Basin Shape Research Articles

Relative active tectonics evaluation using geomorphic and drainage indices, in Dadra and Nagar Haveli, western India

The present study area, Dadra and Nagar Haveli, contains several lineaments and traces of active faults. The various aspect of the geomorphic analysis, i.e., stream length (SL) gradient, hypsometric integral (HI), basin shape (BS), valley floor (VF), have been applied to evaluate the relative index of active tectonics (RIAT) of the Damanganga watershed. The high and low zones of tectonic activity have been identified based on the geomorphic analysis of the watershed. After evaluation of all indices, three classes, class II- high (1.3 ≤ RIAT < 1.5), class III- moderate (1.5 ≤ RIAT < 1.8), and class IV- low (1.8 ≤ RIAT), have been obtained to outline the degree/gradation of comparative tectonic activities in the study area. The appraised outcome of the RIAT dispersal is also well reinforced by the geomorphic evidence in the field. The collective outcomes of geomorphic evidence, such as stream deflection and analysis of lineament, deflection of streams, and geomorphic indices, conceal that the Damanganga watershed is affected by tectonic activity.

Effects of Climate, Basin Characteristics, and High‐Capacity Wells on Baseflow in the State of Wisconsin, United States

AbstractWhen it comes to water resources management, it is critical to understand the factors that affect baseflow processes. Declines in baseflow due to increased use of the groundwater from unconfined aquifers is well documented, but that is not the case for confined aquifers. Furthermore, since the groundwater basin size and shape can be different than the surface water basin, the use of the surface basin to determine well withdrawal rates can affect baseflow and be problematic. This study used the variables determined to be related to baseflow variability (precipitation, temperature, drainage class, available storage, land use, and slope) and the withdrawal rates of wells located within the study basins to create regression models for the state of Wisconsin, United States. We find that: (1) precipitation and temperature variable are significant in explaining the temporal variability of baseflow, whereas land cover variables are important when the temporal variability is not considered; (2) evaporation and soil drainage are important in basins over unconfined aquifers, whereas precipitation the most significant over confined aquifers; (3) whether to use surface water or groundwater divides to delineate basins matters in particular conditions, and (4) groundwater withdrawal rates do not significantly affect baseflow when using statistical analysis. Therefore, analyzing baseflow should be supplemented by a process‐based model for the effects of groundwater withdrawals.

Large-Gradient Interferometric Phase Unwrapping Over Coal Mining Areas Assisted by a 2-D Elliptical Gaussian Function

Phase unwrapping (PU) is a key step in InSAR surface monitoring, which is directly related to the accuracy of the LOS displacement observations. Underground coal mining generally results in large gradient displacements, producing dense and aliasing fringes in interferograms. In this case it is challenging to accurately unwrap interferometric phases using traditional methods. This letter proposes an iterative algorithm to unwrap interferometric phases over underground coal mining areas. Firstly, differential interferogram is unwrapped by the minimum cost flow (MCF) method to obtain unwrapped phases at the edge of the mining subsidence basin. Then, a 2D elliptical Gaussian function, which could approximately describe the spatial shape of mining subsidence basin, is used to iteratively reduce the phase gradients of interferograms, so that residual wrapped phases at more pixel in subsidence basin can be unwrapped. The presented method was tested over Datong coal mine, China, based on 16 TerraSAR-X acquisitions. The result suggests that the accuracy of time-series displacements along the line-of-sight direction solved from the unwrapped phases using the new PU method is 1.1cm, indicating an improvement of 73.2% compared with that of using the traditional MCF method.

Vortex profile analysis under different diffuser size for inlet channel of gravitational water vortex power plant

Hydropower is a renewable technology to store the amount of electricity which is the least expensive. Gravitational Water Vortex Power Plant is an ultra-low head micro hydropower system working ranging from 0.7 m to 2m without having the needs of a large reservoir and installation area. Several researches have been conducted on its basin configuration, orifice diameter, blade configuration, the geometry of the basin shape but not onto the addition of the diffuser at the inlet channel. The function of the diffuser is to direct the water into the basin allowing the water vortex to travel towards the tangential direction where this phenomenon will increase the rate of speed flow through the turbine. The simulation results showed that the addition of the diffuser has significantly increased the tangential velocity and the kinetic energy of the vortices. The increase in the velocity of the flow increased the height of the vortex which also led to the increase in the strength of the vortex and affects the vortex uniformity.

Deformation characterization of oil and gas pipeline by ACM technique based on SSA-BP neural network model

Accurate and quantitative characterization of deformation in oil and gas pipelines is essential. This paper proposed a novel ACM (alternating current magnetization) based technique to detect the deformation of oil and gas pipelines. Numerical simulations and experiments reveal the relationships between the deformation factors (height, length, tilt angle) and the detected waveform signals. Meanwhile, the peak value, integral area, first-order differential peak and valley value, peak and valley length of the waveform signals are selected as the features. In addition, a BP neural network model optimized by SSA (sparrow search algorithm) was introduced to identify the deformation of the pipelines. The results show that the waveform signals corresponding to the deformation due to external stress and corrosion are distributed in the mountain peak and basin shape, respectively. With features as input, the proposed SSA-BPalgorithm can efficiently characterize the deformation within the mean relative error of 10%.

Transposing flood risk from extreme rainfall events: A case study of Hurricane Harvey

AbstractHurricane Harvey produced unprecedented flooding that altered flood frequency statistics near Houston, Texas. While Harvey could have made landfall elsewhere along the Gulf coast, traditional flood frequency methodologies only consider the risk of Harvey in the region that it hit. This may be a shortcoming of flood frequency methodologies as the intensity of Harvey was greater due to climate change; therefore, Harvey may be more indicative of future hurricanes than other historical observations. To that end, this study investigates what effect Harvey would have had on flood frequency statistics if it had made landfall elsewhere. To do so, a Monte Carlo simulation was used to shift Harvey's rainfall within alternative landfall locations. This rainfall was then applied to synthetic unit hydrographs to estimate peak flows that were applied in Log Pearson III and Regional Flood Frequency Analyses. Log Pearson III analyses with simulated Harvey streamflows produced median 100‐year peak flows that were 17%–66% higher than analyses that only used historical records. A regional flood frequency analysis in the central coastal geomorphologic region of Texas showed that predictive equations, based upon basin area and shape factor, had an average increase of 30.2% in the 100‐year peak discharge.

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

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.

Numerical investigation of pavement responses under TSD and FWD loading

The Traffic Speed Deflectometer (TSD) overcomes the limitations of the Falling Weight Deflectometer (FWD) in terms of traffic interruption and testing inefficiency, thus has been used for network-level pavement structural evaluation. However, compared to FWD, which has accumulated plenty of data and comprehensive evaluation methods over decades, the applicability of TSD is yet to verify. It is imperative to compare pavement responses under TSD and FWD to validate the applicability and substitutability of TSD. Based on the difference between TSD and FWD in loading characteristics and asphalt concrete (AC) properties, six 3D-Move models were established successively to explore the influence of different testing factors on pavement responses. The simulation results show that under the same load magnitude, peak deflections and peak strains caused by TSD were always greater than that of FWD due to the lower equivalent load frequency of TSD. Compared to the peak deflection, the deflection basin shape of TSD was more sensitive to the dynamic effects and the viscoelasticity of the AC layer. Besides, AC viscoelasticity and damping caused the lag in TSD deflections and strains. In the layer modulus back-calculation from TSD deflections, the dual circular load and dynamic effect of TSD were crucial, but the AC viscoelasticity could be neglected. The use of FWD-based programs to back-calculate the layer modulus from the TSD deflection would result in a stiffer AC layer and a stiffer subgrade.

The Delta of Shatt Al-Arab River, Framework and Evolution

Shatt Al-Arab Delta was built at the northern end of the Arabian Gulf (AG) on the top of a longitudinal shallow marine basin shape. Today the hydrologic regime of Shatt Al-Arab River is suffering from many changes caused by anthropogenic activity impacts, led to a significant decrease in water feeding about 1000 m3/sec in 1990 into less than 50m3/sec in 2016. Many previous studies have been discussed as well as performing a marine geophysical surveys to assess the evolution of Shatt Al-Arab Delta during the history. Many phenomenon and progradational parts of the Delta: Prodelta, distributary channel, bay fill, and beach ridge have been identified from marine geophysical survey. The lower reflector is appear as irregular surface, which could indicate the presence of an ancient beach that appear as a terraces region due to fluctuation in the sea level. The second reflector appear as a layer have had variation depth, which may represent a beginning of the ancient delta creation after of the sea level stability (&lt; 5000 years ago). The top layers have been deposited, which represent the present day delta. This present result suggests that there are three phases of delta evolution during history, the first phase represents the beginning of the modern origin of this delta during 1000-2000 yr. ago when the Tigris and Euphrates Rivers are connected together, at that time the delta was not so large and have been formed by the excess sediment that coming from the marshes after the two Rivers dumping most of their sedimentary load there. The second phase represents the activation of this delta with stabilized coastline, especially after the manmade connection between Karun and Shatt Al-Arab Rivers, which occurred before thousand years ago. The third phase represents the last half of the previous century when several factors contributed on the evolution of Shatt Al-Arab delta, including hydrological, climatological and anthropogenic factors.

Rainfall and drainage basin shape strongly control temporal and spatial variation of dissolved organic matter in a tropical lake

Rainfall and drainage basin shape strongly control temporal and spatial variation of dissolved organic matter in a tropical lake

Morpho-tectonic Assessment of the Abu-Dabbab Area, Eastern Desert, Egypt: Insights from Remote Sensing and Geospatial Analysis

The Abu-Dabbab area, located in the central part of the Egyptian Eastern Desert, is an active seismic region where micro-earthquakes (≈ML &lt; 2.0) are recorded regularly. Earthquake epicenters are concentrated along an ENE–WSW trending pattern. In this study, we used morphological indexes, including the valley floor width-to-valley floor height ratio (Vf), mountain front sinuosity (Smf), the asymmetry factor index (Af), the drainage basin shape index (Bs), the stream length–gradient index (SL), hypsometric integral (Hi) water drainage systems, and a digital elevation model analysis, to identify the role of tectonics. These indexes were used to define the relative tectonic activity index (RTAI), which can be utilized to distinguish low (RTAI &lt; 1.26), moderate (RTAI = 1.26–1.73), and high (RTAI &gt; 1.73) tectonic activity signals all over the study area. Firstly, our results indicate low to medium tectonic activity and general anomaly patterns detected along the major tectonic zones of the study area. Secondly, based on most of the low to medium tectonic activity distributed in the study area and the detected anomalies, we discuss two potential drivers of the seismicity in the Abu-Dabbab area, which are fault-controlled and deep-rooted activities.

Understanding the role of lithium bonds in doped graphene nanoribbons as cathode hosts for Li‐S batteries: A first‐principles study

Using first-principles calculations, we investigate a family of doped graphene nanoribbons (GNRs) for their suitability as cathode hosts in lithium-sulfur batteries. We probe the role played by the lone pairs of the dopants in confining the lithium polysulfides (LiPS) to understand the mechanism of binding. Our results show that the Li bond between the polysulfides and the doped GNRs is analogous to a hydrogen bond and also dipole-dipole interactions play a key role in anchoring the polysulfides. A critical donor-Li-acceptor angle of 180° is found to be essential for proper adsorption of LiPS, highlighting the importance of the directionality of lone pairs. The charge lost by the sulfur atom of the polysulfide upon adsorption and shape of the lone pair basins and the value of Electron Localization Function (ELF) at the dopant position can provide a quick estimate of the strength of the bond. Significant contractions in the ELF profiles are also observed upon Li2S adsorption, further providing evidence for the hydrogen bond-like nature of the Li bond. Our results corroborate the fact that all acceptors capable of forming hydrogen bonds can be employed as suitable dopants for carbon-based cathode hosts in Li-S batteries.

Effects of different cooling conditions on friction stir processing of A356 alloy: Numerical modeling and experiment

In the present work, the effects of in-process cooling are investigated on the material flow, temperature distribution, axial force, wear resistance, and microstructural and mechanical properties of friction stir processed (FSPed) Al-Si aluminum alloy. The finite element method (FEM) was developed for modeling the process, based on the eulerian-lagrangian technique, and then verified by the experimental force and temperature histories. Next, the material flow and temperature distribution during the friction stir process (FSP) with in-process cooling under different conditions were considered. After that, the experimental investigations, including the optical microscopy, hardness, and wear tests, were conducted. Finally, the stir zone (SZ) shape obtained by experiments and simulation model were compared for the FSPed samples without cooling and with air cooling. The material flow achievements reveal that using a coolant affects the material flow in the pin-driven zone more significantly than in the shoulder-driven zone, leading the SZ to change from the basin shape into the V shape. The SZ shapes obtained from the experiments and the simulation model show a good agreement between the shapes of the samples FSPed without cooling and with air cooling. Moreover, experimental results showed that using in-process cooling reduces Si particles' size and thus significantly increases the hardness and wear resistance. The Si particles size is reduced from 10 μm in the base metal to 2.6 μm and 2 μm in the air-cooled and water-cooled samples. Consequently, the wear mass loss reduced almost 28% and 40%, and hardness increased almost 35% and 80% for the air-cooled and water-cooled samples compared to the processed samples without coolant.

Active Tectonics of Gülbahçe Fault Zone (GBFZ) by Using Geomorphic Indices, İzmir Province, Western Anatolia, Turkey

The Gülbahçe Fault Zone is a dextral strike-slip fault that extends for ~24 km on land and ~46 km under the sea, which consists of the significant southernmost active segments of İzmir Balıkesir Transfer Zone. In this study, the active tectonic behaviour of the Gulbahçe Fault Zone was evaluated by using of morphometric analysis of geomorphic indices. 30 sub-basins identified using ArcGIS ®10.5 (ESRI). All sub-basins were calculated by using mountain-front sinuosity (Smf), valley-floor width to valley height ratio (Vf), basin asymmetry factor (Af), basin shape indice (Bs), drainage density (Dd), and hypsometric integral (Hi) values. The obtained mean results of values are to define each sub-basin's relative tectonic activity (Iat). The Smf, Vf, Af, Bs, Dd, and Hi values range from 1.05 to 1.33; from 0.21 to 4.09; from 25 to 77; from 1.03 and 3.06; from 0.28 to 0.67, respectively. All the results were gathered under three classes, which sign high tectonics activity (Class 1), moderately active tectonic (Class 2), and low tectonics activity (Class 3). The results show that relative active tectonics indice value (Iat) was obtained between 1.33 and 2.33, indicating very high to moderately tectonic activity.

Analysis of Basin Morphologic Characteristics and Their Influence on the Water Yield of Mountain Watersheds Upstream of the Xiongan New Area, North China

In this study, based on the DEM, we extracted the drainage networks and watersheds of the Daqing River with ArcGIS, investigated the basin characteristics and the differences in their spatial distributions and analyzed the relations of the drainage density with some surface conditions and how the drainage density influenced the water yield. The results suggested a power function between the mainstream length and drainage area, showing that with the increase in basin area, the basins became longer. The result of the power function between the relief and drainage area with negative exponent values means the relief changed more slowly with increasing basin area. The values of the circularity ratio and elongation ratio indicate that the basin shape of the mountain watersheds in the Daqing River was narrow and predisposed to flooding during periods of heavy rainfall. The orders of the streams in the mountain watersheds ranged from five to seven. The average bifurcation ratio of those nine mountainous watersheds reveals the order of the u + 1 rivers in each basin of the Daqing River was on average 4 times larger than that of order u rivers. The drainage density (Dd) was high in the north and low in the south of the Daqing River. Rainfall was negatively correlated with drainage density, but the correlation between them was not significant at the 0.05 level. Drainages developed in places with poor vegetation cover. The drainages in the southwest, north and west developed considerably, while drainages in the east and southeast did not develop much. Yet, the available data showed the impact of the watershed area, elongation ratio and drainage density on the water yield was not significant. In contrast, there was a significant positive correlation between channel slope and the water yield modulus. The hypsometric integrals and the relation between drainage density and hypsometric integral suggest that the landform evolution of the mountain basins along the Daqing River were in the old stage with no further increase trend of drainage density in the future.

Patterns and Variation of Littoral Habitat Size Among Lakes

AbstractThe littoral zone varies in size among lakes from ∼3% to 100% of lake surface area. In this paper, we derive a simple theoretical scaling relationship that explains this variation, and test this theory using bathymetric data across the size spectra of freshwater lakes (surface area = 0.01–82,103 km2, maximum depth = 2–1,741 m). Littoral area primarily reflects the ratio of the maximum depth of photosynthesis to maximum lake depth. However, lakes that are similar in these characteristics can have different relative littoral areas because of variation in basin shape. Hypsometric (area‐elevation) models that describe these patterns for individual lakes can be generalized among lakes to accurately predict the relative size of littoral habitat when there is incomplete bathymetric information. Collectively, our results provide simple rules for understanding patterns of littoral habitat size at the regional and global scales.

Susceptibility assessment of “2020.3.30” Xichang post-fire debris flow using a machine learning method

In this study, a machine learning method, i.e., random forest (RF) model, was employed to assess post-fire debris flow (PFDF) susceptibility after the Xichang forest fire occurred on 30 March, 2020. First, we conducted a tracking survey in the rainy season, on-site tests, and remote sensing image interpretation and obtained 10 impacting factors, i.e., the basin area, relief ratio, basin shape coefficient, percentage of area with a slope greater than 50%, proportion of moderate or high severity burned areas, distribution of gravel in the basin, vegetation types and distribution in the basin, early cumulative erosion after fire, peak rainfall in a 1-h interval, and peak rainfall in a 24-h interval, after their correlation test to build a spatial database. Subsequently, a total of 181 PFDF events in the database were randomly divided into training (70%) and validation (30%) samples. Thereafter, the RF model was used to acquire the susceptibility of PFDF in the study area. Finally, receiver operating characteristic (ROC) curve, area under curve (AUC) value, sensitivity, specificity, and accuracy were utilized to validate the predictive performance of the model. Results show that the RF model has good predictive ability with AUC of 93.4%, sensitivity of 88.3%, specificity of 99.3%, and accuracy of 97.8%. This study provides a scientific basis for PFDF disaster prevention and risk management in Xichang City and its surrounding areas.

Original

Basin morphometry is a crucial method of analysis to understand the geology, lithological structure, infiltration rate of rainwater, runoff, eroded load carrying capacity and flooding potential of a drainage basin. The quantitative techniques applied for linear, aerial and relief aspects of the drainage basin elucidate the rate of erosion, the intensity of denudation and subsequently the potential of the Nandakini river basin to flooding. The morphometric analysis of the Nandakini river basin in the Garwhal Himalayan region of Uttarakhand reveals that the Rf value of the Nandakini river basin is 0.28, indicating an elongated basin shape leading to quick flooding and poor draining out of floodwaters. Similarly, an elevation difference between the highest and lowest elevation is 5380 metres aids quick runoff and deposition of eroded debris in the drainage channels, another cause of channel overflow. The Rh value is high (0.12), indicating a high channel gradient with intense erosional processes operating due to steep gradient and this has a considerable impact on the rate of erosive geomorphic processes operating. The higher elevation on the Eastern part of the basin due to the Vaikrita Thrust, the Munsiyari Thrust (ie. the southern tilting Main Central Thrust) and the Baijnath Klippe has resulted in metamorphism in Miocene and Pliocene explaining the low rate of infiltration and rapid runoff.

Using morphometric and geomorphic indices to assess Western São Francisco Craton neotectonic traces

Recently, geomorphometric properties of river networks and catchments have been described and applied as an efficient tool in the investigation of the landforms' response to neotectonics. Geometric parameters of the Cotovelo River catchment extracted from an Alos-Palsar digital elevation model were used to compute morphometric and geomorphic indices to investigate whether the bedrock structure and recent active tectonics influence the local drainage network. The Cotovelo catchment is situated in the Middle to Upper Proterozoic western foreland basin of the São Francisco craton, in northwestern Minas Gerais, Southeastern Brazil; it is presumed to be a stable piece of earth’s crust. The automatically generated streams were processed at the sub-catchment scale to calculate the hypsometric integral, relief ratio, stream frequency, and drainage density morphometric indices as well as supported a geomorphic study based on the basin shape, asymmetry factor, valley floor width-to-height ratio, mountain front sinuosity, transverse topographic symmetry factor, and stream-length gradient index. Achieved results revealed recent and low-rate tectonic activity and structural control on the fluvial morphology. Prominent knickpoints, aligned with mapped fault scarps, disclose straight erosive fronts away from stratigraphic borders, indicating these features are unrelated to lithological changes. Despite the catchment location, the area exhibits impressive fluvial anomalies, and dissection occurs preferentially along ancient faults and fractures densely occurring in the rocky strata. Channel parallelism in context of medium to high relief and steep slopes, remarkably structurally drive fluvial dissection, asymmetric and elongated drainage catchments, and aligned landforms suggest neotectonic influence on the drainage network.

کاربرد مدلهای شبکه عصبی مصنوعی، نسبت فراوانی و تابع شواهد قطعی در تهیه نقشه حساسیت به وقوع سیل در حوزه آبخیز هراز: الگویی برای مطالعات مخاطرات سیلاب شهری

کاربرد مدلهای شبکه عصبی مصنوعی، نسبت فراوانی و تابع شواهد قطعی در تهیه نقشه حساسیت به وقوع سیل در حوزه آبخیز هراز: الگویی برای مطالعات مخاطرات سیلاب شهری