@article{ClubbBookhagenRheinwalt2019,
  author    = {Clubb, Fiona J. and Bookhagen, Bodo and Rheinwalt, Aljoscha},
  title     = {Clustering river profiles to classify geomorphic domains},
  series = {Journal of geophysical research : Earth surface},
  volume    = {124},
  journal   = {Journal of geophysical research : Earth surface},
  number    = {6},
  publisher = {American Geophysical Union},
  address   = {Hoboken},
  issn      = {2169-9003},
  doi       = {10.1029/2019JF005025},
  pages     = {1417 -- 1439},
  year      = {2019},
  abstract  = {The structure and organization of river networks has been used for decades to investigate the influence of climate and tectonics on landscapes. The majority of these studies either analyze rivers in profile view by extracting channel steepness or calculate planform metrics such as drainage density. However, these techniques rely on the assumption of homogeneity: that intrinsic and external factors are spatially or temporally invariant over the measured profile. This assumption is violated for the majority of Earth's landscapes, where variations in uplift rate, rock strength, climate, and geomorphic process are almost ubiquitous. We propose a method for classifying river profiles to identify landscape regions with similar characteristics by adapting hierarchical clustering algorithms developed for time series data. We first test our clustering on two landscape evolution scenarios and find that we can successfully cluster regions with different erodibility and detect the transient response to sudden base level fall. We then test our method in two real landscapes: first in Bitterroot National Forest, Idaho, where we demonstrate that our method can detect transient incision waves and the topographic signature of fluvial and debris flow process regimes; and second, on Santa Cruz Island, California, where our technique identifies spatial patterns in lithology not detectable through normalized channel steepness analysis. By calculating channel steepness separately for each cluster, our method allows the extraction of more reliable steepness metrics than if calculated for the landscape as a whole. These examples demonstrate the method's ability to disentangle fluvial morphology in complex lithological and tectonic settings.},
  language  = {en}
}
@article{GrieveHalesParkeretal.2018,
  author    = {Grieve, Stuart W. D. and Hales, Tristram C. and Parker, Robert N. and Mudd, Simon M. and Clubb, Fiona J.},
  title     = {Controls on Zero-Order Basin Morphology},
  series = {Journal of geophysical research : Earth surface},
  volume    = {123},
  journal   = {Journal of geophysical research : Earth surface},
  number    = {12},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9003},
  doi       = {10.1029/2017JF004453},
  pages     = {3269 -- 3291},
  year      = {2018},
  abstract  = {Zero-order basins are common features of soil-mantled landscapes, defined as unchanneled basins at the head of a drainage network. Their geometry and volume control how quickly sediment may reaccumulate after landslide evacuation and, more broadly, zero order basins govern the movement of water and sediment from hillslopes to the fluvial network. They also deliver water and sediment to the uppermost portions of the fluvial network. Despite this role as the moderator between hillslope and fluvial processes, little analysis on their morphology has been conducted at the landscape scale. We present a method to identify zero-order basins in landscapes and subsequently quantify their geometric properties using elliptical Fourier analysis. We deploy this method across the Coweeta Hydrologic Laboratory, USA. Properties such as length, relief, width, and concavity follow distinct probability distributions, which may serve as a basis for testing predictions of future landscape evolution models. Surprisingly, in a landscape with an orographic precipitation gradient and large hillslope to channel relief, we observe no correlation between elevation or spatial location and basin geometry. However, we find that two physiographic units in Coweeta have distinct zero-order basin morphologies. These are the steep, thin soiled, high-elevation Nantahala Escarpment and the lower-gradient, lower-elevation, thick soiled remainder of the basin. Our results indicate that basin slope and area negatively covary, producing the distinct forms observed between the two physiographic units, which we suggest arise through competition between spatially variable soil creep and stochastic landsliding.},
  language  = {en}
}