# Monitoring Water Area Dynamics in Kashgar (2003-2023) Using Multi-Source Remote Sensing Data
## 3 Results and Analysis
### Drivers of Water Body Area Change in the Kashgar Region  
Precipitation is a crucial driver of water body area change, particularly in regions with high precipitation levels, where it serves as the primary determinant of water body dynamics. In the Kashgar region, seasonal water bodies constitute 50-60% of the total water body area, highlighting the significant influence of precipitation on water body fluctuations. This study investigates the correlation between changes in water body area and precipitation to elucidate the mechanisms by which precipitation variability impacts water body dynamics. Specifically, we analyzed the relationship between water body area and annual average rainfall in Kashgar from 2003 to 2023. Figure 11a depicts the spatially heterogeneous distribution of precipitation in Kashgar, with concentrations primarily in the southern and western regions, while the central, eastern, and northern regions experience relatively lower precipitation. Figure 11b reveals a general downward trend in annual average precipitation from 2003 to 2023, exhibiting an average annual change rate of \(-3.86666\) mm/year. Precipitation peaked in 2010 (233.818 mm) and reached its minimum in 2022 (107.188 mm). Figure 11c illustrates the temporal trends of surface water area and annual precipitation in Kashgar from 2003 to 2023, demonstrating a general concordance between the two trends. This suggests that precipitation is a key factor influencing inland water area changes in Kashgar. Furthermore, Figure 11d reveals a statistically significant positive correlation between changes in surface water area and average annual precipitation, although the correlation coefficient (R\({}^{2}\)) is relatively weak (0.2431). The extremely low \(p\)-value (2.6 \(\times\) 10\({}^{-34}\) \(<\) 0.05) strongly supports the conclusion that precipitation is a direct and important driver of surface water area changes. Given the increasing global warming trend and accelerated water cycle, this study further investigated the relationship between surface water area and annual average temperature in Kashgar. Figure 12a illustrates a decreasing temperature gradient from southwest to northeast, with the southwest exhibiting the lowest temperatures, likely influenced by topographic factors. Figure 12b reveals a general downward trend in annual average temperature from 2003 to 2023, with an average annual change rate of \(-0.03885\)  
Figure 10: Comparative analysis of permanent and seasonal water body distribution in Kashgar (2003, 2013, 2023). The highest temperature was recorded in 2002 (20.62 \({}^{\circ}\)C), while the lowest temperature occurred in 2008 (18.686 \({}^{\circ}\)C). Figure 12c depicts the temporal trends of surface water area and annual average temperature, demonstrating a general concordance between the two trends. This suggests that temperature is a significant factor influencing inland water area changes in Kashgar. Furthermore, Figure 12d reveals a statistically significant positive correlation between changes in surface water area and annual average temperature. Although the correlation coefficient (R\({}^{2}\)) is relatively weak (0.3481), the extremely low \(p\)-value (1.8 \(\times\) 10\({}^{-35}\) < 0.05) strongly supports the conclusion that temperature is a direct and important driver of surface water area changes. Evaptranspiration is a pivotal process within the terrestrial water cycle, playing a crucial role in understanding the water cycle's response to climate change and anthropogenic activities. Rising temperatures are projected to enhance evaporation rates, consequently diminishing surface runoff recharge. This study investigated the relationship between surface water area and mean annual evapotranspiration in the Kashgar region. As depicted in Figure 13a, evapotranspiration in the Kashgar region exhibited a fluctuating upward trend from 2003 to 2023, with an average annual change rate of 11.99885 mm.