## 4 Computational Results and Discussions
### Crop Pattern Scenarios  
This experiment shows the sensitivity of the results on the availability of crop pattern restriction in each zone. The experiment was conducted considering the limitations of the type of crops separated into six different plans. The configuration of the percentage of crops permitted to be cultivated in each area of plans 1 to 5 is shown in Table 7. For example, in Plan 1, only rice can be cultivated in all the zone. Other crops were not allowed to be cultivated. Similar experiments were represented in Plan 2, and Plan 3, in which the only crops allowed to be cultivated are corns and cassava, respectively. In Plan 4, rice, corns, and cassava cultivation areas were limited to be cultivated at most at 25% of the total area. Plan 5 is the most flexible plan. Each zone was allowed to cultivate crops without restricting the percentage area of each crop. In this plan, the program would calculate the most suitable cultivation plan for the highest income under the conditions of sufficient water amounts throughout the year. Plan 6 referred to the current cultivation plan used in the six zones. Table 8 displays the percentages of irrigated areas of all six zones in Huay Mae Thor Reservoir. The plan is based on the survey on the actual data obtained. In this plan, the minimum area for each type of crop cultivation was fixed. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Name**} & \multicolumn{2}{c}{**AMPL**} & \multicolumn{2}{c}{**SA**} \\ \cline{3-6}  & & **Objective Solution** & **Solving Time (s)** & **Objective Solution** & **Solving Time (s)** \\ \hline  
Average & & & 2.40 & & 6.95 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Comparison between AMPL and SA. Figure 7 shows the comparison of the result generated by each plan in terms of the expected generated income. The result indicates that Plan 2, Plan 4, and Plan 5 have the most generated income with an estimated revenue of 62,303,100 Baht. Next, the rank on total generated income is followed by Plan 3, then Plan 1. Meanwhile, the least generated income is the current applied plan, Plan 6. The analysis shows that the current plan used in Huay Mae Thor Reservoir can be improved by applying more well-designed and optimized crop planning. However, this analysis considers limited factors only, such as the expected crop yield, crop price, land area availability, and water availability. This study has not yet tackled many complicated considerations that might be available in the field, such as uncertainty of water availability, changes in crop demand, or risk of crop failure. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Crop’s Species**} & \multirow{2}{*}{**Variety**} & \multicolumn{5}{c}{**Agricultural Area Limitation**} \\ \cline{3-6}  & & **Zone 1** & **Zone 2** & **Zone 3** & **Zone 4** & **Zone 5** & **Zone 6** \\ \hline \multirow{6}{*}{Rice} & Chai Nat & 25–100\% & 88–100\% & 52–100\% & 49–100\% & 17–100\% & 42–100\% \\ \cline{2-6}  & Phitsanulok & 37–100\% & 12–100\% & 48–100\% & 46–100\% & 4–100\% & 56–100\% \\ \cline{2-6}  & RD49 & 1–100\% & 0 & 0 & 4–100\% & 55–100\% & 1–100\% \\ \cline{2-6}  & Hom Pathum & 3–100\% & 0 & 0 & 1–100\% & 3–100\% & 0 \\ \cline{2-6}  & Jasmine105 & 0 & 0 & 0 & 0 & 13–100\% & 0 \\ \cline{2-6}  & Suphan 90 & 0 & 0 & 0 & 0 & 0 \\ \hline \multirow{6}{*}{Corns} & CP 999 & 5–100\% & 0 & 0 & 0 & 0 \\ \cline{2-6}  & CP 369 & 0 & 0 & 0 & 0 & 4–100\% & 0 \\ \cline{2-6}  & CP 777 & 1–100\% & 0 & 0 & 0 & 0 \\ \cline{2-6}  & Sticky rice & 7–100\% & 0 & 0 & 0 & 4–100\% & 0 \\ \hline \multirow{6}{*}{Cassava} & Rayong 5 & 12–100\% & 0 & 0 & 0 & 0 & 2–100\% \\ \cline{2-6}  & Kak Dum & 5–100\% & 0 & 0 & 0 & 0 & 0 \\ \cline{1-1} \cline{2-6}  & Rayong 72 & 1–100\% & 0 & 0 & 0 & 0 & 0 \\ \cline{1-1} \cline{2-6}  & Rayong 9 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{1-1} \cline{2-6}  & Rayong 7 & 3–100\% & 0 & 0 & 0 & 0 & 0 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Percentages of existing irrigated area in Huay Mae Thor Reservoir.