## 4 Results and Analysis
### Evolution of River Planform Morphology
#### 4.2.2 Channel Erosion and Sedimentation Changes  
Based on satellite imagery from the flood season between 1993 and 2024, the riverbank lines of the Xinjaman-Kelelik River section were extracted. Typical years (1993, 1996, 2000, 2004, 2008, 2012, 2016, 2020, and 2024) were selected to construct the river channel boundary closure areas and quantify the areas of erosion and deposition patches on both banks. The results indicate that from 1993 to 2024, the river reach showed a general siltation trend, with a net siltation area of 3.23 km\({}^{2}\). However, there were significant differences in the sedimentation and erosion conditions across different periods. During the erosion-dominated periods (1993-1996, 2000-2004, 2008-2016, and 2020-2024), the total erosion area reached 15.25 km\({}^{2}\). Between 2020 and 2024, which saw the most intense erosion, the erosion area was 5.59 km\({}^{2}\) (Figure 8c). During this time, In the Kuerqiaoer Reach and the Yueliangwan Scenic Area Reach, the erosion on both sides of the river was serious (Figure 8b). This was primarily due to the increase in annual runoff from 2020 to 2024. In 2022, the annual runoff amounted to 8.562 billion m\({}^{3}\), marking the highest level in 32 years. The intensified flooding eroded the riverbanks, leading to collapses. Driven by the increased runoff, the eroded sediment was transported by the water flow and deposited in various downstream areas. During the sedimentation-dominated periods (1996-2000, 2004-2008, and 2016-2020), the total siltation area was 18.48 km\({}^{2}\). Between 1996 and 2000, the most intensive siltation period, the siltation area reached 9.53 km\({}^{2}\) (Figure 8c). During this period, the reduced annual runoff (only 2.623 billion m\({}^{3}\) in 2000) caused significant sediment deposition along the riverbanks, forming extensive siltation flats. Along the banks of Tuyang Village, downstream of the Jigedalaxi Diversion Sluice, and along the banks of Ajinamu Reach (Figure 8a), these flats have fully developed. Spatially, the total erosion area on the southern bank (13.18 km\({}^{2}\)) was substantially greater than that on the northern bank (5.47 km\({}^{2}\)), whereas the total deposition area on the northern bank (13.19 km\({}^{2}\)) significantly exceeded that on the southern bank (8.69 km\({}^{2}\)), indicating a prevailing erosional trend along the southern bank and depositional conditions along the northern bank (Figure 8d). Overall, the river channel has exhibited a southward migration, shifting toward the Taklamakan Desert, which reflects the long-term interactions between regional hydrodynamic and sediment transport processes and fluvial geomorphology. This study quantifies the significant spatial differentiation of shoreline erosion and deposition: the net erosion on the south bank is 4.49 km\({}^{2}\), and the net deposition on the north bank is 7.72 km\({}^{2}\), resulting in the overall southward movement of the river. This is  
Figure 8: The scouring and silting conditions of the Xinqiman–Kelelik reach from 1993 to 2024: (**a**) erosion and accumulation patches in Xinqiman–Kelelik reach from 1996 to 2000; (**b**) erosion and accumulation patches in Xinqiman–Kelelik reach from 2020 to 2024; (**c**) river erosion and deposition area; (**d**) erosion and deposition area on both sides of the river. (note: + represents siltation; – represents erosion). consistent with the strong asymmetric erosion and deposition observed by [PERSON] [8] and [PERSON] [9]. However, this study combines hydrological data (Figure 2) and human activity information (Figure 9) to further clarify that this differentiation in the upper reaches of the Tarim River is not only controlled by the influence of natural bend circulation, but also strongly affected by the location of diversion sluices, the distribution of revetment projects, and the destruction of bank slope stability by farmland reclamation.