# Assessing Spatiotemporal LST Variations in Urban Landscapes Using Diurnal UAV Thermography
## 4 Results
### GWR Results
These low adjusted \(R^{2}\) values overall indicate that proximity to grasslands has a minimal and unstable association with temperature variations, suggesting that other environmental or human-induced factors may override any potential cooling or warming effects of grassland areas. The bandwidth for grassland remains relatively consistent (around 77-80), indicating a uniform spatial scale that, however, does not translate into a strong explanatory relationship. Paved roads demonstrate a relatively robust association with temperature variations, particularly during the afternoon, evening, and midnight periods. The morning model yields an adjusted \(R^{2}\) of about 0.246 (\(R^{2}\approx 0.35\)), but this increases to approximately 0.403 in the afternoon, peaks at about 0.567 in the evening, and remains high at 0.514 at midnight. These elevated adjusted \(R^{2}\) values suggest that the thermal effects associated with paved surfaces--possibly due to heat absorption and retention--are more pronounced later in the day. The varying bandwidth (from 57 in the morning to 92 in the afternoon) indicates that the spatial influence of paved roads is not uniform throughout the day, potentially \begin{table}
\begin{tabular}{l l r r} \hline
**LULC Class** & **Timeframe** & **Bandwidth** & **Adjusted \(R^{2}\)** \\ \hline \multirow{4}{*}{Bare Soil} & Morning & 67.0 & 0.142 \\  & Afternoon & 94.0 & \(-\)0.053 \\  & Evening & 81.0 & 0.515 \\  & Midnight & 73.0 & 0.460 \\ \hline \multirow{4}{*}{Building} & Morning & 79.0 & 0.149 \\  & Afternoon & 80.0 & 0.162 \\  & Evening & 94.0 & 0.231 \\  & Midnight & 86.0 & 0.255 \\ \hline \multirow{4}{*}{Grassland} & Morning & 80.0 & 0.057 \\  & Afternoon & 77.0 & 0.227 \\  & Evening & 80.0 & 0.030 \\  & Midnight & 80.0 & \(-\)0.010 \\ \hline \multirow{4}{*}{Paved Road} & Morning & 57.0 & 0.246 \\  & Afternoon & 92.0 & 0.403 \\  & Evening & 81.0 & 0.567 \\  & Midnight & 76.0 & 0.514 \\ \hline \multirow{4}{*}{Water Body} & Morning & 53.0 & 0.617 \\  & Afternoon & 57.0 & 0.339 \\ \cline{1-1}  & Evening & 57.0 & 0.638 \\ \cline{1-1}  & Midnight & 53.0 & 0.550 \\ \hline \end{tabular}
\end{table} 
Table 3: Detailed GWR analysis across LULC classes and timeframes. reflecting differences in urban morphology or surface material properties that affect heat storage and release. Among the LULC types examined, proximity to water bodies shows the strongest and most consistent relationship with temperature variation. In the morning, the model explains roughly 62% of the variance (adjusted \(R^{2}\approx 0.617\), \(R^{2}\approx 0.68\)), and similarly high values are observed in the evening (adjusted \(R^{2}\approx 0.638\), \(R^{2}\approx 0.69\)) and midnight (adjusted \(R^{2}\approx 0.550\), \(R^{2}\approx 0.62\)) periods. The afternoon model, while lower (adjusted \(R^{2}\approx 0.339\), \(R^{2}\approx 0.44\)), still suggests a substantial association. The consistently high adjusted \(R^{2}\) values imply that water bodies exert a strong localized influence on temperature, likely due to their capacity to moderate local climates through evaporative cooling and thermal inertia. This inference is supported by the relatively small bandwidth values (53-57), indicating that the cooling effect of water bodies is highly localized. To quantify the temporal variations in LULC thermal influence, we calculated the percentage changes in adjusted \(R^{2}\) values between consecutive time periods (Table 4). The most pronounced temporal shift occurred in bare soil, which experienced a dramatic decrease from morning to afternoon (\(-137.3\%\)), followed by a substantial recovery in the evening period (\(+1071.7\%\)). Water bodies demonstrated notable diurnal fluctuation patterns with a 45.1% decrease in explanatory power from morning to afternoon, followed by an 88.2% increase from afternoon to evening, highlighting their dynamic role in thermal regulation throughout the day.