## 5 Conclusions  
In this paper, a hierarchical analysis approach is introduced to describe the micro-macro architecture of braided river systems. The excellently exposed three-dimensional Quaternary outcrops of the braided river system in the Songyuan area of the Songliao Basin provide a good, measured profile for detailed observation and description of the sedimentary structure, scale characteristics, superposition, and cross-cutting relationships of the strata. By classifying the architecture and analyzing the evolution process of these strata, the main conclusions are as follows:  
1. Methodological innovation in hierarchical classification: We establish a micro-to-macro four-level framework (lithofacies, elements, element associations, and archetypes) tailored to coarse sandy-gravelly braided rivers. This approach, rarely applied to such systems, enables the systematic linkage of depositional processes (e.g., downstream vs. lateral accretion) to sedimentary products (e.g., bar-channel interactions). By decoupling descriptive features (e.g., lithofacies) from process-based inferences (e.g., flood-stage dynamics), the framework overcomes the limitations of traditional 2D facies analysis and provides a standardized method for characterizing complex braided river architectures. 2. Novel insights into depositional dynamics: Our identification of five architectural elements and four genetically distinct associations reveals previously unrecognized patterns in braided river evolution. Specifically, quantitative relationships between bankfull channel depth (d), mean depth (d\({}_{\text{m}}\)), and width (W\({}_{\text{b}}\)) (d\({}_{\text{m}}\) = 0.617 d; W\({}_{\text{b}}\) = 56.025 d\({}_{\text{m}}\)\({}^{0.9656}\)) challenge existing models for gravelly braided rivers, highlighting the role of temperate monsoon climates (seasonal discharge) and cohesive banks (vegetation-stabilized) in constraining channel dimensions. 3. Practical implications for reservoir characterization: The braided river archetype, built from element associations, offers a predictive tool for subsurface reservoir modeling. By quantifying element scales (e.g., bar thickness and channel width) and their contact relationships, this study bridges outcrop observations with underground reservoir properties, aiding in the assessment of heterogeneity in analogous petroleum or groundwater reservoirs. The hierarchical approach also provides a blueprint for designing flume experiments, ensuring better replication of natural braided river processes (e.g., bar migration and channel abandonment). These contributions not only enhance the theoretical understanding of braided river systems under specific climatic and tectonic settings but also provide actionable methodologies for resource exploration and geological modeling. **Author Contributions:** Conceptualization, Z.L. (Zongbao Liu), Z.D. and Y.W. methodology, Z.D., Z.L. (Zongbao Liu) and Y.Z. ; software, Z.D. and Z.L. ([PERSON]); validation: Z.D., J.H. and Y.Z. ; formal analysis, Z.D. and Z.L. ([PERSON]); investigation, Z.D. ; resources, Z.D., Z.L. ([PERSON]); data curation, Z.D. ; writing--original draft preparation, Z.D. ; writing--review and editing, Z.D., Z.L. ([PERSON]), Y.W.,Y.Z., J.H. and Z.L. ([PERSON]); visualization, Z.D. ; supervision, Z.L. ([PERSON]); project administration, Z.L. ([PERSON]). All authors have read and agreed to the published version of the manuscript. **Funding:** The authors acknowledge the financial support by Heilongjiang Provincial Natural Science Foundation of China: ZL2024D003). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** All data and materials are available on request from the corresponding author. The data are not publicly available due to ongoing research using some of the data. **Acknowledgments:** We thank [PERSON] from Wuzhou Medical College for her valuable assistance in the editing of this manuscript.