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Drainage basins
Published in Richard J. Chorley, Stanley A. Schumm, David E. Sugden, Geomorphology, 2019
Richard J. Chorley, Stanley A. Schumm, David E. Sugden
Another interesting aspect of drainage evolution is stream capture, the natural diversion of one stream by another. Usually one stream is either flowing at a lower level or is much more aggressive due to high discharge which permits it to erode into the adjacent drainage area (Figure 13.27). Numerous locations where capture is imminent or where it has probably occurred can be noted in Figure 13.24 (especially C-D and G-H). Capture thus appears to be a major ingredient of drainage pattern evolution. Capture is not only of geomorphic interest because, if the beheaded stream contains gold or diamonds, paleoplacers are preserved in the beheaded channel; and exploration for placers frequently involves working out the original drainage pattern that is now disrupted by capture.
Dynamic river basins and hypsometric analyses: implications to land management and prioritization in Bohol, Central Philippines
Published in International Journal of River Basin Management, 2022
Imelida G. Torrefranca, R. E. S. Otadoy, A. F. Tongco
A river basin, the unit of analysis in IRBM, is a hydrologically defined landform comprising drainage divides and stream channel networks. Drainage divides and river networks are dynamic elements of river basins that continue to change in response to tectonic and erosional forcings (Willett et al., 2014), with critical implications on how land resources will be managed and used. Drainage divides play a significant role in shaping drainage basins by setting the boundary between adjacent basins. At the same time, the network of stream channels is the pathways of bedrock erosion, water, nutrient, and sediment transport from uplands to oceans (Willett et al., 2014). Drainage basins are previously assumed to be stationary. However, observations of stream capture (Linkevičiene, 2009; Bloxom & Burbey, 2015; Shugar et al., 2017), long-term erosion studies (Beeson et al., 2017), and numerical modeling (Goren et al., 2014) demonstrate that basin geometry and network topologies continuously approach asymptotic value. Differential erosion rates between adjacent basins drive the geometric adjustments (Goren et al., 2014). Goren et al. (2014) further explain that continuously migrating divides become sources of autogenic sediment flux variations in a landscape, potentially impacting resource management.