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J. Basic. Appl. Sci. Res., 1(10)1709-1714, 2011
© 2011, TextRoad Publication
ISSN 2090-424X Journal of Basic and Applied
Scientific Research www.textroad.com
*Corresponding Author: Subandiyah Azis, Doctoral Program of Agriculture Sciences, Brawijaya University, Head of Life Environmental Department, the Government Regency of Malang, Indonesia. Email: [email protected]
Analysis of Irrigation Water Requirement for Anticipating Global Climate Change
Subandiyah Azis
Doctoral Program of Agriculture Sciences, Brawijaya University Head of Life Environmental Department, the Government Regency of Malang, Indonesia
ABSTRACT
This paper studied the analysis of irrigation water requirement due to anticipate climate change. Irrigation water requirement was analyzed by using Pasten Method (FPR-LPR), which had been used in Indonesia since the Netherland Era. This method had been used without to consider too of 2 parameters: rainfall and soil physical condition. Result was used as comparison to existing irrigation water requirement which was analyzed using water balance method and Cropwat 8.0. KEY WORDS: irrigation water requirement, Pasten Method, water balance, Cropwat 8.0.
INTRODUCTION
International innovations and experiences due to water policy and the arrangements of local governments were shared through various international meetings. The assumption was that the experiences provided information to decision makers who were finding some ways for improving regional or country water resources system planning and analysis. The wealth of international reports showed that there were no interesting cases and good practices from kind of sources. Organizations and individuals were often very willing to share their experiences in public forum [1]. Therefore, it had to be written about analytical support for the potential interested policy makers. There was less action had been directed estimating water demand in developing economy? Analysis of water demand was an economic cornerstone of water supply planning, water management and determination of water value [2]. The developed water demand was typically due to micro level data that included the amount of water consumed by municipal water supplier over some time period. Water consumption was influenced by the structure of water storage and supply. It was mentioning that estimating of renewable water resources was river runoff, which usually provided the volume of water use. Analysis of changes in the characteristics of water resources uses with the consideration of economic trends and climatic conditions were generally used for forecasting water use. The issue of water resources uses had long been of scientific important. This was due to the increasing role of anthropogenic factors related to water consumption by population, industry, and agriculture irrigation [3].
MATERIALS AND METHODS This study was carried out at Molek Irrigation Area. It is located at Kepanjen, Malang Regency. East Java Province of Indonesia. Molek Irrigation Area is included 3 districts namely Kepanjen District, Kromengan District, and Sumberpucung District. Map of location is as in Figure 1.Some data was used in this study. The data was included: 1. Yearly rainfall from 1999 to 2009. 2. Intake discharge at Blobo Spillway from 1994 to 2009. 3. Irrigation map at the year of 2008/2009 4. Map of construction scheme at the year of 2008/2009 5. Irrigated and unirrigated area number at the year of 2008/2009 6. Data of climate from 2005 to 2009 7. Initial study of Molek Irrigation Work. 8. Software of Cropwat 8.0
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Azis, 2011
Figure 1 Map of Location
Pasten Method Water need for irrigation was included of water need for cropping and area preparation, consumptive use, percolation and seepage, changes for efficiency of irrigation, and effective rainfall. Water need for cropping was formulated by the factor of relative second crop. The method was developed from Pasten Method which was used in Netherland. The formulation was [4] FPR = ……………………………………………………………….. (1)
Note FPR = factor of relative second crop Q = discharge flow in river (l/s/ha) LPR = area number of relative second crop
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J. Basic. Appl. Sci. Res., 1(10)1709-1714, 2011
Based on texture of land, the factor of relative second crop was as Table 1 [4] Table 1 Factor of relative second crop
Texture of land
FPR (l/s/ha.second crop) Less water Enough water Available water
Alluvial 0,18 0,18-0,36 0,36 Latosol 0,12 0,12-0.23 0,23 In turn Yes Possible No
Formula of intake discharge
IRpadi = efficiency
NFRx A ............................................................................ (2)
IRpalawija = efficiency
RC effektifT x A ...................................................................... (3)
Note: IRpadi = water requirement for rice (l/s) IRpalawija = water requirement for second crop (l/s) A = area number (ha)
RESULTS AND DISCUSSION For irrigation design and planning, it was needed to analyze dependable discharge for any kind of seasons. In this study, analysis was carried out for dependable discharge of normal season, dry season and wet season. For normal season was dependable discharge of 80%. For dry season It was 90% and for wet season was 25%. These 3 conditions was described as in Figure 2 below. Dependable rainfall was analyzed too for 50% and 80%. The result was expressed as in Table 2. Water irrigation need for existing condition, using water balance method, Cropwat method, and Pasten Method was describes as in 3. 4. And 5 below.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Bulan
Deb
it m
3/de
t
Debit Andalan 80 % Tahun Musim Normal Debit Andalan 25 % Tahun Musim Basah Debit Andalan 90 % Tahun Musim Kering
Debit Andalan 25 % Tahun Musinm Basah
Debit Andalan 80 % Tahun Musinm Normal
Debit Andalan 90 % Tahun Musinm Kering
Figure 2 Dependable discharge of 80 % for normal season, 90 % for dry season, and 25 % wet season
discharge of 25 % for wet season
discharge of 90 % for dry season
discharge of 80 % for normal season
Intake Discharge
l/s
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Azis, 2011
Table 2 Dependable rainfall for 80% and 50%
Month Period R 80 (mm) R 50 (mm) Month Period R 80 (mm) R 50 (mm)
Jan 1 72.09 77.66 July 1 0.00 1.41 2 29.32 55.80 2 0.00 0.00 3 98.04 95.02 3 0.00 0.00
Feb 1 71.77 121.63 Aug 1 0.00 0.00 2 122.96 61.68 2 0.00 0.00 3 71.19 102.42 3 0.00 0.00
Mar 1 123.02 37.64 Sep 1 0.00 0.00 2 87.31 84.56 2 0.00 0.06 3 26.13 192.76 3 0.00 2.94
Apr 1 82.52 119.91 Oct 1 0.00 20.56 2 63.62 99.42 2 0.00 41.37 3 46.64 0.01 3 24.31 43.02
May 1 24.43 47.22 Nov 1 11.54 73.98 2 32.68 31.43 2 41.77 58.50 3 0.00 0.49 3 72.52 73.59
June 1 0.00 5.39 Dec 1 30.26 210.53 2 0.00 14.12 2 43.95 15.88 3 0.00 0.49 3 122.86 92.94
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Okt Nov Des Jan Feb Mar Apr Mei Jun Jul Agust Sept
MKII MH MKI MKII
Periode Tanam
Deb
it In
take
(m3/
det)
Debit Andalan 80 % Musim Normal
Debit Andalan 90 % Musim Kering
Debit Andalan 25 % Musim BasahKebutuhan Air Irigasi Intake DI Molek Pola Tata Tanam RTTG Eksisting Padi-Palawija-Tebu Metode FPR-LPR
Figure 3 Curve of irrigation water need at intake of Molek irrigation area
(Existing condition for rice-second crop-sugar reed)
Q of 80 % for normal season
Q of 90 % for dry season
Q of 25 % for wet season irrigation water need at intake of Molek irrigation area
Intake Discharge
l/s
Cropping period
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J. Basic. Appl. Sci. Res., 1(10)1709-1714, 2011
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Okt Nov Des Jan Feb Mar Apr Mei Jun Jul Agust Sept
MKII MH MKI MKII
Periode Tanam
Deb
it In
take
(m3/
det) Debit Andalan 80 % Musim Normal
Debit Andalan 90 % Musim Kering
Debit Andalan 25 % Musim Basah
Kebutuhan Air Irigasi Intake DI Molek Pola Tata Tanam RTTG Eksisting Padi-Palawija-Tebu Metode Water Balance/ PU
Figure 4 Curve of irrigation water need at intake of Molek irrigation area
(Water Balance Method)
0
1
2
3
4
5
6
7
8
9
10
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Okt Nov Des Jan Feb Mar Apr Mei Jun Jul Agust Sept
MKII MH MKI MKII
Periode Tanam
Deb
it In
take
(m3/
det) Debit Andalan 80 % Musim Normal
Metode CROPWAT Model Pola Tata Tanam RTTG Eksisting
Metode FPR / Faktor Palawijo Relatif Pola Tata Tanam RTTG Eksisting
Debit Andalan 90 % Musim Kering
Debit Andalan 25 % Musim Basah
Figure 5 Curve of irrigation water need at intake of Molek irrigation area
(Cropwat Method and Pasten Method)
Based on 3 figures as above, each method had any kind of each specification. It could be explained as follow:
1.Cropwat 8.0 had pattern almost the same as Water Balance Method, but it was different with Pasten Method. Pasten Method in average had less value than Cropwat and Water Balance one.
2.Pasten Method in average had pattern almost the same as Water Balance Method. 3.Based on irrigation water need at Molek intake, Cropwat Method was enough dominant for each season (wet
season, normal season, and dry season) except for second cropping season on October.
irrigation water need at intake of Molek irrigation area
Q of 25 % for wet season
Q of 80 % for normal season
Q of 90 % for dry season
Cropping period
Intake Discharge
l/s
Intake
Discharge l/s
Cropping period
irrigation water need Cropwat Method irrigation water need Pasten Method
Q of 25 % for wet season
Q of 80 % for normal season
Q of 90 % for dry season
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Azis, 2011
4.Pasten Method produced not enough water need at dry season at dry season on September-October and normal season on January.
5.Water Balance Method Metode produced the most irrigation water need at rainy season on January and at dry season on September-October
Conclusions Based on the analysis using Cropwat Method, Water Balance Method, and Pasten Method, it could conclude for irrigation water need was as follow:
1.Cropwat Method had pattern almost the same as Water Balance Method, but it had the difference pattern with Pasten Method. In average, Pasten Method produced less irrigation water need than the others.
2.The available analysis of irrigation water need was to use Pasten Method by adding the parameters of rainfall and soil physical condition.
REFERENCES
1. Hermans, Leon M. 2011. An Approach to Support Learning from International Experience with Water Policy. Journal
of Water Resource Manage, 25: 373-393
2. Cheesman, Jeremy; Bennett, Jeff; and Son, Tran Vo Hung Son. 2008. Journal of Water Resources Research, Vol. 44, W11428, doi 10: 1029/2007/WR006265
3. Shiklomadov, I.A.; Babkiu, V.I.; and Balouishu;kov, Zh.A. 2011. Water Resources, Their Use, and Water Availability in Rusia: Current Estimates and Forecasts. Journal of Water Resources (38) no. 2, p 139-148
4. Proyantoro. Dwi and Montarcih, Lily. 2011. Water Supply System at Tibunangka Irrigation Area, Lombok Indonesia. Journal of Mathematics and Technology, Vol. 2 No 1: 8-13
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