The study focuses on a Sarawak River in east Malaysia, which falls under the 10.1% areas in Malaysia that are prone to flooding. The river is located around the provincial capital of Sarawak, Kuching. Furthermore, it is characterized by its meandering course and low-lying terrain which shows geographical complexities. The interplay of dynamic factors makes the Sarawak River a critical area to research for flood modelling. The tools that can be used for this are Geoinformatics Geographic Information Systems (GIS) and remote Remote sensing Sensing methods which provide valuable geospatial data from the investigated area. The methodology employs a GIS-based process model to estimate inundation extents for predefined water levels, enabling comparative analysis of flood-prone areas derived from different DEMs with varying topographic representations and spatial resolutions. Additionally, cross-sectional profiles at multiple river segments are extracted to assess and evaluate the accuracy of geometric reconstruction across the DEM datasets.