Need of higher-level snow-survey courses in the Colorado River drainage-area of western Colorado

1939 ◽  
Vol 20 (1) ◽  
pp. 69
Author(s):  
F. C. Merriell ◽  
M. C. Hinderlider
Keyword(s):  
Colorado River ◽  
Drainage Area ◽  
River Drainage ◽  
Western Colorado ◽  
Survey Courses

scholarly journals Gis Approach Of Inundation Analysis In The Dongjiang(East River) Drainage Area

2012 ◽  
Vol 12 ◽  
pp. 1063-1070 ◽  
Author(s):  
Huaixiang Liu ◽  
Yongjun Lu ◽  
Zhaoyin Wang
Keyword(s):  
Drainage Area ◽  
River Drainage ◽  
East River

Postglacial Palynology and Archaeology in the Naknek River Drainage Area, Alaska

1963 ◽  
Vol 29 (1) ◽  
pp. 74-81 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Snow Accumulation ◽  
Drainage Area ◽  
Alaska Peninsula ◽  
River Drainage ◽  
Pollen Diagrams ◽  
Heavy Snow

AbstractSamples were collected from four excavations and three muskegs for palynological examination in connection with a study of human prehistory in the Naknek drainage area, upper Alaska Peninsula. The purpose was to reconstruct the sequence of environments dating back to the earliest recognizable cultural phase, close to 4000 B.P. Pollen diagrams for muskeg show birch and alder as the principal arboreal types. Increasing percentages of alder occur during a late interval of hypsithermal time dating about 5500 B.P. Birch thereafter gained in proportion and between approximately 5000 and 2500 B.P. achieved maxima. Subsequently percentages of birch declined. Pollen spectra disclose that migration of spruce from the interior into this area took place within recent centuries. A climate cooler and drier than at present is interpreted from the diagrams to have been in effect during the earliest cultural phase and probably lasted until about 2500 B.P. Later, climate became slowly warmer and increasingly more humid. Temperature, however, was at first lower than at present and, coupled with greater precipitation, presumably caused heavy snow accumulation in the Aleutian Range which resulted in glacial advances during recent centuries.

Divide mobility controls knickpoint migration on the Roan Plateau

2020 ◽  
Author(s):  
Wolfgang Schwanghart ◽  
Dirk Scherler
Keyword(s):  
Colorado River ◽  
Drainage Area ◽  
Lagrangian Model ◽  
Drainage Network ◽  
Migration Rates ◽  
Tectonic History ◽  
Area Loss ◽  
Temporal Aspects ◽  
History Of ◽  
River Profiles

<p>Knickpoints in longitudinal river profiles provide proxies for the climatic and tectonic history of active mountains. The analysis of river profiles commonly relies on the assumption that drainage network configurations are stable. Here we show that this assumption must made cautiously if changes in contributing area are fast relative to knickpoint migration rates. We study the Parachute Creek basin in the Roan Plateau, Colorado, United States. Low spatial variations in climate and erosional efficiency permit us to reveal and quantify drainage-area loss that occurred in one of the subbasins where observed knickpoint locations are farther upstream than predicted by a model that takes present-day drainage areas into account. We developed a Lagrangian model of knickpoint migration which enables us to study the kinematic links between drainage area loss and knickpoint migration and that provides us with constraints on the temporal aspects of area loss. Modelled onset and amount of area loss are consistent with cliff retreat rates along the margin of the Roan Plateau inferred from the incisional history of the upper Colorado River.</p>

scholarly journals Topographic Map Analysis of the North Platte River-South Platte River Drainage Divide Area, Western Larimer County, Colorado, USA Eric Clausen

2021 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Eric Clausen
Keyword(s):  
Colorado River ◽  
The United States ◽  
River Valley ◽  
Topographic Map ◽  
Platte River ◽  
River Drainage ◽  
South Platte River ◽  
The North ◽  
Cache La Poudre River ◽  
South Platte

The United States Supreme Court settled legal disputes concerning four different Larimer County (Colorado) locations where water is moved by gravity across the high elevation North Platte-South Platte River drainage divide, which begins as a triple drainage divide with the Colorado River at Thunder Mountain (on the east-west continental divide and near Colorado River headwaters) and proceeds in roughly a north and northeast direction across deep mountain passes and other low points (divide crossings) first as the Michigan River (in the North Platte watershed)-Cache la Poudre River (in the South Platte watershed) drainage divide and then as the Laramie River (in the North Platte watershed)-Cache la Poudre River drainage divide. The mountain passes and nearby valley and drainage route orientations and other unusual erosional features can be explained if enormous and prolonged volumes of south-oriented water moved along today’s north-oriented North Platte and Laramie River alignments into what must have been a rising mountain region to reach south-oriented Colorado River headwaters. Mountain uplift in time forced a flow reversal in the Laramie River valley while flow continued in a south direction along the North Platte River alignment only to be forced to flow around the Medicine Bow Mountains south end and then to flow northward in the Laramie River valley and later to be captured by headward erosion of the east-oriented Cache la Poudre River-Joe Wright Creek valley (aided by a steeper gradient and less resistant bedrock). Continued uplift next reversed flow on the North Platte River alignment to create drainage routes seen today. While explaining Larimer County North Platte-South Platte drainage divide area topographic map drainage system and erosional landform evidence this interpretation requires a completely different Cenozoic history than the geologic history geologists usually describe.

scholarly journals Use of HAND terrain descriptor for estimating flood-prone areas in river basins

2021 ◽  
Vol 56 (3) ◽  
pp. 501-516
Author(s):  
Ana Alice Rodrigues Dantas ◽  
Adriano Rolim Paz
Keyword(s):  
River Basin ◽  
Flood Hazard ◽  
Mitigation Strategies ◽  
Drainage Area ◽  
Hazard Mapping ◽  
Morphological Pattern ◽  
River Drainage ◽  
Variable Approach ◽  
The Impact ◽  
Flooded Areas

The flood hazard mapping in a river basin is crucial for flooding risk management, mitigation strategies, and flood forecasting and warning systems, among other benefits. One approach for this mapping is based on the HAND (Height Above Nearest Drainage) terrain descriptor, directly derived from the Digital Elevation Model (DEM), in which each pixel represents the elevation difference of this point in relation to the river drainage network to which it is connected. Considering the Mamanguape river basin (3,522.7 km²; state of Paraíba, Brazil) as the study location, the present research applied this method and verified it as for five aspects: consideration of a spatially variable minimum drainage area for denoting the river drainage initiation; the impact of considering a depressionless DEM; evaluation of hydrostatic condition; effect of incorporating an existing river vector network; and comparative analysis of basin morphology regarding longitudinal river profiles. According to the results, adopting a uniform minimum drainage area for the river network initiation is a simplification that should be avoided, using a spatially variable approach, which influences the amount and spatial distribution of flooded areas. Additionally, considering the depressionless DEM leads to higher values of HAND and to a smaller flooded area (difference ranging between 3% and 99%), when compared with the use of DEM with depression, despite 3.1% of the pixels representing depressions. The use of the depressionless DEM is recommended, whereas the DEM pre-processing by incorporating a vector network (stream burning) generates dubious results regarding the relation between HAND and the morphological pattern presented in the DEM. Moreover, the estimation of flooded areas based on HAND does not guarantee the hydrostatic condition, but this disagreement comprises a negligible area for practical purposes.

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