Modelling Landscape Evolution - Environmental Modelling: Finding Simplicity in Complexity - page 307

Detachment-limited stream-power model

m = 1; n = 1 (RMS = 80 m)

800

m = 0.4; n = 1 (RMS = 53 m)

m = 0.4; n = 0.7 (RMS = 45 m)

m = 0.3; n = 0.7 (RMS = 42 m)

600

400

200

250 200 150

Distance from source (km)

100 50 0

(a)

Undercapacity model

Linear, Constant width, L f = 1 KM (RMS = 54 m)

Linear, Constant width, L f = 30 KM (RMS = 67 m)

800

Linear, Variable width, L f = 30 KM (RMS = 55 m)

Non-Linear, Variable width, L f = 50 KM (RMS = 38 m)

600

400

200

250 200 150

Distance from source (km)

100 50 0

(b)

Figure 19.4 Comparison of observed present-day fluvial profile for the Lachlan River (SE Australia) with that predicted by (a) the
detachment-limited stream-power model (Equation 20.7) for different values of K , m ,and n and (b) the 'undercapacity' model
(Equation 20.11) for different values of K s , L f , m s ,and n s . Reconstructed 21-Ma profile used as initial condition is also indicated
(Adapted with permission from van der Beek, P.A. and Bishop, P. (2003) Cenozoic river profile development in the Upper Lachlan
catchment (SE Australia) as a test of quantitative fluvial incision models. Journal of Geophysical Research , 108, 2309, doi:
2310.1029/2002JB002125).