## 4 Results
### Crop Type Dynamics  
The main factors driving crop type transition have been highlighted via an analysis of classification maps and crop type changes in five time periods (Figure 7). The highest crop type transformation occurred for a recent period between 2016 and 2021 of 9966 km\({}^{2}\), followed by 2011 to 2016 (8740 km\({}^{2}\)), 2001 to 2006 (4876 km\({}^{2}\)) and 2006 to 2011 (1068 km\({}^{2}\)). Between 2001 and 2006, the crop transition with the greatest increase in terms of area can be related to sugarcane (1579 km\({}^{2}\)) and cassava (1009 km\({}^{2}\)). However, this increase resulted in a reduction in rice cultivation of 1993 km\({}^{2}\). The largest percentage increases in areas under cultivation have been observed for cassava (405 km\({}^{2}\)) and rice (39 km\({}^{2}\)) between the years 2006 and 2011. In contrast, a decrease in crop area was seen in sugarcane, which covered 438 km\({}^{2}\). Between the years 2011 and 2016, the crop areas that have the potential to generate the highest increase in yield are sugarcane (1615 km\({}^{2}\)) and para rubber (2502 km\({}^{2}\)). In contrast, rice areas dropped by 4169 km\({}^{2}\). From 2016 to 2021, the areas of major crops expanded, in particular for cassava (5804 km\({}^{2}\)) and para rubber (220 km\({}^{2}\)). In contrast, rice areas decreased to a total of 2217 km\({}^{2}\) due to encouragement from the government's policy for changing crop cultivation in northeast Thailand. Moreover, Figure 7 illustrates the crop type area transition for the four five-year periods, highlighted in the chord diagrams. From 2001 to 2006, the highest crop type transition was from rice to cassava. From 2006 to 2011 and 2011 to 2016, the same changes occurred in the major crop types, from rice to sugarcane. The largest change from rice to cassava-cultivated areas was observed between 2016-2021.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline
**2016** & \multicolumn{8}{c}{**Reference Data**} \\ \cline{2-10}
**Crop Types** & **Cassava** & **Rice** & **Para Rubber** & **Sugarcane** & **Built-Up** & **Forest** & **Water** & **Bare soil** & **Total** & **UA (\%)** \\ \hline Cassava & 106 & 5 & 1 & 17 & 0 & 0 & 0 & 129 & 82.17 \\ Rice & 18 & 237 & 0 & 8 & 0 & 1 & 0 & 0 & 264 & 89.77 \\ Para rubber & 2 & 0 & 98 & 0 & 0 & 1 & 0 & 0 & 101 & 97.03 \\ Sugarcane & 16 & 4 & 2 & 111 & 0 & 0 & 0 & 0 & 133 & 83.46 \\ Built-up & 0 & 4 & 0 & 0 & 145 & 0 & 0 & 1 & 150 & 96.67 \\ Forest & 0 & 3 & 0 & 0 & 0 & 101 & 0 & 0 & 104 & 97.12 \\ Water & 0 & 6 & 0 & 2 & 3 & 2 & 45 & 0 & 58 & 77.59 \\ Bare soil & 0 & 1 & 0 & 1 & 0 & 0 & 0 & 46 & 48 & 95.83 \\ Total & 142 & 260 & 101 & 139 & 148 & 105 & 45 & 47 & 987 & \\ PA (\%) & 74.65 & 91.15 & 97.03 & 79.86 & 97.97 & 96.19 & 100.00 & 97.87 & \\ \hline \multicolumn{8}{c}{OA = 90.07\%; Kappa = 88.21\%} \\ \hline
2021 & Cassava & Rice & Para rubber & Sugarcane & Built-up & Forest & Water & Bare soil & Total & UA (\%) \\ \hline Cassava & 119 & 3 & 3 & 16 & 0 & 5 & 0 & 0 & 146 & 81.51 \\ Rice & 3 & 185 & 0 & 4 & 1 & 0 & 0 & 1 & 194 & 95.36 \\ Para rubber & 0 & 0 & 98 & 0 & 0 & 5 & 0 & 0 & 103 & 95.15 \\ Sugarcane & 18 & 2 & 0 & 136 & 0 & 0 & 0 & 0 & 156 & 87.18 \\ Built-up & 0 & 2 & 0 & 0 & 147 & 0 & 0 & 1 & 150 & 98.00 \\ Forest & 0 & 0 & 2 & 0 & 0 & 94 & 0 & 0 & 96 & 97.92 \\ Water & 0 & 1 & 0 & 0 & 0 & 3 & 60 & 0 & 64 & 93.75 \\ Bare soil & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 78 & 78 & 100.00 \\ Total & 140 & 193 & 103 & 156 & 148 & 107 & 60 & 80 & 987 & \\ PA (\%) & 85.00 & 95.85 & 95.15 & 87.18 & 99.32 & 87.85 & 100.00 & 97.50 & \\ \hline \multicolumn{8}{c}{OA = 92.91\%; Kappa = 91.76\%} \\ \hline \end{tabular}
\end{table}
Table 5: Accuracy assessment using independent validation datasets for eight crop type/land cover (LC) classification results in 2016 and 2021 based on all available Landsat datasets and a random forest (RF) classifier. (OA: overall accuracy, PA: producer’s accuracy, UA: user’s accuracy).