Implications of a specific storm event for understanding adjustment of urban dryland channels

Abstract

Dryland stream channels adjusting to urbanization are difficult to study without some indication of the extent and frequency of specific hydrological events. Investigations of changing channels in Fountain Hills, Arizona, urbanized since 1970, can benefit from knowledge gained from a storm event of over 55 mm rainfall in January 2016, equivalent to 25% of annual precipitation. Morphological flow capacity was reached with this rainfall event, which had a recurrence interval of 1.4 years for a 24-h period and 3.6 years for a 3-day duration. This storm is typical of events that occur in less than half the years of record, occurring between zero and three times each year in the 26 years of record available. Analysis of this event assists in the calibration of measured cross-sections, providing a useful benchmark for space-time substitution in dryland environments where flow is ephemeral. Correspondence of the recurrence interval of the storm to somewhat frequent 'bankfull' channelforming events, despite signs of flashiness, suggests a tight coupling between rainfall and runoff and a tempered response to urbanization effects in Fountain Hillsachievable through decades of proactive planning and adaptive wash management in a master-planned community.

Introduction to the Women in Geomorphology special issue

“…Field (26) Atkins et al, 2023;Bernatek-Jakiel & Nadal-Romero, 2023;Biausque et al, 2022;Brooks et al, 2022;Bywater-Reyes et al, 2022;Chin, 2022;Gervasi et al, 2021;Glover et al, 2022; Goodman et al, in press;Guiney & Lininger, 2022; Gurnell et al, 2022;Harvey et al, 2022;Hinshaw et al, 2022;Hooke, 2022;Konlechner & Hilton, 2022;Kooijman et al, 2022;Lane et al, 2022;Lefebvre et al, 2022;Marchetti et al, 2022;McKeon et al, 2022;Mol & Grenfell, 2022;Mossa & Chen, 2022;Opalka et al, 2022;Patton et al, 2022;Quock et al, 2022;Regalla et al, 2022;Reitman et al, 2022;Sampietro-Vattuone et al, 2021;Schoch-Baumann et al, 2022;Souza Fonseca et al, 2022;Spiske et al, 2022;Thompson et al, 2022;Uphues et al, 2022;Valentine et al, 2022;Van Soest et al, 2022;Wohl, 2022;Zhang et al, 2022 (Continues)…”

“…Many of the major research directions in contemporary geomorphology are reflected in this collection of papers. With respect to fluvial environments, including alluvial fans, individual papers examine use of images to detect sediment motion during physical experiments (Vah et al, 2022); comparison of grain‐size distributions from field measurements and remotely acquired images (Marchetti et al, 2022); physical experiments on bedload saltation under differing conditions (Demiral et al, 2022); numerical modelling of critical shear stress for grain entrainment based on imagery of bed‐rock channels (Hodge & Buechel, 2022); biogeomorphology (Bywater‐Reyes et al, 2022; Gurnell et al, 2022); channel morphology and classification (Lane et al, 2022), hydromorphology of ephemeral streams (Rabanaque et al, 2022) and interpretation of geomorphic unit assemblages (Fryirs & Brierley, 2022); flood effectiveness (Gervasi et al, 2021); channel evolution, terraces and sediment sources (Guyez et al, 2022) and the influence of sediment supply on gravel‐bed river widening (Rachelly et al, 2022); hydrological variation and meander morphodynamics (Hooke, 2022); the dynamics of wood in river corridors (Guiney & Lininger, 2022; Gurnell et al, 2022; Wohl, 2022) and numerical modelling of wood‐related processes (Friedrich et al, 2022); numerical model validation (Negreiros et al, 2022) and numerical modelling of groundwater‐driven network evolution (Cullen et al, 2022); base‐level controls and landscape evolution (Fadul et al, 2022); long‐term dryland channel response to urbanization (Chin, 2022); watershed restoration and management, including human alterations of process and form (Atkins et al, 2023; Davis et al, 2021; Goodman et al, in press; Gurnell et al, 2022; Hinshaw et al, 2022; Mossa & Chen, 2022; Sampietro‐Vattuone et al, 2021; Valentine et al, 2022); and alluvial fan dynamics (Opalka et al, 2022; Quock et al, 2022; Regalla et al, 2022; Schoch‐Baumann et al, 2022). Papers addressing process and form in coastal environments include examinations of dune morphodynamics and evolution (Hovenga et al,...…”

Professor Kenneth John Gregory (1938–2020): The career, contributions and legacy of an eminent geographer and fluvial geomorphologist

“…The results show a greater ecosystem engineering effect of more complex, natural, wood jams compared to the simple structures that tend to be more common in river restoration, with implications for both physical and ecological recovery post intervention. Chin (2022) builds on a sequence of papers jointly authored with Ken Gregory concerning the impacts of urban development on the dryland fluvial system at Fountain Hills, Arizona, USA. Here, she investigates the role of a 'bankfull' flow event in January 2016 in causing channel change at surveyed cross sections.…”

“…Chin (2022) builds on a sequence of papers jointly authored with Ken Gregory concerning the impacts of urban development on the dryland fluvial system at Fountain Hills, Arizona, USA. Here, she investigates the role of a ‘bankfull’ flow event in January 2016 in causing channel change at surveyed cross sections.…”