Ecological design of multifunctional open channels for flood control and conservation planning

Abstract

Historically, typical open channel flood control systems have been designed for a single function: to enhance human safety by preventing flood damage to human landscape infrastructure. This single-purpose objective is increasingly an untenable practice. Because river systems in human-dominated landscapes often play important conservation roles for biota (e.g. endangered species), it is important that flood control planning be integrated with conservation planning principles and goals. 'Regenerative design' seeks to intentionally enable an environment to continually replace ecosystem structures through natural processes, which is a design paradigm that can achieve multiple socio-ecological goals. In river systems, flood control channels need to be multifunctional where feasible, and be designed to accommodate vegetation as well as geomorphic processes, such as meander dynamics. A heuristic analysis of three areas from California's existing but antiquated Sacramento River flood control system (including two bypass channels) was used to illustrate these concepts with a series of expansion scenarios for each channel. Minimum dynamic area was gamed (by expanding the average channel width and adjusting Manning's n roughness coefficients) in the main channel (river miles 84-144) to more than double the existing conveyance, which resulted in nearly quadrupling the roughness coefficient allowing for increased riparian vegetation. The bypass channel widths and roughness coefficients were also gamed to achieve 100-and (alternatively) 200-yr flood protection while providing increased potential for riparian vegetation and flood refugia for terrestrial animal species. These scenarios conceptually illustrate that expanding the flood channel footprint while increasing design roughness coefficients can effectively meet multifunctional objectives. RESEARCH HIGHLIGHTS• We propose 6 principles for a new design paradigm for flood control open channels.• These principles are applied to simulate retrofits to an antiquated flood system.• Co-equal goals of increased flood protection and wildlife habitat were demonstrated.• Habitat of endangered species in river systems could be increased by this approach.• Human communities would benefit from greater levels of flood protection.

A riparian conservation network for ecological resilience

“…In addition, factors other than species conservation are already driving riparian protection, such as ecosystem services. One clear example of agency coordination to manage riparian areas for multiple benefits is the Yolo Basin near Sacramento, California (Opperman et al, 2009); other such solution have been recently proposed (Greco and Larsen 2014). This area supports multiple, typically competing interests by managing rice farming and wildlife conservation, while allowing flood water storage during critical times with the added benefit of migratory bird habitat.…”

Spatiotemporal Patterns of the Use of Urban Green Spaces and External Factors Contributing to Their Use in Central Beijing

“…Several studies have demonstrated that urban green spaces offer benefits relating to individuals’ health and wellbeing such as relaxation [1], recreational opportunities [2,3], and a connection to nature [1]. Other studies have also confirmed that urban green spaces are key components of ecosystem services that evidently contribute to the mitigation of high temperatures [4,5,6,7], abatement of air pollution [8], noise reduction [5], the provision of wildlife habitats [9,10,11,12], and the prevention of floods and soil erosion [13]. Furthermore, studies have revealed important benefits associated with cultural services provided by urban green spaces such as landscape aesthetics, outdoor recreation, and spiritual and cultural values [14,15].…”

Perceptions of spatial patterns of visitors in urban green spaces for the sustainability of smart city

“…A number of studies have found that urban green areas, such as rest, 1 leisure, 2,3 and a connection to nature, 1 bring health advantages and well-being. Other studies have already shown that urban greenery is a key component of environmental services that contributes directly to the extenuation of extreme temperatures, 4,5 air pollution mitigation, 6 noise reduction, wildlife habitat, 7 and flood and soil erosion prevention. Surveys have shown that cultural amenities provided by green areas have also been of considerable benefit, such as protect the surface, outdoor recreation and moral and cultural values.…”