out three (3) times in total at the Masang-2 intake weir site. The samples were taken to a laboratory for further analysis.
The laboratory test results are presented in Table 32. The table shows that the pH of the water in the Masang River is around 8. It is therefore judged that the water in the Masang River will have no adverse effect on turbine and metal for hydropower use, because adverse effect is expected to occur under the pH value smaller than 4.5.
JICA Project for the Master Plan Study of 16-31 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 1 Monthly Mean Air Temperature
Station Name: Tabing-Padang Elevation: 2.0m Unit: ℃ Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1971 26.1 26.0 25.7 26.2 26.4 26.1 25.8 25.2 25.6 25.4 25.0 25.0 25.7 1972 25.6 25.7 25.9 26.0 26.3 26.3 25.9 25.7 25.8 25.8 26.0 26.2 25.9 1973 26.5 26.8 26.2 26.4 26.5 26.2 25.9 25.6 25.4 25.4 25.7 25.2 26.0 1974 26.2 25.7 25.9 25.8 25.9 25.7 25.7 25.8 25.1 25.3 25.8 25.7 25.7 1975 25.5 25.6 25.9 26.2 26.3 25.7 25.1 25.5 25.4 25.4 25.3 25.3 25.6 1976 25.5 25.7 26.1 26.1 26.3 25.5 26.4 25.4 25.7 25.5 25.5 25.8 25.8 1977 26.1 25.7 26.6 26.7 26.4 26.3 25.9 25.8 26.0 25.8 25.7 26.1 26.1 1978 26.1 26.2 26.5 26.5 26.7 26.2 25.8 26.0 25.5 25.8 25.9 26.1 26.1 1979 26.6 26.0 26.5 26.5 26.4 26.1 25.2 25.6 25.7 26.1 25.7 26.5 26.1 1980 26.1 26.3 26.1 26.0 26.8 26.4 25.8 25.5 25.7 25.6 25.9 25.8 26.0 1981 - 26.1 27.1 26.5 - 26.5 25.7 25.7 25.5 25.5 25.5 26.1 26.0 1982 25.6 25.7 25.9 26.3 26.3 26.0 25.7 25.4 25.2 - 25.8 26.2 25.8 1983 26.9 26.9 27.5 26.9 26.6 - 26.2 26.0 26.0 25.9 26.0 25.7 26.4 1984 25.6 25.7 25.9 25.9 26.3 26.0 26.0 25.4 - 25.6 25.5 25.4 25.8 1985 26.0 25.8 26.0 26.1 26.3 25.3 25.1 25.8 25.3 26.0 25.6 26.3 25.8 1986 26.1 26.2 25.5 26.4 26.4 26.1 25.3 25.4 25.6 25.5 25.4 26.2 25.8 1987 26.8 26.3 26.5 25.6 26.6 26.8 25.9 26.1 26.0 26.0 25.9 26.3 26.2 1988 26.2 26.0 26.3 26.8 26.7 26.0 26.0 25.4 25.4 26.0 25.2 26.3 26.0 1989 26.4 26.1 - 26.6 26.8 - 25.5 - 25.9 25.9 26.0 26.3 26.2 1990 26.1 26.9 27.0 26.7 26.6 26.2 - 25.9 25.9 26.0 26.0 26.1 26.3 1991 26.3 26.5 26.8 26.3 26.8 26.6 26.3 25.9 26.1 25.8 25.4 26.1 26.2 1992 26.7 26.6 26.9 26.9 26.5 26.5 26.0 26.0 25.6 25.9 26.0 26.0 26.3 1993 26.0 26.5 26.0 26.5 26.4 26.8 26.2 25.8 25.8 26.0 26.0 26.2 26.2 1994 26.3 26.4 26.3 26.9 26.9 26.5 26.0 25.5 24.9 25.4 26.0 26.2 26.1 1995 26.7 - 27.7 27.0 26.9 26.9 26.3 - 26.4 26.2 - 25.9 26.7 1996 - 26.4 - - - 26.5 25.8 25.8 - - 26.1 25.7 26.0 1997 26.6 - 27.2 26.5 - 26.7 - 25.8 25.6 - - 26.2 26.4 1998 27.2 27.3 27.5 27.8 27.9 27.0 26.8 26.1 26.1 26.3 26.1 26.0 26.8 1999 26.0 26.5 26.7 26.9 26.4 26.4 25.8 25.9 26.0 25.9 25.9 26.2 26.2 2000 26.6 26.7 26.1 26.5 26.7 26.6 26.0 25.8 25.7 26.1 26.2 26.6 26.3 2001 ------2002 27.1 ------27.1 Min 25.5 25.6 25.5 25.6 25.9 25.3 25.1 25.2 24.9 25.3 25.0 25.0 Max 27.2 27.3 27.7 27.8 27.9 27.0 26.8 26.1 26.4 26.3 26.2 26.6 Ave 26.3 26.2 26.4 26.5 26.6 26.3 25.9 25.7 25.7 25.8 25.7 26.0 26.1 Source: (1971-1989) Masang-3 HEPP Report, 1999 (1990-2002) BMKG
JICA Project for the Master Plan Study of T-1 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 2 Monthly Mean Relative Humidity
Station Name: Tabing-Padang Elevation: 2.0m Unit: % Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1971 81.0 80.0 81.0 82.0 79.0 79.0 79.0 85.0 84.0 84.0 86.0 86.0 82.2 1972 82.0 84.0 82.0 86.0 86.0 84.0 84.0 83.0 85.0 84.0 85.0 84.0 84.1 1973 80.0 81.0 84.0 85.0 83.0 82.0 82.0 82.0 83.0 84.0 82.0 83.0 82.6 1974 81.0 80.0 82.0 84.0 83.0 83.0 81.0 82.0 86.0 82.0 83.0 83.0 82.5 1975 83.0 84.0 83.0 84.0 82.0 82.0 84.0 82.0 83.0 83.0 84.0 83.0 83.1 1976 81.0 84.0 82.0 83.0 82.0 84.0 84.0 82.0 84.0 86.0 85.0 83.0 83.3 1977 83.0 80.0 82.0 84.0 83.0 80.0 81.0 81.0 82.0 86.0 85.0 85.0 82.7 1978 82.0 82.0 84.0 82.0 82.0 80.0 81.0 81.0 81.0 83.0 84.0 84.0 82.2 1979 82.0 83.0 81.0 82.0 81.0 83.0 84.0 83.0 84.0 84.0 85.0 81.0 82.8 1980 81.0 81.0 82.0 86.0 81.0 80.0 82.0 83.0 82.0 83.0 84.0 81.0 82.2 1981 - 83.0 83.0 82.0 - 80.0 82.0 80.0 85.0 85.0 83.0 83.0 82.6 1982 83.0 85.0 84.0 85.0 85.0 82.0 83.0 83.0 84.0 - 89.0 86.0 84.5 1983 81.0 85.0 84.0 84.0 84.0 - 83.0 83.0 85.0 84.0 82.0 85.0 83.6 1984 79.0 80.0 85.0 84.0 83.0 82.0 84.0 81.0 - 83.0 87.0 84.0 82.9 1985 80.0 82.0 82.0 83.0 82.0 81.0 81.0 82.0 40.0 83.0 84.0 83.0 78.6 1986 83.0 80.0 86.0 84.0 83.0 84.0 82.0 84.0 83.0 85.0 84.0 84.0 83.5 1987 83.0 83.0 84.0 85.0 86.0 83.0 84.0 85.0 86.0 89.0 87.0 84.0 84.9 1988 86.0 84.0 87.0 86.0 84.0 84.0 82.0 87.0 88.0 86.0 88.0 77.0 84.9 1989 77.0 78.0 - 78.0 81.0 - 80.0 - 83.0 84.0 85.0 81.0 80.8 1990 80.7 80.2 80.9 82.0 80.6 81.1 - 78.6 82.4 84.8 83.9 83.1 81.7 1991 83.1 81.3 - 83.4 85.1 80.4 81.2 81.5 82.4 83.8 86.1 84.6 83.0 1992 78.3 78.9 82.8 82.4 84.4 80.1 81.2 81.8 82.6 79.7 82.8 82.6 81.5 1993 80.5 80.0 82.5 82.4 84.4 78.9 81.9 81.1 83.3 83.3 84.4 82.2 82.1 1994 83.2 80.7 82.5 81.8 81.5 81.9 78.2 81.0 83.0 85.1 87.1 83.9 82.5 1995 79.1 - 80.6 81.9 81.6 79.5 79.6 - 82.3 81.0 - 81.4 80.8 1996 - 79.4 - - - 82.1 79.7 80.3 - - 81.8 82.2 80.9 1997 76.8 - 77.5 83.2 - 81.0 - 81.5 84.6 - - 85.5 81.5 1998 82.9 83.2 - 83.2 81.6 80.7 79.3 82.6 83.8 81.7 83.7 83.9 82.4 1999 84.0 81.1 80.4 78.2 82.0 80.0 79.7 81.8 83.2 83.1 83.8 81.7 81.6 2000 78.7 73.0 77.9 80.8 79.5 79.9 80.6 81.9 85.4 83.8 84.5 81.3 80.6 2001 ------2002 76.8 ------76.8 Min 76.8 73.0 77.5 78.0 79.0 78.9 78.2 78.6 40.0 79.7 81.8 77.0 Max 86.0 85.0 87.0 86.0 86.0 84.0 84.0 87.0 88.0 89.0 89.0 86.0 Ave 81.1 81.3 82.4 83.0 82.6 81.4 81.6 82.2 82.2 83.9 84.6 83.1 82.5 Source: (1971-1989) Masang-3 HEPP Report, 1999 (1990-2002) BMKG
JICA Project for the Master Plan Study of T-2 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 3 Monthly Mean Sunshine Duration
Station Name: Tabing-Padang Elevation: 2.0m Unit: % Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1971 - - - 45.0 36.0 29.0 26.0 22.0 19.0 25.0 15.0 27.0 27.1 1972 46.0 34.0 26.0 29.0 40.0 42.0 40.0 40.0 20.0 10.0 9.0 35.0 30.9 1973 56.0 61.0 47.0 39.0 53.0 57.0 65.0 43.0 34.0 47.0 44.0 38.0 48.7 1974 37.0 55.0 65.0 63.0 43.0 56.0 63.0 50.0 42.0 38.0 40.0 50.0 50.2 1975 50.0 47.0 54.0 52.0 69.0 60.0 61.0 68.0 55.0 50.0 46.0 48.0 55.0 1976 59.0 63.0 50.0 54.0 74.0 59.0 66.0 71.0 51.0 40.0 36.0 57.0 56.7 1977 57.0 44.0 66.0 55.0 68.0 64.0 61.0 58.0 42.0 40.0 44.0 62.0 55.1 1978 40.0 58.0 53.0 57.0 49.0 51.0 56.0 54.0 42.0 52.0 45.0 42.0 49.9 1979 66.0 51.0 69.0 45.0 61.0 56.0 53.0 56.0 52.0 43.0 37.0 68.0 54.8 1980 62.0 68.0 57.0 44.0 71.0 59.0 55.0 32.0 53.0 57.0 34.0 46.0 53.2 1981 - 50.0 69.0 62.0 - 81.0 62.0 82.0 49.0 48.0 53.0 67.0 62.3 1982 68.0 62.0 56.0 68.0 56.0 80.0 78.0 69.0 44.0 - 40.0 53.0 61.3 1983 68.0 62.0 56.0 68.0 56.0 80.0 78.0 69.0 44.0 - 40.0 53.0 61.3 1984 42.0 43.0 45.0 47.0 63.0 60.0 47.0 46.0 - 45.0 52.0 35.0 47.7 1985 70.0 50.0 43.0 41.0 62.0 52.0 51.0 53.0 31.0 41.0 34.0 60.0 49.0 1986 37.0 66.0 37.0 60.0 58.0 60.0 59.0 48.0 42.0 39.0 49.0 62.0 51.4 1987 46.0 70.0 54.0 29.0 67.0 65.0 73.0 63.0 40.0 47.0 48.0 58.0 55.0 1988 61.0 77.0 56.0 73.0 72.0 75.0 76.0 60.0 45.0 57.0 34.0 71.0 63.1 1989 64.0 59.0 - 80.0 73.0 - 58.0 - 68.0 49.0 59.0 67.0 64.1 1990 64.8 59.9 66.3 59.1 72.8 60.1 - 62.3 48.2 39.6 48.8 62.4 58.6 1991 57.9 67.6 65.4 62.5 60.7 78.3 75.1 63.3 27.9 25.0 34.0 36.1 54.5 1992 52.4 57.4 58.6 59.3 63.8 61.6 66.3 55.6 43.5 57.3 54.2 50.8 56.7 1993 61.6 72.3 46.2 64.6 46.7 68.6 59.7 66.4 55.1 46.7 42.6 51.7 56.9 1994 52.3 60.4 43.7 61.8 62.6 56.4 76.2 57.4 43.6 14.9 41.4 59.8 52.5 1995 53.1 - 53.4 55.0 56.3 71.4 65.1 - 43.6 52.5 - 55.5 56.2 1996 - 51.3 - - - 61.0 47.0 42.8 - - 38.9 33.9 45.8 1997 43.0 - 63.6 62.2 - 76.8 - 47.3 - - - 47.1 56.7 1998 52.8 55.7 53.8 60.2 54.8 51.4 61.7 52.0 38.4 36.0 32.4 23.9 47.7 1999 23.0 49.1 32.8 53.2 57.5 56.2 65.6 65.6 ----50.4 2000 ------2001 ------2002 43.8 ------43.8 Min 23.0 34.0 26.0 29.0 36.0 29.0 26.0 22.0 19.0 10.0 9.0 23.9 Max 70.0 77.0 69.0 80.0 74.0 81.0 78.0 82.0 68.0 57.3 59.0 71.0 Ave 53.1 57.4 53.3 55.3 59.5 61.7 60.9 55.4 42.9 41.7 40.4 50.7 52.7 Source: (1971-1989) Masang-3 HEPP Report, 1999 (1990-2002) BMKG
JICA Project for the Master Plan Study of T-3 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 4 Monthly Mean Wind Velocity
Station Name: Tabing-Padang Elevation: 2.0m Unit: m/sec Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1971 1.5 2.1 1.5 1.5 1.5 2.1 2.1 2.1 2.1 3.1 2.6 3.1 2.1 1972 2.1 2.1 2.1 2.6 2.1 2.6 2.6 2.6 2.6 2.1 2.6 3.6 2.4 1973 3.6 3.1 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.1 2.7 1974 1.5 2.6 2.6 2.1 2.1 2.1 2.6 2.1 2.6 2.6 2.6 1.5 2.2 1975 2.1 2.1 2.1 2.1 2.1 1.5 1.5 2.1 2.1 2.6 2.6 2.6 2.1 1976 3.1 6.2 6.7 3.1 1.5 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.9 1977 2.1 2.6 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 1978 2.1 2.1 2.1 1.5 2.1 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.4 1979 1.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1.0 0.5 0.5 0.5 0.6 1980 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 2.1 0.5 0.5 0.5 0.6 1981 - 0.5 1.0 1.0 - 1.0 1.0 0.5 1.0 0.5 1.0 1.0 0.9 1982 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - 1.0 1.0 1.0 1983 1.0 1.0 1.0 1.0 1.0 - 1.5 1.0 1.0 1.0 1.0 1.0 1.1 1984 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - 1.0 1.0 1.0 1.0 1985 1.5 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.1 1986 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 1.5 1.2 1987 1.5 1.5 1.5 1.0 1.5 1.0 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1988 1.5 1.5 1.0 1.5 1.5 1.0 1.5 1.0 1.5 1.5 1.5 1.5 1.4 1989 1.5 1.5 - 1.5 1.0 - 1.0 - 1.5 1.0 1.5 1.0 1.3 1990 0.1 0.2 0.1 0.1 0.1 0.2 - 0.1 0.2 0.2 0.2 0.2 0.2 1991 0.2 0.2 - 0.2 0.2 0.2 0.1 0.2 0.1 0.1 0.2 0.1 0.2 1992 0.3 0.2 0.1 0.1 0.1 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 1993 0.1 0.2 0.1 0.1 0.1 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 1994 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.1 0.1 0.1 1995 0.1 - 0.1 0.1 0.1 0.1 0.1 - 0.1 0.1 - 0.1 0.1 1996 - 0.2 - - - 0.1 0.1 0.1 - - 0.1 0.1 0.1 1997 0.1 - 0.2 0.2 - 0.1 - 0.2 0.2 - - 0.2 0.2 1998 0.2 0.2 - 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 1999 0.1 0.2 0.2 0.2 0.1 0.2 0.2 0.2 0.2 0.1 0.2 0.1 0.2 2000 0.2 0.2 0.2 0.5 0.5 0.5 0.6 0.6 0.6 0.6 0.6 0.5 0.5 2001 ------2002 6.2 ------6.2 Min 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Max 6.2 6.2 6.7 3.1 2.6 2.6 2.6 2.6 2.6 3.1 2.6 3.6 Ave 1.3 1.3 1.3 1.1 1.0 0.9 1.1 1.0 1.1 1.1 1.1 1.1 1.1 Source: (1971-1989) Masang-3 HEPP Report, 1999 (1990-2002) BMKG
JICA Project for the Master Plan Study of T-4 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 5 Monthly Mean Pan Evaporation
Station Name: Lubuk Sukaping Unit: mm/day Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1979 - 4.7 3.6 4.1 ------4.1 1980 ----4.24.74.34.52.93.02.63.13.7 1981 4.8 3.8 - - 2.5 4.1 3.7 4.0 3.1 2.6 4.1 4.6 3.7 1982 5.0 3.7 3.1 2.8 3.2 2.1 3.9 5.0 4.3 3.8 3.7 3.9 3.7 1983 4.6 4.7 4.9 4.3 4.1 4.5 4.4 4.1 4.2 4.3 3.8 4.1 4.3 1984 4.5 4.0 4.3 4.3 4.3 4.4 4.6 3.4 3.4 4.1 5.2 4.6 4.3 1985 5.3 5.4 5.6 4.2 4.0 4.5 3.8 4.4 3.5 - - - 4.5 Min 4.5 3.7 3.1 2.8 2.5 2.1 3.7 3.4 2.9 2.6 2.6 3.1 Max 5.3 5.4 5.6 4.3 4.3 4.7 4.6 5.0 4.3 4.3 5.2 4.6 Ave 4.8 4.4 4.3 3.9 3.7 4.1 4.1 4.2 3.6 3.6 3.9 4.1 4.1 Source: Masang-3 HEPP Report, 1999
Station Name: Tanjung Pati Unit: mm/day Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average 1975 3.6 3.5 4.7 3.5 4.2 3.5 3.6 4.0 3.6 5.0 4.2 3.8 3.9 1976 3.6 3.7 5.5 4.5 4.1 4.5 4.2 5.7 3.4 4.0 3.0 3.4 4.1 1977 2.6 3.6 3.4 3.7 3.9 3.7 4.8 3.7 3.0 - 2.0 3.9 3.5 1978 3.7 3.9 3.7 4.3 4.0 4.7 5.0 4.6 5.5 5.0 - 2.3 4.2 1979 3.9 3.3 3.4 4.4 4.9 3.0 3.5 4.1 3.6 4.1 - 3.4 3.8 1980 - 4.3 2.4 2.8 3.2 - 3.0 - - 3.7 2.5 4.2 3.3 1981 3.4 5.7 2.7 - 3.4 2.6 3.2 4.7 - 4.8 3.8 - 3.8 1982 - 4.3 2.9 - 3.0 2.4 2.7 2.7 4.1 4.2 3.3 2.8 3.2 1983 2.2 2.9 3.5 3.5 3.0 3.7 2.8 3.2 3.1 3.1 2.9 3.1 3.1 1984 3.5 3.0 3.2 2.7 3.4 3.4 3.2 3.2 3.1 3.1 3.1 4.8 3.3 1985 3.0 6.6 3.5 2.8 2.9 - 3.1 2.6 2.6 - - - 3.4 Min 2.2 2.9 2.4 2.7 2.9 2.4 2.7 2.6 2.6 3.1 2.0 2.3 Max 3.9 6.6 5.5 4.5 4.9 4.7 5.0 5.7 5.5 5.0 4.2 4.8 Ave 3.3 4.1 3.5 3.6 3.6 3.5 3.6 3.9 3.6 4.1 3.1 3.5 3.6 Source: Masang-3 HEPP Report, 1999
JICA Project for the Master Plan Study of T-5 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 6 Monthly Rainfall Records (1/13)
Station Name: Maninjau Station ID: 52B Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 144 176 89 267 177 142 67 126 82 122 262 173 1,827 1970 156 90 128 143 110 101 39 150 420 363 314 103 2,117 1971 56 287 234 200 104 75 73 231 240 72 59 77 1,708 1972 37 148 250 84 73 145 29 54 160 46 7 172 1,205 1973 133 71 - 418 314 64 105 265 275 184 74 183 - 1974 79 229 105 294 220 260 112 237 493 261 248 101 2,639 1975 132 259 56 328 188 144 203 ------1976 32 228 191 183 3 175 217 194 90 339 235 231 2,118 1977 250 79 135 296 153 103 128 124 104 134 278 235 2,019 1978 186 272 279 169 134 278 133 101 73 202 100 165 2,092 1979 ------1980 66 89 177 134 352 308 428 350 436 598 152 580 3,670 1981 297 236 260 658 120 308 428 120 457 610 811 580 4,885 1982 297 254 437 228 321 248 254 329 217 315 336 297 3,533 1983 133 13 408 365 619 336 378 217 369 552 313 230 3,933 1984 400 264 368 431 353 421 451 274 783 402 811 433 5,391 1985 495 148 355 313 235 324 338 190 589 290 566 410 4,253 1986 250 186 451 332 529 238 664 474 470 558 753 178 5,083 1987 286 204 221 395 343 125 279 284 303 471 595 605 4,111 1988 ------2331,088412- 1989 807 400 221 202 321 327 175 71 258 473 365 192 3,812 1990 361 83 194 172 463 120 369 193 193 183 - - - 1991 - 129 - 153 538 - - 231 319 - 876 577 - 1992 42 134 154 564 129 17 200 353 294 365 380 170 2,802 1993 291 156 260 253 428 168 331 156 324 264 - 362 - 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 32 13 56 84 3 17 29 54 73 46 7 77 Max 807 400 451 658 619 421 664 474 783 610 1,088 605 Ave 224 180 237 286 271 201 246 215 316 320 411 294 3,199 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-6 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 7 Monthly Rainfall Records (2/13)
Station Name: Limau Purut Station ID: 52C Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 ------1972 ------1973 - - - 503 309 271 71 452 393 400 332 371 - 1974 157 218 200 578 469 259 196 237 590 314 410 410 4,038 1975 411 320 312 416 226 44 359 250 487 408 - 329 - 1976 182 330 246 309 97 249 265 215 273 869 691 288 4,014 1977 362 379 283 292 222 134 92 - 218 304 469 203 - 1978 ------1979 ------1980 244 111 216 331 210 226 410 411 243 551 - 426 - 1981 ------1982 ---- 150--289413296418-- 1983 229 101 487 449 348 184 178 73 220 252 227 229 2,977 1984 - 109 ------1985 - - 183 - 127 185 115 171 272 210 365 219 - 1986 97 114 197 181 278 114 337 282 263 218 330 489 2,900 1987 462 223 365 377 164 198 182 510 517 303 480 318 4,099 1988 ------229- 1989 300 334 207 1 335 65 276 247 396 273 511 381 3,326 1990 452 257 308 288 - 344 432 77 514 - 318 338 - 1991 457 146 561 379 178 58 126 185 227 71 392 491 3,271 1992 100 238 316 152 387 59 - 367 202 251 224 220 - 1993 221 227 361 320 - - 274 105 263 677 427 477 - 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 97 101 183 1 97 44 71 73 202 71 224 203 Max 462 379 561 578 469 344 432 510 590 869 691 491 Ave 283 222 303 327 250 171 237 258 343 360 400 339 3,491 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-7 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 8 Monthly Rainfall Records (3/13)
Station Name: Padang Panjang Station ID: 53 Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 371 392 431 459 339 301 415 417 206 204 582 465 4,582 1970 186 111 338 381 181 194 137 62 295 413 557 258 3,113 1971 243 168 448 220 195 176 229 209 416 384 400 518 3,606 1972 346 355 559 573 216 248 185 64 268 109 290 551 3,764 1973 247 252 302 947 763 247 411 1,088 943 720 786 950 7,656 1974 277 581 873 1,030 899 401 342 105 413 138 500 581 6,140 1975 224 236 134 339 169 86 203 308 321 262 287 354 2,923 1976 161 112 393 329 112 260 324 217 421 490 709 193 3,721 1977 ------1978 258 421 289 343 232 328 101 - - 572 451 348 - 1979 162 208 170 356 245 312 218 165 141 498 423 216 3,114 1980 258 138 175 171 156 160 250 336 203 315 384 285 2,831 1981 ------1982 - - - 553 464 - - 232 187 - 334 - - 1983 590 62 60 292 346 192 229 413 194 233 290 239 3,140 1984 308 357 384 - - 251 215 ------1985 ---- 362213282126319257422411- 1986 327 138 447 457 400 82 217 172 604 625 366 508 4,343 1987 268 329 254 434 545 189 273 181 148 245 291 410 3,567 1988 279 184 317 312 181 209 162 - 408 411 621 314 - 1989 418 456 459 153 275 209 85 206 352 439 333 245 3,630 1990 525 157 392 86 158 385 168 299 269 449 280 197 3,365 1991 277 260 274 361 220 83 43 179 182 135 634 469 3,117 1992 56 50 143 143 227 74 160 172 161 262 282 360 2,090 1993 - 173 158 138 45 66 212 31 224 245 215 214 - 1994 ------1995 ------1996 ------1997 ------1998 ------402-- 1999 398 315 566 321 232 - - 253 315 617 521 497 - 2000 ------2001 - - 444 ------2002 ------180361---- 2003 ------2004 ------2005 ------2006 ------2007 ------Min 56 50 60 86 45 66 43 31 141 109 215 193 Max 590 581 873 1,030 899 401 415 1,088 943 720 786 950 Ave 294 248 348 382 303 212 221 246 320 365 432 390 3,760 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-8 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 9 Monthly Rainfall Records (4/13)
Station Name: Bukit Tinggi Station ID: 54 Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 ------1972 - 154 196 209 194 107 27 ------1973 - 84 124 238 174 111 85 258 156 251 60 130 - 1974 ------1975 ------1976 ------1977 ------1978 - - - 316 ------1979 ------1980 ------1981 ------146- 1982 ------93----- 1983 - - 196 ------1984 ------1985 179 153 218 - 201 28 48 62 328 187 234 98 - 1986 231 58 415 242 136 120 90 68 172 223 167 106 2,028 1987 107 70 272 222 132 37 86 121 95 274 151 225 1,792 1988 ------196- 1989 333 - 139 75 119 24 105 77 253 224 186 - - 1990 - 463 ------1991 ------1992 - - 233 169 - - - 56 - - 290 154 - 1993 135 102 252 273 269 85 162 72 251 231 256 191 2,279 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 107 58 124 75 119 24 27 56 95 187 60 98 Max 333 463 415 316 269 120 162 258 328 274 290 225 Ave 197 155 227 218 175 73 86 101 209 232 192 156 2,021 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-9 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 10 Monthly Rainfall Records (5/13)
Station Name: Baso Station ID: 54A Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 199 159 406 488 287 141 138 230 137 197 454 384 3,220 1970 204 126 193 169 42 80 99 21 235 294 275 131 1,869 1971 132 114 192 360 48 92 90 230 262 30 67 209 1,826 1972 154 122 286 383 287 70 52 48 137 - - 157 - 1973 609 100 69 179 279 62 38 151 61 665 - 169 - 1974 73 220 13 257 168 141 92 122 450 74 79 244 1,933 1975 82 276 162 258 97 40 130 99 241 31 92 39 1,547 1976 ------1977 ------1978 127 - - 189 ----- 182295249- 1979 285 452 - 190 ---- 229316284-- 1980 89 166 355 172 - 175 - 165 ---- - 1981 ------1982 ------5570---- 1983 266 - 293 255 ------1984 ------1985 ------1986 ------1987 ------1988 ------56-106- 1989 273 84 118 203 128 87 56 149 154 243 - 239 - 1990 70 - 100 65 - 55 - - - 164 - - - 1991 88 36 255 115 147 42 4 26 52 - 197 384 - 1992 85 38 141 53 201 2 164 35 158 66 - - - 1993 ------1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 70 36 13 53 42 2 4 21 52 30 67 39 Max 609 452 406 488 287 175 164 230 450 665 454 384 Ave 182 158 199 222 168 82 86 111 182 193 218 210 2,012 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-10 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 11 Monthly Rainfall Records (6/13)
Station Name: Padang Mangatas Station ID: 54C Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 253 206 336 357 299 60 47 166 54 206 454 440 2,878 1970 177 181 269 195 107 46 55 35 86 149 255 168 1,723 1971 218 168 232 236 103 130 129 321 145 39 164 222 2,107 1972 147 86 252 369 217 158 40 129 148 102 179 288 2,115 1973 161 141 144 211 154 102 68 153 117 173 19 56 1,499 1974 30 188 72 233 111 121 246 152 345 77 126 98 1,799 1975 60 353 65 196 45 44 244 145 322 26 - - - 1976 143 71 257 173 107 106 140 115 148 289 328 348 2,225 1977 322 196 158 397 ------1978 - - - 313 153 61 179 76 46 340 229 462 - 1979 117 38 220 37 50 284 - 63 24 176 525 134 - 1980 ------1981 ------1982 ------1983 241 ------1984 ------1985 ------1986 ------1987 ------1988 ------10981259- 1989 - 237 - - - 10 - - 131 - - - - 1990 ----- 46----170450- 1991 - 126 ------1992 ------24-37219398- 1993 196 120 116 164 257 70 93 43 227 - 256 186 - 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min303865374510402424261956 Max 322 353 336 397 299 284 246 321 345 340 525 462 Ave 172 162 193 240 146 95 124 119 149 144 231 270 2,045 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-11 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 12 Monthly Rainfall Records (7/13)
Station Name: Payakumbuh Station ID: 56 Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 159 140 387 133 222 30 3 81 84 89 304 444 2,076 1970 313 75 241 197 84 71 136 96 203 223 189 127 1,955 1971 172 195 101 190 50 140 124 357 200 12 119 239 1,899 1972 196 96 - 495 478 209 148 76 - 83 173 - - 1973 154 101 - 345 275 128 - 298 182 - - - - 1974 48 182 89 443 199 129 121 150 - 38 96 121 - 1975 75 288 177 264 79 90 240 127 324 20 64 47 1,795 1976 82 47 230 169 69 155 146 201 180 204 - 319 - 1977 359 221 257 287 206 168 133 92 82 202 422 445 2,874 1978 302 178 483 321 239 82 117 33 93 320 254 469 2,891 1979 217 234 126 134 95 164 106 104 112 153 388 111 1,944 1980 189 109 189 198 210 172 87 165 186 165 352 121 2,143 1981 189 - - - 210 175 87 165 ---- - 1982 ------1983 167 84 - - - 34 126 65 149 303 47 - - 1984 186 169 ------1985 - - - 36 184 8 29 61 143 281 203 86 - 1986 47 74 638 143 227 43 43 31 204 256 180 180 2,066 1987 111 64 147 150 195 63 110 98 85 - - - - 1988 ------4553994- 1989 - 291 ------424--- 1990 - - - 584 231 36 475 3 764 1,313 212 258 - 1991 90 116 406 374 109 57 41 121 23 115 147 299 1,898 1992 142 30 89 109 31 - 77 6 68 35 482 70 - 1993 10 50 11 168 356 64 74 10 174 367 350 143 1,777 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min103011363183323124747 Max 359 291 638 584 478 209 475 357 764 1,313 539 469 Ave 160 137 238 249 187 101 121 111 181 232 251 210 2,181 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-12 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 13 Monthly Rainfall Records (8/13)
Station Name: Koto Tinggi Station ID: 56A Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------99---275-- 1971 209 158 161 181 152 141 194 177 140 115 157 206 1,991 1972 174 156 216 203 156 151 90 0 205 150 222 184 1,907 1973 148 219 239 240 186 135 132 183 191 344 154 241 2,412 1974 129 193 191 287 239 191 185 197 355 193 276 286 2,722 1975 167 227 178 243 140 156 239 157 258 140 178 155 2,238 1976 171 160 185 489 194 243 257 275 237 314 305 203 3,033 1977 225 192 217 442 195 218 174 233 228 317 347 214 3,002 1978 191 184 207 312 190 58 149 133 164 371 281 320 2,560 1979 87 125 140 128 71 134 134 132 22 156 310 165 1,604 1980 3 236 330 510 93 76 8 83 41 13 366 464 2,223 1981 137 239 225 319 413 69 108 45 207 141 246 366 2,515 1982 274 254 361 671 205 92 12 87 114 311 396 366 3,143 1983 184 90 214 201 108 114 133 120 227 224 294 303 2,212 1984 179 215 197 252 269 242 296 161 286 259 656 546 3,558 1985 189 186 300 185 262 175 97 126 281 320 315 182 2,618 1986 392 138 198 218 235 334 180 160 227 400 197 142 2,821 1987 227 80 297 425 349 65 170 310 71 410 205 272 2,881 1988 234 ------194289210380129- 1989 437 205 104 81 138 60 76 155 201 283 277 317 2,334 1990 163 202 185 227 314 192 182 173 220 351 307 230 2,746 1991 339 95 447 240 266 67 95 68 71 241 265 845 3,039 1992 214 483 735 175 320 29 284 95 150 208 296 332 3,321 1993 172 132 397 231 285 91 256 122 160 706 380 247 3,179 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 3 80 104 81 71 29 8 0 22 13 154 129 Max 437 483 735 671 413 334 296 310 355 706 656 845 Ave 202 190 260 285 217 138 154 147 189 269 295 292 2,638 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-13 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 14 Monthly Rainfall Records (9/13)
Station Name: Suliki Station ID: 56B Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 148 109 111 127 104 96 136 124 95 76 108 146 1,380 1972 122 103 153 143 199 104 57 54 146 103 158 129 1,471 1973 30 14 83 244 85 12 41 145 131 159 109 119 1,172 1974 60 152 79 182 149 236 279 207 503 116 156 161 2,280 1975 61 152 79 185 16 43 189 45 210 17 78 42 1,117 1976 67 32 139 148 14 140 147 156 9 11 22 21 906 1977 151 106 128 187 130 9 60 120 121 215 383 112 1,722 1978 246 94 310 324 170 115 7 124 6 257 199 267 2,119 1979 149 102 217 128 51 207 181 236 165 160 503 383 2,482 1980 82 80 128 151 145 126 76 83 129 167 379 186 1,732 1981 192 96 123 102 237 126 76 9 67 196 73 29 1,326 1982 47 89 194 354 177 114 119 86 271 176 253 102 1,982 1983 153 33 51 66 166 102 67 71 127 232 107 80 1,255 1984 172 194 277 186 184 146 156 18 149 70 353 282 2,187 1985 204 127 191 107 226 19 76 133 258 124 349 149 1,963 1986 283 98 418 223 194 72 41 29 130 197 181 229 2,095 1987 97 89 389 213 501 25 34 154 218 496 218 128 2,562 1988 488 294 451 388 115 89 142 412 351 62 558 88 3,438 1989 766 112 221 181 136 85 81 194 396 560 417 186 3,335 1990 823 321 228 188 424 18 200 0 227 689 416 516 4,050 1991 608 192 1,486 1,092 365 202 65 92 297 364 722 1,441 6,926 1992 164 372 347 100 281 17 261 93 401 149 429 626 3,240 1993 515 321 162 376 598 140 109 19 790 1,545 853 489 5,917 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 - - 0 254 0 87 0 ------Min301406609006112221 Max 823 372 1,486 1,092 598 236 279 412 790 1,545 853 1,441 Ave 245 143 249 235 194 97 108 113 226 267 305 257 2,440 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-14 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 15 Monthly Rainfall Records (10/13)
Station Name: Kota Baharu Station ID: 57 Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 ------1972 - - - 362 382 146 44 61 - 319 346 - - 1973 183 261 349 379 348 219 - 205 239 - - - - 1974 61 276 154 217 135 127 99 74 143 153 93 253 1,785 1975 196 121 272 142 180 85 268 193 208 151 323 160 2,299 1976 123 114 89 89 64 123 58 211 151 372 - - - 1977 - - 202 234 22 42 14 31 148 63 207 216 - 1978 96 90 - 354 204 208 - 91 29 - 390 812 - 1979 275 459 278 372 182 130 106 129 36 288 503 374 3,132 1980 374 380 313 328 - 117 149 83 315 93 - 142 - 1981 90 570 478 64 226 38 211 30 270 533 108 362 2,980 1982 - - 239 - 362 ------1983 392 173 - 122 290 122 135 ------1984 ------1985 - - - 75 206 2 94 57 366 254 226 289 - 1986 399 100 409 324 147 89 165 47 - 377 413 507 - 1987 204 234 321 175 433 ------1988 ------179146-- 1989 466 159 405 247 238 47 57 186 416 446 402 382 3,451 1990 - 468 - - 185 101 115 6 104 622 331 501 - 1991 463 - 408 623 210 36 23 130 219 146 420 874 - 1992 386 241 365 372 263 59 194 85 307 97 - - - 1993 ------1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min61908964222146296393142 Max 466 570 478 623 433 219 268 211 416 622 503 874 Ave 265 260 306 263 227 99 115 101 211 273 301 406 2,828 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-15 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 16 Monthly Rainfall Records (11/13)
Station Name: Bonjol Station ID: 58C Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 ------1972 ------1973 ------120393374416303341- 1974 177 160 368 516 227 185 160 156 508 115 289 292 3,153 1975 159 175 150 374 74 140 286 80 131 251 90 223 2,133 1976 ------1977 ------1978 ------1979 ------1980 ------1981 ------1982 ------291347-477-- 1983 224 143 546 925 560 357 - 420 492 - 766 - - 1984 - 453 451 - - 276 408 349 658 499 1,126 - - 1985 569 330 604 444 835 139 340 358 510 587 585 316 5,617 1986 423 165 496 487 523 359 512 453 494 664 348 119 5,043 1987 162 149 499 840 1,091 ------1988 ------421996527- 1989 262 370 277 243 424 131 267 416 637 681 742 181 4,631 1990 - - - 407 320 ---- 705-516- 1991 391 211 622 548 274 189 119 230 433 437 794 655 4,903 1992 - 178 271 528 408 157 301 325 384 385 372 292 - 1993 272 267 481 419 - 200 399 237 312 563 482 481 - 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 159 143 150 243 74 131 119 80 131 115 90 119 Max 569 453 622 925 1,091 359 512 453 658 705 1,126 655 Ave 293 236 433 521 474 213 291 309 440 477 567 358 4,613 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-16 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 17 Monthly Rainfall Records (12/13)
Station Name: Jambak Station ID: 58F Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 ------1972 ------1973 ------144360284430162218- 1974 39 205 200 445 323 198 183 214 620 205 416 444 3,492 1975 117 288 344 493 287 117 478 236 495 237 259 293 3,644 1976 ------1977 285 202 265 844 211 268 155 307 295 523 600 252 4,207 1978 274 239 547 625 687 199 335 246 219 550 756 354 5,031 1979 204 264 339 305 136 354 551 312 282 372 716 247 4,082 1980 177 219 589 587 555 262 300 256 292 469 391 501 4,598 1981 244 225 182 784 560 262 300 106 618 550 231 268 4,330 1982 113 301 493 401 307 144 199 149 273 276 409 220 3,285 1983 115 125 250 730 413 461 158 313 338 298 335 244 3,780 1984 268 213 220 751 222 190 383 159 415 296 786 289 4,192 1985 269 245 500 172 497 80 186 290 524 464 549 373 4,149 1986 411 119 433 241 359 271 226 153 300 431 585 248 3,777 1987 194 118 490 623 350 84 245 402 397 630 308 311 4,152 1988 298 149 368 304 185 188 115 479 334 20 191 499 3,130 1989 221 269 191 221 213 33 136 140 393 195 344 86 2,442 1990 266 167 272 169 239 116 312 95 309 415 399 318 3,077 1991 252 200 482 464 320 151 138 95 470 470 713 570 4,325 1992 80 192 203 372 364 169 239 233 261 333 249 341 3,036 1993 226 147 424 304 438 204 207 197 333 456 442 445 3,823 1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 39 118 182 169 136 33 115 95 219 20 162 86 Max 411 301 589 844 687 461 551 479 620 630 786 570 Ave 213 205 357 465 351 197 250 237 373 381 442 326 3,797 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-17 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 18 Monthly Rainfall Records (13/13)
Station Name: Lubuk Sikaping Station ID: 59 Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1969 ------1970 ------1971 314 288 289 300 285 279 306 298 279 266 287 313 3,504 1972 297 284 318 311 338 285 253 251 313 284 320 301 3,555 1973 255 246 284 374 286 245 306 298 279 266 287 313 3,439 1974 297 284 318 311 338 285 253 251 313 284 320 301 3,555 1975 255 246 284 374 286 245 144 359 283 430 165 218 3,289 1976 146 119 182 375 207 332 369 414 316 516 491 230 3,697 1977 285 202 301 844 211 268 155 307 295 523 600 252 4,243 1978 274 239 547 625 687 199 335 246 219 550 156 354 4,431 1979 204 264 279 300 136 354 551 312 282 372 216 247 3,517 1980 177 219 589 587 555 262 300 256 272 473 408 328 4,426 1981 244 225 182 784 560 262 300 78 618 550 231 268 4,302 1982 71 263 556 365 412 192 219 43 228 216 409 127 3,101 1983 115 92 250 730 388 461 144 313 338 298 335 166 3,630 1984 268 177 187 340 261 190 383 148 415 296 786 246 3,697 1985 273 286 460 344 477 80 186 177 638 388 544 373 4,226 1986 411 240 175 335 357 298 280 146 284 427 - - - 1987 194 111 490 559 330 ------1988 ------160- 1989 ------1990 ------1991 ------1992 ------1993 ------1994 ------1995 ------1996 ------1997 ------1998 ------1999 ------2000 ------2001 ------2002 ------2003 ------2004 ------2005 ------2006 ------2007 ------Min 71 92 175 300 136 80 144 43 219 216 156 127 Max 411 288 589 844 687 461 551 414 638 550 786 373 Ave 240 223 335 462 360 265 280 244 336 384 370 262 3,760 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
JICA Project for the Master Plan Study of T-18 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 19 Selected Hourly Rainfall Records
Unit:mm Total Hour Station Name Date Rainfall 123456789101112 Gunung 1982/12/12 55.2 10.2 8.5 2.6 1.8 16.1 4.5 0.2 0.6 3.7 4.7 2.3 Melintang 1983/1/12 59.9 40.9 0.2 1.0 17.8 1983/3/22 59.4 13.3 30.3 7.0 1.3 2.2 3.5 1.8 1983/4/30 55.4 14.5 33.3 5.3 0.7 0.1 1.5 1983/9/6 54.6 20.2 28.0 5.3 0.8 0.3 1983/12/8 54.6 18.3 19.3 4.0 5.3 4.8 2.9 1984/3/16 79.7 67.0 8.5 4.2 1984/4/13 95.6 0.3 5.4 66.0 11.7 1.8 2.1 3.2 2.1 1.7 1.1 0.2 1984/4/23 76.8 4.2 70.0 2.6 1984/10/17 52.8 49.0 2.3 1.5 1984/11/3 78.1 42.3 30.0 4.3 1.5 1984/11/9 118.0 18.0 50.0 45.0 3.7 1.3 1984/11/18 55.3 4.2 37.0 4.0 2.5 3.3 1.0 2.3 1.0 1985/1/3 65.9 25.0 25.0 15.0 0.9 1985/1/6 51.3 44.5 2.5 1.2 2.1 0.8 0.2 1985/1/25 64.5 28.1 35.1 0.6 0.7 1985/2/11 95.1 3.0 40.3 20.5 1.2 23.1 6.0 0.8 0.2 1985/3/11 99.5 6.6 0.5 15.0 27.4 35.0 14.2 0.8 1985/3/31 52.9 24.6 20.7 5.6 2.0 1985/5/6 62.0 30.0 13.3 1.1 10.5 5.4 1.7 1985/5/14 132.6 5.2 50.5 7.2 2.2 13.3 31.0 18.0 4.0 0.7 0.4 0.1 1985/9/11 60.5 55.0 3.9 0.9 0.7 1985/10/8 55.8 50.9 0.1 1.2 1.4 1.1 0.4 0.7 1986/3/9 76.2 4.5 32.4 3.1 1.8 3.7 1.3 6.2 0.3 0.1 0.9 1.3 20.6 Maninjau 1986/5/29 103.6 9.2 10.0 10.0 20.0 40.0 14.4 1986/7/8 116.8 2.6 43.0 60.0 11.2 1986/7/13 58.0 11.0 20.0 20.0 6.9 0.1 1986/8/3 55.6 1.0 1.8 0.8 34.0 4.0 14.0 1986/10/10 71.3 2.8 0.3 0.1 0.1 3.2 6.0 20.0 17.0 3.0 16.0 1.8 1.0 1987/8/1 83.0 83.0 1987/10/7 54.5 53.5 1.0 Sungai Talang 1991/9/29 70.5 68.0 2.0 0.5 Barat 1991/12/28 68.0 4.0 2.0 2.0 2.0 20.0 12.0 8.0 3.0 3.0 4.0 4.0 4.0 1992/3/8 66.2 1.0 1.5 30.0 4.2 8.0 2.0 4.5 2.0 5.0 8.0 Solok Bio-Bio 1991/10/18 63.7 3.0 3.2 10.2 0.0 0.0 10.2 12.0 25.1 1992/3/7 54.8 45.2 0.8 2.0 1.2 5.6 Muara Paiti 1984/10/17 63.3 31.5 31.3 0.3 0.2 1984/11/3 87.5 5.3 5.3 0.2 32.7 41.1 1.5 1.4 1984/11/5 74.2 37.7 12.5 14.4 0.2 0.1 1.1 6.0 2.2 1984/11/18 59.3 14.0 32.9 2.6 3.2 1.5 4.5 0.4 0.2 1984/12/1 67.1 14.7 43.3 4.5 2.7 1.9 1985/2/10 99.9 42.2 50.0 4.0 3.6 0.1 1985/3/9 77.5 60.0 8.2 8.9 0.3 0.1 1985/8/16 67.3 1.8 60.0 3.0 1.8 0.5 0.2 1985/10/6 55.8 40.9 5.5 0.8 1.6 2.1 3.4 1.3 0.2 1986/12/7 54.3 16.8 30.0 5.2 2.0 0.3 1987/1/29 92.6 30.0 40.0 15.0 6.0 1.6 1987/2/8 65.5 7.4 40.0 15.0 3.1 1988/9/5 50.8 47.8 1.2 0.7 0.8 0.3 1988/9/11 82.5 22.5 45.0 5.0 7.7 2.3 1989/1/10 55.9 44.6 11.3 1989/1/16 61.4 0.9 20.6 0.6 0.2 14.2 20.0 3.0 1.0 0.9 1989/1/18 70.9 3.4 5.5 1.3 0.1 33.1 27.4 0.1 1989/6/25 52.4 17.5 19.0 12.0 1.7 1.5 0.7 1989/11/7 58.7 30.1 10.8 2.6 1.2 3.3 0.7 2.1 3.2 0.5 3.6 0.3 0.3 1989/11/13 51.6 33.2 9.2 6.7 2.5 Patir 1989/4/3 154.0 3.0 3.0 1.0 127.0 13.0 7.0 Puar Datar 1992/12/9 82.0 34.0 18.0 7.0 16.0 6.0 1.0 Halaban Dua 1991/8/30 82.2 49.3 28.1 4.8 1991/11/19 60.0 10.0 30.0 2.0 4.0 14.0 1991/12/14 76.8 3.8 34.0 15.2 2.0 8.1 11.3 0.9 1.5 1991/12/28 81.8 22.1 4.0 7.1 19.2 8.1 11.2 6.0 4.0 0.1 1992/4/23 80.3 6.0 28.0 1.2 32.0 4.0 5.1 4.0 Source:Masang-3 HEPP, 1999.
JICA Project for the Master Plan Study of T-19 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 20 Monthly Mean Runoff Records
Station Name: Sipisang Station ID: 01-164-00-01 Unit: m3/s Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1975 ------2.913.417.215.4- 1976 14.8 12.1 15.2 18.1 15.9 16.8 15.5 13.6 12.9 21.1 29.0 62.8 20.7 1977 - - 18.8 20.4 20.0 16.4 14.2 12.8 12.3 16.8 - - - 1978 20.9 18.4 - 18.9 13.7 - - 10.9 14.0 16.4 25.6 21.6 - 1979 ------16.3-17.4--- 1980 16.4 15.4 19.6 21.0 15.8 19.3 16.4 ------1981 ----24.416.513.612.216.326.421.620.5- 1982 16.0 18.0 20.5 27.2 29.4 18.2 14.7 13.9 12.9 14.3 18.2 23.3 18.9 1983 17.7 12.6 15.7 22.6 26.5 18.0 15.7 16.3 21.4 19.2 18.9 18.3 18.6 1984 16.5 13.7 14.6 25.0 17.3 16.4 14.5 12.7 16.9 21.0 40.4 28.6 19.8 1985 25.3 21.6 25.1 23.3 24.3 22.9 17.6 14.5 20.0 18.9 25.9 22.6 21.8 1986 22.6 17.3 25.4 23.7 35.8 24.8 19.3 19.0 17.8 21.5 18.5 16.3 21.8 1987 13.1 10.2 14.9 18.1 25.1 - 10.3 24.1 ---- - 1988 ------1989 ------1990 ------19.922.5-- 1991 17.6 19.4 24.7 25.5 19.9 14.7 12.6 11.8 12.3 14.8 27.2 39.2 20.0 1992 - - - 17.0 ------1993 31.0 36.0 39.1 40.1 43.7 42.5 26.5 30.3 25.2 21.2 22.5 21.8 31.7 1994 21.8 19.0 21.0 21.3 22.1 16.2 17.6 17.8 15.2 12.1 22.9 32.0 19.9 1995 22.3 24.4 21.9 25.4 26.1 21.5 17.3 19.6 18.6 25.2 21.8 23.4 22.3 1996 27.0 28.7 29.4 29.5 20.2 23.8 17.3 18.7 18.1 23.2 26.0 27.9 24.2 1997 17.6 12.4 13.8 15.9 16.5 9.7 8.4 7.7 7.9 8.7 10.4 12.1 11.8 1998 12.6 11.2 9.9 13.6 11.6 8.2 7.5 17.9 25.2 21.1 22.8 37.1 16.6 1999 33.7 22.2 23.6 18.2 16.8 11.4 14.9 16.1 27.2 34.3 45.5 49.3 26.1 2000 34.2 18.6 18.2 20.4 15.8 14.1 16.1 15.1 13.9 18.5 59.0 38.3 23.5 2001 - 3.7 - - 12.1 12.3 7.4 - - 6.6 2.2 - - 2002 ------2003 ------2004 ------2005 20.5 19.9 20.7 34.2 21.9 16.4 17.9 18.2 38.4 41.6 46.8 36.0 27.7 2006 39.5 37.8 33.7 32.5 26.2 20.0 22.0 14.9 26.7 27.7 38.9 42.2 30.2 2007 24.6 32.2 22.3 22.2 23.0 17.5 26.9 25.9 36.3 26.9 30.7 25.0 26.1 2008 21.1 33.0 25.9 30.3 24.5 29.4 38.7 47.6 38.2 40.1 36.2 31.0 33.0 Min 12.6 3.7 9.9 13.6 11.6 8.2 7.4 7.7 2.9 6.6 2.2 12.1 Max 39.5 37.8 39.1 40.1 43.7 42.5 38.7 47.6 38.4 41.6 59.0 62.8 Ave 22.1 19.9 21.5 23.5 21.9 18.6 16.8 17.8 19.6 21.1 27.1 29.3 21.6 Source: Pusair. Masang-3 HEPP, 1999.
JICA Project for the Master Plan Study of T-20 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 21 Regression Analysis of Monthly Rainfall Records
Number of Data 52B 52C 53 54 54A 54C 56 56A 56B 57 58C 58F 59 Maninjau 52B 241 161 196 83 102 102 179 241 241 154 120 200 178 Limau Purut 52C 161 173 159 71 78 69 140 173 173 127 115 158 109 Padang Panjang 53 196 159 230 80 118 113 183 224 230 153 123 188 152 Bukit Tinggi 54 83 71 80 85 32 35 60 85 85 51 63 74 48 Baso 54A 102 78 118 32 118 75 94 118 118 89 69 90 80 Padang Mangatas 54C 102 69 113 35 75 120 108 120 120 78 51 78 96 Payakumbuh 56 179 140 183 60 94 108 204 204 204 154 100 167 150 Koto Tinggi 56A 241 173 224 85 118 120 204 270 270 179 132 228 196 Suliki 56B 241 173 230 85 118 120 204 270 276 179 132 234 196 Kota Baharu 57 154 127 153 51 89 78 154 179 179 179 93 156 133 Bonjol 58C 120 115 123 63 69 51 100 132 132 93 132 132 78 Jambak 58F 200 158 188 74 90 78 167 228 234 156 132 234 154 Lubuk Sikaping 59 178 109 152 48 80 96 150 196 196 133 78 154 196
Correlation Ratio 52B 52C 53 54 54A 54C 56 56A 56B 57 58C 58F 59 Maninjau 52B 1.000 0.269 0.162 0.275 0.194 0.146 0.123 0.248 0.274 0.144 0.572 0.331 0.286 Limau Purut 52C 0.269 1.000 0.341 0.236 0.441 0.348 0.364 0.339 0.322 0.262 0.260 0.413 0.277 Padang Panjang 53 0.162 0.341 1.000 0.185 0.240 0.131 0.274 0.198 0.081 0.247 0.254 0.187 0.128 Bukit Tinggi 54 0.275 0.236 0.185 1.000 0.548 0.655 0.651 0.529 0.503 0.668 0.445 0.565 0.582 Baso 54A 0.194 0.441 0.240 0.548 1.000 0.428 0.370 0.345 0.208 0.406 0.364 0.489 0.129 Padang Mangatas 54C 0.146 0.348 0.131 0.655 0.428 1.000 0.632 0.511 0.423 0.533 0.203 0.596 0.260 Payakumbuh 56 0.123 0.364 0.274 0.651 0.370 0.632 1.000 0.287 0.384 0.419 0.393 0.307 0.244 Koto Tinggi 56A 0.248 0.339 0.198 0.529 0.345 0.511 0.287 1.000 0.516 0.401 0.467 0.439 0.445 Suliki 56B 0.274 0.322 0.081 0.503 0.208 0.423 0.384 0.516 1.000 0.553 0.361 0.317 0.327 Kota Baharu 57 0.144 0.262 0.247 0.668 0.406 0.533 0.419 0.401 0.553 1.000 0.375 0.261 0.130 Bonjol 58C 0.572 0.260 0.254 0.445 0.364 0.203 0.393 0.467 0.361 0.375 1.000 0.619 0.608 Jambak 58F 0.331 0.413 0.187 0.565 0.489 0.596 0.307 0.439 0.317 0.261 0.619 1.000 0.780 Lubuk Sikaping 59 0.286 0.277 0.128 0.582 0.129 0.260 0.244 0.445 0.327 0.130 0.608 0.780 1.000
Slope of Formula (Y=aX) X 52B 52C 53 54 54A 54C 56 56A 56B 57 58C 58F 59 Maninjau 52B 1.000 0.851 0.647 1.562 0.997 0.945 0.846 1.034 0.824 0.888 0.727 0.828 0.752 Limau Purut 52C 0.834 1.000 0.731 1.405 1.506 1.509 1.193 1.087 0.691 0.976 0.633 0.818 0.816 Padang Panjang 53 0.904 0.962 1.000 1.648 1.525 1.576 1.098 1.177 0.720 1.020 0.722 0.836 0.983 Bukit Tinggi 54 0.452 0.516 0.375 1.000 0.733 0.929 0.745 0.659 0.454 0.589 0.364 0.521 0.505 Baso 54A 0.539 0.464 0.374 1.004 1.000 0.894 0.562 0.668 0.388 0.529 0.385 0.476 0.558 Padang Mangatas 54C 0.597 0.480 0.357 0.910 0.737 1.000 0.828 0.810 0.658 0.647 0.404 0.503 0.532 Payakumbuh 56 0.544 0.549 0.498 1.033 1.007 0.959 1.000 0.734 0.534 0.695 0.416 0.517 0.511 Koto Tinggi 56A 0.626 0.685 0.543 1.223 0.958 0.972 0.786 1.000 0.668 0.741 0.529 0.634 0.626 Suliki 56B 0.585 0.723 0.542 1.383 1.000 0.921 0.911 0.925 1.000 0.823 0.610 0.654 0.421 Kota Baharu 57 0.592 0.683 0.610 1.445 1.257 1.135 0.867 0.941 0.768 1.000 0.541 0.621 0.566 Bonjol 58C 1.112 1.156 0.899 2.210 1.645 1.514 1.317 1.461 0.873 1.272 1.000 1.206 1.235 Jambak 58F 0.860 0.975 0.789 1.602 1.514 1.547 1.126 1.212 0.821 1.031 0.703 1.000 1.020 Lubuk Sikaping 59 0.934 0.941 0.695 1.696 1.147 1.360 1.347 1.292 1.663 1.117 0.682 0.900 1.000
JICA Project for the Master Plan Study of T-21 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 22 Estimated Monthly Basin Mean Rainfall at Sipisang AWLR Station
Unit: mm Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 1973 126 99 206 360 262 75 105 234 241 218 96 190 2,213 1974 89 213 122 281 217 242 145 225 462 231 245 150 2,622 1975 133 241 86 294 160 137 210 80 144 156 93 149 1,882 1976 67 193 184 250 48 187 219 209 116 300 230 204 2,207 1977 234 108 153 319 160 120 132 149 134 184 304 218 2,215 1978 193 234 266 217 150 211 124 111 87 246 152 211 2,202 1979 107 132 174 150 70 177 244 164 121 183 375 164 2,061 1980 37 100 164 190 186 162 192 177 209 275 187 373 2,252 1981 178 165 175 365 170 160 215 62 249 313 410 335 2,797 1982 195 176 289 287 202 138 123 169 146 224 260 221 2,430 1983 114 30 229 209 306 180 199 127 222 310 212 176 2,314 1984 229 182 230 261 231 250 276 156 415 238 533 339 3,339 1985 275 119 240 187 183 181 174 123 342 210 349 232 2,615 1986 225 121 280 214 299 186 329 242 266 350 385 132 3,029 1987 184 114 202 288 277 71 162 208 168 345 323 334 2,675 1988 228 177 278 239 75 61 88 201 259 161 336 128 2,231 1989 397 174 105 86 124 53 70 138 201 265 256 254 2,121 1990 201 184 169 192 279 149 167 133 197 337 281 228 2,516 1991 313 96 476 290 243 74 83 63 100 232 291 771 3,030 1992 176 397 582 156 278 31 243 90 157 183 267 314 2,874 1993 181 131 328 217 282 89 209 102 200 671 373 245 3,027 Min37308686483170628715693128 Max 397 397 582 365 306 250 329 242 462 671 533 771 Ave 185 161 235 240 200 140 177 151 211 268 284 255 2,507
JICA Project for the Master Plan Study of T-22 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 23 Annual Rainfall Loss of Various River Basins in Sumatra
/sec) (mm) (mm) 3 ,821 225.0 1,666 1,155 0.59 1960-1984 Rainfall Runoff Depth Loss 8 2,250 28.4 1,082 1,168 0.48 1973-1993 ) (mm) (m 081 2,012 33.1 966 1,046 0.48 1977-1993 2 (km ology, Hydro Inventory Study, July 1997 July Study, Hydro Inventory ology, Name Basin Area Mean Mean Runoff Rainfall Coeff. Period 1 Lhok Nibong2 Kr. Jambu Aye Stabat3 Sipelanduk Lb. 01-027-01-02Pane Bt. 4 Lb. Bendahara Rokan S. 5 Wampu S. 4,583 Tj. Ampalu6 Sungai Dareh 01-055-03-02 Kuantan Bt. 7 2,685Hari Bt. 01-040-01-01 01-058-02-01 Muara Inum8 MartapuraHari Bt. 175.7 01-066-04-01 82 9 3,870 3,325 Banjarmasin Musi A. 01-071-01-01 1,209 W. Tl. Bawang 2,215 3,099 2,589 01-071-02-01 01-077-02-07 4,452 1,476 2,211 206.8 141.5 01-074-01-01 1,455 0.45 3,239 604 1,685 1,342 77.6 1972-1993 4,260 3,346 310.2 3,125 1,414 1,247 1,105 2 107.6 2,197 0.54 0.52 36.8 1,106 1974-1993 1974-1993 2,332 1,042 0.50 1,921 1975-1993 1,014 0.68 1975-1993 1,204 0.70 1973-1987 0.61 1972-1993 No. StationID CatchmentAnnualRunoff BasinAnnual River Gauge Observation Annual 12 Tui Kareng13 Hp. Baru Kr. Teunom14 Air Batu15 Toru Bt. Air Gadang 01-205-01-0116 DespetahIndrapura Bt. Pasaman Bt. 2,403Hydr 2 : Vol. : Sectoral Report Source 01-141-01-01 01-178-01-01 Musi A. 01-165-01-01 3,437 2,773 1,339 468 183.9 01-074-01-02 2,843 3,600 2,887 2,413 128.9 627 121.3 31.3 1,024 1,466 3,100 2,857 0.70 2,109 1982-1993 1,377 45.2 743 778 0.52 2,273 0.79 1972-1993 0.73 1973-1993 1973-1993 827 0.73 1974-1991 10 Kunyir11 Kp. Darang Kr. Aceh W. Sekampung 01-080-01-04 01-001-01-01 438 1, 2,740 23.1 1,663 1,077 0.61 1968-1993
JICA Project for the Master Plan Study of T-23 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 24 Area Reduction Factor for Masang River Basin
Point Rainfall (mm) Area No Date Average Reduction Maninjau Payakumbuh Factor 1 1973/9/19 115 0 58 0.50 2 1974/5/3 90 6 48 0.53 3 1980/9/8 161 2 82 0.51 4 1984/1/9 91 45 68 0.75 5 1985/9/28 125 0 63 0.50 6 1986/11/26 148 0 74 0.50 7 1987/4/8 129 35 82 0.64 8 1988/11/23 175 44 110 0.63 Maninjau 9 1989/6/7 200 0 100 0.50 10 1990/1/16 81 0 41 0.50 11 1991/12/29 126 53 90 0.71 12 1992/4/18 125 0 63 0.50 13 1993/9/14 115 0 58 0.50 14 1973/5/10 1 103 52 0.50 15 1974/5/26 0 65 33 0.50 16 1981/1/20 0 65 33 0.50 17 1983/9/5 37 55 46 0.84 18 1985/10/8 64 103 84 0.81 19 1986/9/28 1 79 40 0.51 20 1987/7/9 0 70 35 0.50 21 1989/2/21 2 57 30 0.52 Payakumbuh 22 1990/7/23 0 200 100 0.50 23 1991/8/13 22 76 49 0.64 24 1992/4/1 30 95 63 0.66 25 1993/5/25 35 70 53 0.75 Average 0.58
JICA Project for the Master Plan Study of T-24 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 25 Annual Maximum 1-Day Rainfall at Payakumbuh Station
Unit: mm Year Rainfall 1951 96 1952 100 1953 76 1954 68 1955 66 1956 67 1957 92 1958 - 1959 85 1960 77 1961 84 1962 130 1963 49 1964 80 1965 75 1966 270 1967 250 1968 95 1969 94 1970 75 1971 93 1972 - 1973 103 1974 65 1975 110 1976 79 1977 113 1978 104 1979 82 1980 150 1981 65 1982 - 1983 55 1984 45 1985 103 1986 79 1987 70 1988 59 1989 97 1990 200 1991 76 1992 95 1993 70
Source: BMKG. Masang-3 HEPP, 1999.
JICA Project for the Master Plan Study of T-25 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 26 Calculation of Probable Maximum Precipitation (PMP)
Annual Maximun 1-Day Precipitation at Payakumbuh Station
Unit: mm Year Rainfall Max = 270 mm (1966) 1951 96 1952 100 n = 40
1953 76 Xn = 96.1 mm
1954 68 Sn = 47.1 mm
1955 66 Xn-m = 91.6 mm
1956 67 Sn-m = 38.2 mm 1957 92
1958 - Xn-m / Xn =0.95
1959 85 Sn-m / Sn =0.81 1960 77 1961 84 Adjustment for Maximum Observed Event
1962 130 fX1 = 97%
1963 49 fS1 = 89% 1964 80 1965 75 Adjustment for Sample Size
1966 270 fX2 = 100.5%
1967 250 fS2 = 101.6% 1968 95 1969 94 Statistical Coefficient
1970 75 Km =15.5 1971 93 1972 - Adjustment for Fixed Observational Time Intervals
1973 103 f0 = 113% 1974 65 1975 110 Computation of PMP
1976 79 Xn = fX1 * fX2 * Xn 1977 113 = 93.6 mm
1978 104 Sn = fS1 * fS2 * Sn 1979 82 = 42.6 mm
1980 150 Xm = Xn + Km * Sn 1981 65 = 754.0 mm
1982 - PMP = f0 * Xm 1983 55 = 852.0 mm 1984 45 1985 103 1986 79 1987 70 1988 59 1989 97 1990 200 1991 76 1992 95 1993 70
JICA Project for the Master Plan Study of T-26 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 27 Ratios for SCS Unit Hydrograph
t/tp q/qp 0.0 0.000 0.1 0.030 0.2 0.100 0.3 0.190 0.4 0.310 0.5 0.470 0.6 0.660 0.7 0.820 0.8 0.930 0.9 0.990 1.0 1.000 1.1 0.990 1.2 0.930 1.3 0.860 1.4 0.780 1.5 0.680 1.6 0.560 1.7 0.460 1.8 0.390 1.9 0.330 2.0 0.280 2.2 0.207 2.4 0.147 2.6 0.107 2.8 0.077 3.0 0.055 3.2 0.040 3.4 0.029 3.6 0.021 3.8 0.015 4.0 0.011 4.5 0.005 5.0 0.000
JICA Project for the Master Plan Study of T-27 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 28 Average Rainfall Loss at Sipisang AWLR Station
Monthly Runoff Sipisang Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1982 16 18 21 27 29 18 15 14 13 14 18 23 1983 18 13 16 23 26 18 16 16 21 19 19 18 1984 16 14 15 25 17 16 15 13 17 21 40 29 1985 25 22 25 23 24 23 18 14 20 19 26 23 1986 23 17 25 24 36 25 19 19 18 21 19 16
Adjusted Monthly Basin Mean Rainfall Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1982 195 176 289 287 202 138 123 169 146 224 260 221 1983 114 30 229 209 306 180 199 127 222 310 212 176 1984 181 143 182 206 182 197 218 123 328 188 420 267 1985 275 119 240 187 183 181 174 123 342 210 349 232 1986 225 121 280 214 299 186 329 242 266 350 385 132
Number of Days Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1982 31 31 31 31 31 31 31 31 31 31 31 31 1983 31 31 31 31 31 31 31 31 31 31 31 31 1984 31 31 31 31 31 31 31 31 31 31 31 31 1985 31 31 31 31 31 31 31 31 31 31 31 31 1986 31 31 31 31 31 31 31 31 31 31 31 31
Runoff Depth Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1982 90 102 116 153 166 103 83 78 73 81 102 131 1983 100 71 88 128 149 102 89 92 121 108 107 103 1984 93 77 82 141 97 92 82 71 95 119 228 161 1985 143 122 141 132 137 129 99 82 113 107 146 127 1986 128 97 143 134 202 140 109 107 101 121 104 92
Rainfall Loss in Rainy Season 1982 0.530 1983 0.449 1984 0.432 1985 0.431 1986 0.520 Average 0.473
JICA Project for the Master Plan Study of T-28 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 29 Probable Flood Hydrographs at Masang-2 Intake Weir Site Unit:m3/s Return Period (year) Period Return 014141414141414141414141414 123 3404 12805 27766 125 3952 4467 4344 9588 4067 13599 114 3267 1493 402 2426 1398 860 1220 1751 1125 1341 109 384 1256 838 1165 821 1010 607 1280 103 1199 360 1091 753 769 1198 965 546 100 1122 1049 347 719 1152 740 904 522 1080 966 93 320 1061 674 682 869 489 994 874 290 959 85 648 617 800 471 899 804 268 883 597 79 568 724 434 827 689 231 756 540 487 70 667 393 709 578 195 634 498 410 571 363 61 594 490 167 537 427 348 480 312 504 53 416 143 456 359 296 407 263 428 47 306 346 224 260 191 101112 121113 82314 560 42315 38216 290 19217 200 38118 87 14019 262 50 75 181 26 364 127 39 16 250 26 14 173 68 341 18 121 15 36 235 14 25 163 329 66 18 115 227 15 35 157 14 24 303 111 63 18 209 15 34 146 275 14 24 103 61 17 191 15 133 33 254 14 23 94 176 57 17 124 219 15 32 14 23 153 88 53 17 108 185 15 30 130 14 22 77 50 17 159 92 14 29 112 14 21 67 136 44 16 80 14 27 97 14 20 58 39 16 70 14 24 14 19 52 35 16 14 23 14 18 32 15 14 21 14 18 15 14 14 Time (hour) PMF 400 200 150 100 80 50 30 20 10 5 3 2 Peak 4344 1493 1341 1280 1198 1152 1061 959 883 756 634 537 456 Catchment Area = 443 km2
JICA Project for the Master Plan Study of T-29 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 30 Probable Floods under Various Schemes in Sumatra
Catchment Probable Peak Discharge (m3/sec) No Scheme River Province Area Return Period (year) PMF (km2) 2 20 100 200 1,000 10,000 1 Tampur-1 Kr. Tampur D.I. Aceh 2,025 2,870 3,590 7,470 2 Teunom-1 Kr. Teunom D.I. Aceh 900 2,300 3,120 8,390 3 Aceh-2 Kr. Aceh D.I. Aceh 323 1,030 1,470 3,510 4 Lawe Alas-4 Lawe Alas D.I. Aceh 5,705 2,500 4,250 12,500 5 Peusangan-4 Kr. Peusangan D.I. Aceh 945 1,600 6 Lake Laut Tawar Kr. Peusangan D.I. Aceh 195 500 810 940 1,670 7 Residual Basin-1 Kr. Peusangan D.I. Aceh 106 360 530 600 1,020 8 Jambu Aye Kr. Jambu Aye D.I. Aceh 3,890 1,939 2,331 3,800 4,850 9 Rubek Kr. Jambu Aye D.I. Aceh 93 142 10 Residual Basin-2 Kr. Peusangan D.I. Aceh 128 320 480 550 940 11 Lalang S. Belawan N. Sumatera 254 250 410 610 12 Tembakau S. Percut N. Sumatera 171 140 230 340 13 Lausimeme S. Percut N. Sumatera 106 180 280 300 14 Helvetia S. Deli N. Sumatera 341 280 530 690 15 Namobatang S. Deli N. Sumatera 93 250 270 16 Baru S. Serdang N. Sumatera 671 470 750 940 17 Pulau Tagor S. Ular N. Sumatera 1,013 430 820 1,070 18 Karai S. Ular N. Sumatera 500 500 560 19 Brohol S. Padang N. Sumatera 759 390 720 940 20 Rampah S. Belutu N. Sumatera 423 180 290 370 21 Renun A. Renun N. Sumatera 139 580 740 820 960 1,900 22 Wampu S. Wampu N. Sumatera 1,570 2,970 23 Limang S. Wampu N. Sumatera 959 300 940 24 Sipan Sihaporas Sipan Sihaporas N. Sumatera 196 269 1,800 25 Batang Bayang-1 Bt. Bayang W. Sumatera 84 590 26 Batang Bayang-2 Bt. Bayang W. Sumatera 36 340 27 Muko-Muko Bt. Antokan W. Sumatera 248 44 74 93 120 28 Masang-3 Bt. Masang W. Sumatera 993 1,136 2,204 2,878 3,168 3,851 4,854 10,419 29 Merangin-5 Bt. Merangin Jambi 2,597 1,970 2,460 5,300 30 Lake Kerinci Siulak Jambi 916 590 1,538 2,177 2,464 3,102 4,092 13,347 31 Batang Hari Bt. Hari Jambi 4,452 1,937 4,192 5,603 6,205 7,601 32 Batang Hari (Alt.) Bt. Hari Jambi 3,825 1,664 3,602 4,814 5,331 6,531 33 Kiri-1 Bt. Kampar Riau 1,187 2,537 7,274 34 Kiri-2 Bt. Kampar Riau 552 1,446 35 Kapoernan Bt. Kampar Riau 699 2,181 36 Kotapanjang Bt. Kampar Riau 3,337 1,183 1,624 8,000 11,400 37 Upper Sinamar Bt. Indragiri Riau 3,180 3,180 8,383 38 Sukam Bt. Indragiri Riau 360 1,755 39 Lower Kuantan Bt. Indragiri Riau 7,453 10,047 40 Ombilin Bt. Ombilin Riau 1,078 118 175 211 263 41 Musi (Intake Dam) A. Musi S. Sumatera 587 240 530 720 780 1,010 1,310 42 Musi (Regulation Dam) A. Musi S. Sumatera 30 79 138 175 190 226 277 43 Martapura Way Komering S. Sumatera 4,260 1,300 1,900 2,200 2,300 2,700 6,300 44 Lematang-4 A. Lematang S. Sumatera 1,321 1,870 2,430 5,500 45 Mine Mouth Steam Plant A. Lematang S. Sumatera 3,667 6,636 46 Ketaun-1 A. Ketaun Bengkulu 449 500 800 980 1,070 7,140 Masang-2 Bt. Masang W. Sumatera 443 456 883 1,198 1,341 4,344 Source: Hydro Inventory Study, Sectral Report Vol.2 Hydrology, July 1997. Masang-3 HEPP, 1999.
JICA Project for the Master Plan Study of T-30 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 31 Calculations of Suspended Load in Masang River
spended load rating curve. e determination of the su the of determination e d load rating curve. ble and not considered in th ation of the suspende Site (m) (m3/s) (mg/L) (ton/day) 12345 Weir Intake 6 Weir Intake 7 Weir Intake 8 Weir Intake 2010/10/69 Weir Intake 2010/10/9 Weir Intake 2010/10/22 Station AWLR Weir Intake Sipisang 2010/10/25 Weir Intake 2010/12/21 2010/11/5 0.84 2010/11/21 0.67 2010/11/25 0.59 2010/12/5 0.69 29.02 0.20 0.84 20.83 0.93 15.48 1.58 19.86 422.33 1,654.33 31,518.00 15.07 0.88 26.54 34.21 1,058.92 42,154.44 384.67 80.50 2,977.32 68.67 1,726.67 456.67 30.96 1,804.67 U 660.06 5,103.59 1,047.17 1,492.33 12,551.84 89.41 3,991.90 D 10 Station AWLR Sipisang 2010/12/25 0.24 17.09 262.33 387.35 D No Sampling Date Water Level Qw C Qs Remarks D: Sampling was carried out atD: Sampling the Sipisang AWLR Station and not considered in determin the Legend U: The is not value concentration relia
JICA Project for the Master Plan Study of T-31 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Table 32 Water Quality Analysis of Masang River
No Water Quality Parameter Unit Sample-1 Sample-2 Sample-3 Date 2010/10/25 2010/11/25 2010/12/25 Weather Clear Cloud Cloud 1 pH 8.09 8.11 8.11 2 Temperature ℃ 25.4 24.9 24.9 3 Total Hardness mg/l 123.7 131 126 4 Temporary Hardness mg/l 52.58 93 97 5 Suspended Matter mg/lit 136 299 295 6 Total Solid mg/lit 261 327 343 7 Ignition Residue mg/lit 0.08 0.07 0.07 8 Permanganate Value as O2 mg/lit 9.69 7.24 3.55 9 Carbonates as CaCO3 mg/lit 0 10.74 8.06 10 Bicarbonates as CaCO3 mg/lit 135.52 115 141 11 Calcium (Ca) mg/lit 37.48 41.64 39.89 12 Magnesium (Mg) mg/lit 7.34 6.57 6.37 13 Sodium (Na) mg/lit 8.36 11.52 9.9 14 Potassium (K) mg/lit 1.96 2.77 2.8 15 Iron (Fe) mg/lit 1.579 0.72 1.28 16 Manganese (Mn) mg/lit <0.02 0.69 0.07 17 Copper (Cu) mg/lit <0.001 0.008 0.008 18 Turbidity NTU 41 37 52 19 Color Pt-Co-Unit 20 10 kol 10 kol 20 Electric Conductivity µ/Cm 254 313 303 21 Aluminum (Al) mg/lit 1.35 1 1.42 22 Silica (SiO2) mg/lit 46.52 17.7 22 23 Lead (Pb) mg/lit 0.008 0.42 0.42 24 Arsenic (As) mg/lit 0.0024 0.002 0.0025 25 Ammonium (NH4) mg/lit 0.784 <0.02 <0.02 26 Albuminoid mg/lit <0.1 <0.1 <0.1 27 Nitrites (NO2) mg/lit 0.002 0.003 0.007 28 Nitrates (NO3) mg/lit 0.516 0.432 0.666 29 Sulfities (SO3) mg/lit 0.155 0.072 <0.02 30 Sulfates (SO4) mg/lit 17.65 21.03 21.9 31 Chlorides (Cl) mg/lit 7.77 8.09 7.87 32 Phosphates (PO4) mg/lit 0.049 <0.002 <0.002 33 Oxygen (O2) mg/lit 7.31 6.79 7.17 34 Carbon Dioxide (CO2) mg/lit 1.73 - - 35 P-value as CaCO3 mg/lit 0.052 <0.02 < 0.002 36 M-Value as CaCO3 mg/lit 25 24.8 24.8
JICA Project for the Master Plan Study of T-32 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 1 Location Map of Meteo-Hydrological Stations
JICA Project for the Master Plan Study of F-1 August, 2010 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Daily Rainfall Records Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Maninjau 52B 22-0052-02
2 Limau Purut 52C 22-0052-03
3 Padang Panjang 53 22-0053-00
4 Bukit Tinggi 54 22-0054-00 1961-
5 Baso 54A 22-0054-01
6 Padang Mangatas 54C 22-0054-03 1965-
7 Payakumbuh 56 22-0056-00 1920-
8 Koto Tinggi 56A 22-0056-01
9 Suliki 56B 22-0056-02 1923-
10 Kota Baharu 57 22-0057-00
11 Bonjol 58C 22-0058-03
12 Jambak 58F 22-0058-06
13 Lubuk Sikaping 59 22-0059-00 Source: BMKG
Monthly Rainfall Records Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Maninjau 52B 22-0052-02
2 Limau Purut 52C 22-0052-03
3 Padang Panjang 53 22-0053-00
4 Bukit Tinggi 54 22-0054-00 1961-
5 Baso 54A 22-0054-01
6 Padang Mangatas 54C 22-0054-03 1965-
7 Payakumbuh 56 22-0056-00 1920-
8 Koto Tinggi 56A 22-0056-01
9 Suliki 56B 22-0056-02 1923-
10 Kota Baharu 57 22-0057-00
11 Bonjol 58C 22-0058-03
12 Jambak 58F 22-0058-06
13 Lubuk Sikaping 59 22-0059-00 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. BMKG
Figure 2 Availability of Climatic Records (1/2)
JICA Project for the Master Plan Study of F-2 August, 2010 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Daily Runoff Records Year DPMA HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1Bt. Masang 01-164 163-01-01 28years - Sipisang -00-01 Source: Pusair Bandung
Daily Water Level Records Year DPMA HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1Bt. Masang 01-164 163-01-01 - Sipisang -00-01 Source: BPSDA Bukit Tinggi
Monthly Runoff Records Year DPMA HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1Bt. Masang 01-164 163-01-01 - Sipisang -00-01 Source: HPPS2 Report, 1999. Masang-3 HEPP Report, 1999. Pusair Bandung.
Air Temperature Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Tabing-Padang 03106 22-0043-01 Source: BMKG
Relative Humidity Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Tabing-Padang 03106 22-0043-01 Source: BMKG
Sunshine Duration Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Tabing-Padang 03106 22-0043-01 Source: BMKG
Wind Velocity Year BMG HPPS2 No. Station Name ID ID Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Tabing-Padang 03106 22-0043-01 Source: BMKG
Pan Evapolation Year Management No. Station Name Body Remarks 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 1 Lubuk Sikaping BMG
2 Tanjung Pati P3SA Source: Masang-3 HEPP Report, 1999
: Complite Data : Incomplite Data
Figure 3 Availability of Climatic Records (2/2)
JICA Project for the Master Plan Study of F-3 August, 2010 Hydropower Development in Indonesia Final Report (Supporting_Pre F/S) Part 16 Hydrological Analysis for Masang-2 HEPP
B. A. Alahanpanjang
Power House Site
B. Masang
Sipisang AWLR station
B. Masang
Masang-2 Basin 443km2 S. Guntung
Masang-2 Intake Weir Site
B. Sianok
Figure 4 Catchment Area of Masang-2 Intake Weir based on 1:50,000 map
JICA Project for the Master Plan Study of F-4 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Monthly Mean Air Temperature Monthly Mean Relative Humidity St. Tabing-Padang St. Tabing-Padang
27.0 85.0
84.0 26.5 83.0
26.0 82.0
81.0
25.5 Humidity( % ) 80.0 Temperature ( ℃ ) Temperature ( ℃
25.0 79.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Month
Monthly Mean Sunshine Duration Monthly Mean Wind Velocity St. Tabing-Padang St. Tabing-Padang
70.0 1.4 60.0 1.2 50.0 1.0 40.0 0.8 30.0 0.6 20.0 0.4 Duration ( % ) Velocity ( m/s ) 10.0 0.2 0.0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Month
Monthly Mean Pan Evaporation Monthly Mean Pan Evaporation St. Lubuk Sukaping St. Tanjung Pati
6.0 6.0
5.0 5.0
4.0 4.0
3.0 3.0
2.0 2.0
1.0 1.0 Evaporation ( mm/day ) ( mm/day Evaporation 0.0 ) ( mm/day Evaporation 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Month
Figure 5 Variations of Principal Climatic Data
JICA Project for the Master Plan Study of F-5 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 6 Location Map of Hourly Rainfall Stations
JICA Project for the Master Plan Study of F-6 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Station Name: Gunung Melintang 160 140 120 100 80 60
Rainfall (mm) 40
Accumulated Hourly 20 0 0123456789101112 Time (hour)
Station Name: Maura Paiti 160 140 120 100 80 60
Rainfall (mm) 40
Accumulated Hourly 20 0 0123456789101112 Time (hour)
Station Name: Maninjau, Sungai Talang Barat, Solok Bio-Bio, Patir, Puar Datar, Halaban Dua 160 140 120 100 80 60
Rainfall (mm) 40 Accumulated Hourly 20 0 0123456789101112 Time (hour)
Figure 7 Accumulated Hourly Rainfall Curves
JICA Project for the Master Plan Study of F-7 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1975 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1976 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1977 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1978 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 8 Daily Runoff Hydrograph (1/7)
JICA Project for the Master Plan Study of F-8 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1979 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1980 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1981 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1982 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 9 Daily Runoff Hydrograph (2/7)
JICA Project for the Master Plan Study of F-9 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1983 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1984 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1985 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1986 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 10 Daily Runoff Hydrograph (3/7)
JICA Project for the Master Plan Study of F-10 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1987 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 100 1990 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1991 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1992 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec Figure 11 Daily Runoff Hydrograph (4/7)
JICA Project for the Master Plan Study of F-11 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1993 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 100 1995 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1996 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 1997 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 12 Daily Runoff Hydrograph (5/7)
JICA Project for the Master Plan Study of F-12 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 1998 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 100 1999 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 2000 90 80 70 60 50 40
Discharge (m3/s) 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 2001 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 13 Daily Runoff Hydrograph (6/7)
JICA Project for the Master Plan Study of F-13 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100 2005 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 2006 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 2007 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
100 2008 90 80 70 60 50 40
Discharge (m3/s) Discharge 30 20 10 0 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 14 Daily Runoff Hydrograph (7/7)
JICA Project for the Master Plan Study of F-14 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
3.00 2004 2.50
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
3.00 2005 2.50
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
3.00
2.50 2006
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
3.00 2007 2.50
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 15 Observed Daily Water Level Records (1/2)
JICA Project for the Master Plan Study of F-15 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
3.00 2008 2.50
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
3.00 2009 2.50
2.00
1.50
1.00 WaterLevel (m)
0.50
0.00 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec
Figure 16 Observed Daily Water Level Records (2/2)
JICA Project for the Master Plan Study of F-16 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
80,000 80,000 1993
60,000 60,000 1993
40,000 y = 1.4072x - 19227 40,000 station Tinggi station y = 0.6675x 20,000 1979 20,000 1978 1971
Accumulation of annual rainfall at Koto at rainfall of annual Accumulation 1971
Accumulation of annual rainfall at annual rainfallManinjau of Accumulation - - - 20,000 40,000 60,000 80,000 - 20,000 40,000 60,000 80,000 Accumulation of average annual rainfall at Accumulation of average annual rainfall at surrounding stations surrounding stations
1993 80,000 80,000
60,000 1993 60,000 y = 1.6882x - 45901
station 40,000
station 40,000 1988
y = 0.656x 1987 20,000 20,000
Accumulation of annual rainfallSuliki at of annual Accumulation 1971 1971 - Jambak annual rainfall at of Accumulation - - 20,000 40,000 60,000 80,000 - 20,000 40,000 60,000 80,000 Accumulation of average annual rainfall at Accumulation of average annual rainfall at surrounding stations surrounding stations
Figure 17 Double Mass Curves of Rainfall Records
JICA Project for the Master Plan Study of F-17 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 18 Thiessen Polygon
JICA Project for the Master Plan Study of F-18 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
2,500
1993 2,000
1,500 0mm 1976 1991 1984 1,000 700mm
Annual Runoff Depth (mm) Depth Runoff Annual 500 1500mm
- - 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 Annual Basin Mean Rainfall (mm)
Figure 19 Relationship between Annual Basin Mean Rainfall and Annual Runoff Depth at Sipisang AWLR Station
4,500
4,000 0 mm
3,500 700 mm
3,000
2,500 1,500 mm
2,000
1,500 Annual Runoff Depth (mm) Depth Runoff Annual
1,000
500
0 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Annual Basin Mean Rainfall (mm) Figure 20 Relationship between Annual Basin Mean Rainfall and Annual Runoff Depth of Various River Basins in Sumatra
JICA Project for the Master Plan Study of F-19 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 21 Concept of Composite Tank Model
JICA Project for the Master Plan Study of F-20 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
0 100 200 300 400 500 600 700
1986/7
1986/1
1985/7
1985/1
1984/7 1984/1
Rain Runoff Observed Runoff Simulated
1983/7
1983/1
1982/7 1982/1 0 70 60 50 40 30 20 10
Figure 22 Comparison of Observed and Simulated Monthly Runoff at Sipisang AWLR Station
JICA Project for the Master Plan Study of F-21 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Observed RunoffObserved Simulated Runoff 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
5 0
50 45 40 35 30 25 20 15 10 Discharge (m3/s) Discharge (m3/s) Error Simulated Runoff Simulated (m3/s) Observed Runoff Observed 0%5% 40.39 28.62 36.45 28.94 10.8% 1.1% 10%15%20%25%30% 25.9435% 25.1240% 24.3845% 23.3150% 22.6355% 26.04 21.5160% 25.32 20.7265% 0.4% 24.22 19.2270% 0.8% 23.04 18.9175% 0.7% 21.33 18.2680% 1.2% 20.57 18.0385% 6.1% 20.04 17.6490% 4.6% 19.70 17.1895% 3.4% 19.34 16.35 2.5% 18.87 15.92 2.2% 18.52 14.71 3.2% 17.77 14.47 2.6% 17.11 13.66 0.7% 16.84 0.4% 16.30 2.9% 15.35 2.4% 14.71 4.2% 14.00 1.6% 2.4% 100% 12.59 12.19 3.3% %
Figure 23 Flow Duration Curve of Observed and Simulated Monthly Runoff at Sipisang AWLR Station
JICA Project for the Master Plan Study of F-22 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
0 100 200 300 400 500 600 700
1993/1
1992/1
1991/1
1990/1
1989/1
1988/1
1987/1
1986/1
1985/1
1984/1
1983/1
1982/1 1981/1
Rain Runoff Observed SimulatedRunoff
1980/1
1979/1
1978/1
1977/1
1976/1
1975/1
1974/1 1973/1 0 70 60 50 40 30 20 10 Figure 24 Simulated Long-term Monthly Runoff at Sipisang AWLR Station
JICA Project for the Master Plan Study of F-23 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Observed and SimulatedObserved Runoff 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
5 0
50 45 40 35 30 25 20 15 10 Discharge (m3/s) Discharge Runoff (m3/s) Observed and Simulated and Observed 0%5% 62.84 30.28 10%15%20%25%30%35%40%45% 26.69 50% 24.38 55% 22.98 60% 21.85 65% 20.51 70% 19.39 75% 18.82 80% 18.17 85% 17.66 90% 17.18 95% 16.54 16.00 15.22 14.57 13.71 12.86 12.03 11.01 100% 6.78 %
average 18.94
Figure 25 Flow Duration Curve of Estimated Monthly Runoff at Sipisang AWLR Station
JICA Project for the Master Plan Study of F-24 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Probability Exceedence of Masang-2 Intake Weir Site Weir Intake Masang-2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
5 0
50 45 40 35 30 25 20 15 10 Runoff (m3/s) Runoff 0%5% 78.99 31.32 10%15%20%25%30% 26.31 35% 22.51 40% 21.43 45% 20.29 50% 18.91 55% 18.05 60% 17.35 65% 16.73 70% 16.19 75% 15.57 80% 15.29 85% 14.55 90% 13.81 95% 13.06 12.31 11.48 10.99 10.03 100% 6.32 (%) (m3/s) Average 17.67 Probability Estimated Runoff
Figure 26 Flow Duration Curve of Estimated Daily Runoff at Masang-2 Intake Weir Site
JICA Project for the Master Plan Study of F-25 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 27 Location Map of Water Level Observation and Discharge Measurement
JICA Project for the Master Plan Study of F-26 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
2.0 Maximum Water Level 2.01m 2010/11/26 6:00
1.5
1.0 Average Water Level 0.75m Water Level (m)
0.5 Minimum Water Level 0.55m 2010/12/23
0.0 2010/10/1 2010/10/16 2010/10/31 2010/11/15 2010/11/30 2010/12/15 2010/12/30
180 Maximum Runoff 156.61 m3/s 2010/11/26 6:00 160
140
120 Estimated Runoff with Discharge Measurement H-Q Rating Curve 100
80 Runoff (m3/s) Average Runoff 60 25.68 m3/s Minimum Runoff 13.60 m3/s 2010/12/23 40
20
0 2010/10/1 2010/10/16 2010/10/31 2010/11/15 2010/11/30 2010/12/15 2010/12/30
Figure 28 Result of Water Level Observation and Hydrograph Calculated with H-Q Rating Curve
JICA Project for the Master Plan Study of F-27 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
2.0 Q=36.55(H+0.06)^2 1.8
1.6
1.4
1.2
1.0
0.8 Water Level (m) 0.6
0.4 Observation 0.2 H-Q Rating Curve 0.0 0 20406080100120140 Discharge (m3/s)
Figure 29 H-Q Rating Curve
JICA Project for the Master Plan Study of F-28 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Total Rainfall Depth >= 50mm 14 100% 100% 84% 90% 12 94% 89% 87% 80% 73% 10 70% 63% 60% 8 48% 50% 6 40%
Number of Data of Number 4 29% 30% 20% 2 13% 10% 2% 5% 0 0% 123456789101112 Time Duration (Hour)
Total Rainfall Depth >= 100mm 3 100% 100%100% 90% 80% 80% 80% 80% 80% 80% 70% 2 60% 50% 40% 40% 1 Number of Data 30% 20% 20% 10% 0 0% 0% 0% 0% 123456789101112 Time Duration (Hour)
Figure 30 Histogram of Rainfall Duration
JICA Project for the Master Plan Study of F-29 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
100%
90%
80%
70%
60% Design Pattern
50%
40% Design Hyetograph 50% Accumulated Rainfall (%) 30% 40% 30%
20% 20%
Rainfall (%) 10%
10% 0% 123456 Time (hour) 0% 0123456 Time (hour)
Figure 31 Accumulated Hourly Rainfall Pattern around Masang River Basin and Design Hyetograph
JICA Project for the Master Plan Study of F-30 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
1.00
0.90
0.80
0.70
0.60
0.50
0.40
Area Reduction Factor 0.30
0.20
0.10
0.00 0 50 100 150 200 250
Point Rainfall Depth (mm)
Figure 32 Area Reduction Factor for Masang River Basin
JICA Project for the Master Plan Study of F-31 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 33 Frequency Curves of Probable Daily Rainfall at Payakumbuh station
JICA Project for the Master Plan Study of F-32 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
110
105
100
Length of record (years) 10 15 20 30 95 50
90 adjustment factor (%) factor adjustment n X
85
80
75
70 0.7 0.75 0.8 0.85 0.9 0.95 1
Xn-m / Xn
Source : Operational Hydrology Report No. 1 Manual for Estimation of Probable Maximum Precipitation Page 97, World Meteorological Organization, 1973 Figure 34 Adjustment of Mean of Annual Series for Maximum Observed Rainfall
JICA Project for the Master Plan Study of F-33 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
120
110
100
10 90 15 Length of record (years) 30 50
80
70 adjustment factor (%) factor adjustment n S 60
50
40
30
20 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 Sn-m / Sn
Source : Operational Hydrology Report No. 1 Manual for Estimation of Probable Maximum Precipitation Page 98, World Meteorological Organization, 1973
Figure 35 Adjustment of Standard Deviation of Annual Series for Maximum Observed Rainfall
JICA Project for the Master Plan Study of F-34 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
130
125
120
115 Adjustment Factor (%) Adjustment Factor
110
Standard Deviation
105
Mean
100 10 15 20 25 30 35 40 45 50 55 Length of Record (years)
Source : Operational Hydrology Report No. 1 Manual for Estimation of Probable Maximum Precipitation Page 99, World Meteorological Organization, 1973
Figure 36 Adjustment of Mean and Standard Deviation of Annual Series for Length of Record
JICA Project for the Master Plan Study of F-35 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
20
15
m Duration K 24 hours 6 hours 10 5 min
1 hour
5 0 50 100 150 200 250 300 350 400 450 500 550 600 Mean Annual Rainfall (mm)
Figure 37 Km as a Function of Rainfall Duration and Mean of Annual Series
114
112
110
108
106
104 Adjustment Factor
102
100
98 0 4 8 12162024 Number of Observational Units
Source : Operational Hydrology Report No. 1 Manual for Estimation of Probable Maximum Precipitation Pages 96 &100, World Meteorological Organization, 1973
Figure 38 Adjustment of Fixed Interval Precipitation Amounts for Number of Observational Units within the Interval
JICA Project for the Master Plan Study of F-36 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Slope 3,000
2,500
2,000
1,500 Height (m) 1,000
500
Tc=5.8hr Tc=0.4hr - - 10,000 20,000 30,000 40,000 50,000 60,000
Distance (m)
Figure 39 Slope of Masang River
25
20
15
10 Discharge (m3/s) Discharge
5
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Figure 40 SCS Unit Hydrograph at Masang-2 Intake Weir Site
JICA Project for the Master Plan Study of F-37 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 41 Daily Runoff Hydrograph at Sipisang AWLR Station
JICA Project for the Master Plan Study of F-38 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 42 Probable Flood Hydrographs at Masang-2 Intake Weir Site
JICA Project for the Master Plan Study of F-39 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 43 Relationship between Probable Peak Discharge and Catchment Area in Sumatra (1/3)
JICA Project for the Master Plan Study of F-40 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 44 Relationship between Probable Peak Discharge and Catchment Area in Sumatra (2/3)
JICA Project for the Master Plan Study of F-41 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 45 Relationship between Probable Peak Discharge and Catchment Area in Sumatra (3/3)
JICA Project for the Master Plan Study of F-42 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Figure 46 Catchment Area of Regulating Pond based on 1:10,000 Map
JICA Project for the Master Plan Study of F-43 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
Masang-2 Basin 443.0 km2
Alahanpanjang Basin 424.1 km2
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Figure 47 Catchment Area of Power House Site based on 1:250,000 Map
JICA Project for the Master Plan Study of F-44 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 48 Sieve Analysis of Suspended Load
JICA Project for the Master Plan Study of F-45 August, 2011 Hydropower Development in Indonesia Final Report (Supporting_PreF/S) Part 16 Hydrological Analysis for Masang-2 HEPP
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Figure 49 Suspended Load Rating Curve
JICA Project for the Master Plan Study of F-46 August, 2011 Hydropower Development in Indonesia
Part 17 Supplemental Financial Evaluation for Simanggo-2 HEPP
Supplemental Financial Evaluation for Simanggo-2
SUPPLEMENTAL FINANCIAL EVALUATION FOR SIMANGGO-2
1. INTRODUCTION
This paper is a supplement to the Main Report on the Project for the Master Plan Study of Hydropower Development in Indonesia, hereinafter referred to as the Main Report. It is to provide an additional financial evaluation in the Simanggo-2 Hydropower Project, which focuses the pseudo electricity selling price governing the project’s revenue. This paper applies the actual electricity sales by PLN to the project revenue, while the Main Report used a shadow electricity tariff that includes the Government subsidy granted to PLN.
2. FINANCIAL EVALUATION
2.1 METHODOLOGY, ASSUMPTIONS, AND FINANCIAL COST The methodology used, the assumptions set, and financial cost assumed are exactly same as those in the Main Report. The financial capital expenditure (CAPEX) applied for the Simanggo-2 Hydropower Project is US$209 million, excluding costs required for the feasibility study.
2.2 FINANCIAL BENEFIT
2.2.1 Electricity Tariff The Main Report has chosen a shadow tariff US¢10.63/kWh (US¢7.48/kWh of the selling price and US¢3.15/kWh of the Government subsidy) as of 2010, while this paper applies the actual electricity selling price US¢7.48/kWh as of 2010 without the Government subsidy, as compared in Table 2-1.
Table 2-1 Electricity Sales and Subsidy Electricity Sales Subsidy Sum Electricity Tariff P Tariff S Year Rp T US$M Rp T US$M US$M(GWh) US¢/kWh US¢/kWh 2002 39,018 4,335 4,739 527 4,862 108,360 4.001 4.487 2003 49,810 5,534 4,097 455 5,990 113,020 4.897 5.300 2004 58,232 6,470 3,470 386 6,856 120,244 5.381 5.702 2005 63,246 7,027 12,511 1,390 8,417 127,370 5.517 6.609 2006 70,735 7,859 32,909 3,657 11,516 133,108 5.905 8.652 2007 76,286 8,476 36,605 4,067 12,543 142,441 5.951 8.806 2008 84,250 9,361 78,577 8,731 18,092 149,437 6.264 12.107 2009 90,172 10,019 53,720 5,969 15,988 156,797 6.390 10.197 2010* N/A N/A 55,100 6,122 N/A 194,459 7.479 10.627 2011* N/A N/A 41,000 4,556 N/A 201,977 7.689 9.945 Electricity = Electricity sold by PLN Tariff P = average electricity charge without subsidy Tariff S = electricity charge with subsidy * Estimations for “Electricity Sold” and “Tariff P” based on the past trends in 2005 to 2009. Rp.9,000/US$ is used for Rupiah to US$ conversion. Source: Study Team based on PLN Statistics 2009 and MOF data
The electricity tariff is assumed to be escalated as same as it was done in the past. The trend line of the past electricity tariff suggests that the electricity tariff would be increased by US¢0.2105 every year as seen in Figure 2-1. The electricity tariff would be then 9.16US¢/kWh in 2018, the first operating year.
1 Supplemental Financial Evaluation for Simanggo-2
10
8 y = 0.2105x + 5.3739
6
4 Tariff (US¢/kWh) 2 Source: Study Team 0 2005 2006 2007 2008 2009 2010 2011 2012 2013 Year
Figure 2-1 Electricity Tariff Projection
2.2.2 Project Revenue The project revenue is of the electricity tariff multiplied by the expected electricity sold. The first operating year revenue as of 2018 is then; US$33.2 mill./year = US$0. 0916/kWh x 362 GWh/year Where 362 GWh/year is the net annual energy. Benefit from Certified Emission Reduction (CER) is exactly same as discussed in the Main Report.
2.3 FINANCIAL ANALYSIS
2.3.1 Interest Free Cash Flow An interest free cash flow here evaluates the project’s profitability without financing charges but with income tax. The financial stream is tabulated in Table 2-2. The key indicators in present worth are:
NPVP = US$17.6 million FIRR = 11.1% B/C = 1.08 The FIRR computed is much greater than 2.0% of the hurdle rate, and therefore PLN as the project-operating entity will be able to make profit from the project with high probability. However, this FIRR does not reach a magnificent level, say 13%, which may make foreign investors keen for investment in the country.
2 Supplemental Financial Evaluation for Simanggo-2
Table 2-2 Interest Free Financial Stream US$ million GWh Cost Benefit Net Energy Year CAPEX O&M T ax Sub-t otal Sales CER Sub-t ot al Benefit Sup p ly 2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 2013 -4 2.02 0.00 0.00 2.02 0.00 0.00 0.00 -2.02 0 2014 -3 17.72 0.00 0.00 17.72 0.00 0.00 0.00 -17.72 0 2015 -2 55.43 0.00 0.00 55.43 0.00 0.00 0.00 -55.43 0 2016 -1 89.38 0.00 0.00 89.38 0.00 0.00 0.00 -89.38 0 2017 0 44.90 0.00 0.00 44.90 0.00 0.00 0.00 -44.90 0 2018 1 0.00 5.61 5.40 11.01 33.19 1.68 34.87 23.86 362 2019 2 0.00 5.79 5.55 11.34 33.95 1.68 35.63 24.29 362 2020 3 0.00 5.98 5.69 11.67 34.71 1.68 36.40 24.73 362 2021 4 0.00 6.17 5.83 12.01 35.48 1.68 37.16 25.15 362 2022 5 0.00 6.37 5.97 12.35 36.24 1.68 37.92 25.57 362 2023 6 0.00 6.58 6.11 12.70 37.00 1.68 38.68 25.99 362 2024 7 0.00 6.80 6.25 13.05 37.76 1.68 39.45 26.40 362 2025 8 0.00 7.03 6.41 13.44 38.53 1.68 40.21 26.77 362 2026 9 0.00 7.26 6.58 13.84 39.29 1.68 40.97 27.13 362 2027 10 0.00 7.51 6.74 14.24 40.05 1.68 41.73 27.49 362 2028 11 0.00 7.76 6.89 14.66 40.81 1.68 42.50 27.84 362 2029 12 0.00 8.03 7.05 15.08 41.58 1.68 43.26 28.18 362 2030 13 0.00 8.30 7.20 15.50 42.34 1.68 44.02 28.52 362 2031 14 0.00 8.59 7.35 15.94 43.10 1.68 44.78 28.84 362 2032 15 0.00 8.88 7.50 16.38 43.86 1.68 45.55 29.16 362 2033 16 0.00 9.19 7.64 16.84 44.63 1.68 46.31 29.47 362 2034 17 0.00 9.52 7.79 17.30 45.39 1.68 47.07 29.77 362 2035 18 0.00 9.85 7.92 17.77 46.15 1.68 47.83 30.06 362 2036 19 0.00 10.20 8.06 18.26 46.91 1.68 48.60 30.34 362 2037 20 0.00 10.56 8.19 18.75 47.68 1.68 49.36 30.61 362 2038 21 0.00 10.94 8.32 19.26 48.44 1.68 50.12 30.86 362 2039 22 0.00 11.34 8.44 19.78 49.20 1.68 50.88 31.11 362 2040 23 0.00 11.75 8.56 20.31 49.96 1.68 51.65 31.34 362 2041 24 0.00 12.18 8.67 20.85 50.73 1.68 52.41 31.56 362 2042 25 0.00 12.62 8.78 21.40 51.49 1.68 53.17 31.77 362 2043 26 0.00 13.09 8.89 21.98 52.25 1.68 53.93 31.96 362 2044 27 0.00 13.57 8.99 22.56 53.01 1.68 54.69 32.13 362 2045 28 0.00 14.08 9.08 23.16 53.78 1.68 55.46 32.30 362 2046 29 0.00 14.61 9.17 23.78 54.54 1.68 56.22 32.44 362 2047 30 0.00 15.16 9.26 24.41 55.30 1.68 56.98 32.57 362 2048 31 0.00 14.14 0.00 14.14 0.00 0.00 0.00 -14.14 0 2049 32 0.00 16.33 9.00 25.33 56.83 1.68 58.51 33.18 362 2050 33 0.00 16.95 9.03 25.98 57.59 1.68 59.27 33.29 362 2051 34 0.00 17.61 9.06 26.66 58.35 1.68 60.03 33.37 362 2052 35 0.00 18.29 9.08 27.36 59.11 1.68 60.79 33.43 362 2053 36 0.00 19.00 9.09 28.09 59.87 1.68 61.56 33.47 362 2054 37 0.00 19.74 9.10 28.83 60.64 1.68 62.32 33.49 362 2055 38 0.00 20.51 9.09 29.61 61.40 1.68 63.08 33.48 362 2056 39 0.00 21.32 9.08 30.40 62.16 1.68 63.84 33.44 362 2057 40 0.00 22.16 9.06 31.23 62.92 1.68 64.61 33.38 362 2058 41 0.00 23.05 9.03 32.08 63.69 1.68 65.37 33.29 362 2059 42 0.00 23.97 8.99 32.96 64.45 1.68 66.13 33.17 362 2060 43 0.00 24.93 8.94 33.87 65.21 1.68 66.89 33.02 362 2061 44 0.00 25.93 8.88 34.81 65.97 1.68 67.66 32.84 362 2062 45 0.00 26.98 8.81 35.79 66.74 1.68 68.42 32.63 362 2063 46 0.00 28.08 8.73 36.81 67.50 1.68 69.18 32.37 362 2064 47 0.00 29.23 8.63 37.86 68.26 1.68 69.94 32.09 362 2065 48 0.00 30.43 8.52 38.95 69.02 1.68 70.71 31.76 362 2066 49 0.00 31.68 8.40 40.08 69.79 1.68 71.47 31.39 362 2067 50 -56.16 32.99 8.26 -14.91 70.55 1.68 72.23 87.14 362 Total 153.29 748.64 393.06 1295.00 2537.40 82.42 2619.82 1324.82 17,748 PV 133.42 45.97 37.27 216.66 224.94 9.36 234.30 17.64 – Annu 13.40 4.62 3.74 21.76 22.59 0.94 23.53 1.77 – US¢6.0/kWh NPVP = 17.64 FIRR = 11.12% B/C = 1.08 Cost = PV stands for a present value discounted by 10% p.a. Annu stands for an annualized value of respective present value. Source: Study Team
2.3.2 Return on Investment Assuming the loan conditions exactly same as the Main Report in Table 2-3, the return on investment was computed as given in Table 2-4 by using a DCF model. The net present value and rate of return are:
3 Supplemental Financial Evaluation for Simanggo-2
NPVI = US$82.4 million ROI = 23.9%
Table 2-3 Loan Conditions Assumed for Financial Cash Flow Interest Rate Front-end Commitment Grace Repay Loan Lender (p.a) fee fee (p.a) period period share Bilateral 1.90% 0.00% 0.75% 7 years 25 years 75% Institution
Notes 1. The front-end fee will be charged only at the time of loan agreement. The commitment fee is charged against unused loan amount and will decrease gradually and end at null when the loan amount is fully disbursed. 2. Interest rate is assumed constant and being composed of 1.4% p.a. of JICA’s standard rate for medium income countries plus 0.5% p.a. of onlending spread by MOF. 3. Grace period includes 4 years of construction. 4. No insurance is counted. Source: Study Team
The project can be evaluated financially feasible from a long term view. The breakeven is 3 years after commissioning. Because no revenue is expected in the replacement year scheduled 30 years after commissioning, however, the project will not be able to fulfill the debt service obligation in the same year. As an enough return is expected, the project can easily overcome the debt service issue. For example, if 4% of the annual net profit is deposited every year into a saving account, the project will easily be able to have enough cash when no revenue is expected due to machine replacement.
80 Tax Interest 60 Principal O&M 40 Revenue PAT
20
0
Revenue and Costmill.) (US$ -20
-40
Source: Study Team -60 2018 2021 2024 2027 2030 2033 2036 2039 2042 2045 2048 2051 2054 2057 2060 2063 2066 Years
Figure 2-2 Cash Inflow and Outflow
Assuming the aforementioned explicit savings for the replacement cost, DSCR and LLCR can be raised as: Minimum DSCR = 1.7 > 1.0 Minimum LLCR = 2.5 > 1.0 Now, all of the indicators show enough numbers and therefore one can evaluate the hydropower project in question is financially viable. The profit and loss calculations are given in Table 2-5.
4 Supplemental Financial Evaluation for Simanggo-2
Table 2-4 Financial Cash Flow for ROI US$ million Cash Generation Benefit Year Invest Sales Residual O&M Interest Repay Tax Net Sum 2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2013 -4 1.83 0.00 0.00 0.00 0.01 0.00 0.00 -1.83 -1.83 2014 -3 15.98 0.00 0.00 0.00 0.05 0.00 0.00 -16.03 -17.86 2015 -2 29.42 0.00 0.00 0.00 0.73 0.00 0.00 -30.15 -48.00 2016 -1 0.00 0.00 0.00 0.00 2.90 0.00 0.00 -2.90 -50.90 2017 0 0.00 0.00 0.00 0.00 3.44 0.00 0.00 -3.44 -54.34 2018 1 0.00 33.19 0.00 5.61 3.10 0.00 5.40 20.76 -33.58 2019 2 0.00 33.95 0.00 5.79 3.10 0.00 5.55 21.20 -12.39 2020 3 0.00 34.71 0.00 5.98 3.10 0.00 5.69 21.63 9.24 2021 4 0.00 35.48 0.00 6.17 3.10 0.00 5.83 22.05 31.30 2022 5 0.00 36.24 0.00 6.37 3.10 0.00 5.97 22.47 53.77 2023 6 0.00 37.00 0.00 6.58 3.10 0.00 6.11 22.89 76.66 2024 7 0.00 37.76 0.00 6.80 3.10 0.00 6.25 23.30 99.96 2025 8 0.00 38.53 0.00 7.03 2.97 6.52 6.41 17.27 117.23 2026 9 0.00 39.29 0.00 7.26 2.85 6.52 6.58 17.76 134.99 2027 10 0.00 40.05 0.00 7.51 2.73 6.52 6.74 18.24 153.23 2028 11 0.00 40.81 0.00 7.76 2.60 6.52 6.89 18.72 171.95 2029 12 0.00 41.58 0.00 8.03 2.48 6.52 7.05 19.18 191.13 2030 13 0.00 42.34 0.00 8.30 2.35 6.52 7.20 19.64 210.77 2031 14 0.00 43.10 0.00 8.59 2.23 6.52 7.35 20.09 230.87 2032 15 0.00 43.86 0.00 8.88 2.11 6.52 7.50 20.53 251.40 2033 16 0.00 44.63 0.00 9.19 1.98 6.52 7.64 20.97 272.37 2034 17 0.00 45.39 0.00 9.52 1.86 6.52 7.79 21.39 293.75 2035 18 0.00 46.15 0.00 9.85 1.73 6.52 7.92 21.80 315.56 2036 19 0.00 46.91 0.00 10.20 1.61 6.52 8.06 22.21 337.76 2037 20 0.00 47.68 0.00 10.56 1.49 6.52 8.19 22.60 360.36 2038 21 0.00 48.44 0.00 10.94 1.36 6.52 8.32 22.98 383.34 2039 22 0.00 49.20 0.00 11.34 1.24 6.52 8.44 23.35 406.68 2040 23 0.00 49.96 0.00 11.75 1.12 6.52 8.56 23.70 430.39 2041 24 0.00 50.73 0.00 12.18 0.99 6.52 8.67 24.05 454.43 2042 25 0.00 51.49 0.00 12.62 0.87 6.52 8.78 24.38 478.81 2043 26 0.00 52.25 0.00 13.09 0.74 6.52 8.89 24.69 503.50 2044 27 0.00 53.01 0.00 13.57 0.62 6.52 8.99 24.99 528.50 2045 28 0.00 53.78 0.00 14.08 0.50 6.52 9.08 25.28 553.77 2046 29 0.00 54.54 0.00 14.61 0.37 6.52 9.17 25.55 579.32 2047 30 0.00 55.30 0.00 15.16 0.25 6.52 9.26 25.80 605.12 2048 31 0.00 0.00 0.00 14.14 0.12 6.52 0.00 -20.79 584.34 2049 32 0.00 56.83 0.00 16.33 0.00 6.52 9.00 26.66 611.00 2050 33 0.00 57.59 0.00 16.95 0.00 0.00 9.03 33.29 644.28 2051 34 0.00 58.35 0.00 17.61 0.00 0.00 9.06 33.37 677.65 2052 35 0.00 59.11 0.00 18.29 0.00 0.00 9.08 33.43 711.08 2053 36 0.00 59.87 0.00 19.00 0.00 0.00 9.09 33.47 744.55 2054 37 0.00 60.64 0.00 19.74 0.00 0.00 9.10 33.49 778.04 2055 38 0.00 61.40 0.00 20.51 0.00 0.00 9.09 33.48 811.51 2056 39 0.00 62.16 0.00 21.32 0.00 0.00 9.08 33.44 844.95 2057 40 0.00 62.92 0.00 22.16 0.00 0.00 9.06 33.38 878.34 2058 41 0.00 63.69 0.00 23.05 0.00 0.00 9.03 33.29 911.63 2059 42 0.00 64.45 0.00 23.97 0.00 0.00 8.99 33.17 944.80 2060 43 0.00 65.21 0.00 24.93 0.00 0.00 8.94 33.02 977.83 2061 44 0.00 65.97 0.00 25.93 0.00 0.00 8.88 32.84 1,010.67 2062 45 0.00 66.74 0.00 26.98 0.00 0.00 8.81 32.63 1,043.29 2063 46 0.00 67.50 0.00 28.08 0.00 0.00 8.73 32.37 1,075.67 2064 47 0.00 68.26 0.00 29.23 0.00 0.00 8.63 32.09 1,107.75 2065 48 0.00 69.02 0.00 30.43 0.00 0.00 8.52 31.76 1,139.51 2066 49 0.00 69.79 0.00 31.68 0.00 0.00 8.40 31.39 1,170.90 2067 50 0.00 70.55 56.16 32.99 0.00 0.00 8.26 87.14 1,258.04 Total 47.22 2,537.40 56.16 748.64 65.97 163.03 393.06 1,258.04 – PV 33.61 224.94 0.27 45.97 18.18 17.15 37.27 82.39 – Annu 3.38 22.59 0.03 4.62 1.83 1.72 3.74 8.28 –
NPVI = 82.39 ROI = 23.95% Source: Study Team PV stands for a present value discounted by 10% p.a. Annu stands for an annualized value of respective present value.
5 Supplemental Financial Evaluation for Simanggo-2
Table 2-5 Profit and Loss US$ million
Year Revenue Interest O&M Cost Depreciation PBT Tax PAT DSCR LLCR
2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2013 -4 0.00 0.01 0.00 0.00 -2.03 0.00 -2.03 2014 -3 0.00 0.05 0.00 0.00 -17.77 0.00 -17.77 2015 -2 0.00 0.73 0.00 0.00 -56.15 0.00 -56.15 2016 -1 0.00 2.90 0.00 0.00 -92.28 0.00 -92.28 2017 0 0.00 3.44 0.00 0.00 -48.34 0.00 -48.34 2018 1 33.19 3.10 5.61 4.55 21.61 5.40 16.21 7.06 3.40 2019 2 33.95 3.10 5.79 4.55 22.19 5.55 16.64 7.47 3.36 2020 3 34.71 3.10 5.98 4.55 22.77 5.69 17.07 7.88 3.32 2021 4 35.48 3.10 6.17 4.55 23.33 5.83 17.50 8.29 3.27 2022 5 36.24 3.10 6.37 4.55 23.90 5.97 17.92 8.71 3.23 2023 6 37.00 3.10 6.58 4.55 24.45 6.11 18.34 9.13 3.19 2024 7 37.76 3.10 6.80 4.55 24.99 6.25 18.74 9.56 3.14 2025 8 38.53 2.97 7.03 4.55 25.65 6.41 19.24 3.26 3.09 2026 9 39.29 2.85 7.26 4.55 26.30 6.58 19.73 3.42 3.15 2027 10 40.05 2.73 7.51 4.55 26.95 6.74 20.21 3.58 3.21 2028 11 40.81 2.60 7.76 4.55 27.58 6.89 20.68 3.75 3.27 2029 12 41.58 2.48 8.03 4.55 28.20 7.05 21.15 3.92 3.34 2030 13 42.34 2.35 8.30 4.55 28.81 7.20 21.61 4.10 3.41 2031 14 43.10 2.23 8.59 4.55 29.41 7.35 22.06 4.28 3.50 2032 15 43.86 2.11 8.88 4.55 30.00 7.50 22.50 4.47 3.59 2033 16 44.63 1.98 9.19 4.55 30.58 7.64 22.93 4.67 3.69 2034 17 45.39 1.86 9.52 4.55 31.14 7.79 23.36 4.87 3.80 2035 18 46.15 1.73 9.85 4.55 31.69 7.92 23.77 5.08 3.92 2036 19 46.91 1.61 10.20 4.55 32.23 8.06 24.17 5.30 4.07 2037 20 47.68 1.49 10.56 4.55 32.75 8.19 24.56 5.53 4.23 2038 21 48.44 1.36 10.94 4.55 33.26 8.32 24.95 5.76 4.42 2039 22 49.20 1.24 11.34 4.55 33.75 8.44 25.31 6.00 4.65 2040 23 49.96 1.12 11.75 4.55 34.23 8.56 25.67 6.25 4.92 2041 24 50.73 0.99 12.18 4.55 34.69 8.67 26.01 6.51 5.25 2042 25 51.49 0.87 12.62 4.55 35.13 8.78 26.34 6.78 5.66 2043 26 52.25 0.74 13.09 4.55 35.55 8.89 26.66 7.05 6.18 2044 27 53.01 0.62 13.57 4.55 35.95 8.99 26.96 7.34 6.89 2045 28 53.78 0.50 14.08 4.55 36.33 9.08 27.25 7.63 7.87 2046 29 54.54 0.37 14.61 4.55 36.69 9.17 27.52 7.94 9.34 2047 30 55.30 0.25 15.16 4.55 37.02 9.26 27.77 8.25 11.79 2048 31 0.00 0.12 14.14 2.18 -16.45 0.00 -16.45 1.84 18.39 2049 32 56.83 0.00 16.33 6.20 35.98 9.00 26.99 4.77 34.80 2050 33 57.59 0.00 16.95 6.20 36.12 9.03 27.09 n.a. n.a. 2051 34 58.35 0.00 17.61 6.20 36.23 9.06 27.17 n.a. n.a. 2052 35 59.11 0.00 18.29 6.20 36.31 9.08 27.23 n.a. n.a. 2053 36 59.87 0.00 19.00 6.20 36.36 9.09 27.27 n.a. n.a. 2054 37 60.64 0.00 19.74 6.20 36.39 9.10 27.29 n.a. n.a. 2055 38 61.40 0.00 20.51 6.20 36.37 9.09 27.28 n.a. n.a. 2056 39 62.16 0.00 21.32 6.20 36.33 9.08 27.25 n.a. n.a. 2057 40 62.92 0.00 22.16 6.20 36.25 9.06 27.19 n.a. n.a. 2058 41 63.69 0.00 23.05 6.20 36.13 9.03 27.10 n.a. n.a. 2059 42 64.45 0.00 23.97 6.20 35.97 8.99 26.98 n.a. n.a. 2060 43 65.21 0.00 24.93 6.20 35.77 8.94 26.83 n.a. n.a. 2061 44 65.97 0.00 25.93 6.20 35.53 8.88 26.65 n.a. n.a. 2062 45 66.74 0.00 26.98 6.20 35.24 8.81 26.43 n.a. n.a. 2063 46 67.50 0.00 28.08 6.20 34.90 8.73 26.18 n.a. n.a. 2064 47 68.26 0.00 29.23 6.20 34.52 8.63 25.89 n.a. n.a. 2065 48 69.02 0.00 30.43 6.20 34.08 8.52 25.56 n.a. n.a. 2066 49 69.79 0.00 31.68 6.20 33.59 8.40 25.19 n.a. n.a. 2067 50 70.55 0.00 32.99 6.20 33.04 8.26 24.78 n.a. n.a. Total 2,537.40 65.97 748.64 256.52 1,339.23 393.06 946.16 – – PV 224.94 18.18 45.97 25.82 10.64 37.27 -26.63 – – Annu 22.59 1.83 4.62 2.59 1.07 3.74 -2.67 – – PV stands for a present value discounted by 10% p.a. Source: Study Team Annu stands for an annualized value of respective present value.
3. FINANCIAL SENSITIVITY
A financial sensitivity was re-demonstrated to examine the extent to which the financial indicators change for different values of the major variables. This supplemental evaluation is compared to the original six cases (Base Case, + CDM, – 10% Tariff, – 10% Annual Energy, + 10% CAPEX & OPEX, and + 1 year delay of commissioning) as given in Table 3-1.
6 Supplemental Financial Evaluation for Simanggo-2
Table 3-1 Financial Indicators Analysis Cases FIRR US$M ROI US$M Source 0. Base Case 10.7% 10.6 24.5% 75.3 the base case Main Report 1. +CDM 11.2% 17.6 25.5% 82.4 CDM benefit added to the base case Main Report 2. –10% Tariff 9.5% -6.3 22.0% 58.5 electricity tariff 10% less Main Report 3. –10% Energy 9.5% -6.3 22.0% 58.5 less annual energy by 10% Main Report 4. +10% CAPEX 9.7% -5.0 22.5% 66.5 greater cost by 10% Main Report 5. COD Delayed by 1 yr 9.9% -1.0 21.4% 65.1 commissioning delayed by 1 year Main Report 6. Supplemental 11.1% 17.6 23.9% 82.4 Actual Tariff applied to Base Case Supplemental Columns with US$M correspond to respective net present values Source: Study Team
7
Part 18 Supplemental Financial Evaluation for Masang-2 HEPP
Supplemental Financial Evaluation for Masang-2
SUPPLEMENTAL FINANCIAL EVALUATION FOR MASANG-2
1. INTRODUCTION
This paper is a supplement to the Main Report on the Project for the Master Plan Study of Hydropower Development in Indonesia, hereinafter referred to as the Main Report. It is to provide an additional financial evaluation in the Masang-2 Hydropower Project, which focuses the pseudo electricity selling price governing the project’s revenue. This paper applies the actual electricity sales by PLN to the project revenue, while the Main Report used a shadow electricity tariff that includes the Government subsidy granted to PLN.
2. FINANCIAL EVALUATION
2.1 METHODOLOGY, ASSUMPTIONS, AND FINANCIAL COST The methodology used, the assumptions set, and financial cost assumed are exactly same as those in the Main Report. The financial capital expenditure (CAPEX) applied for the Masang-2 Hydropower Project is US$193 million, excluding costs required for the feasibility study.
2.2 FINANCIAL BENEFIT
2.2.1 Electricity Tariff The Main Report has chosen a shadow tariff US¢10.63/kWh (US¢7.48/kWh of the selling price and US¢3.15/kWh of the Government subsidy) as of 2010, while this paper applies the actual electricity selling price US¢7.48/kWh as of 2010 without the Government subsidy, as compared in Table 2-1.
Table 2-1 Electricity Sales and Subsidy Electricity Sales Subsidy Sum Electricity Tariff P Tariff S Year Rp T US$M Rp T US$M US$M(GWh) US¢/kWh US¢/kWh 2002 39,018 4,335 4,739 527 4,862 108,360 4.001 4.487 2003 49,810 5,534 4,097 455 5,990 113,020 4.897 5.300 2004 58,232 6,470 3,470 386 6,856 120,244 5.381 5.702 2005 63,246 7,027 12,511 1,390 8,417 127,370 5.517 6.609 2006 70,735 7,859 32,909 3,657 11,516 133,108 5.905 8.652 2007 76,286 8,476 36,605 4,067 12,543 142,441 5.951 8.806 2008 84,250 9,361 78,577 8,731 18,092 149,437 6.264 12.107 2009 90,172 10,019 53,720 5,969 15,988 156,797 6.390 10.197 2010* N/A N/A 55,100 6,122 N/A 194,459 7.479 10.627 2011* N/A N/A 41,000 4,556 N/A 201,977 7.689 9.945 Electricity = Electricity sold by PLN Tariff P = average electricity charge without subsidy Tariff S = electricity charge with subsidy * Estimations for “Electricity Sold” and “Tariff P” based on the past trends in 2005 to 2009. Rp.9,000/US$ is used for Rupiah to US$ conversion. Source: Study Team based on PLN Statistics 2009 and MOF data
The electricity tariff is assumed to be escalated as same as it was done in the past. The trend line of the past electricity tariff suggests that the electricity tariff would be increased by US¢0.2105 every year as seen in Figure 2-1. The electricity tariff would be then 9.16US¢/kWh in 2018, the first operating year.
1 Supplemental Financial Evaluation for Masang-2
10
8 y = 0.2105x + 5.3739
6
4 Tariff (US¢/kWh) 2 Source: Study Team 0 2005 2006 2007 2008 2009 2010 2011 2012 2013 Year
Figure 2-1 Electricity Tariff Projection
2.2.2 Project Revenue The project revenue is of the electricity tariff multiplied by the expected electricity sold. The first operating year revenue as of 2018 is then; US$19.15 mill./year = US$0. 0916/kWh x 209 GWh/year Where 209 GWh/year is the net annual energy. Benefit from Certified Emission Reduction (CER) is exactly same as discussed in the Main Report.
2.3 FINANCIAL ANALYSIS
2.3.1 Interest Free Cash Flow An interest free cash flow here evaluates the project’s profitability without financing charges but with income tax. The financial stream is tabulated in Table 2-2. The key indicators in present worth are:
NPVP = -US$40.7 million FIRR = 6.8% B/C = 0.77 The FIRR computed is much greater than 2.0% of the hurdle rate, and therefore PLN as the project-operating entity will be able to make profit from the project with high probability. However, its NPVP shows a negative value (as FIRR is less than 10% of discount rate) and therefore profit expected from the project should be evaluated marginal.
2 Supplemental Financial Evaluation for Masang-2
Table 2-2 Interest Free Financial Stream US$ million GWh Cost Benefit Net Energy Year CAPEX O&M T ax Sub-t otal Sales CER Sub-t ot al Benefit Sup p ly 2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 2013 -4 2.32 0.00 0.00 2.32 0.00 0.00 0.00 -2.32 0 2014 -3 15.83 0.00 0.00 15.83 0.00 0.00 0.00 -15.83 0 2015 -2 53.59 0.00 0.00 53.59 0.00 0.00 0.00 -53.59 0 2016 -1 76.04 0.00 0.00 76.04 0.00 0.00 0.00 -76.04 0 2017 0 45.12 0.00 0.00 45.12 0.00 0.00 0.00 -45.12 0 2018 1 0.00 4.49 2.19 6.68 19.15 0.97 20.12 13.44 209 2019 2 0.00 4.64 2.26 6.90 19.59 0.97 20.56 13.66 209 2020 3 0.00 4.79 2.33 7.12 20.03 0.97 21.00 13.87 209 2021 4 0.00 4.95 2.40 7.35 20.47 0.97 21.44 14.08 209 2022 5 0.00 5.12 2.47 7.59 20.91 0.97 21.88 14.29 209 2023 6 0.00 5.29 2.54 7.83 21.35 0.97 22.32 14.49 209 2024 7 0.00 5.47 2.60 8.07 21.79 0.97 22.76 14.68 209 2025 8 0.00 5.66 2.69 8.35 22.23 0.97 23.20 14.84 209 2026 9 0.00 5.86 2.78 8.64 22.67 0.97 23.64 15.00 209 2027 10 0.00 6.06 2.87 8.93 23.11 0.97 24.08 15.15 209 2028 11 0.00 6.27 2.96 9.22 23.55 0.97 24.52 15.29 209 2029 12 0.00 6.49 3.04 9.53 23.99 0.97 24.96 15.43 209 2030 13 0.00 6.72 3.12 9.84 24.43 0.97 25.40 15.56 209 2031 14 0.00 6.95 3.20 10.15 24.87 0.97 25.84 15.68 209 2032 15 0.00 7.20 3.28 10.48 25.31 0.97 26.28 15.80 209 2033 16 0.00 7.46 3.35 10.81 25.75 0.97 26.72 15.91 209 2034 17 0.00 7.73 3.42 11.15 26.19 0.97 27.16 16.01 209 2035 18 0.00 8.01 3.49 11.50 26.63 0.97 27.60 16.10 209 2036 19 0.00 8.30 3.56 11.86 27.07 0.97 28.04 16.18 209 2037 20 0.00 8.60 3.62 12.22 27.51 0.97 28.48 16.25 209 2038 21 0.00 8.92 3.68 12.60 27.95 0.97 28.92 16.32 209 2039 22 0.00 9.25 3.73 12.98 28.38 0.97 29.36 16.37 209 2040 23 0.00 9.59 3.79 13.38 28.82 0.97 29.80 16.42 209 2041 24 0.00 9.95 3.84 13.79 29.26 0.97 30.24 16.45 209 2042 25 0.00 10.33 3.88 14.21 29.70 0.97 30.67 16.47 209 2043 26 0.00 10.72 3.92 14.64 30.14 0.97 31.11 16.48 209 2044 27 0.00 11.12 3.96 15.08 30.58 0.97 31.55 16.47 209 2045 28 0.00 11.55 3.99 15.54 31.02 0.97 31.99 16.46 209 2046 29 0.00 11.99 4.02 16.01 31.46 0.97 32.43 16.43 209 2047 30 0.00 12.45 4.04 16.49 31.90 0.97 32.87 16.38 209 2048 31 0.00 12.02 0.00 12.02 0.00 0.00 0.00 -12.02 0 2049 32 0.00 13.44 3.76 17.19 32.78 0.97 33.75 16.56 209 2050 33 0.00 13.96 3.73 17.70 33.22 0.97 34.19 16.50 209 2051 34 0.00 14.51 3.71 18.22 33.66 0.97 34.63 16.41 209 2052 35 0.00 15.09 3.67 18.76 34.10 0.97 35.07 16.31 209 2053 36 0.00 15.68 3.63 19.32 34.54 0.97 35.51 16.20 209 2054 37 0.00 16.31 3.59 19.90 34.98 0.97 35.95 16.06 209 2055 38 0.00 16.96 3.53 20.50 35.42 0.97 36.39 15.90 209 2056 39 0.00 17.64 3.47 21.12 35.86 0.97 36.83 15.72 209 2057 40 0.00 18.36 3.41 21.76 36.30 0.97 37.27 15.51 209 2058 41 0.00 19.10 3.33 22.43 36.74 0.97 37.71 15.28 209 2059 42 0.00 19.88 3.24 23.13 37.18 0.97 38.15 15.03 209 2060 43 0.00 20.69 3.15 23.85 37.62 0.97 38.59 14.75 209 2061 44 0.00 21.55 3.05 24.59 38.06 0.97 39.03 14.44 209 2062 45 0.00 22.43 2.94 25.37 38.50 0.97 39.47 14.10 209 2063 46 0.00 23.36 2.81 26.18 38.94 0.97 39.91 13.74 209 2064 47 0.00 24.34 2.68 27.02 39.38 0.97 40.35 13.34 209 2065 48 0.00 25.35 2.54 27.89 39.82 0.97 40.79 12.90 209 2066 49 0.00 26.42 2.38 28.80 40.26 0.97 41.23 12.44 209 2067 50 -42.95 27.53 2.21 -13.21 40.70 0.97 41.67 54.89 209 Total 149.95 616.57 157.83 924.34 1463.88 47.55 1511.43 587.09 10,239 PV 122.89 37.26 15.68 175.83 129.77 5.40 135.17 -40.66 – Annu 12.34 3.74 1.58 17.66 13.03 0.54 13.58 -4.08 – US¢8.5/kWh NPVP = -40.66 FIRR = 6.84% B/C = 0.77 Cost = PV stands for a present value discounted by 10% p.a. Annu stands for an annualized value of respective present value. Source: Study Team
2.3.2 Return on Investment Assuming the loan conditions exactly same as the Main Report in Table 2-3, the return on investment was computed as given in Table 2-4 by using a DCF model. The net present value and rate of return are:
3 Supplemental Financial Evaluation for Masang-2
NPVI = US$18.9 million ROI = 14.4%
Table 2-3 Loan Conditions Assumed for Financial Cash Flow Interest Rate Front-end Commitment Grace Repay Loan Lender (p.a) fee fee (p.a) period period share Bilateral 1.90% 0.00% 0.75% 7 years 25 years 75% Institution
Notes 1. The front-end fee will be charged only at the time of loan agreement. The commitment fee is charged against unused loan amount and will decrease gradually and end at null when the loan amount is fully disbursed. 2. Interest rate is assumed constant and being composed of 1.4% p.a. of JICA’s standard rate for medium income countries plus 0.5% p.a. of onlending spread by MOF. 3. Grace period includes 4 years of construction. 4. No insurance is counted. Source: Study Team
The project can be evaluated financially feasible from a long term view. A breakeven of the investment will be 5 years after commissioning. Because no revenue is expected in the replacement year scheduled 30 years after commissioning, however, the project will not be able to fulfill the debt service obligation in the same year. As an enough return is expected, the project can overcome the debt service issue. For example, if 7% of the annual net profit is deposited every year into a saving account, the project will easily be able to have enough cash when no revenue is expected due to machine replacement.
50 Tax Interest 40 Principal
30 O&M Revenue 20 PAT
10
0
-10 Revenue and Costmill.) (US$ -20
-30 Source: Study Team -40 2018 2021 2024 2027 2030 2033 2036 2039 2042 2045 2048 2051 2054 2057 2060 2063 2066 Years
Figure 2-2 Cash Inflow and Outflow
Assuming the aforementioned explicit savings for the replacement cost, DSCR and LLCR can be raised as: Minimum DSCR = 1.4 > 1.0 Minimum LLCR = 1.6 > 1.0 Now, all of the indicators show enough numbers and therefore one can evaluate the hydropower project in question is financially viable. The profit and loss calculations are given in Table 2-5.
4 Supplemental Financial Evaluation for Masang-2
Table 2-4 Financial Cash Flow for ROI US$ million Cash Generation Benefit Year Invest Sales Residual O&M Interest Repay Tax Net Sum 2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2013 -4 2.09 0.00 0.00 0.00 0.01 0.00 0.00 -2.10 -2.10 2014 -3 14.28 0.00 0.00 0.00 0.05 0.00 0.00 -14.33 -16.43 2015 -2 27.12 0.00 0.00 0.00 0.74 0.00 0.00 -27.86 -44.29 2016 -1 0.00 0.00 0.00 0.00 2.55 0.00 0.00 -2.55 -46.84 2017 0 0.00 0.00 0.00 0.00 3.20 0.00 0.00 -3.20 -50.03 2018 1 0.00 19.15 0.00 4.49 2.85 0.00 2.19 10.59 -39.45 2019 2 0.00 19.59 0.00 4.64 2.85 0.00 2.26 10.81 -28.64 2020 3 0.00 20.03 0.00 4.79 2.85 0.00 2.33 11.02 -17.62 2021 4 0.00 20.47 0.00 4.95 2.85 0.00 2.40 11.23 -6.39 2022 5 0.00 20.91 0.00 5.12 2.85 0.00 2.47 11.44 5.05 2023 6 0.00 21.35 0.00 5.29 2.85 0.00 2.54 11.64 16.69 2024 7 0.00 21.79 0.00 5.47 2.85 0.00 2.60 11.83 28.52 2025 8 0.00 22.23 0.00 5.66 2.74 6.00 2.69 6.10 34.62 2026 9 0.00 22.67 0.00 5.86 2.62 6.00 2.78 6.37 40.99 2027 10 0.00 23.11 0.00 6.06 2.51 6.00 2.87 6.64 47.63 2028 11 0.00 23.55 0.00 6.27 2.40 6.00 2.96 6.89 54.52 2029 12 0.00 23.99 0.00 6.49 2.28 6.00 3.04 7.14 61.66 2030 13 0.00 24.43 0.00 6.72 2.17 6.00 3.12 7.39 69.05 2031 14 0.00 24.87 0.00 6.95 2.05 6.00 3.20 7.62 76.68 2032 15 0.00 25.31 0.00 7.20 1.94 6.00 3.28 7.85 84.53 2033 16 0.00 25.75 0.00 7.46 1.83 6.00 3.35 8.08 92.61 2034 17 0.00 26.19 0.00 7.73 1.71 6.00 3.42 8.29 100.90 2035 18 0.00 26.63 0.00 8.01 1.60 6.00 3.49 8.50 109.39 2036 19 0.00 27.07 0.00 8.30 1.48 6.00 3.56 8.69 118.09 2037 20 0.00 27.51 0.00 8.60 1.37 6.00 3.62 8.88 126.97 2038 21 0.00 27.95 0.00 8.92 1.25 6.00 3.68 9.06 136.03 2039 22 0.00 28.38 0.00 9.25 1.14 6.00 3.73 9.23 145.26 2040 23 0.00 28.82 0.00 9.59 1.03 6.00 3.79 9.38 154.64 2041 24 0.00 29.26 0.00 9.95 0.91 6.00 3.84 9.53 164.17 2042 25 0.00 29.70 0.00 10.33 0.80 6.00 3.88 9.67 173.84 2043 26 0.00 30.14 0.00 10.72 0.68 6.00 3.92 9.79 183.63 2044 27 0.00 30.58 0.00 11.12 0.57 6.00 3.96 9.90 193.53 2045 28 0.00 31.02 0.00 11.55 0.46 6.00 3.99 10.00 203.52 2046 29 0.00 31.46 0.00 11.99 0.34 6.00 4.02 10.08 213.60 2047 30 0.00 31.90 0.00 12.45 0.23 6.00 4.04 10.15 223.75 2048 31 0.00 0.00 0.00 12.02 0.11 6.00 0.00 -18.14 205.62 2049 32 0.00 32.78 0.00 13.44 0.00 6.00 3.76 10.56 216.17 2050 33 0.00 33.22 0.00 13.96 0.00 0.00 3.73 16.50 232.67 2051 34 0.00 33.66 0.00 14.51 0.00 0.00 3.71 16.41 249.08 2052 35 0.00 34.10 0.00 15.09 0.00 0.00 3.67 16.31 265.40 2053 36 0.00 34.54 0.00 15.68 0.00 0.00 3.63 16.20 281.59 2054 37 0.00 34.98 0.00 16.31 0.00 0.00 3.59 16.06 297.65 2055 38 0.00 35.42 0.00 16.96 0.00 0.00 3.53 15.90 313.55 2056 39 0.00 35.86 0.00 17.64 0.00 0.00 3.47 15.72 329.26 2057 40 0.00 36.30 0.00 18.36 0.00 0.00 3.41 15.51 344.77 2058 41 0.00 36.74 0.00 19.10 0.00 0.00 3.33 15.28 360.05 2059 42 0.00 37.18 0.00 19.88 0.00 0.00 3.24 15.03 375.08 2060 43 0.00 37.62 0.00 20.69 0.00 0.00 3.15 14.75 389.83 2061 44 0.00 38.06 0.00 21.55 0.00 0.00 3.05 14.44 404.27 2062 45 0.00 38.50 0.00 22.43 0.00 0.00 2.94 14.10 418.37 2063 46 0.00 38.94 0.00 23.36 0.00 0.00 2.81 13.74 432.11 2064 47 0.00 39.38 0.00 24.34 0.00 0.00 2.68 13.34 445.44 2065 48 0.00 39.82 0.00 25.35 0.00 0.00 2.54 12.90 458.35 2066 49 0.00 40.26 0.00 26.42 0.00 0.00 2.38 12.44 470.78 2067 50 0.00 40.70 42.95 27.53 0.00 0.00 2.21 54.89 525.67 Total 43.50 1,463.88 42.95 616.57 60.72 150.10 157.83 525.67 – PV 30.99 129.77 0.21 37.26 16.73 15.79 15.68 18.94 – Annu 3.11 13.03 0.02 3.74 1.68 1.59 1.58 1.90 –
NPVI = 18.94 ROI = 14.39% Source: Study Team PV stands for a present value discounted by 10% p.a. Annu stands for an annualized value of respective present value.
5 Supplemental Financial Evaluation for Masang-2
Table 2-5 Profit and Loss US$ million
Year Revenue Interest O&M Cost Depreciation PBT Tax PAT DSCR LLCR
2011 -6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2012 -5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2013 -4 0.00 0.01 0.00 0.00 -2.33 0.00 -2.33 2014 -3 0.00 0.05 0.00 0.00 -15.88 0.00 -15.88 2015 -2 0.00 0.74 0.00 0.00 -54.33 0.00 -54.33 2016 -1 0.00 2.55 0.00 0.00 -78.59 0.00 -78.59 2017 0 0.00 3.20 0.00 0.00 -48.32 0.00 -48.32 2018 1 19.15 2.85 4.49 4.03 8.74 2.19 6.56 4.17 1.81 2019 2 19.59 2.85 4.64 4.03 9.04 2.26 6.78 4.52 1.78 2020 3 20.03 2.85 4.79 4.03 9.32 2.33 6.99 4.88 1.76 2021 4 20.47 2.85 4.95 4.03 9.60 2.40 7.20 5.24 1.73 2022 5 20.91 2.85 5.12 4.03 9.88 2.47 7.41 5.60 1.70 2023 6 21.35 2.85 5.29 4.03 10.14 2.54 7.61 5.97 1.67 2024 7 21.79 2.85 5.47 4.03 10.40 2.60 7.80 6.34 1.64 2025 8 22.23 2.74 5.66 4.03 10.77 2.69 8.08 2.22 1.61 2026 9 22.67 2.62 5.86 4.03 11.13 2.78 8.35 2.32 1.63 2027 10 23.11 2.51 6.06 4.03 11.48 2.87 8.61 2.42 1.66 2028 11 23.55 2.40 6.27 4.03 11.82 2.96 8.87 2.53 1.68 2029 12 23.99 2.28 6.49 4.03 12.16 3.04 9.12 2.64 1.71 2030 13 24.43 2.17 6.72 4.03 12.48 3.12 9.36 2.76 1.74 2031 14 24.87 2.05 6.95 4.03 12.80 3.20 9.60 2.88 1.77 2032 15 25.31 1.94 7.20 4.03 13.11 3.28 9.83 3.01 1.81 2033 16 25.75 1.83 7.46 4.03 13.40 3.35 10.05 3.14 1.85 2034 17 26.19 1.71 7.73 4.03 13.69 3.42 10.27 3.28 1.90 2035 18 26.63 1.60 8.01 4.03 13.96 3.49 10.47 3.42 1.95 2036 19 27.07 1.48 8.30 4.03 14.22 3.56 10.67 3.57 2.01 2037 20 27.51 1.37 8.60 4.03 14.47 3.62 10.86 3.72 2.08 2038 21 27.95 1.25 8.92 4.03 14.71 3.68 11.03 3.88 2.16 2039 22 28.38 1.14 9.25 4.03 14.94 3.73 11.20 4.04 2.25 2040 23 28.82 1.03 9.59 4.03 15.15 3.79 11.36 4.21 2.36 2041 24 29.26 0.91 9.95 4.03 15.34 3.84 11.51 4.38 2.50 2042 25 29.70 0.80 10.33 4.03 15.52 3.88 11.64 4.56 2.68 2043 26 30.14 0.68 10.72 4.03 15.68 3.92 11.76 4.75 2.90 2044 27 30.58 0.57 11.12 4.03 15.83 3.96 11.87 4.94 3.21 2045 28 31.02 0.46 11.55 4.03 15.96 3.99 11.97 5.14 3.63 2046 29 31.46 0.34 11.99 4.03 16.07 4.02 12.05 5.35 4.27 2047 30 31.90 0.23 12.45 4.03 16.16 4.04 12.12 5.56 5.33 2048 31 0.00 0.11 12.02 2.23 -14.36 0.00 -14.36 1.39 8.57 2049 32 32.78 0.00 13.44 5.30 15.02 3.76 11.27 2.50 16.07 2050 33 33.22 0.00 13.96 5.30 14.93 3.73 11.20 n.a. n.a. 2051 34 33.66 0.00 14.51 5.30 14.83 3.71 11.12 n.a. n.a. 2052 35 34.10 0.00 15.09 5.30 14.69 3.67 11.02 n.a. n.a. 2053 36 34.54 0.00 15.68 5.30 14.53 3.63 10.90 n.a. n.a. 2054 37 34.98 0.00 16.31 5.30 14.35 3.59 10.76 n.a. n.a. 2055 38 35.42 0.00 16.96 5.30 14.14 3.53 10.60 n.a. n.a. 2056 39 35.86 0.00 17.64 5.30 13.89 3.47 10.42 n.a. n.a. 2057 40 36.30 0.00 18.36 5.30 13.62 3.41 10.22 n.a. n.a. 2058 41 36.74 0.00 19.10 5.30 13.32 3.33 9.99 n.a. n.a. 2059 42 37.18 0.00 19.88 5.30 12.98 3.24 9.73 n.a. n.a. 2060 43 37.62 0.00 20.69 5.30 12.60 3.15 9.45 n.a. n.a. 2061 44 38.06 0.00 21.55 5.30 12.19 3.05 9.14 n.a. n.a. 2062 45 38.50 0.00 22.43 5.30 11.74 2.94 8.81 n.a. n.a. 2063 46 38.94 0.00 23.36 5.30 11.25 2.81 8.44 n.a. n.a. 2064 47 39.38 0.00 24.34 5.30 10.72 2.68 8.04 n.a. n.a. 2065 48 39.82 0.00 25.35 5.30 10.14 2.54 7.61 n.a. n.a. 2066 49 40.26 0.00 26.42 5.30 9.52 2.38 7.14 n.a. n.a. 2067 50 40.70 0.00 27.53 5.30 8.85 2.21 6.64 n.a. n.a. Total 1,463.88 60.72 616.57 223.73 417.52 157.83 259.69 – – PV 129.77 16.73 37.26 22.81 -64.72 15.68 -80.40 – – Annu 13.03 1.68 3.74 2.29 -6.50 1.58 -8.08 – – PV stands for a present value discounted by 10% p.a. Source: Study Team Annu stands for an annualized value of respective present value.
3. FINANCIAL SENSITIVITY
A financial sensitivity was re-demonstrated to examine the extent to which the financial indicators change for different values of the major variables. This supplemental evaluation is compared to the original six cases (Base Case, + CDM, – 10% Tariff, – 10% Annual Energy, + 10% CAPEX & OPEX, and + 1 year delay of commissioning) as given in Table 3-1.
6 Supplemental Financial Evaluation for Masang-2
Table 3-1 Financial Indicators Analysis Cases FIRR US$M ROI US$M Source 0. Base Case 6.6% -40.5 15.0% 19.1 the base case Main Report 1. +CDM 7.0% -36.4 15.9% 23.2 CDM benefit added to the base case Main Report 2. –10% Tariff 5.6% -50.6 12.5% 9.0 electricity tariff 10% less Main Report 3. –10% Energy 5.6% -50.6 12.5% 9.0 less annual energy by 10% Main Report 4. +10% CAPEX 5.8% -54.5 12.8% 11.1 greater cost by 10% Main Report 5. COD Delayed by 1 yr 6.2% -47.0 13.4% 13.9 commissioning delayed by 1 year Main Report 6. Supplemental 6.8% -40.7 14.4% 18.9 Actual Tariff applied to Base Case Supplemental Columns with US$M correspond to respective net present values Source: Study Team
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