Is the river system naturally heterogeneous or homogeneous?
Increasing the heterogeneity or complexity of channels and floodplains with the intention of increasing habitat availability and biodiversity is often a key focus in river rehabilitation initiatives. However, blanket applications of the heterogeneity paradigm are not always appropriate. In some instances, the natural geomorphic structure and behavior of a river may be relatively simple. A classic example is a chain-of-ponds river. These discontinuous watercourses comprise swampy valley fill, scour ponds, and indistinct preferential drainage lines (McTaggart et al. 2008). Aquatic flora and fauna have subsequently adapted to this simple structure. The notion of natural simplicity or complexity of geomorphic structure can also be viewed at broader scales. For example, a catchment with two different types of river is no less worthy than a catchment with 10 river types. In some instances, enhanced heterogeneity of river structure may be an unintended geomorphic response to human disturbance
