Quantifying the Geomorphology of the Drainage Basins Along the Greater Khingan Mountains in NE China

Drainage basins are fundamental elements of the earth’s surface, and quantifying their geomorphic features is essential to understand the interaction between tectonics, climatic, and surface processes. In this study, 40 basins of the Greater Khingan Mountains were selected for hypsometric analysis using a 90-m Shuttle Radar Topography Mission digital elevation model. The hypsometric integral values range from 0.13 to 0.44, with an average value of 0.30, and most hypsometric curves exhibit remarkable downward concave shapes. This feature indicates that most drainage basins and the landscape of the Greater Khingan Mountains are approaching the old-age development stage, consistent with the present moderately stable tectonic activity. The spatial distribution of the χ values is characterized by unambiguously higher values on the western flank than those on the eastern flank in the middle and southern segments of the Greater Khingan Mountains. We interpret this as an indicator of the disequilibrium across the main divide. The interpolation of the erosion rates and channel steepness for the catchments on both sides of the Greater Khingan Mountains revealed westward divide migration, which is consistent with the lower χ values, a higher slope, and local relief observed along the eastern flanks. Considering the long-term tectonic evolution pattern between the Greater Khingan Mountains and Songliao Basin, the landscape decay and slow westward divide migration were mostly driven by the inherited Cenozoic tectonics and precipitation gradient across East Asia.

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 < 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 < 1.26), moderate (RTAI = 1.26–1.73), and high (RTAI > 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.

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 Riverwith ArcGIS, investigated the basin characteristicsandthe differences in their spatial distributions and analyzed the relations of the drainagedensity with some surface conditions and how the drainagedensityinfluenced the water yield. The results suggested a power function between the mainstream length and drainage area, showing that withthe 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 andelongation ratio indicatethat the basin shape of the mountain watersheds in theDaqing 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 wasnegatively correlated with drainage density, but the correlation between them was notsignificant atthe 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 alongthe Daqing Riverwerein the old stage with no furtherincrease trend of drainage density in the future.

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.

Quantitative Geomorphological Parameters Analysis for the Aynalem- Illala Streams, Tigray, Northern Ethiopia

Morphometric analysis is the measurement and mathematical analysis of the configuration of the surface, shape, and dimension of landforms. The objective of this study is to characterize the Aynalem and Illala streams using the morphometric parameter. The topographic map at a scale of 1:50,000 taken from the Ethiopian National Mapping Agency was used to characterize the linear and areal aspects. ASTER Digital Elevation Model with 10m resolution was used to characterize the relief aspect. The Arc GIS 10.4.1 was used during the morphometric analysis. The analysis result of the streams is summarized based on the linear, areal, and relief aspects. The area is characterized by a dendritic drainage pattern which is characteristics of massive hard rock terrain. The Aynalem and Illala streams are 4th and 5th order streams. Considering the number of streams in the Aynalem (75.81%) and Illala (74.66%) is composed of first-order streams that indicate a flashy flood and the mean bifurcation value of Aynalem (6.8) and Illala (4.7) shows that the Aynalem area is more structurally affected than Illala but both show less stream integration. The analysis of areal aspects such as elongation ratio, circularity ratio, and form factor has indicated that both streams are characterized as elongated streams, this implies that both streams are flowing in heterogeneous rock material, presences of structural effect, and slow runoff discharge. The other areal aspect such as drainage density, stream frequency, infiltration number, and length of overland flow all show smaller values in both streams. This implies that the streams are characterized by a relatively permeable rock material with a higher infiltration capacity. The relief aspect of the Aynalem and Illala was also analyzed using basin relief, relief ratio, ruggedness number, hypsometric curves, and Hypsometric integral. The streams are characterized by a lower relief ratio and ruggedness number which implies a relatively flat slope and lower relief. The hypsometric curves and the Hypsometric Integral of the streams indicate that the Aynalem and Illala are at the maturity stage. This shows the area is characterized by higher erosion but less affected by recent structures. Based on the morphometric parameter analysis result it is possible to conclude that the stream development is dependent on the topography and geology of the study area and both streams show similar morphometric character.

Assessment of soil erosion, flood risk and groundwater potential of Dhanari watershed using remote sensing and geographic information system, district Uttarkashi, Uttarakhand, India

Quantitative morphometric analysis of Dhanari watershed has been done using remote sensing and Geographical Information System (GIS). The impact of climate, lithology, tectonics, structural antecedents, vegetation cover and land use on hydrological processes is assessed by quantifying geomorphic parameters. The Dhanari River (a tributary of the Bhagirathi River) and its tributaries Dhanpati Gad and Kali Gad forms Dhanari watershed covering 91.8 Km2 area. Several geomorphic aspects viz. linear, areal, relief were computed to comprehend potentials of soil erosion, groundwater, flood vulnerability and the geomorphic response of watershed. LISS-III image is used to generate the Land Use and Land Cover (LULC) map and assess the watershed dynamics. Values of computed hypsometric integral and morphometric parameters viz. drainage density ($$D_{{\text{d}}}$$ D d ), stream frequency ($$F_{{\text{s}}}$$ F s ), stream length ratio ($$L_{{{\text{ur}}}}$$ L ur ), bifurcation ratio ($$R_{{\text{b}}}$$ R b ), rho coefficient (ρ), drainage texture ($$D_{{\text{t}}}$$ D t ), circularity ratio ($$R_{{\text{c}}}$$ R c ), relief ratio ($$R_{{{\text{hl}}}}$$ R hl ), elongation ratio ($$R_{{\text{e}}}$$ R e ), form factor ($$F_{{\text{f}}}$$ F f ), basin shape ($$B_{{\text{s}}}$$ B s ), drainage intensity ($$D_{{\text{i}}}$$ D i ), compactness coefficient ($$C_{{\text{c}}}$$ C c ) and infiltration number ($$I_{{\text{f}}}$$ I f ) have shown a moderate and steady erosion rate, with low groundwater potential and low to moderate flood vulnerability in the watershed. Hypsometry presents a dependable geomorphic parameter to understand the erosion and geomorphic response of a watershed to hydrological processes. Hypsometric integral value (0.51) of Dhanari watershed suggests a mature topography with steady erosion in the watershed.

Watershed prioritization for soil erosion mapping for the Lesser Himalayan Indian basin using PCA, WSA method in conjunction with morphometric parameters and GIS-based approach

Watersheds in the subtropical Himalayan basins are highly prone to land degradation due to deforestation, landslides, intensive agriculture, population pressure, and overgrazing, in particular, where various fluvial and denudation processes occur. It is important to assess the magnitude of problem and to understand the erosion process under normal conditions, so that effective measures can be implemented. Therefore, the study selected Kalsa watershed from the Lesser Himalayan region, where soil erosion is more prominent. Regarding this issue, to identify the hotspot of soil erosion of the basin, watershed prioritization methods using advanced geographical information system and remote sensing techniques integrated with weighted sum analysis (WSA) and principal component analysis (PCA). In addition, a comparison has been made to evaluate the performance of these models. The study considered sixteen different morphometric parameters, including linear (Rho coefficient, stream frequency, drainage density, length of overland flow, drainage texture, and constant of channel maintenance); landscape (relative relief, relief ratio, basin slope, and ruggedness number); and shape (elongation ratio, form factor, circulatory ratio, and compactness coefficient). Both the method PCA and WSA indicate the same results showing high priority, meaning the outlet watersheds have high priority. The sub-watersheds in the north-eastern part have the lowest priority. The results also show that the length overland flow, relative relief, basin relief ratio and hypsometric integral are the most important indicators. The sub-watersheds prioritize high ranks, medium ranks, and low ranks out of 10 sub-watersheds covering about 45.32%, 27.78% and 26.90% area of the Kalsa River watershed, respectively. This study will help regional planners, farmers, and governments take more detailed decisions to propose efficient soil erosion control measures and conservation priorities of the watershed. The study findings have implications for sustainable land management and conservation goal targets (target 2.3 and 2.4; target 3.9; target 13.1, 13.2 and 13.3; target 15.3 and 15.4), which finally helps to achieve the United Nation’s 2030 Agenda for Sustainable Development.

Predicting Fault Locations based on Morphometric Features of Alluvial Fans and Basins using Artificial Neural Networks

The aim of this study is to investigate the morphometry of alluvial fans located in the vicinity of the Sabzevar and Sang-Sefid faults in northeastern Iran to determine their influence on erosion Principal component analysis (PCA) was used to select the most important morphometric factors affecting erosion. The data regarding the important parameters were input into adaptive neural-fuzzy networks (ANFIS) to predict erosion rates. The asymmetric factor (Af), hypsometric integral (Hi), and basin shape (BS) indicate that most of the sub-basins are tectonically active. The results of the PCA revealed that the most important parameters affecting erosion were Af, Pf, Lf, Rf, Vf, Pb, Ab, LC, Lb, Dd, and the geological unit. The ANFIS method showed that among the soil erosion prediction models, the FCM hybrid model had the highest accuracy. It is concluded that morphometric features can be used to predict the erosion processes in the basin.

Exploring the causes of glacier velocity anomalies in High Mountain Asia: Analysis from the Karakoram, Spiti Lahaul and Eastern Himalaya

&lt;p&gt;Glaciers in High Mountain Asia (HMA) have been experiencing enhanced mass loss and velocity slowdown since the late 1990s, coincident with rising global and regional temperatures. In each HMA region with distinct climatic characteristics, the dynamical responses of glaciers vary substantially; yet these intra-regional variations are overlooked in regional assessments due to large-scale oversampling. In particular, the role of glacier morphological factors (e.g. size, elevation, hypsometry) in causing the different responses is poorly understood.&lt;/p&gt;&lt;p&gt;We investigated the velocity changes of the glaciers in three regions &amp;#8212; the Eastern Himalaya, Spiti Lahaul, and Karakoram &amp;#8212; between 2000 and 2016 in order to understand the key components of glacier sensitivity and their relationship with glacier morphology. Using the NASA Inter-Mission Time Series of Land Ice Velocity and Elevation dataset as input, we extracted glacier-specific velocities (and associated errors) using a bespoke MATLAB script, and compiled these into &amp;#8220;mean annual velocity anomaly&amp;#8221; series following established methods. Anomalies were analysed with glacier morphometric parameters using a linear regression approach, with statistically significant relationships identified.&lt;/p&gt;&lt;p&gt;Our results show that mean velocity anomaly within the Eastern Himalaya varies with glacier aspect, with mean annual anomalies of 0.09 &amp;#177; 2.32 m yr&lt;sup&gt;-1 &lt;/sup&gt;per year for north-flowing glaciers and &amp;#8211;0.1 &amp;#177; 1.59 m yr&lt;sup&gt;-1&lt;/sup&gt; per year for south-flowing glaciers. Glaciers in the Karakoram also show opposing trends, with anomalies of &amp;#8211;0.86 &amp;#177; 5.69 m yr&lt;sup&gt;-1&lt;/sup&gt; per year and &amp;#8211;3.23 &amp;#177; 2.53 m yr&lt;sup&gt;-1 &lt;/sup&gt;per year in the north west, and 1.00 &amp;#177; 3.80 m yr&lt;sup&gt;-1&lt;/sup&gt; per year in the south east. Glacier slowdown in Spiti Lahaul is &amp;#8211;0.37 &amp;#177; 4.50 m yr&lt;sup&gt;-1 &lt;/sup&gt;per year, and we do not document contrasts in intra-regional glacier response&lt;strong&gt;.&lt;/strong&gt; Overall, glacier size, minimum elevation and hypsometric integral are the most significantly correlated parameters to mean velocity anomaly. Percentage and area of debris, flow line length, slope and termination environment were also found to be important autocorrelations. Importantly, we find no consistent morphometric interactions contributing to glacier anomaly between all three regions, implying that glacier responses are unique and a cumulative product of their morphometric variability.&lt;/p&gt;

Monsoon-driven incision and exhumation of the Eastern Tibetan Plateau

&lt;p&gt;The formation and uplift history of the Tibetan Plateau, driven by the India-Eurasia collision, is the subject of intense research. We analyse the link between climate and tectonics in the central and eastern Tibetan Plateau using geomorphic indices of surface roughness (SR) hypsometric integral (HI) and elevation-relief ratio (ZR) and mean annual precipitation, thermochronology and erosion rate data. Geomorphic indices capture the landscape response to competition between climate and tectonics and reflect the spatial distribution of erosion. This is a region where competing tectonic models suggest either early Cenozoic plateau growth, or a late phase of crustal thickening, surface uplift and plateau growth driven by lower crustal flow (&amp;#8220;channel flow&amp;#8221;). Swath profiles of rainfall, elevation and the geomorphic indices were constructed, orthogonal to the internal drainage boundary. Each profile was analysed to find the location of maximum change in trend. We identify a broad &amp;#732;WSW-ENE trending transition in the landscape where changes in landscape and precipitation are grouped and in alignment. It represents, from east to west, a sharp decline in precipitation (interpreted as the western extent of the East Asian monsoon), a change to a low relief landscape at 4500-5000 m elevation, an increase in ZR and a transition to low HI and SR. This zone cuts across structural boundaries and is not a drainage divide: the main rivers have their headwaters further West, in the interior of the plateau. We argue that this geomorphic-climatic transition zone represents a change from incised to non-incised landscapes, the location of which is controlled by the western extent of the monsoon. Modern erosion rates are lower in the non-incised region, west of the monsoon extent (mean 0.02 mm/yr), than the incised region (mean 0.26 mm/yr). Compiled thermochronology data shows an increase in exhumation from &amp;#732;25 Ma in the incised area but no evidence of this increased exhumation in the non-incised area. This pattern supports a model of early Cenozoic growth of the eastern Tibetan Plateau, superimposed by incision driven by Miocene monsoon intensification. Our results do not support the channel flow model, which would predict an eastwards wave of surface uplift and therefore erosion and exhumation during the Miocene, which are not present in the data.&lt;/p&gt;