Réponse des bassins versants à l'activité tectonique : l'exemple de la terminaison orientale de la chaîne pyrénéenne. Approche morphotectonique / Drainage basins response to active tectonics: example from Eastern Pyrenees. Morphotectonic approach

2000 ◽  
Vol 6 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Jean-Michel Carozza ◽  
Bernard Delcaillau
Keyword(s):  
Active Tectonics ◽  
Drainage Basins ◽  
Eastern Pyrenees

Topographic disequilibrium, landscape dynamics and active tectonics: an example from the Bhutan Himalayas

2021 ◽  
Author(s):  
Martine Simoes ◽  
Timothée Sassolas-Serrayet ◽  
Rodolphe Cattin ◽  
Romain Le Roux-Mallouf ◽  
Matthieu Ferry ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Spatial Scales ◽  
Active Tectonics ◽  
Recent Change ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Drainage Basins ◽  
Equilibrium Conditions ◽  
Longitudinal Band ◽  
Active Tectonic

<p>The quantification of active tectonics from geomorphological and morphometric approaches most often implies that erosion and tectonics have reached a certain balance. Such equilibrium conditions may however be seldom found in nature, in particular because drainage basins may be quite dynamic even though tectonic and climatic conditions remain constant. Here, we document this drainage dynamics from the particular case example of the Bhutan Himalayas. Evidence for out-of-equilibrium morphologies have for long been noticed in Bhutan, from major (> 1 km high) river knickpoints and from the existence of high-altitude low-relief regions within the mountain hinterland. These peculiar morphologies were generally interpreted as representing a recent change in climatic and/or tectonic conditions. To further characterize these morphologies and their dynamics, and from there discuss their origin and meaning, we perform field observations and a detailed quantitative morphometric analysis using Chi plots and Gilbert metrics of drainages over various spatial scales, from major Himalayan rivers to local streams draining the low-relief regions. We first find that the river network is highly dynamic and unstable. Our results emphasize that the morphology of Bhutan does not result from a general wave of incision propagating upstream, as expected from most previous interpretations. Also, the specific spatial organization in which all major knickpoints and low-relief regions are located along a longitudinal band in the Bhutan hinterland, whatever their spatial scale and the dimensions of the associated drainage basins, calls for a common local supporting mechanism most probably related to active tectonic uplift. Our results emphasize the need for a precise documentation of landscape dynamics and disequilibrium over various spatial scales as a first-order step in morpho-tectonic studies of active landscapes.</p>

scholarly journals Geomorphological Analysis of Xilokastro Fault, Central Gulf of Corinth, Greece

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 516
Author(s):  
Sotirios Verroios ◽  
Vasiliki Zygouri
Keyword(s):  
Geographical Information Systems ◽  
Active Tectonics ◽  
Normal Fault ◽  
Fault Scarp ◽  
Geographical Information ◽  
Drainage Basins ◽  
Gulf Of Corinth ◽  
Morphometric Index ◽  
Fault Trace ◽  
High Degree

The Gulf of Corinth is a rapidly opening area with high seismicity associated with extensive building collapses, destruction of cities, and even the deaths of inhabitants. Rapid residential development, especially in the southern part of the Gulf of Corinth, and the construction of crucial technical infrastructures necessitate understanding the activity across crustal-scale faults that host devastating earthquakes. The evolution of landforms affected by fault action is a dominant issue in geological science. In the present study, was selected the 20 km long Xilokastro pure normal fault. In this fault, we apply eight geomorphological indices in footwall catchments that drain perpendicular to its trace. In total, more than 5000 measurements were made in 102 catchments. The determination of geomorphological indices requires the construction of morphological profiles either perpendicular to the faults or perpendicular to the main tributaries of the drainage basins under consideration through the use of the geographical information systems (ArcGIS platform). Τhe application of these indices along catchments draining the Xilokastro fault scarp show high active tectonics. Its high activity is evidenced by the high values of the length-slope index near the fault trace, the low values of the width to height ratio index, the strong asymmetry of the drainage basins, especially in the overlapping zones between its segments, and the elongated shape of the drainage basins. This study supports the idea that the application of a single morphometric index is unable to reflect the distribution of active tectonics across faults, which makes inevitable the systematic comparison of a series of tectonic morphometric indices from which a new combined index emerges (Iat). The Iat classifies the Xilokastro fault in the high degree of activity at a rate of 75% of its length.

Quantifying active tectonics in the case of dynamic and instable landscape: an example from the Bhutan Himalayas

2020 ◽  
Author(s):  
Timothee Sassolas-Serrayet ◽  
Martine Simoes ◽  
Rodolphe Cattin ◽  
Romain Le Roux-Mallouf ◽  
Matthieu Ferry ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Active Tectonics ◽  
Recent Change ◽  
Climatic Conditions ◽  
Mountain Range ◽  
Theoretical Studies ◽  
Drainage Basins ◽  
Equilibrium Conditions ◽  
Regional Tectonic ◽  
Climatic Evolution

<p>The quantification of active tectonics from geomorphological and morphometric approaches most often implies that erosion and tectonics have reached a certain balance. Such equilibrium conditions may however be seldom found in nature, as questioned and documented by recent theoretical studies, in particular because drainage basins may be quite dynamic even though tectonic and climatic conditions remain constant.</p><p>Here, we document this drainage dynamics from the particular case example of the Bhutan Himalayas. Evidence for out-of-equilibrium landscape features have for long been noticed in Bhutan, from major (> 1 km high) river knickpoints and from the existence of high-altitude low-relief surfaces within the mountain range. These geomorphologies were generally interpreted in the literature as representing a recent change in climatic and/or tectonic conditions, either related to the uplift of the Shillong Plateau (climate/tectonic change) or to the initiation of uplift over a blind ramp within the mountain range (tectonic change).</p><p>To further characterize these geomorphologies and discuss their origin and meaning in terms of regional tectonic or climatic evolution, we perform a detailed quantitative geomorphometric analysis using c plots and basin averaged aggressivity metrics, at various spatial scales, from large Himalayan rivers to local streams draining the low-relief surfaces. Our results first emphasize that the morphology of Bhutan does not result from a general wave of incision propagating upstream, as expected from most previous interpretations. Rather, we find that the river network is highly unstable and dynamic, in particular for the rivers draining the low-relief surfaces, hampering a proper quantification of tectonics from classical approaches based on denudation or incision rates. Finally, we discuss the origin and meaning of the observed dynamics, and from there draw some useful guidelines for future morpho-tectonic studies of active landscapes.</p>

scholarly journals Evaluation of Active Tectonics in Northwest of Saveh

2021 ◽  
Author(s):  
Bahar Rezaeinahal ◽  
Mohsen PourKermani ◽  
Mehdy Zare ◽  
Maryam Dehbozorgi ◽  
Reza Nozaem
Keyword(s):  
Drainage Basin ◽  
Active Tectonics ◽  
Tectonic Activity ◽  
Drainage Basins ◽  
The North ◽  
Level Of Activity ◽  
Digital Elevation ◽  
Arc Gis ◽  
Elevation Model ◽  
Gis Software

Abstract The northwest zone of Saveh city is located in the fault zone of the Indes, Koosh e Nosrat, Avaj and Aipak. Indes faults, Cox Nosrat, Avaj and Aipak are considered as the major faults of central Iran, which are also active in the Quaternary and the last movements of these faults are attributed to the present covenant, therefore, the estimation of morphometri in order to identify the effect of active tectonics on the tectonic evolution of drainage basins seems necessary. Therefore, in this study, six important morphotectonic indexes were analyzed; longitudinal gradient of the river, asymmetry of drainage basin, hypometric integral, Drainage basin shape,the ratio of the width of the floor to the height of the valley and forehead of the mountain is discussed.to create the basins on the studied area, Arc Hydro software (Arc GIS software) has been used based on data from a digital elevation model, Then, 6 morphotectonic indexes have been compiled and classified on each of the basins.Finally, according to which the region has been classified into 4 categories of high, medium and low tectonic activity the, Active Tectonic Index (IAT) has been calculated.According to the IAT index, 5% of the study area shows very high tectonic activity, 25% of the studied area has high tectonic activity, the average tectonic activity has 65% and about 5% of the tectonic activity are low. In this study, the highest level of tectonic activity is in the north-eastern part of the region. In most of the sectors, the level of activity is high and moderate, which is related to the activity of Koshk E Nosrat, Aipak, Avaj faults.

scholarly journals Topographic disequilibrium, landscape dynamics and active tectonics: an example from the Bhutan Himalayas

2020 ◽  
Author(s):  
Martine Simoes ◽  
Timothée Sassolas-Serrayet ◽  
Rodolphe Cattin ◽  
Romain Le Roux-Mallouf ◽  
Matthieu Ferry ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Spatial Scales ◽  
Active Tectonics ◽  
Recent Change ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Drainage Basins ◽  
Equilibrium Conditions ◽  
Longitudinal Band ◽  
Active Tectonic

Abstract. The quantification of active tectonics from geomorphological and morphometric approaches most often implies that erosion and tectonics have reached a certain balance. Such equilibrium conditions may however be seldom found in nature, as questioned and documented by recent theoretical studies, in particular because drainage basins may be quite dynamic even though tectonic and climatic conditions remain constant. Here, we document this drainage dynamics from the particular case example of the Bhutan Himalayas. Evidence for out-of-equilibrium morphologies have for long been noticed in Bhutan, from major (> 1 km high) river knickpoints and from the existence of high-altitude low-relief regions within the mountain hinterland. These peculiar morphologies were generally interpreted as representing a recent change in climatic and/or tectonic conditions. To further characterize these morphologies and their dynamics, and from there discuss their origin and meaning, we perform field observations and a detailed quantitative morphometric analysis using Chi plots and Gilbert metrics of drainages over various spatial scales, from major Himalayan rivers to local streams draining the low-relief regions. We first find that the river network is highly dynamic and unstable. Our results emphasize that the morphology of Bhutan does not result from a general wave of incision propagating upstream, as expected from most previous interpretations. Also, the specific spatial organization in which all major knickpoints and low-relief regions are located along a longitudinal band in the Bhutan hinterland, whatever their spatial scale and the dimensions of the associated drainage basins, calls for a common local supporting mechanism most probably related to active tectonic uplift. From there, we discuss previous interpretations of the observed landscape in Bhutan. Our results emphasize the need for a precise documentation of landscape dynamics and disequilibrium over various spatial scales as a first-order step in morpho-tectonic studies of active landscapes.

scholarly journals Topographic disequilibrium, landscape dynamics and active tectonics: an example from the Bhutan Himalaya

2021 ◽  
Vol 9 (4) ◽  
pp. 895-921
Author(s):  
Martine Simoes ◽  
Timothée Sassolas-Serrayet ◽  
Rodolphe Cattin ◽  
Romain Le Roux-Mallouf ◽  
Matthieu Ferry ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Spatial Scales ◽  
Active Tectonics ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Drainage Basins ◽  
Equilibrium Conditions ◽  
Longitudinal Band ◽  
Active Tectonic ◽  
Landscape Response

Abstract. The quantification of active tectonics from geomorphological and morphometric approaches commonly implies that erosion and tectonics have reached a certain balance. Such equilibrium conditions are however rare in nature, as questioned and documented by recent theoretical studies indicating that drainage basins may be perpetually re-arranging even though tectonic and climatic conditions remain constant. Here, we document these drainage dynamics in the Bhutan Himalaya, where evidence for out-of-equilibrium morphologies have for long been noticed, from major (> 1 km high) river knickpoints and from high-altitude low-relief regions in the mountain hinterland. To further characterize these morphologies and their dynamics, we perform field observations and a detailed quantitative morphometric analysis using χ plots and Gilbert metrics of drainages over various spatial scales, from major Himalayan rivers to their tributaries draining the low-relief regions. We first find that the river network is highly dynamic and unstable, with much evidence of divide migration and river captures. The landscape response to these dynamics is relatively rapid. Our results do not support the idea of a general wave of incision propagating upstream, as expected from most previous interpretations. Also, the specific spatial organization in which all major knickpoints and low-relief regions are located along a longitudinal band in the Bhutan hinterland, whatever their spatial scale and the dimensions of the associated drainage basins, calls for a common local supporting mechanism most probably related to active tectonic uplift. From there, we discuss possible interpretations of the observed landscape in Bhutan. Our results emphasize the need for a precise documentation of landscape dynamics and disequilibrium over various spatial scales as a first step in morpho-tectonic studies of active landscapes.

DRAINAGE BASIN AS A COMPLEX SOCIO-NATURAL HIERARCHICAL SYSTEM

2020 ◽  
Vol 42 (3) ◽  
pp. 293-303
Author(s):  
VALERIY BONDAREV
Keyword(s):  
Drainage Basin ◽  
Temporal Analysis ◽  
Large River ◽  
Hierarchical Level ◽  
Effective Management ◽  
Drainage Basins ◽  
Time Intervals ◽  
Natural Systems ◽  
Spatial And Temporal Analysis ◽  
Entire Complex

The theoretical and methodological basis of the systems hierarchical spatial and temporal analysis of a drainage basin, which addresses the problems of effective management in socio-natural systems of different ranks, is considered. It is proposed to distinguish 9 orders of forms that are relevant to the analysis of drainage basins, where the first level is represented by individual aggregates and particles, and the last - by basins of large and the largest rivers. As part of the allocation of geological, historical and modern time intervals, the specificity of the implementation of processes in basins of different scales from changing states, through functioning to evolution is demonstrated. The interrelation of conditions and factors that determine the processes occurring within the drainage basins is revealed. It is shown that a specific combination of conditions and factors that determine processes in the drainage basin is associated with the hierarchy of the objects under consideration, i.e. the choice of a spatial-temporal hierarchical level is crucial for the organization of study within drainage basins. At one hierarchical level, some phenomenon can be considered as a factor, and at another - as a condition. For example, tectonic processes can be considered as an active factor in the evolution of large river basins in the geological perspective, but for small drainage basin, this is already a conservative background condition. It is shown that at the historical time the anthropogenic factor often comes to the fore, with the appearance of which in the functioning of the drainage basin, there is a need to take into account the entire complex of socio-environmental problems that can affect the sustainable state of various territories, especially in the field of water and land use. Hierarchical levels of managing subjects are identified, which are primarily responsible for effective management at the appropriate hierarchical level of the organization of the socio-natural system within the catchment area, starting from an individual to humankind as a whole.

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