塔里木河中游因坡度平缓和来水条件复杂多变，导致河道的泥沙情势变化显著，进而加速河床演变，对附近生态环境产生破坏。为了明晰不同来水情况对河道形态的影响，本文根据实测地形资料，建立塔河干流中游典型河段8.41 km的泥沙输运模型，模拟了2023年4月1日至11月30日的河道冲淤演变过程，进行河道特征断面冲淤演变规律的探讨。结果表明：流量日变化量相比于流量、含沙量、含沙量日变化量是影响河道断面深泓点冲淤变化强度的主要水文因素；在不同水文时期，即汛前枯水期、汛前中水期、汛期以及汛后期，流量日变化量与深泓点高程日变化量之间的相关性呈现出依次递增的趋势，其中汛后期的相关性最为显著；河槽冲淤过程具有显著季节性分异特征，不同时段对河道主槽演变效应的排序为：汛后期>汛期>汛前中水期>汛前枯水期。本研究为深入理解塔里木河干流中游河道演变规律提供了重要参考，可为生态修复提供科学依据。

[Objectives] The objective of this study is to quantitatively identify the dominant hydrological drivers controlling the morphological changes of the river channel in the middle reaches of the Tarim River. Specifically, we aim to achieve the following goals: to determine the relative impacts of flow, daily flow variation, sediment concentration, and daily sediment concentration variation on the river channel’s scouring and silting dynamics; to quantify the seasonal changes in the relationships between key drivers and morphological responses during different hydrological periods (pre-flood low-water period, pre-flood medium-water period, flood season, and post-flood period); and to delineate the differentiated morphological evolution patterns of straight, naturally bifurcated, and artificially realigned river segments under different flow conditions. [Methods] A high-resolution two-dimensional water-sediment transport model was developed for a typical 8.41 km section of the main stream of the Tarim River at Tatilik Village. The key innovative methods include: high-precision initialization, where airborne laser bathymetry conducted during the low-water period (April 1, 2023) minimized the interference of suspended sediment, generating a high-precision digital elevation model with a resolution of 3 meters as the initial riverbed topography; one-dimensional-two-dimensional coupled modeling, where the validated one-dimensional model provided boundary conditions for the two-dimensional model, including the time series of flow at the inlet boundary and water depth at the outlet boundary; and integrated spatio-temporal analysis, where the model simulated daily morphological changes from April 1, 2023, to November 30, 2023, and output data at 21 characteristic sections, bifurcated river sections, and realigned river sections with a spacing of approximately 400 meters. [Results] The results indicate that the daily variation in flow is the main hydrological factor affecting the intensity of scouring and silting changes at the thalweg of river sections, compared with flow, sediment concentration, and daily variation in sediment concentration. During different hydrological periods, including the pre-flood low-water period, pre-flood medium-water period, flood season, and post-flood period, the correlation between daily flow variation and daily thalweg elevation variation increases progressively, with the most significant correlation observed in the post-flood period. The scouring and silting process of the river channel exhibits significant seasonal differences, with the order of impact on the main channel evolution being: post-flood period > flood season > pre-flood medium-water period > pre-flood low-water period. [Conclusions] This study provides unprecedented quantitative insights into the driving factors of riverbed evolution in the middle reaches of the Tarim River, which is of great significance for basin management and ecological restoration. We have clearly confirmed that daily flow variation is the main direct driver of daily channel elevation changes, with seasonal patterns. The correlation increases progressively from the pre-flood low-water period to the post-flood period, reaching the strongest association and maximum net scouring intensity after the flood peak. Given the disproportionate impact of the post-flood period on channel remodeling, management strategies should prioritize monitoring during this period and prepare for intervention. The established sequence of evolution intensity (post-flood period > flood season > pre-flood medium-water period > pre-flood low-water period) provides a framework for predicting periods of high geomorphological activity and related ecological impacts, such as habitat gains and losses, and bank stability. The differentiated evolution trajectories of bifurcated rivers and the drastic adjustments dominated by scouring in artificially realigned sections indicate that management and restoration measures must be customized for specific river segment types. This study provides a scientific basis for river planning, responses to water diversion, climate change, or engineering interventions, which will effectively support the sustainable restoration practices of the Tarim River ecosystem.