## 4 Results
### VUG from 2012 to 2020\(-\)Wuhan
The heights are categorized from less than 3 m to over 90 m, indicating a substantial increase in taller buildings over time. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline Year & 2012 & 2016 & 2020 & 2012 & 2016 & 2020 & 2012 & 2016 & 2020 & 2012 & 2016 & 2020 \\ \hline \hline
**Height** & \multicolumn{3}{c}{\textless{}3 m} & \multicolumn{3}{c}{3–9 m} & \multicolumn{3}{c}{9–27 m} & \multicolumn{3}{c}{27–90 m} & \multicolumn{3}{c}{\textgreater{}90 m} \\ \hline
**Districts** & & & & & & & & & & & & & & \\ \hline
**Caidian** & 5610 & 2244 & 289 & 626 & 1818 & 2097 & 646 & 2019 & 2745 & 192 & 896 & 1607 & 6 & 103 & 342 \\ \hline
**Dongxihu** & 6272 & 2142 & 490 & 712 & 2176 & 2223 & 593 & 2303 & 2724 & 208 & 1020 & 1814 & 16 & 160 & 550 \\ \hline
**Hanyang** & 7466 & 3260 & 482 & 1078 & 2170 & 2155 & 1330 & 2955 & 3422 & 425 & 1679 & 3135 & 17 & 252 & 1122 \\ \hline
**Hongshan** & 16246 & 6557 & 846 & 2545 & 4777 & 4817 & 3176 & 6836 & 8370 & 1742 & 4935 & 7433 & 68 & 672 & 2311 \\ \hline
**Jiang’an** & 4924 & 1480 & 198 & 1270 & 1824 & 1523 & 1675 & 3269 & 3601 & 757 & 1848 & 2601 & 41 & 246 & 744 \\ \hline
**Jianghan** & 3083 & 949 & 108 & 895 & 1103 & 866 & 1292 & 2402 & 2628 & 566 & 1219 & 1721 & 41 & 204 & 554 \\ \hline
**Jiangxia** & 5175 & 1955 & 209 & 921 & 1625 & 1608 & 1141 & 2798 & 3618 & 410 & 1156 & 1848 & 11 & 124 & 375 \\ \hline
**Qiaoku** & 3755 & 1358 & 269 & 971 & 1475 & 1296 & 1040 & 2129 & 2418 & 399 & 1100 & 1734 & 15 & 118 & 463 \\ \hline
**Qingshan** & 2368 & 837 & 54 & 558 & 796 & 658 & 697 & 1463 & 1686 & 230 & 670 & 1075 & 9 & 96 & 389 \\ \hline
**Wuchang** & 7808 & 2470 & 365 & 1645 & 2471 & 2204 & 2091 & 4562 & 5104 & 1110 & 2762 & 3935 & 86 & 475 & 1132 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Number of grids by building height in different districts of Wuhan (2012–2020). In particular, the Hanyang, Wuchang, and Hongshan districts have seen pronounced increases in buildings over 90 m. For example, in Hanyang, the number of grids containing buildings taller than 90 m rose from 17 in 2012 to 1122 in 2020, representing a 66-fold increase. Despite Hanyang's moderate GDP growth of 2.80%, this surge in high-rise buildings corresponds with a significant 14.17% increase in government revenue, suggesting a link between fiscal health and vertical development. Similarly, Wuchang has demonstrated significant vertical growth, with the number of such grids increasing from 86 in 2012 to 1132 in 2020, aligning with high economic development and a government revenue increase of 17.63%. Hongshan shows the most dramatic rise, with grids containing buildings over 90 m growing from 68 in 2012 to 2311 by 2020, a substantial 34-fold increase. This aligns with substantial growth in gross output construction (31.93%) and GDP (9.17%), underscoring rapid urban development. In contrast, districts like Caidian and Qingshan, which displayed lower socio-economic growth, witnessed more modest increases. Caidian's grids with buildings over 90 m grew from 6 in 2012 to 342 in 2020, and Qingshan's from 9 to 389. These results demonstrate how economic prosperity and infrastructure investments drive the construction of taller buildings, contributing to the changing skyline of Wuhan. While a detailed investigation into specific municipal zoning codes or urban master plan revisions between 2012 and 2020 is beyond the data scope of this remote sensing analysis, the observed spatial patterns--particularly the concentration of VUG in central districts like Hanyang, Wuchang, and Hongshan--are highly consistent with typical urban planning strategies favouring high-density development in core areas with established infrastructure. The previously mentioned strategic development plans [33; 34] likely guided these differential growth trajectories across the city. Understanding the precise interplay between policy, economics, and VUG remains a key area for future interdisciplinary research.