## 4 Results and Analysis
### Spatiotemporal Evolution Characteristics of Thalweg
Figure 5: Thalweg changes at typical reaches of the Xinqiman–Kelelik segment: (**a**) the thalweg from Xinqiman–Kelelik section in typical years from 1993 to 2024; (**b**) the overall thalweg change amplification diagram of the river section, the entire study area is divided into six parts, numbered 1–6 in the figure; (**c**) the change of thalweg in the Tarim Farm Area 5 reach; (**d**) the change of thalweg in the Paman reservoir reach; (**e**) the change of thalweg in the Kuerqiaoer reach; (**g**) the change of thalweg in the Yueliangwan Scenic Area reach. In the Yueliangwan Scenic Area Reach (Figure 5g), the thalweg migrated southward from 1993 to 2016. From 1993 to 2004, the migration rate reached 119.6 m/a. After the meander cutoff and straightening in 2002, the river length shortened, the longitudinal slope increased, and flow energy became more concentrated. This enhanced vertical erosion capacity while weakening lateral erosion, resulting in a decrease in the migration rate to 6.9 m/a from 2004 to 2016. Between 2016 and 2024, the thalweg migrated northward. The migration rate was 9.1 m/a from 2016 to 2020 and increased to 21.5 m/a from 2020 to 2024. This accelerating northward shift threatens the flood prevention safety of the scenic area. To address this, it is essential to curb the accelerating northward migration of the thalweg by prioritizing the implementation of diversion projects, such as sills and spur dikes, along with ecological bank reinforcement to stabilize the river course. The thalweg evolution in the Xinjaman-Kelelik segment exhibits significant spatial heterogeneity, influenced by both natural hydraulics and human interventions. In the typical areas, the river courses of the Tarim Farm Area 5 Reach, Paman Reservoir Reach, and Pama Reach have migrated northward (towards the Tianshan Mountains), eroding the bank slopes and posing flood control threats to the adjacent areas. The river course evolution in the Kuerqiaoer Reach and Yueliangwan Scenic Area Reach is active, with significant meander cutoffs and straightening. The overall river course has migrated southward (towards the Taklamakan Desert), necessitating priority measures to control erosion risks and prevent flood hazards caused by river course alterations. The above studies clearly reveal the significant spatial and temporal heterogeneity and high migration rate of the thalweg in the Xinjaman-Kelelik section of the upper reaches of the Tarim River, and deepen the understanding of the evolution mechanism of rivers in arid areas. Compared with typical arid rivers such as the Nile River [17] and the Niger River [19], this study has quantified the thalweg oscillation characteristics of glacier-supplied inland rivers under strong human intervention for the first time. It confirms the conclusion of [PERSON] [2] on \"strong lateral erosion\" and \"high risk of bending\" in the middle reaches of the Tarim River, and also conforms to the mechanism of morphological transformation caused by breaking the critical value of bending rate observed by [PERSON] [10]. However, this study further quantified the migration rate under the background of strong human activities (farmland expansion to 5140 hectares, intensive distribution of diversion sluices) (such as the peak value of Tarim Farm Area 5, 324.6 m/a). This complements the multi-factor driven framework proposed by [PERSON] [13] in the Tana River. At the same time, the significant inhibitory effect of revetment projects (such as after 2008) on the migration rate was clearly quantified. For example, the thalweg migration rate of Tarim Farm Area 5 decreased from