Tributary confluences and discontinuities in channel form and sediment texture: Rio Chama, NM

2014 ◽  
Vol 39 (14) ◽  
pp. 1927-1943 ◽  
Author(s):  
Benjamin J. Swanson ◽  
Grant Meyer
2020 ◽  
Author(s):  
Alice Hinzmann ◽  
◽  
Trent Foky ◽  
Chantal Iosso ◽  
April I. Phinney ◽  
...  
Keyword(s):  

2021 ◽  
Vol 11 (7) ◽  
pp. 3030
Author(s):  
Marcos A. Martínez-Segura ◽  
Carmelo Conesa-García ◽  
Pedro Pérez-Cutillas ◽  
Pedro Martínez-Pagán ◽  
Marco D. Vásconez-Maza

Differences in deposit geometry and texture with depth along ephemeral gravel-bed streams strongly reflect fluctuations in bedload which are due to environmental changes at the basin scale and to morphological channel adjustments. This study combines electrical resistivity tomography (ERT) with datasets from borehole logs to analyse the internal geometry of channel cross-sections in a gravel-bed ephemeral stream (southeast Spain). The survey was performed through longitudinal and transverse profiles in the upper channel stretch, of 14 to 30 m in length and 3 to 6 m in depth, approximately. ERT values were correlated with data on sediment texture as grain size distribution, effective grain sizes, sorting, and particle shape (Zingg’s classification). The alluvial channel-fills showed the superposition of four layers with uneven thickness and arrangement: (1) the softer rocky substrate (<1000 Ω.m); (2) a thicker intermediate layer (1000 to 2000 Ω.m); and (3) an upper set composed of coarse gravel and supported matrix, ranging above 2000 Ω.m, and a narrow subsurface layer, which is the most resistive (>5000 Ω.m), corresponding to the most recent armoured deposits (gravel and pebbles). The ERT results coupled with borehole data allowed for determining the horizontal and vertical behaviour of the materials in a 3D model, facilitating the layer identification.


Author(s):  
Joanna Gmitrowicz-Iwan ◽  
Sławomir Ligęza ◽  
Jacek Pranagal ◽  
Halina Smal

2017 ◽  
Vol 82 (2) ◽  
pp. 397-413 ◽  
Author(s):  
B. Sunday Eiselt ◽  
J. Andrew Darling ◽  
Samuel Duwe ◽  
Mark Willis ◽  
Chester Walker ◽  
...  

Previous research on agriculture in the American Southwest focuses overwhelmingly on archaeological survey methods to discern surface agricultural features, which, in combination with climatological, geological, and geographical variables, are used to create models about agricultural productivity in the past. However, with few exceptions, the role of floodplain irrigation and floodwater farming in ancestral Pueblo agriculture is generally downplayed in scholarly discourse. Using a variety of methods, including Unmanned Aerial Vehicles (UAV), satellite imagery, pedestrian survey, and supervised classification of remotely sensed imagery, we examine this issue through a consideration of how ancestral Ohkay Owingeh (Tewa) people solved the challenges of arid land farming in the lower Rio Chama watershed of New Mexico during the Classic period (A.D. 1350–1598). Based on acreage estimates, our results indicate that runoff and rainwater fields in terrace environments would have been insufficient to supply the nutritional needs of an ancestral Tewa population exceeding 10,000 individuals. Based on these observations, we present a case for the substantial role of subsistence agriculture in the floodplain of the Rio Chama and its associated tributaries.


2005 ◽  
Vol 98 (1) ◽  
pp. 96-109 ◽  
Author(s):  
Daphne van der Wal ◽  
Peter M.J. Herman ◽  
Annette Wielemaker-van den Dool

Author(s):  
Carl Legleiter

The Snake River is a central component of Grand Teton National Park, and this dynamic fluvial system plays a key role in shaping the landscape and creating diverse aquatic and terrestrial habitat. The river’s complexity and propensity for change make effective characterization of this resource difficult, however, and conventional, ground-based methods are simply inadequate. Remote sensing provides an appealing alternative approach that could facilitate resource management while providing novel insight on the factors controlling channel form and behavior. In this study, we evaluate the potential to measure the morphology and dynamics of a large, complex river system such as the Snake using optical image data. Initially, we made use of existing, publicly available images and basic digital aerial photography acquired in August 2010. Analysis to date has focused on estimating flow depths from these data, and preliminary results indicate that remote bathymetric mapping is feasible but not highly accurate, with important constraints related to the limited radiometric resolution of these data sets. Additional, more sophisticated hyperspectral data are scheduled for collection in 2011, along with further field work.


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