**2.7 Results and discussions**

To adopt proper irrigation supplies, the appropriate information system is a prerequisite to make the right decision on water allocation as well as possible remedial actions as the season advances. Typical results produced using the GIS based assessment tool is presented in the following sections for visualization in colored maps, charts and tables as the season

The system allows for storing of all inputs and outputs into the MS Access database simply by clicking on the Command Button "Save". It has also capabilities of retrieving, editing, deleting records from database for a particular day upon selection. The Command Button "Backup" helps to keep all files as backup any time. The dialog wizard linked with the Command Button "View Inputs & Outputs" in Fig. 3 allows interactive viewing for all input and output databases. It enables to users viewing data in table and graph formats. The records of the selected table are displayed. The records from the selected Table can be viewed for a specified duration and the selected fields. The easily obtained comprehensive information allows the manager to characterize the irrigation delivery performance faster. The dialog wizard for exploring the scheme's information can also be viewed on clicking the command button "Detailed Scheme Information" in Fig. 3. This sub-module gives salient

features of the scheme in the form of maps, graphs and tabular formats.

Fig. 3. Dialog Wizard for Characterizing Irrigation Delivery Performance for the Main

To adopt proper irrigation supplies, the appropriate information system is a prerequisite to make the right decision on water allocation as well as possible remedial actions as the season advances. Typical results produced using the GIS based assessment tool is presented in the following sections for visualization in colored maps, charts and tables as the season

Season

**2.7 Results and discussions** 


(a) Input Selection Dialog Wizard


(b) Input Dialog Wizard for Daily Meteorological Data

Fig. 4. Computing Daily ETo using FAO Penman-Monteith Method

Paddy Water Management for Precision Farming of Rice 121

The irrigation performance characterizes as over supply for RRWS > 1.0, undersupply for RRWS < 1.0 and good performance for RRWS = 1.0. Therefore, the irrigation manager can easily quantify how irrigation water ought to be allocated with the available water resources

After clicking on the Command Button "Rice Relative Water Supply (RRWS)" in Fig. 3, irrigation delivery performances from the beginning to the current days for the current irrigation season are plotted as shown in Fig. 6. The irrigation performance characterizes as over supply for RRWS > 1.0, undersupply for RRWS < 1.0 and good performance for RRWS = 1.0. Therefore, the irrigation manager can easily quantify how irrigation water ought to be

Fig. 6. Characterizing Daily Irrigation Delivery Performance using RRWS for Main Season

The RRWS\_I, RRWS\_II and RRWS\_III represent Rice Relative Water Supply for Irrigation Service Areas I, II and III where irrigation supply is staggered by one month, respectively.

Irrigation Delivery Conditions by ISA Month ISA I ISA II ISA III August Oversupply No Supply No Supply September Under Supply Oversupply No Supply October Oversupply Under Supply Under Supply

From Fig. 6, the following decisions can be drawn (Table 2):

Table 2. Characterization of Irrigation Delivery Conditions

delivered with respect to the available water resources for the next day.

for the next day or irrigation period.

2003

**2.7.2 Rice Relative Water Supply (RRWS)** 

advances. The system provides useful information of the actual field condition with respect to the water demand as the season progresses and helps allocate the right amount of irrigation supplies for the next day or period.

### **2.7.1 Characterizing irrigation delivery performance**

The characterization is essential to evaluate irrigation deliveries among tertiary canals and for their remedial measures as the season advances. A dialog wizard like that in Fig. 3 appears by clicking on the Menu Item "Irrigation Delivery Performance" in the dialog wizard shown in Fig. 3. To get the output, the user needs to enter the required inputs and the appropriate options. Inputs are directly fed from the input database by clicking on the Command Button "Data from Input Files" or manually. After that, the results for a particular day can be computed and viewed on a screen instantly like that shown in Fig. 5 by clicking on the Command Button "Monitoring Irrigation Performance" in Fig. 3. New performance indicators RRWS and PWI are used for evaluating and characterizing irrigation delivery performance and compared the advantages and disadvantages with the RWS concept especially for paddy irrigation system. The 18,000 ha irrigation scheme is divided into 3 Irrigation Service Areas (ISA) with a staggered supply of one month.


Fig. 5. Output Dialog Window for Characterizing Irrigation Delivery Performance on 20 October 2003

advances. The system provides useful information of the actual field condition with respect to the water demand as the season progresses and helps allocate the right amount of

The characterization is essential to evaluate irrigation deliveries among tertiary canals and for their remedial measures as the season advances. A dialog wizard like that in Fig. 3 appears by clicking on the Menu Item "Irrigation Delivery Performance" in the dialog wizard shown in Fig. 3. To get the output, the user needs to enter the required inputs and the appropriate options. Inputs are directly fed from the input database by clicking on the Command Button "Data from Input Files" or manually. After that, the results for a particular day can be computed and viewed on a screen instantly like that shown in Fig. 5 by clicking on the Command Button "Monitoring Irrigation Performance" in Fig. 3. New performance indicators RRWS and PWI are used for evaluating and characterizing irrigation delivery performance and compared the advantages and disadvantages with the RWS concept especially for paddy irrigation system. The 18,000 ha irrigation scheme is divided

into 3 Irrigation Service Areas (ISA) with a staggered supply of one month.

Fig. 5. Output Dialog Window for Characterizing Irrigation Delivery Performance on 20

October 2003

irrigation supplies for the next day or period.

**2.7.1 Characterizing irrigation delivery performance** 

The irrigation performance characterizes as over supply for RRWS > 1.0, undersupply for RRWS < 1.0 and good performance for RRWS = 1.0. Therefore, the irrigation manager can easily quantify how irrigation water ought to be allocated with the available water resources for the next day or irrigation period.
