scholarly journals Traveltime and reaeration of selected streams in the North Platte and Yampa River basins, Colorado

1989 ◽  
Keyword(s):  
River Basins ◽  
The North ◽  
Yampa River

scholarly journals Multiple controls on sediment grain properties of Peruvian coastal river basins

2017 ◽  
Author(s):  
Camille Litty ◽  
Fritz Schlunegger ◽  
Willem Viveen
Keyword(s):  
Grain Size ◽  
Drainage Basin ◽  
River Basins ◽  
Humid Climate ◽  
Sediment Properties ◽  
Peruvian Andes ◽  
Southern Group ◽  
Gravel Beds ◽  
The North ◽  
Grain Properties

Abstract. Twenty-one coastal rivers located on the western Peruvian margin were analyzed to determine the relationships between fluvial and environmental processes and sediment grain properties such as grain size, roundness and sphericity. Modern gravel beds were sampled along a north-south transect on the western side of the Peruvian Andes, and at each site the long a-axis and the intermediate b-axis of about 500 pebbles were measured. Morphometric properties such as river gradient, catchment size and discharge of each drainage basin were determined and compared against measured grain properties. Grain size data show a constant value of the D50 percentile all along the coast, but an increase in the D84 and D96 values and an increase in the ratio of the intermediate and the long axis from south to north. Our results then yield better-sorted and less spherical material in the south when compared to the north. No correlations were found between the grain size and the morphometric properties of the river basins when considering the data together. Grouping the results in a northern and southern group shows better-sorted sediments and lower D84 and D96 values for the southern group of basins. Within the two groups, correlations were found between the grain size distributions and morphometric basins properties. Our data indicates that fluvial transport is the dominant process controlling the erosion, transport and deposition of sediment in the southern basins while we propose a geomorphic control on the grain size properties in the northern basins. Sediment properties in the northern and southern basins could not be linked to differences in tectonic controls. On the other hand, the north-south trend in the grain size and in the b/a ratio seems controlled by a shift towards a more humid climate and towards a stronger El Nino impact in northern Peru. But, generally speaking, the resulting trends and differences in sediment properties seem controlled by differences in the complex geomorphic setting along the arc and forearc regions.

scholarly journals Tree-Ring Width and Carbon Isotope Chronologies Track Temperature, Humidity, and Baseflow in the Tianshan Mountains, Central Asia

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1308
Author(s):  
Yuting Fan ◽  
Huaming Shang ◽  
Ye Wu ◽  
Qian Li
Keyword(s):  
Stable Isotopes ◽  
Tree Ring ◽  
Ring Width ◽  
River Basins ◽  
Tianshan Mountains ◽  
Limiting Factor ◽  
Source Water ◽  
Tree Ring Width ◽  
The North ◽  
Temperature And Precipitation

Concerns have been raised about the negative impacts of global warming on the hydrological climate change and ecosystems of Asia. Research on the high-altitude mountainous regions of Asia with relatively short meteorological and hydrological records relies on paleoclimate proxy data with long time scales. The stable isotopes of tree-rings are insightful agents that provide information on pre-instrumental climatic and hydrological fluctuations, yet the variability of these data from different regions along the Tianshan Mountains has not been fully explored. Herein, we related climate data with tree-ring width (TRW) chronologies and δ13C (stable carbon isotope discrimination) series to discern if the Picea schrenkiana in the Ili and Manas River Basins are sensitive to climatic factors and baseflow (BF). The results show significant correlations between temperature and TRW chronologies, temperature and δ13C, relative humidity and TRW chronologies, and BF and δ13C. Temperature, particularly the mean late summer to early winter temperature, is a pronounced limiting factor for the tree-ring and the δ13C series in the Manas River Basin, located in the middle of the North Tianshan Mountains. Meanwhile, mean early spring to early autumn temperature is a limiting factor for that of the Ili River Basin, located on the southern slope of the North Tianshan Mountains. We conclude that different seasonal variations in temperature and precipitation of the two river basins exerted significant control on tree growth dynamics. Tree-ring width and tree-ring δ13C differ in their sensitivity to climate and hydrological parameters to which tree-ring δ13C is more sensitive. δ13C showed significant lag with precipitation, and the lag correlation showed that BF, temperature, and precipitation were the most affected factors that are often associated with source water environments. δ13C series correlated positively to winter precipitation, suggesting baseflow was controlling the length of the growing season. The tree-ring δ13C provided information that coincided with TRW chronologies, and supplied some indications that were different from TRW chronologies. The carbon stable isotopes of tree-rings have proven to be powerful evidence of climatic signals and source water variations.

VII.—Submerged River-valleys.

1913 ◽  
Vol 10 (6) ◽  
pp. 262-263
Author(s):  
R. M. Deeley
Keyword(s):  
North Atlantic ◽  
River Basins ◽  
The North ◽  
Continental Shelves ◽  
The North Atlantic ◽  
River Valleys

Bathymetric surveys have revealed much that is very interesting concerning the ocean floors, not only as regards the deeper portions, but also as concerns the continental shelves. Hull has constructed charts of the North Atlantic and shown that many of the shallower areas are of such a form as to suggest that they were originally portions of existing river-basins, and that the submerged valleys may be traced along the sea bottoms to depths of more than a thousand feet round the present continents. Similar submerged troughs have also been noted along the margin of the Asiatic continent. Two such well-marked channels occur in the ocean at the mouths of the Indus and Ganges. Indeed, the phenomenon would seem to be one common to all the continental shelves.

scholarly journals Mean and extreme precipitation over European river basins better simulated in a 25 km AGCM

2018 ◽  
Vol 22 (7) ◽  
pp. 3933-3950 ◽  
Author(s):  
Reinhard Schiemann ◽  
Pier Luigi Vidale ◽  
Len C. Shaffrey ◽  
Stephanie J. Johnson ◽  
Malcolm J. Roberts ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Models ◽  
Global Climate ◽  
River Basins ◽  
Global Climate Models ◽  
Sensitivity Experiment ◽  
Scale Parameters ◽  
The North ◽  
Resolution Model ◽  
High Resolution Model

Abstract. Limited spatial resolution is one of the factors that may hamper applications of global climate models (GCMs), in particular over Europe with its complex coastline and orography. In this study, the representation of European mean and extreme precipitation is evaluated in simulations with an atmospheric GCM (AGCM) at different resolutions between about 135 and 25 km grid spacing in the mid-latitudes. The continent-wide root-mean-square error in mean precipitation in the 25 km model is about 25  % smaller than in the 135 km model in winter. Clear improvements are also seen in autumn and spring, whereas the model's sensitivity to resolution is very small in summer. Extreme precipitation is evaluated by estimating generalised extreme value distributions (GEVs) of daily precipitation aggregated over river basins whose surface area is greater than 50 000 km2. GEV location and scale parameters are measures of the typical magnitude and of the interannual variability of extremes, respectively. Median model biases in both these parameters are around 10 % in summer and around 20 % in the other seasons. For some river basins, however, these biases can be much larger and take values between 50 % and 100 %. Extreme precipitation is better simulated in the 25 km model, especially during autumn when the median GEV parameter biases are more than halved, and in the North European Plains, from the Loire in the west to the Vistula in the east. A sensitivity experiment is conducted showing that these resolution sensitivities in both mean and extreme precipitation are in many areas primarily due to the increase in resolution of the model orography. The findings of this study illustrate the improved capability of a global high-resolution model in simulating European mean and extreme precipitation.

scholarly journals Hydrological Variability and Changes in the Arctic Circumpolar Tundra and Its Largest Pan-Arctic river Basins from 2002 to 2016

2017 ◽  
Author(s):  
Kazuyoshi Suzuki ◽  
Koji Matsuo ◽  
Dai Yamazaki ◽  
Kazuhito Ichii ◽  
Yoshihiro Iijima ◽  
...  
Keyword(s):  
River Basin ◽  
River Basins ◽  
The Arctic ◽  
Lena River ◽  
North American Continent ◽  
The North ◽  
Hydrological Variability ◽  
Basin Scale ◽  
Northern Regions ◽  
Terrestrial Water

The Arctic freshwater budget is critical for understanding the climate in the northern regions. However, the hydrology of the Arctic circumpolar tundra region (ACTR) and the largest pan-Arctic rivers are still not well understood. In the present paper, we analyze the spatiotemporal variations in terrestrial water storage (TWS) of the ACTR, including three of its largest pan-Arctic river basins (Lena, Mackenzie, Yukon), using monthly Gravity Recovery and Climate Experiment (GRACE) data from 2002 to 2016. Together with global land reanalysis, river runoff, and inundation extent area (IEA) data, we identify declining TWS trends throughout the ACTR that we attribute largely to increasing evapotranspiration driven by increasing summer air temperatures. In terms of regional changes, large and significant negative trends in TWS are observed mainly over the North American continent. At basin scale, we show that, in the Lena River basin, the autumnal TWS signal persists until the winter of the following year, while in the Mackenzie River basin, the TWS levels in the autumn and winter has no significant impact on the following year. As global warming is expected to be particularly significant in the northern regions, our results are important for understanding future TWS trends, with possible further decline.

scholarly journals Global hydrobelts: improved reporting scale for water-related issues?

2012 ◽  
Vol 9 (8) ◽  
pp. 9119-9162
Author(s):  
M. Meybeck ◽  
M. Kummu ◽  
H. H. Dürr
Keyword(s):  
Population Density ◽  
Global Analysis ◽  
River Basins ◽  
Global Scale ◽  
General Symmetry ◽  
Latitude Belt ◽  
Average Temperature ◽  
The North ◽  
Natural Boundaries ◽  
North And South

Abstract. Questions related to water such as its availability, water needs or stress, or management, are mapped at various resolutions at the global scale. They are reported at many scales, mostly along political or continental boundaries. As such, they ignore the fundamental heterogeneity of the hydroclimate and the natural boundaries of the river basins. Here, we describe the continental landmasses according to eight global-scale hydrobelts strictly limited by river basins, defined at a 30′ (0.5°) resolution. The belts were defined and delineated, based primarily on the annual average temperature (T) and runoff (q), to maximise interbelt differences and minimise intrabelt variability. The belts were further divided into 29 hydroregions based on continental limits. This new global puzzle defines homogeneous and near-contiguous entities with similar hydrological and thermal regimes, glacial and postglacial basin histories, endorheism distribution and sensitivity to climate variations. The Mid-Latitude, Dry and Subtropical belts have northern and southern analogues and a general symmetry can be observed for T and q between them. The Boreal and Equatorial belts are unique. The hydroregions (median size 4.7 Mkm2) contrast strongly, with the average q ranging between 6 and 1393 mm yr−1 and the average T between −9.7 and +26.3 °C. Unlike the hydroclimate, the population density between the North and South belts and between the continents varies greatly, resulting in pronounced differences between the belts with analogues in both hemispheres. The population density ranges from 0.7 to 0.8 p km−2 for the North American Boreal and some Australian hydroregions to 280 p km−2 for the Asian part of the Northern Mid-Latitude belt. The combination of population densities and hydroclimate features results in very specific expressions of water-related characteristics in each of the 29 hydroregions. Our initial tests suggest that hydrobelt and hydroregion divisions are often more appropriate for water-relative global analysis and reporting than conventional continental or political divisions.

scholarly journals MORPHOMETRIC CHARACTERISTICS OF RIVER BASINS OF THE NORTH-WESTERN SLOPE OF THE CRIMEAN MOUNTAINS (ZAPADNYY BULGANAK, ALMA, KACHA, BELBEK, CHERNAYA RIVER BASINS)

2021 ◽  
Vol 7 (73) (3) ◽  
pp. 267-278
Author(s):  
V. A. Tabunshchik
Keyword(s):  
River Basin ◽  
Calculated Data ◽  
River Basins ◽  
Shuttle Radar Topography Mission ◽  
Western Slope ◽  
Morphometric Characteristics ◽  
Crimean Peninsula ◽  
Crimean Mountains ◽  
The North ◽  
North Western

Zapadnyy Bulganak, Alma, Kacha, Belbek, Chernaya rivers belong to the rivers of the north-western slope of the Crimean Mountains. The sources of the rivers are located on the north-western slopes of the Main Ridge of the Crimean Mountains, then the rivers flow from east to west almost parallel to each other. Up to about the middle of their course, they have a character typical of mountain streams (except for the Zapadnyy Bulganak River). The river valleys in the upper reaches are V-shaped, narrow, their slopes are dissected by numerous gullies and tributaries. There are almost no tributaries in the middle and lower reaches. In the low-water period (low-water period), drying is observed in the estuaries of rivers. The catchment basins have an elongated shape along the river, expanded in the upper part, which is the main feeding area.The considered river basins, although they have, in comparison with the rest, the river basins of the Crimean Peninsula, are better studied in general, but they are not sufficiently studied. In the article author deals with the main morphometric characteristics of river basins of the North-Western slope of the Crimean Mountains. Using Shuttle Radar Topography Mission (SRTM) and ArcGIS software for river basins Zapadnyy Bulganak, Alma, Kacha, Belbek, Chernaya are analyzed the following morphometric parameters – area of the basin, the symmetry of the basin, length of the basin, width of the basin, configuration and irregularity of the outline of river basin, the highest and lowest elevation within the basin, the average altitude of the river basin, the average slope of the river basin. Some of the morphometric indicators are calculated for the first time. For morphometric indicators that were partially previously calculated using topographic maps and published in literature, a comparison and analysis with the calculated data is provided. It is established that the using of SRTM and the ArcGIS software allows for fairly accurate measurements of morphometric indicators of the river basin.

scholarly journals Economic, Environmental, and Land-Use Planning Utilizing the Empiric Model

1972 ◽  
Vol 1 (01) ◽  
pp. 192-200
Author(s):  
John W. Green ◽  
Ronald J. Glass
Keyword(s):  
Land Use ◽  
New England ◽  
North Atlantic ◽  
Land Use Planning ◽  
River Basins ◽  
Comprehensive Planning ◽  
The North ◽  
The North Atlantic ◽  
Joint Plan ◽  
Comprehensive Studies

The New England River Basins Commission (NERBC) has placed first priority on implementation of its responsibilities for comprehensive planning. Its enabling legislation resulted in a resolution specifying that NERBC participate vigorously in the prosecution of a framework study for the region (The North Atlantic Study), and shall initiate promptly comprehensive studies of major subregions as elements of the comprehensive coordinated joint plan. The Southeastern New England (SENE) is the first such major subregion to be studied.

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