A decision support system for identifying the habitat quality and rehabilitation potential of urban rivers

Abstract

Few habitat survey, classification or assessment methodologies have been developed specifically for urban or heavily engineered rivers, and yet these rivers need careful assessment if management options are to be considered and prioritised in an economically and environmentally effective way. This paper presents a refinement of a previously proposed urban river survey (URS), which is a modification of the Environment Agency's River Habitat Survey. It then describes indices and classifications that have been developed from URS data and that provide a link between the type of engineering applied to a stretch of urban river and its habitat characteristics. Finally, some simple decision trees and scenario‐modelling tools are presented that allow (i) newly surveyed urban stretches to be classified and (ii) some simple scenarios of channel management change to be assessed in order to prioritise management options for stretches of urban river across urban catchments.

Urban rivers: novel ecosystems, new challenges

“…(This may be indicative of a severe hysteretic shift in ecosystem state, wherein removal of the original disturbances or stresses does not result in a return to a historic state, as the system has changed irrevocably.) This echoes observations made elsewhere in the literature, and is particularly true for urban rivers: although restoration is theoretically possible for some urban rivers, particularly those that are at a lower level of urbanization, in heavily urbanized systems the options are significantly more limited . Urban river interventions have primarily been focused around the principles of restoration (aiming to return a river to a historic and desirable state), rehabilitation (returning it toward a historic state but without an intention to fully recreate the state), and enhancement (improving quality but without a past reference state in mind) .…”

Climate and rivers

“…Natural flow regimes remain an important concept in rivers research and applications and were of great interest to Geoff Petts (e.g., Boitsidis, Gurnell, Scott, Petts, & Armitage, ; Yin, Petts, & Yang, ; Yin, Yang, & Petts, ) as they provide a point of reference for understanding the structure and function of a riverine ecosystem and setting ecologically sustainable flows in highly managed river systems (Wood & Petts, ). Because the river regime paradigm postulates that riparian and aquatic species are dictated by the pattern of temporal variation in river flows (Lytle & Poff, ), there has been much interest in establishing the nature of flow regimes for ungauged basins.…”

From Research to Application: Management Implications from Studies of Urban River Channel Adjustment

“…A decision support system was proposed (Davenport et al. 2004) to assess scenarios of channel management in relation to habitat quality and rehabilitation potential (Boitsidis et al. 2006).…”

“…Tang et al (2005) Simple decision trees and scenario-modelling tools allow newly surveyed urban stretches to be classified and some simple scenarios of channel management change to be assessed in order to prioritise management options for stretches of urban river across urban catchments. Boitsidis et al (2006) Conclusion Source Creek, California, 1983-1993(Trimble 1997. Additionally, problems can arise during events, as in North Sydney, when the recurrence interval of a storm greatly exceeded the design capacity of stormwater systems (Riley et al 1986).…”

“…The Urban River Survey, developed from the River Habitat Survey in the UK, illustrates how consequences of changed engineering and Management of urban river channel adjustment 317 of scenarios of vegetation and water quality management can be explored (Davenport et al 2004). A decision support system was proposed (Davenport et al 2004) to assess scenarios of channel management in relation to habitat quality and rehabilitation potential (Boitsidis et al 2006).…”