Comparisons of Watershed Delineation of River Network Representation and Morphometric Analysis in Karnaphuli River Basin, Chittagong, Bangladesh: A study with Different Digital Elevation Model (DEM)

Abstract

The present study aimed to delineate robust watershed boundary and extract its morphometric parameters in Karnaphuli watershed, Bangladesh using different types of digital elevation models (DEMs). Two DEMs, such as Shuttle Radar Topographic Mission (SRTM) and the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), were utilized to delineate watershed boundary and evaluate several morphometric characteristics. From the findings, it is revealed that there is a visual difference between the data sets as ASTER has a larger watershed area than SRTM. Also, regarding stream order, there are actually 1 to 6 orders of stream, so there are so many small, medium and main channels of the river, where the drainage density for SRTM (spatial resolution: 30m) and ASTER (spatial resolution: 30m) is 0.52 km/km2 and 0.51 km/km2. The bifurcation ratio ranges from 1.94 and 2.45 for SRTM and ASTER, respectively, representing the influence of geological structure as well as suffering more structural disturbances. The form factor denotes the study area's elongated shape. The entire dimension of the stream and the extent of the watershed imply that the mean annual rainfall discharge is moderate. The watershed has rather high denudation rates, according to the basin relief. The watershed's drainage density is low, demonstrating that infiltration is more important. This study may help policymakers to take decisions on the Karnaphuli River on conservation of the river stream and flow path, which will ultimately enrich the river ecology and other vegetation cover in Chittagong, Bangladesh.

Determinación de inicios de cauces a partir de Modelos Digitales de Superficie. Cuenca alta del arroyo La Ventana (Buenos Aires, Argentina)

“…En la actualidad, gracias al desarrollo de los Sistemas de Información Geográfica y la evolución de los sensores satelitales que hicieron posible la creación de Modelos Digitales de Superficie (MDS) precisos y de alta resolución, estas dificultades están siendo superadas y los métodos tradicionales de digitalización de las redes de drenaje han sido reemplazados por metodologías más avanzadas (López-Vicente et al, 2014;Nikolakopoulos et al, 2015;Kok et al, 2018;Shavers & Stanislawski, 2020). La disponibilidad de nuevas tecnologías para la medición de la elevación de la superficie terrestre ha abordado la ausencia de datos de alta resolución, lo que ha llevado a un aumento de la utilización de este tipo de herramientas en la realización de estudios de modelado hidrológico, hidráulico y geomorfológico (Manfreda et al, 2011;Samela et al, 2016;Niyazi et al, 2019;Epuh et al, 2022;Kale et al, 2022;Roy et al, 2022).…”