Determination of Irrigation Performance Indices for Paddy Cultivation
Evaluation and monitoring of paddy irrigation schemes (field plot level) traditionally use conventional indices, namely, Relative Water Supply (RWS) and Water Use Efficiency (WUE). Where continuous irrigation was practice, low WUE and high RWS were obtained giving the impression that little water...
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| Format: | Thesis |
| Language: | English English |
| Published: |
1999
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10367/1/FK_1999_34_A.pdf |
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| Summary: | Evaluation and monitoring of paddy irrigation schemes (field plot level)
traditionally use conventional indices, namely, Relative Water Supply (RWS) and
Water Use Efficiency (WUE). Where continuous irrigation was practice, low WUE
and high RWS were obtained giving the impression that little water management had
been carried out. This is partly blamed on the incorrect use of these indices because
the aim of the agency is different from those for which RWS and WUE were
developed. A study at field plot level was conducted in Bagan Serai, Perak for one
main season to measure the components of water balance in an irrigated paddy field.
The components of the water balance were individually measured using a range of
equipment. Observations were made to find indicators that can show the performance
of water management according to the aim of the agency. These indicators were incorporated in the proposed indices. Plot Consumption Index (PCI) and Effective
Water Use Index (EWUI) were developed and proposed to evaluate and monitor the
irrigation performance at field plot level. These indices were developed in line with
the aim of the agency and that was to maintain the 'Design Water Depth' (DWD) in
the field. DWD is the depth of water that should be maintain throughout the planting
season. Results of the components of the water balance were used to calculate WUE,
RWS, PCI and EWUI. For most of the season, daily values of EWUI were less than 1
but more than 0, indicating that excess water was supplied. Some days recorded
negatives values ranging from -0.1 to -6.9. On these days there was heavy rains and
the field was flooded. On the weekly basis, week two had a value of 0.32 while week
six had a value of 0.16, while the weekly basis, week tw had a value of 0.32 while
week six had a value of 0.16, while the last week recorded 2.71 , indicating under
supply, a situation commensurate with the end of season. All other weeks indicated
excess or flood conditions by its negative values. |
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