## 8 Discussion and Further Required Research
### Limitations, Uncertainties, and Further Potential Development  
This work provides a workflow to estimate near-shore impulse-wave magnitude in terms of flow depth at the shoreline (see \"Excel spreadsheet\"Computational tool\" in the Supplementary Materials). By contrast, most other studies report impacts in terms of inundation distance and run-up height, metrics that are not considered in this work. Nonetheless, shoreline water depth provides a preliminary characterization of run-up potential and inundation, although these are also heavily affected by the morphology and the steepness of the surrounding topography. As a result, observations of an impulse wave or post-event measurements of its impacts provide only a very general indication of the large-scale variability of flow depth at the shoreline. A more reasonable assessment of this new approach can be achieved using previously established relationships that independently estimate flow depth at the shoreline, as was done for the Chehalis Lake case study (Section 6). A current disadvantage of this work is the lack of adequate validation. The Chehalis Lake case study and comparison of the results with those based on the ETH equations are insufficient to fully evaluate the validity of this approach. Proper validation would entail a comparison of the results derived using this method with real data collected in the field. However, flow depths at the shoreline caused by an impulse wave are not directly observable in the field and therefore must be calculated independently. Such calculation requires the use of detailed, site-specific, retrospective numerical simulations capable of accurately recreating a landslide-generated wave event. Future extension and expansion of the proposed approach will involve two critical steps: (1) implementing numerical analyses on well documented, real-world events to validate the geometry-based strategy as a predictor of flow depth at the shoreline; and (2) developing rapid, low-computational-cost methods for estimating run-up and flooding potential from flow depth at the shoreline. This next phase of development will expand the range of outputs to include expected run-up, thereby extending the applicability of the proposed approach and enchaining opportunities to reliably validate it. Another possible limitation of this study is its applicability to large lakes and a single impact volume. The size and properties of the impacting landslide substantially influence wave characteristics. For example, the maximum wave height resulting from an impact is dependent on landslide volume and competence, debris thickness and frontal width, impact speed, and slope angle and roughness [17; 37]. Further research that addresses these issues is required. For example, the approach can be extended to consider diverse characteristics of the impacting volume to provide a relation for _WDPP_ that considers landslide properties in addition to the geometrical characteristics of the lake (the _ShpP_). Incorporation of additional consideration into the workflow--including by varying impact processes, volumes, and velocities--might lead to the development of additional equations that can be applied to the full range of real-world situations. This can be accomplished in Flow-3D by adopting the concept of the impacting volume being a dense fluid, as done in the present study. Different volumes, shapes, impact velocities, and slope angles can be implemented in the model set-up. Scaling impact volumes relative to lake volume may assist in standardizing comparisons between lakes. In this work, the slide source is located halfway along the long side of the lake. Further development of the approach should consider different impacting locations along the lakesbore to extend the applicability of the suggested method. Moreover, it would be valuable to consider submerged slide sources, as subaqueous mass movements can also trigger lake impulse waves [47; 48].