Spatial organization of process domains in headwater drainage basins of a glaciated foothills region with complex longitudinal profiles

Abstract

[1] Lithologic transitions and glaciations create complex longitudinal profiles that control contemporary erosion and deposition processes. In areas with these characteristics, traditional morphometric approaches for predicting process domains, such as area-slope plots, can be augmented by considering other predictors measured from high resolution lidar-derived digital elevation models (DEMs). Ordinal logistic regression was used to model the distribution of hillslope, swale, colluvial channel, and fluvial channel domains, as identified during field surveys. The study area was a glaciated region of the Rocky Mountain foothills with a complex lithostructural setting. Relationships between domains and a suite of geographic information system-derived descriptors were explored. Predictors included profile anomalies measured at the reach and basin scale using a normalized stream length-gradient (SL/k) index. Drainage area was the dominant factor controlling domains. A model with area as the only predictor was 82% accurate. Reach slope relations were not consistent. A model that also included lithology and basin-scale SL/k index variation was 87% accurate. Domain transitions had larger area thresholds in basins with resistant conglomerate versus sandstone or shale formations and where SL/k index was more variable along a profile. In a restricted model of hillslope, swale, and colluvial channel domains, profile curvature measured over 100 m was also related to domain occurrence. A model for regional-scale mapping applications with six additional predictors was 95% accurate. The results showed that ordinal logistic regression can be used to predict and map process domains in regions with complex physiography using descriptors measured from highresolution DEMs.

Spatial controls on groundwater response dynamics in a snowmelt-dominated montane catchment

“…where p is the probability of a response being in a given or higher level category. An extensive review of OLR can be found in McCullagh (1980). An example of OLR applied in a watershed context can be found in McCleary et al 2011.…”

Effects of glacial retreat on proglacial streams and riparian zones in the Coast and North Cascade Mountains

“…The calculation of SL / k in this study was a modification by McCleary et al . () of the equation used by Pérez‐Peña et al . (): where h s is the river head elevation (m), h r is the reach mid‐point elevation (m), and x r is the distance from the stream source to the middle of the reach (m).…”

Assessing channel geometry in response to land use disturbance in a low‐relief, glacially conditioned setting

“…Fluvial systems in deglaciated basins are often still responding to inherited topography and sediments at post‐glacial timescales, creating knick‐points along channel profiles due to differential erosion. These channels tend not to conform to the typical ‘graded’ concave‐up profile (Collins & Montgomery, 2011; McCleary et al, 2011; Phillips & Desloges, 2014; Thayer et al, 2016). Rivers carving through diverse deglaciated surfaces may experience a disequilibrium between stream energy and bed clast size leading to downstream variations in morphology (Desloges et al, 2020; Phillips & Desloges, 2014, 2015).…”