## 4 Results Analysis
### Land-Use Rising/Falling Tupu Analysis  
#### 4.3.1 Land-Use Rising Tupu  
The examination of the differences in the transitions of the land-use structure in Putian City was conducted by creating the ascending Tupu for the periods from 2000 to 2010 and from 2010 to 2020, as depicted in Figure 4. Additionally, a statistical analysis was performed on the data pertaining to the transitions, which is summarized in Table 7.  
Table 7 and Figure 4a present data indicating that between 2000 and 2010, the areas of land use that underwent change and those that remained unchanged in Putian City were 246.45 km\({}^{2}\) and 3676.32 km\({}^{2}\), respectively. These figures represent 6.28% and 93.72% of the total area of the study region. Within the areas that experienced change, the most significant increase was observed in BL, which added up to 136.45 km\({}^{2}\), or 55.37% of the total area that saw an increase. This was followed by UL (48.93 km\({}^{2}\)), FL (16.89 km\({}^{2}\)), CL (15.63 km\({}^{2}\)), GL (14.65 km\({}^{2}\)), WB (10.52 km\({}^{2}\)), and OL (3.38 km\({}^{2}\)). In terms of regional distribution, Xianyou \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Code** & **Transition Tupu Unit** &
\begin{tabular}{c} **Number of Tupu** \\ **Unit/No.** \\ \end{tabular} & **Transition Area/km\({}^{2}\)** & **Change Ratio/\%** \\ \hline
16 & Cultivated land (CL)\(\rightarrow\)Built-up land (BL) & 94,999 & 85.50 & 46.67 \\
17 & Cultivated land\(\rightarrow\)Unused land (UL) & 40,640 & 36.58 & 19.96 \\
21 & Forest land (FL)\(\rightarrow\)Cultivated land & 18,329 & 16.50 & 9.00 \\
12 & Cultivated land\(\rightarrow\)Forest land & 15,545 & 13.99 & 7.64 \\
14 & Cultivated land\(\rightarrow\)Grassland (GL) & 8320 & 7.49 & 4.09 \\
41 & Grassland\(\rightarrow\)Cultivated land & 5939 & 5.35 & 2.92 \\
24 & Forest land\(\rightarrow\)Grassland & 4256 & 3.83 & 2.09 \\
76 & Unused land\(\rightarrow\)Built-up land & 3154 & 2.84 & 1.55 \\
71 & Unused land\(\rightarrow\)Cultivated land & 2175 & 1.96 & 1.07 \\
23 & Forest land\(\rightarrow\)Orchard land (OL) & 2014 & 1.81 & 0.99 \\ \hline \hline \end{tabular} Sources: Drawings from this study.  
\end{table} 
Table 6: Tupu unit ranking of LUCs in Putian City from 2010 to 2020 (Top 10). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
County had the largest proportion of land that remained unchanged, at 48.49%, suggesting that it experienced the most stable land-use changes (LUCs) during the period. On the contrary, Licheng District had the smallest proportion of unaltered areas, at 6.57%, and the largest addition to BL, with an area of 30.04 km\({}^{2}\). This highlights its prominent role in the land-use changes (LUCs) within the study area. When it comes to the extent of newly added land types, Xianyou County had the greatest expanse of new cultivated land at 6.52 km\({}^{2}\), followed by Xiuyu District (3.56 km\({}^{2}\)), Hanjiang District (2.46 km\({}^{2}\)), Chengxiang District (2.00 km\({}^{2}\)), and Licheng District (1.10 km\({}^{2}\)). In the context of FL, Xianyou County, Hanjiang District, and Chengxiang District were identified as the top three areas with the most significant additions of new forest land, collectively accounting for 92.78% of the total new FL added. As the primary fruit production hubs within Putian City, both Hanjiang District and Xianyou County saw an addition of 3.28 km\({}^{2}\) to their OL, which constituted 97.04% of the overall new OL that was added. It is also notable that among the areas where BL expanded, Xiuyu District had the largest increase, with 57.87 km\({}^{2}\) of new BL, followed by Licheng District, Chengxiang District, Xianyou County, and Hanjiang District. As a result, the conversion of land use to BL was most pronounced in Xiuyu District during the observed period, whereas Chengxiang District exhibited a comparatively stable land-use pattern.