Hypsometric Integral Values Research Articles

Morphometry and active tectonics of the Konkan coast, western India

The Indian western coast is petroliferous drawing attention from academicians and industrial experts. In this work, geomorphic indices have been calculated to decode neotectonics of the Konkan onshore region on India’s west coast. Earthquake and Bouguer anomaly data have been used along with the present-day stress data from the World Stress Map project. Gravity modeling was performed in order to gain seismotectonic insights. The b-values were determined using Z-MAP 7.1 (2021). Morphometric analysis at both linear and spatial scales were performed using the digital elevation model from the data derived from the Shuttle Radar Topography Mission, analysed with ArcGIS 10.3 (2014) software. Maps depicting slopes, aspects, and reliefs were created. NW-SE trending lineaments in the Konkan plain guided the major stream courses. Two of the five watersheds, watersheds 4 and 5, reveal high tectonic activity, are landslide-prone and host hot springs. Interestingly, watersheds 4 and 5 show high b-values (except near the rivers’ sources), low Bouguer anomalies, and higher Hypsometric integral values (0.18523 and 0.16698) than the other watersheds. A low b-value in watershed 3 indicates stress accumulation. Over a larger area, the gravity trend varies from ∼ -80 to 30 mGal. The lineaments diagram deduced from the first vertical derivative technique shows that the structural fabrics mostly trend ∼ NW-SE at the west of the Western Ghat Escarpment (WGE) while it is NE-SW at the east. The tilt derivative ratio technique reveals a major NE-SW trend to the west of the WGE and an E-W trend to the east. Structural interpretations based on drill-cores around Koyna combined with geophysical studies for deep crust will be required are required for a better understanding of the blind (active) structures in the region.

Tectonic evolution of Bursa Yenişehir Basin, Turkey from the Neogene to the Quaternary using a morphotectonic approach

In this study, the morphotectonic features of the Yenişehir pull‐apart basin in Bursa in northwestern Turkey were analysed. The faults in the region are the most important structural elements that characterize the morphology of the Yenişehir pull‐apart basin. The aim of this study is to show the deformation effects of these active faults on the geomorphology with some basic morphometric indices. The morphotectonic features were evaluated using the hypsometric curve and hypsometric integral (Hi), drainage basin asymmetry (the asymmetry factor (AF) and the transverse topographic symmetry factor (T)), river length gradient index, mountain front sinuosity, and valley floor ratio. The morphometric indices that play an important role in the analysis of catchment areas are the Hi, AF, and T indices, which indicate tilting and erosion activities. According to the results of the hypsometric curve and hypsometric integral, the Yenişehir Basin is a young basin with a uniform topography as expected in an active pull‐apart basin formed by faulting in the Quaternary. The relative tectonic activity index (Iat) of the study area was calculated using the values of hypsometric integral, transverse topographic symmetry factor, asymmetry factor, mountain front sinuosity, valley floor ratio and stream length gradient index. The Iat values indicate the tectonic activity of the basin from Pliocene to Recent. Three different tectonic classes were identified in the study area. These are class 1 (high relative tectonic activity), class 2 (moderate relative tectonic activity), and class 3 (low relative tectonic activity). The Iat classification data show that the impact of tectonic activity on the geomorphology is lower in the Iat class 3 indices than in the others. The Iat data show high tectonic activity in the region where active faults of the North Anatolian Fault Zone southern branch are located.

Implications of active Gavilgarh/Salbardi fault on the evolution of the late Quaternary landscape in Central India

The morphometric indices (MI) have been calculated along the Gavilgarh/Salbardi Fault (G/SF) to investigate active deformation, tectonic uplift, and basin tilt to find out its impact on the late Quaternary landscape. To explore the tectonic intensity, we computed MI such as stream-length gradient index (SL), hypsometric integral (HI), transverse topographic symmetry factor (T), asymmetry factor (Af), basin elongation ratio (Re), mountain front sinuosity (Smf) and valley floor width to valley height ratio (Vf). The necessary field investigations were carried out on the evolution of the Quaternary landscape to ascertain the various morphometric indices. The evaluated values of SL, HI, Re, Smf, and Vf show the high uplift of the northern block exists as opposed to the southern block, and the tilt and asymmetric character of the basins are shown by T and Af values. The presence of sedimentary landscapes like Quaternary alluvium, triangular facets, natural levees, and boulder-pebbly beds, indicates that the area has recently experienced tectonic activity. The assessed values of MI with supporting field evidence proposed that the northern block is uplifted and the basins are tilted because of the effect of G/SF.

Assessing the level of river basin evolution, erosion susceptibility and its correlation with morphometric characteristics using Geoinformatics techniques

The application of Geoinformatics have become fastest and improved advanced tools to analyse and interpret the topography and hydrological characteristics. This study aimed to utilize the advantage of high resolution (30 m) remote sensing data of Shuttle Radar Topography Mission (SRTM) and the geoinformatic tools of Quantum Geographical Information System (QGIS) for extraction of detailed and accurate drainage morphometry and elevation information in preparation of hypsometric curves. Making use of QGIS, the SRTM data and topographic maps are georeferenced and pre-processed algorithm tools of stream burning and fill-DEM are applied for DEM preparation and extraction of accurate drainage network and its basin areas. From the DEM map, the details of elevation and area of basins are extracted for preparation of hypsometric curves. Hypsometric curves are analyzed to interpret and understand the heterogeneity in the levels of basin evolution/development and erosion at 4th order sub-basin level. The concave hypsometric curves of main basin and sub-basins indicate that total basin as well as sub-basins reached the old/monadnock stage due to the dominance of fluvial process. Based on the hypsometric area/integral (Ea) and Concavity of hypsometric curve values (Eh), five classes/stages of basin development and erosion levels are identified within the old/monadnock stage. The Ea values range from 0.10 to 0.35 and Eh range from 0.25 to 0.77 in this study area. Initial old/monadnock stage of basins have Ea values > 0.28 and Eh values < 0.4 indicating low levels of erosion among the sub-basins. Low hypsometric area/integral value (Ea) indicates the higher level of landmass removal by erosion and basin development. The oldest stage basins are identified with Ea values range from 0.10 to 0.15 and Eh values range from 0.61 to 0.77 indicating higher level of landmass removal/erosion. The lithological variation plays a significant role on hypsometry of the basins. The high hypsometric integral (Ea) values (i.e., 0.28 to 0.35) of 1,2 and 3 sub-basins indicating the early/ initial level of old stage in its’ basin development, since the resistant basalt formation is sandwiched between sandstones prevented deep erosion and depicting less dissected topography. The hypsometric integral has positive correlation with form factor and negative correlation with drainage morphometric characteristics. It indicates that the level of basin evolution increases as the form factor decreases but number of streams, length of streams, mean bifurcation ratio, relief, relief ratio and ruggedness ratio increases. This study is highly useful to understand the relation among morphometric characteristics, basin development and erosion levels through the analysis of hypsometric curves making use of Geoinformatic techniques.

Active tectonic evolution of two adjoining thrust sheets in the Indo-Myanmar fold-thrust belt, Northeast India

The active tectonic aspects of the Indo-Myanmar Range (IMR) have not yet been studied in detail in spite of the fact that it’s seismically active. In the present study qualitative and quantitative geomorphic analyses have been carried out to understand the active tectonic evolution of Nungba, and Barak-Makru thrust sheets (NBTS and BMTS) in the central part of IMR. The focus of the study is on understanding the active spatial growth pattern of adjacent thrust sheets in an evolving mountain range and providing baseline data for further detailed seismotectonic and seismic hazard vulnerability analyses. Drainage characteristics, disposition of landforms and statistical analyses of Normalized Steepness Index (ksn), Hypsometric Integral (HI) and Transverse Topography Symmetry Factor (T), computed for a total of 164 4th-order drainage basins, reveal that both of these adjoining thrust sheets are actively uplifting. Higher values of ksn (mode = 111) and HI (mode = 0.46) in NBTS suggest its faster uplift than the BMTS, which has comparatively lower values of ksn (mode = 56) and HI (mode = 0.43). Moreover, the northern parts of the both the thrust sheets are uplifting faster than their southern parts due to along-strike variations in the movement on their basal thrusts, as a result of which the NBTS has been south-southeastwardly down-tilting and the BMTS is south-southwestwardly down-tilting. The study reveals that both the adjacently lying NBTS and BMTS have almost the same spatial growth patterns that are mainly controlled by the movements on their basal thrusts.

Appraisal of Active Tectonics: An Insight from the Morphotectonic Study of Drainage Basins and OSL Dating in the Kangra Area, Himachal Pradesh

ABSTRACT A morphotectonic investigation of the drainage basins and an estimation of the rate of upliftment have been conducted in the vicinity of Palampur, located in the Kangra district of Himachal Pradesh. The assessment utilized the geomorphic index of active tectonics (IAT) and the Optically Stimulated Luminescence (OSL) dating technique. The study area is situated within the epicentral zone of the 1905 Kangra earthquake and is drained by three significant perennial tributaries of the Beas river, namely Baner, Neogal, and Awa. To evaluate the tectonic influence on these drainage basins, Digital Elevation Model (DEM) data with a resolution of 30m, Survey of India toposheets, and Google Earth images were processed using ArcGIS and Global Mapper software. The findings of this investigation indicate that the drainage basins have been impacted by tectonic activity, resulting in the formation of asymmetrical, elongated basins with deep V-shaped valleys and active mountain fronts. The hypsometric integral values derived from the study suggest that these basins have reached an equilibrium stage. Originating from elevations exceeding 4500m in the Dhauladhar range, these rivers, like other Himalayan rivers, partake in active downcutting and erosional processes, as observed in the presence of terraces. By employing the OSL dating technique, the terraces of the Neogal river were dated, enabling the calculation of an upliftment rate ranging from 0.6 ± 0.03 mm/year to 1.7 ± 0.1 mm/year for the area.

Geomorphic evolution of a tropical river basin in the Deccan Volcanic Province: a critical water supply source to Mumbai metropolitan region (MMR), India

ABSTRACT Reservoir siltation lowers a dam’s effective storage capacity, which is mostly determined by the sediment discharge from soil erosion in the watersheds. The morphometric parameters are significant in determining erosional susceptibility of watersheds. In the present study, morpho-hypsometric aspects of the Surya sub-basin, a major tributary of Vaitarna river, has been considered. This river system and associated dams provide the major source of drinking water supply to the Mumbai Metropolitan Region (MMR). A major part of the river flows through the Deccan Volcanic Province (comprising basalts) and Quaternary alluvial deposits. The seven sub-watersheds (SWs) of Surya sub-basin were analysed using the morphological parameters (linear, areal, and basin shape aspects), along with ratio factors and hypsometric integral (HI) values. The HI values for the SWs range from 0.11 (SW-1) to 0.51 (SW-6) with a HI value of 0.21 for the whole Surya sub-basin. The relatively high HI values of SW-6 (0.51) and SW-7 (0.31) indicate that these SWs are relatively prone to high erosion and sediment discharge resulting in dam siltation, and will be a great threat to livelihood of millions of people in the MMR. Therefore, prioritizing these SWs for proper engineering measures could reduce erosion and improve recharge.

Digital topographic analysis and lineament interpretation south of the Lena Delta, North Siberia: Landscape expression of its tectonic activity

This study applies semi-automated techniques to analyze the landforms, morphostructure, and geology of the Kharaulakh and Chekanovsky sectors, south of the Lena Delta, northern Siberia. High-resolution data, including TanDEM-X 30 m spatial resolution Digital Elevation Models (DEM), 2 m spatial resolution ArcticDEM Digital Surface Models (DSM), and Sentinel-2 satellite imagery, serve as the basis for the analysis. Digital terrain classification and identification of tectonic lineaments are performed using the Benthic Terrain Modeler (BTM) and Linear Extraction (LINE) algorithm, respectively. Additionally, a hypsometric analysis is conducted to assess areas of potential neotectonic activity. 873 lineaments are identified, primarily in NE-SW and E-W orientations. NW-SE lineaments perpendicular to the lithological and fold belt strikes in the Kharaulakh Ridge suggest inheritance from original depositional settings or later compressional tectonics, now appearing as valleys and weak zones facilitating erosion and river incision. Longer N-S or NNW-SSE lineaments in the Kharaulakh Sector are associated with thrust sheets of the Verkhoyansk fold-and-thrust belt and Cenozoic graben structures linked to the formation of the Laptev Sea Rift System and ongoing regional deformation. The Chekanovsky Sector, marked by epiplatform blocks and hills, presents a dissected plateau with steep valleys. Here, high hypsometric integral values are attributed to compression and uplift near the southwestern boundary of the Laptev Sea Microplate.

Morphometric analysis of the Middle Tuirial watershed, Mizoram, India and its significance for soil loss risk

This study aims to highlight the quantitative analysis of Middle Tuirial watershed in Mizoram, India and its significance for soil loss risk. In addition to understanding landscape evolution and hydrological characteristics of the river basin, it is crucial to implement appropriate soil and water conservation practices, to reduce further soil erosion risk in the basin. Linear, areal and relief aspects of morphometric parameters were analyzed using a survey of India topographical maps, advanced land observing satellite (ALOS) phased array type L-band synthetic aperture radar (PALSAR) digital elevation model (DEM), and geographic information system (GIS). The study reveals a high drainage density of 5.22 km/km2 and stream frequency of 10.58 km2, which denotes the basin exhibits high surface run-off with low groundwater recharge. In addition, it has 0.6 form factor, 0.3 elongated ratio and 0.43 circularity ratio indicating a highly elongated shape of the basin. Furthermore, the hypsometric integral values of 0.48 with an s-curve show the basin has attained a mature stage of landscape evolution.

Quantitative and qualitative study of the Tawi basin: Inferences from Digital Elevation Model (DEM) using geospatial technology

The quantitative and qualitative analysis of the basin is fundamental to understand the structural and hydrological control of the basin. In the present study morphometric and morph tectonic parameters of the Tawi basin has been analyzed to infer the geological variation, topographic information, structural and complex tectonic behavior at a watershed scale. The assessment of several of drainage network and their relative parameters has been quantified by using the Digital Elevation Model (DEM) based analysis in the Geographic Information System (GIS) environment. Based on the quantitative analysis in terms of linear, aerial and relief it is well understood that the basin is inhomogeneous in nature, less structurally stable, very gentle to steep slopes, compounded by aggradational and denudational processes in large scale, exhibited by incompetent rocks and a portion of the basin is prone to flood particularly in the lower reaches. The quantified results show that in the various watersheds of the Tawi basin bifurcation ratio (Rb) varies from 0.001 to 6.80 and the mean bifurcation ratio (Rbm) varies from 2.58 to 4.11. The mean stream length (Lsm) in the various watersheds of Tawi basin varies from 0.019 to 60.26 km. The drainage density (Dd) of Tawi basin varies from 0 to 9.63 km/km2, and the value of the drainage texture (Td) varies from 3.76 to 13.38 km-1. The qualitative analysis based on the asymmetric factor (AF) of the Tawi basin shows that the watersheds W5 and W6 are moderately asymmetric, and W2 and W4 as strongly asymmetric in nature, whereas the hypsometric integral (HI) values reveal that watershed W1 is the most stable watershed with a highest HI value of 0.89, while the W7 is the least stable with a HI value of 0.28, providing a comprehensive understanding of the geomorphic dynamics in the Tawi basin.

Assessing the importance of hypsometry for catchment soil erosion: A case study of the Yanze watershed, Rwanda

Implementing a watershed erosion control programme requires resource-intensive and time-consuming preliminary studies to prioritize such interventions and to focus on those sub-catchments where they are most likely to yield the most effective results.&#x0D; In this study, we explore and document the effectiveness of using hypsometric analysis as a method to prioritize erosion control measures and apply it to the Yanze watershed located in central Rwanda.&#x0D; Based on a 30m-resolution DEM of the watershed and using ArcGIS and R software, we made estimates of hypsometric integral values and calculated soil loss estimates through RUSLE modelling and by using data from different sources, namely the Rwanda Meteorological Agency (rainfall data), ISRIC (soil data), and Sentinel-2 images (land cover maps).&#x0D; The hypsometric integral values of the Yanze sub-catchments were high, ranging from 0.5 to 0.936. This, combined with the overall convex upward hypsometric curves, indicates that the Yanze watershed is still at a youthful stage in its erosional cycle.&#x0D; The results of the RUSLE model showed that the average potential soil loss in the Yanze watershed is 55.63 tonnes.ha-1.year-1, which is comparable to the national average estimated at 62 tonnes.ha-1.year-1.&#x0D; The correlation analysis that we conducted between the hypsometric integral values of the Yanze sub-catchments and their respective mean soil loss values revealed no correlation between the two variables. From the results of this study, we conclude that in watersheds where lithology affects soil erosion significantly, morphology can indeed indicate the potential for erosion. However, we further concluded that future studies to characterize erosion potential using morphometry should employ additional morphometric parameters in the regression model.

Watershed prioritization of drainage basins based on geomorphometric parameters, Neyyar watershed, India

Prioritisation of sub-watersheds (SWs) is becoming increasingly important in the conservation of natural resources, particularly in watershed planning. In this study, sub-watershed for the Neyyar basin was prioritised using three methods: morphometric analysis, principal component analysis (PCA) and hypsometric analysis. Morphometric analysis and hypsometric analysis were carried out using remote sensing (RS) and geographic information system (GIS) techniques, while PCA was performed for dimensionality reduction of morphometric parameters. The watershed was divided into 11 sub-watersheds (SW1–SW11), and each sub-watershed was given priority. To rank and prioritise SWs, 15 morphometric parameters were selected from the quantitative measures of morphometric analysis, including linear, relief, and areal. PCA was used to rank and prioritise SWs based on three highly correlated morphometric parameters. The hypsometric integral (HI) values were determined using the elevation relief ratio approach, and HI values were utilised to prioritise SWs. For both methods, such as morphometric analysis and PCA, a higher priority has been given to SW1. Using hypsometric analysis, higher priorities have been assigned to SW1, SW7, SW8, SW9, SW10 and SW11. The most common SWs that belong to the same priority of SWs and have a high correlation between them among the three methods are SW1, SW2, and SW5.The results of this analysis indicate that SW1 is a common high priority area with a significant risk of soil erosion, runoff and peak discharge. Therefore, decision-makers may utilise the high-priority sub-watershed to guide planning and development, measure conservation efforts and manage the land to prevent.

Morphometric analysis of the North Liuleng Shan Fault in the northern Shanxi Graben System, China: Insights into active deformation pattern and fault evolution

The North Liuleng Shan Fault (NLSF) is one of the major active faults in the northern Shanxi Graben System (SGS) in North China. Although the fault has been investigated extensively in terms of late Quaternary activity, its active deformation pattern is still poorly characterized. In this study, we conducted a morphometric analysis of the fault using various geomorphic indices to assess the along-strike relative uplift rates, which include basin relief, slope, mountain front sinuosity (Smf), hypsometric integral (HI) and curves, valley floor width-to-height ratio (Vf), asymmetry factor (Af), basin elongation ratio (Re), and normalized channel steepness indices (ksn). Our findings indicate that the central portion of the fault has experienced higher relative uplift rates than the southwestern and northeastern portions, as demonstrated by higher basin-averaged slopes and ksn values, and lower Vf, Re, and Smf values. This spatial distribution pattern of relative uplift rates appears to correlate well with along-strike changes in the fault geometry and kinematics of the NLSF. We interpret the EW-striking, central portion of the NLSF as a releasing bend formed by the NE-striking, right-stepping, en-echelon southwestern and northeastern portions of the fault system, which are characterized by right-lateral oblique slip. Furthermore, the northeastward increase in HI values along with the regional basin evolution history suggest that the NLSF likely propagated from southwest to northeast. We propose that the southwestern portion of the fault most probably initiated earlier and that the central and northeastern portions formed later as extensional structures at the termini of the fault zone. Our findings contribute to a better understanding of the tectonics and genesis of the basin-and-range geomorphology in the northern SGS.

Prioritizing sub-watersheds for soil erosion using geospatial techniques based on morphometric and hypsometric analysis: a case study of the Indian Wyra River basin

The hydrological availability and scarcity of water can be affected by geomorphological processes occurring within a watershed. Hence, it is crucial to perform a quantitative evaluation of the watershed’s geometry to determine the impact of such processes on its hydrology. Geographic information systems (GIS) and remote sensing (RS) techniques have become increasingly significant because they enable decision-makers and strategists to make accurate and efficient decisions. To prioritize sub-watersheds within the Wyra watershed, this research employs two methods: morphometric analysis and hypsometric analysis. The watershed was divided into eleven sub-watersheds (SWs). The prioritization of sub-watersheds in the Wyra watershed involved assessing several morphometric parameters, such as relief, linear, and areal features, for each sub-watershed. Furthermore, the importance of the sub-watersheds was determined by computing hypsometric integral (HI) values using the elevation–relief ratio method. The final prioritization of sub-watersheds based on morphometric analysis was determined through the integration of principal component analysis (PCA) and weighted sum approach (WSA). SW2 and SW9 have had higher priorities using morphometric analysis, whereas SW6, SW7, and SW10 have obtained higher priorities using hypsometric analysis. SW4 is the most common SW that shares the same priority. The most vulnerable sub-watersheds are those with the highest priority, and therefore, programmes for soil and water conservation should pay more attention to them. The conclusions of the study may prove useful to various stakeholders involved in initiatives related to watershed development and management.

Sub-watershed prioritization using morphometric analysis, principal component analysis, hypsometric analysis, land use/land cover analysis, and machine learning approaches in the Peddavagu River Basin, India

Abstract Water resource management is critical in the face of climate change to reduce water scarcity and meet the demands of an expanding population. Prioritization of watersheds has gained significance in natural resource management, particularly in the context of watershed management. This study prioritizes sub-watersheds for the Peddavagu basin using five methods. The four methods mentioned above can be estimated utilizing remote sensing (RS) and geographic information system (GIS) approaches, while linear discriminant analysis (LDA) is estimated using machine learning techniques. The catchment resulted in the formation of 13 sub-watersheds. The quantitative measurements of morphometric analysis, including linear, relief, and areal, were considered, and 18 morphometric characteristics were chosen to rank and prioritize sub-watersheds. Principal component analysis (PCA) was used to rank and prioritize sub-watersheds based on four highly correlated morphometric parameters. The land use/land cover (LULC) analysis used four features to prioritize sub-watersheds. The LDA analysis used two features to prioritize sub-watersheds. Using hypsometric integral (HI) values, prioritization has been done. Sub-watersheds were prioritized. Based on five methods, the sub-watersheds were classified as low, medium, and high. Among the sub-watersheds identified as high priority, immediate priority is assigned to SW10. Decision-makers in the research region can use the findings to plan and implement watershed management techniques.

Response of the Stream Geomorphic Index to Fault Activity in the Lianfeng–Ningnan Segment (LNS) of the Lianfeng Fault on the Eastern Margin of the Tibetan Plateau

The response of the stream geomorphic index to fault activity is important for assessing the regional seismic hazard. The data used in this paper are 12 m resolution TanDEM-X data. The Fill tool in the Hydrology toolset in ArcGIS 10.5 was used to first process the digital elevation model (DEM), then analyse the flow direction of the DEM after filling and finally extract streams with catchment areas of more than 9 km2. Based on the DEM spatial analysis, the stream geomorphic index of the Lianfeng–Ningnan segment (LNS) of the Lianfeng fault was extracted, including the stream length gradient (SL) and the hypsometric integral (HI). This information, combined with the analysis of typical field geomorphology and terrace profiles, was used to define the fault activity period. To analyse the activity characteristics of the LNS, the LNS was divided into northern (Lianfeng to Jinyang), middle (Jinyang to Duiping town) and southern segments (Duiping town to Ningnan). The stream geomorphic index showed spatial variations, with mean SL and HI values of 384 and 0.45, respectively, in the northern segment; 175 and 0.41, respectively, in the middle segment; and 378 and 0.45, respectively, in the southern segment. These results indicate that the northern and southern segments of the LNS are more active than the middle segment, that there is little difference between the northern and southern segments, and that the activity of the middle segment is relatively weak. By comprehensively analysing the lithology, climate and tectonics in the LNS region, we conclude that tectonics are the main factor controlling the stream geomorphology in the LNS region. Based on this information and the analysis and dating of field geomorphology and terrace profiles, we found that the Lianfeng fault was active in the Holocene, which is consistent with the latest research results.

Evaluation of the geomorphological scenario of Shimsha River Basin, Karnataka, India.

Drainage morphometric analysis is very substantial in determining the characteristics of a river basin. It is performed through spatial analysis, which helps study the various hydrological interactions and responses in the watershed. In this research, the authors have tried to study the geomorphological scenario of the Shimsha River basin using the remote sensed data, toposheets, and geographic information systems tools. In the current study, linear, aerial, and relief parameters are derived and analysed to evaluate the runoff and erosion characteristics of the basin. The stream pattern of the Shimsha River is mostly dendritic with a sixth-order stream and a drainage density of 0.56 km/km2. According to the morphometric characteristics, the study area appears to be in the equilibrium stage of development, slightly elongated, with moderate to low flow rates and reduced sensitivity to erosion. The hypsometric curve and hypsometric integral value of the Shimsha River basin show the mature phase of the geomorphic evolution of the basin and imply that runoff will be moderate to high. The asymmetry factor of the Shimsha River basin is 49.3, which specifies that the basin is slightly tilted towards the right. The study's results clarify the phenomena of runoff and erosion, which is crucial for watershed management initiatives.

Morphometric analysis of Chapecó river basin: Searching for vestigial trace of neotectonic on a basaltic landscape at southern Brazil

The Chapecó River Basin (CRB) is located in the west of Santa Catarina State (South Brazil) and has a relief modelled by a large basalt lava outpouring that occurred in the Paraná Sedimentary Basin. The CRB is characterised by two plateau compartments resulting from regional denudation and associated with a river network that was formed after the basaltic lava completed its flow phase in the Lower Cretaceous. Elements of structural geology together with weathering of rocks and its products, such as regolith, have been commonly used to analyse and interpret the landforms in CRB, whose fluvial landscape is shaped by bedrock channels and incision valleys. Nevertheless, there is a lack of detailed studies about such structural factors in terms of type and origin, and to what extent they may be proxies of tectonic tensions of an intra-plate character. In the lack of guide levels and deposits that allow a better interpretation of recent tectonic deformations, in this work we aimed to evaluate tectonic-structural factors involved in the landscape evolution of the CRB through measurement and analysis of morphometric indices derived from the ALOS PALSAR DEM. We analysed the following morphometric parameters for 43 sub-basins: the basin asymmetry (FA), hypsometric integral (HI), elongation, local relief, slopes distribution, Hack index for the two main river channels (Chapecó and Chapecozinho), and concavity index of the main channels of sub-basins. The results obtained from the morphometric analysis of the river network indicate the existence of a geomorphological disequilibrium of its relief. This result was observed in the transition from the medium to the low basin and in the base levels of the Chapecó and Chapecozinho rivers. Such disequilibrium is shown by convex and irregular longitudinal profiles, knickpoints, sub-basins with high values of asymmetry and hypsometric integral (HI), as well as a low correlation between slope and channel gradients for the sub-basins analysed. This context is consistent with the neotectonic hypothesis of a regional uplift that provide energy to the system to reactivate faults, tilt blocks, and deepened the incision of the river network, leading to the creation of new knickpoints and a transient river network. From the results and analysis, we can conclude that the largest knickzones and waterfalls in the study area can be considered markers associated with quaternary tectonic forcings, although many of these geomorphological features may have originated simply by joints and fractures in the rocks.

Quantitative analysis of Nayaseri watershed in the northern slopes of Shimla (Himachal Pradesh, India)

The Nayaseri watershed has been analyzed in this research paper using quantitative techniques. This watershed lies in the Northern slopes of Shimla mountainous range and forms the part of Shimla district of Himachal Pradesh. The basin has rocks of tertiary age with beds belonging to the carbonaceous system (Karol and Blaini groups). The metamorphic rocks of the basin consist of mostly black carboniferous, garnetiferous, phyllites, slates, quartzites and highly crushed dolomite. Overall climate of the basin is cool and moist. The pattern of streams in the catchment is pinnate and dendritic mixed with parallel patterns. The linear, areal and relief aspects are involved in quantitative analyses of watershed. The linear and areal investigation of the watershed indicates the incidences of truncation, upliftment, subsidence and tilt in the basin. Hypsometric integral value, elongation ratio, sinuosity index and channel gradient suggest a young stage of landforms development of drainage basin.

Large-scale spatial variability in loess landforms and their evolution, Luohe River Basin, Chinese Loess Plateau

Loess landform variability across large spatial extents needs to be analyzed to understand the formation and evolution of loess landscapes. This is becoming increasingly possible via the automated analysis of remotely-sensed data. Here, we quantify loess landforms using an object-based image analysis (OBIA) method and use this classification to describe the spatial variability of loess landforms. Quantitative indicators are used to drive the spatial variability analysis of loess landforms and explain their spatio-temporal evolution. Moreover, the hypsometric integral (HI) and topographic interpolation are employed to investigate soil erosion and development patterns of loess landscape. Results show that the OBIA method classified loess landforms to an accuracy of 88.7 %. The derived metrics in terms of the area, slope and complexity of landform shape allow the determination of the spatial structure of the loess landscapes. The HI value of the entire basin is 0.486, representing the mature stage of landform development, with relatively severe surface erosion. Correlation analysis of HI values and related indicators in the sub-basins shows that HI is poorly correlated with the area proportion of loess landform types and the total erosion volume in the basin but shows a relatively strong correlation with the volume of erosion per unit area.