scholarly journals Anisotropic scaling of remotely sensed drainage basins: the differential anisotropy scaling technique

2007 ◽  
Vol 14 (4) ◽  
pp. 337-350 ◽  
Author(s):  
A. Beaulieu ◽  
H. Gaonac'h ◽  
S. Lovejoy
Keyword(s):  
Loess Plateau ◽  
Drainage System ◽  
Wave Number ◽  
Drainage Basins ◽  
Scale Invariant ◽  
Scaling Technique ◽  
Higher Dimensional ◽  
Anisotropic Scaling ◽  
Rotation Parameters ◽  
Scaling Fields

Abstract. We investigate the statistical properties of dendritic drainage areas from diverse geological environments (Deception Canyon, Utah and the Loess Plateau, China) using narrow band visible ASTER satellite images. We show that from 240 m to 7680 m, the isotropic (angle integrated) energy spectra E(k) of all the fields closely follow a power law form: E(k)∝k−β where k is a wave number and β a scale invariant exponent. In spite of this good isotropic scaling, images with very similar β's and similar isotropic multifractal exponents have distinct textures; we suggest that the differences are primarily due to anisotropy, which is nevertheless scaling. We develop the new "Differential Anisotropy Scaling" technique to characterize this scale-by-scale (differential) anisotropy and we test it on simulated anisotropic scaling fields. The method gives useful characterizations of the scale by scale anisotropy irrespective of whether or not the analyzed field is scaling. When the anisotropy is not too strong, the parameters can be interpreted as scale invariant anisotropy exponents. Viewed as a method of estimating these exponents, it has the advantage of relying on two linear regressions rather than on complex higher dimensional nonlinear ones. When applied to dendritic drainage basins we find that they have distinct anisotropies characterized by differential anisotropy stretching and rotation parameters as well as by a distinct absolute anisotropy at the reference scale of 960 m. Our new method allows us to statistically distinguish, not only between two geologically different drainage basins (the China Loess Plateau and Utah Deception Canyon), but also between different regions of the same China drainage system.

THE MULTIFRACTAL SCALING OF CLOUD RADIANCES FROM 1M TO 1KM

Fractals ◽  
2002 ◽  
Vol 10 (03) ◽  
pp. 253-264 ◽  
Author(s):  
D. SACHS ◽  
S. LOVEJOY ◽  
D. SCHERTZER
Keyword(s):  
Entire Range ◽  
Atmospheric Dynamics ◽  
Wave Number ◽  
Two Dimensional ◽  
Scale Invariant ◽  
Spectral Exponent ◽  
Scaling Properties ◽  
Anisotropic Scaling ◽  
Multifractal Scaling ◽  
Cloud Thickness

The cloud radiances and atmospheric dynamics are strongly nonlinearly coupled, the observed scaling of the former from 1 km to planetary scales is prima facae evidence for scale invariant dynamics. In contrast, the scaling properties of radiances at scales <1 km have not been well studied (contradictory claims have been made) and if a characteristic vertical cloud thickness existed, it could break the scaling of the horizontal radiances. In order to settle this issue, we use ground-based photography to study the cloud radiance field through the range scales where breaks in scaling have been reported (30 m to 500 m). Over the entire range 1 m to 1 km the two-dimensional (2D) energy spectrum (E(k)) of 38 clouds was found to accurately follow the scaling form E(k)≈ k-β where k is a wave number and β is the spectral exponent. This indirectly shows that there is no characteristic vertical cloud thickness, and that "radiative smoothing" of cloud structures occurs at all scales. We also quantitatively characterize the type of (multifractal) scaling showing that the main difference between transmitted and reflected radiance fields is the (scale-by-scale) non-conservation parameter H. These findings lend support to the unified scaling model of the atmosphere which postulates a single anisotropic scaling regime from planetary down to dissipation scales.

In situ observation of three-dimensional anisotropies and scalings of space plasma turbulence at kinetic scales

2021 ◽  
Author(s):  
Tieyan Wang ◽  
Jiansen He ◽  
Olga Alexandrova ◽  
Malcolm Dunlop ◽  
Denise Perrone
Keyword(s):  
Three Dimensional ◽  
Wave Model ◽  
Structure Functions ◽  
Alfven Wave ◽  
Wave Number ◽  
Order Structure ◽  
In Situ Observation ◽  
Scale Invariant ◽  
Anisotropic Scaling ◽  
Background Magnetic Field

&lt;p&gt;The energy distribution at wave number space is known to be anisotropic in space plasmas. At kinetic scales, the standard Kinetic Alfven Wave model predicts anisotropy scaling of k&lt;sub&gt;par&lt;/sub&gt; &amp;#8733; k&lt;sub&gt;perp&lt;/sub&gt;&lt;sup&gt;(1/3)&lt;/sup&gt;, whereas the latest models considering the intermittency, or tearing instabilities, predict scalings such as k&lt;sub&gt;par&lt;/sub&gt; &amp;#8733; k&lt;sub&gt;perp&lt;/sub&gt;&lt;sup&gt;(2/3)&lt;/sup&gt; and k&lt;sub&gt;par&lt;/sub&gt; &amp;#8733; k&lt;sub&gt;perp&lt;/sub&gt;&lt;sup&gt;(3/3)&lt;/sup&gt;. Recent numerical simulations also payed considerable attention to this issue. Based on a unified analysis of five-point structure functions of the turbulence in three kinetic simulations, Cerri et al. 2019 obtained a converging result of l&lt;sub&gt;par&lt;/sub&gt; &amp;#8733; l&lt;sub&gt;perp&lt;/sub&gt;&lt;sup&gt;(3/3)&lt;/sup&gt;. To enrich our knowledge of the anisotropic scaling relation from an observational point of view, we conducted a statistical survey for the turbulence measured by MMS in the magnetosheath. For the 349 intervals with burst mode data, abundant evidence of 3D anisotropy at the sub-proton scale (1-100 km) is revealed by five-point second order structure functions. In particular, the eddies are mostly elongated along background magnetic field &lt;strong&gt;B&lt;sub&gt;0&lt;/sub&gt;&lt;/strong&gt; and shortened in the two perpendicular directions. The ratio between eddies&amp;#8217; parallel and perpendicular lengths features a trend of rise then fall toward small scales, whereas the anisotropy in the perpendicular plane appears scale invariant. Moreover, over 30% of the events exhibit scaling relations close to l&lt;sub&gt;par&lt;/sub&gt; &amp;#8733; l&lt;sub&gt;perp&lt;/sub&gt;&lt;sup&gt;(2/3)&lt;/sup&gt;. In order to explain such signature, additional factors such as intermittency caused by different coherent structures may be required in addition to the critical balance premise.&lt;/p&gt;

scholarly journals Evaluation of the drainage system of Zagros Basin (Greater Zab River, northern Iraq) and insights into tectonic geomorphology

2020 ◽  
Vol 13 (22) ◽  
Author(s):  
Ziyad Elias ◽  
Varoujan K. Sissakian ◽  
Nadhir Al-Ansari
Keyword(s):  
Drainage System ◽  
Tectonic Activity ◽  
Mature Stage ◽  
Tectonic Geomorphology ◽  
Drainage Basins ◽  
Main Trunk ◽  
Northern Iraq ◽  
Clastic Rocks ◽  
North Iraq ◽  
Anomaly Index

AbstractGeomorphological evaluation was carried out for three drainage basins named Hareer, Dwaine, and Hijran, which are tributaries of the Greater Zab River in the northern part of Erbil Governorate, the Iraqi Kurdistan Region, north Iraq. The exposed rocks in the three basins are mainly clastic rocks (sandstone, claystone, and conglomerate, with subordinate gypsum and limestone beds). However, in the uppermost parts of the basins, thick and massive carbonate rocks are exposed. Tectonically, the three basins are located in the Low Folded and High Folded Zones, which belong to the Zagros Fold–Thrust Belt. The main aim of the current study is to deduce the tectonic activity of the area occupied by the studied three basins. We have used and interpreted Radar Topography Mission (SRTM) data to perform the geomorphological evaluation. Different geomorphological indices and forms were used to deduce the tectonic activity of the area occupied by the three basins. Accordingly, seven orders of streams were identified in the three basins. The number of the streams with low order (i.e., 1) joining with higher order (i.e., 6 and 7) is considerably higher in the three basins. The Hat values of the three basins are 12,971, 10,479, and 7014 in Hareer, Dwaine, and Hijran basins, respectively. The values of hierarchical anomaly index (Δa) of the three basins are 1.87, 1.35, and 2.37 in Hareer, Hijran, and Dwaine basins, respectively. It was observed that the shape of Hareer and Shakrook anticlines has a significant impact on the main trunk of the channel. Therefore, when an anticline and syncline are close to each other (due to thrust faulting), then the hierarchical anomaly increases because the river trunk receives a lot of first-order streams, e.g., in Dwaine and Hijran basins. The lateral growth in the eastern part of Safin anticline had caused increasing of the Δa. The increased hierarchical anomaly index is attributed to the existence of faults and lineaments, which represent weakness zones. The hypsometric curves of the three basins have a typical shape of old stage with rejuvenation in their central and terminal portions which is changed into mature stage, most probably due to the local uplift which is caused by normal, thrust, and strike–slip (oblique) faults which exist in the study area and the near surroundings. The Bs and Hat values in Hareer, Dwaine, and Hijran basins indicate that the basins exhibit low, medium, and high tectonic activity, respectively.

scholarly journals Mass balance of the Lambert Glacier–Amery Ice Shelf system, East Antarctica: a comparison of computed balance fluxes and measured fluxes

2000 ◽  
Vol 46 (155) ◽  
pp. 561-570 ◽  
Author(s):  
Helen A. Fricker ◽  
Roland C. Warner ◽  
Ian Allison
Keyword(s):  
Mass Balance ◽  
Drainage System ◽  
Radar Altimeter ◽  
Drainage Basins ◽  
Ice Shelf ◽  
Amery Ice Shelf ◽  
Ice Sheet Mass Balance ◽  
Lambert Glacier ◽  
Lambert Glacier Basin

AbstractWe combine European Remote-sensing Satellite (ERS-1) radar altimeter surface elevations (Fricker and others, 2000) with six different accumulation distributions to compute balance fluxes for the Lambert Glacier–Amery Ice Shelf drainage system. These interpolated balance fluxes are compared with fluxes derived from in situ measurements of ice thickness and velocity at 73 stations of the Lambert Glacier basin traverse and at 11 stations further downstream, to assess the system’s state of balance. For the upstream line we obtain a range of imbalance estimates, from −23.8% to +19.9% of the observed flux, reflecting the sensitivity to the accumulation distributions. For some of the accumulation distributions the imbalance estimates vary significantly between different parts of the line. Imbalance estimates for the downstream line range from −17.7% to +70.2%, with four of the estimates exceeding +30%, again reflecting the sensitivity of the result to input accumulation, and strongly suggesting that the mass balance of the region between the two lines is positive. Our results confirm the importance of accurate estimates of accumulation in ice-sheet mass-balance studies. Furthermore, they suggest that it is not possible to accurately determine the state of balance of large Antarctic drainage basins on the basis of currently available accumulation distributions.

scholarly journals The biochronology and palaeobiogeography of Baru (Crocodylia: Mekosuchinae) based on new specimens from the Northern Territory and Queensland, Australia

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3458 ◽  
Author(s):  
Adam M. Yates
Keyword(s):  
Middle Miocene ◽  
New Records ◽  
Drainage System ◽  
Northern Territory ◽  
Valid Species ◽  
Late Oligocene ◽  
Drainage Basins ◽  
Local Fauna ◽  
The North ◽  
North Western

New records of the Oligo–Miocene mekosuchine crocodylian, Baru, from Queensland and the Northern Territory are described. Baru wickeni and Baru darrowi are accepted as valid species in the genus and their diagnoses are revised. Both species are present in Queensland and the Northern Territory but are restricted in time, with B. wickeni known from the late Oligocene and B. darrowi from the middle Miocene. The broad geographic distributions and restricted time spans of these species indicate that this genus is useful for biochronology. The record of B. wickeni from the Pwerte Marnte Marnte Local Fauna in the Northern Territory establishes that the species inhabited the north-western margin of the Lake Eyre Basin (LEB) drainage system. More southerly Oligo–Miocene sites in the LEB contain only one crocodylian species, Australosuchus clarkae. The Pwerte Marnte Marnte occurrence of B. wickeni indicates that the separation of Baru and Australosuchus did not correspond with the boundaries of drainage basins and that palaeolatitude was a more likely segregating factor.

Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, U.S.A.

1992 ◽  
Vol 38 (128) ◽  
pp. 51-64 ◽  
Author(s):  
Andrew G. Fountain
Keyword(s):  
Flow System ◽  
Water Discharge ◽  
Drainage System ◽  
Base Flow ◽  
Main Stream ◽  
Drainage Basins ◽  
Glacier Surface ◽  
One Dimensional ◽  
Flow Through ◽  
Artificial Tracers

AbstractThe subglacial drainage system of South Cascade Glacier is inferred by examining how discharges of water, solutes and artificial tracers in streams draining the glacier respond to meltwater and precipitation on the glacier surface. Results indicate that the glacier is divided into three (two large and one small) drainage basins, each drained by a single stream. The positions of drainage divides on the glacier surface do not always lie directly over those at the base of the glacier. Comparisons of water discharge and cation load in each of the two main streams indicate that subglacial hydraulic processes differ between drainage basins. One stream drains from a conduit that is isolated in its lower reach from the surrounding subglacial region and receives water routed englacially from the surface. The upper reach of the conduit also receives water routed englacially from the surface as well as from a distributed subglacial flow system. The other main stream drains from a conduit coupled to a debris layer beneath the glacier. Observations of the layer in natural ice tunnels indicate that the water may flow within a thin layer of debris. A one-dimensional model of flow through the debris layer can explain both the base-flow and diurnal variations of the second main stream.

scholarly journals Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, U.S.A.

1992 ◽  
Vol 38 (128) ◽  
pp. 51-64 ◽  
Author(s):  
Andrew G. Fountain
Keyword(s):  
Flow System ◽  
Water Discharge ◽  
Drainage System ◽  
Base Flow ◽  
Main Stream ◽  
Drainage Basins ◽  
Glacier Surface ◽  
One Dimensional ◽  
Flow Through ◽  
Artificial Tracers

Abstract The subglacial drainage system of South Cascade Glacier is inferred by examining how discharges of water, solutes and artificial tracers in streams draining the glacier respond to meltwater and precipitation on the glacier surface. Results indicate that the glacier is divided into three (two large and one small) drainage basins, each drained by a single stream. The positions of drainage divides on the glacier surface do not always lie directly over those at the base of the glacier. Comparisons of water discharge and cation load in each of the two main streams indicate that subglacial hydraulic processes differ between drainage basins. One stream drains from a conduit that is isolated in its lower reach from the surrounding subglacial region and receives water routed englacially from the surface. The upper reach of the conduit also receives water routed englacially from the surface as well as from a distributed subglacial flow system. The other main stream drains from a conduit coupled to a debris layer beneath the glacier. Observations of the layer in natural ice tunnels indicate that the water may flow within a thin layer of debris. A one-dimensional model of flow through the debris layer can explain both the base-flow and diurnal variations of the second main stream.

scholarly journals GIS-based Assessment of Morphological and Hydrological Parameters of Ribeira dos Socorridos and Ribeira do Vigario Basins, Madeira Island, Portugal

2021 ◽  
Vol 16 (2) ◽  
pp. 408-426
Author(s):  
Sergio Lousada ◽  
Rui Alexandre Castanho
Keyword(s):  
Sediment Transport ◽  
Drainage System ◽  
Drainage Basins ◽  
Hydrographic Basin ◽  
Madeira Island ◽  
Digital Terrain ◽  
Terrain Models ◽  
System Components ◽  
Hydraulic Infrastructure

The main objective is to identify hydraulic and hydrologic features of drainage basins of Ribeira dos Socorridos, and Ribeira do Vigário located in Madeira Island, (Câmara de Lobos).So, the research analyzed, theoretically, the sediment transport in the above-mentioned cases, and consequently, possible measures for torrential correction were studied. Thereby, hydrographic, geological, and hydrological features of this Archipelago were analyzed in the first phase. Thus, a geographic framing of drainage basins was made - using digital terrain models and deep characterization of the understudy drainage basins. In this regard, it was possible to obtain data regarding the geometric, relief, and drainage system components, using the Geographic Information Systems (GIS).In fact, the use of GIS makes it possible to characterize all descriptive indices/parameters of a hydrographic basin. These indices/parameters linked to the region's climate explain the need for human intervention to construct river hydraulic infrastructure and implement mitigation measures.Moreover, torrential correction techniques were presented to anticipate and mitigate this typology of events. Contextually, this study provides us several goals to consider in the future, including the most relevant actions and guidelines to enhance the characterization of drainage basins and clarify the characterization and accounting of sediment transport.

scholarly journals The biochronology and palaeobiogeography of Baru (Crocodilia: Mekosuchinae) based on new specimens from the Northern Territory and Queensland, Australia

2017 ◽  
Author(s):  
Adam M Yates
Keyword(s):  
Middle Miocene ◽  
New Records ◽  
Drainage System ◽  
Northern Territory ◽  
Valid Species ◽  
Late Oligocene ◽  
Drainage Basins ◽  
Local Fauna ◽  
The North ◽  
North Western

New records of the Oligo-Miocene mekosuchine crocodilian, Baru, from Queensland and the Northern Territory are described. B. wickeni and B. darrowi are accepted as valid species in the genus and their diagnoses are revised. Both species are present in Queensland and the Northern Territory but are restricted in time, with B. wickeni known from the late Oligocene and B. darrowi from the middle Miocene. The broad geographic distributions and restricted time spans of these species indicate that this genus is useful for biochronology. The record of B. wickeni from the Pwerte Marnte Marnte Local Fauna in the Northern Territory establishes that the species inhabited the north-western margin of the Lake Eyre Basin drainage system. More southerly Oligo-Miocene sites in the Lake Eyre Basin contain only one crocodilian species, Australosuchus clarkae. The Pwerte Marnte Marnte occurrence of B. wickeni indicates that the separation of Baru and Australosuchus did not correspond with the boundaries of drainage basins and that palaeolatitude was a more likely segregating factor.

Sign in / Sign up

Export Citation Format

Share Document