Hypsometric Index Research Articles

Morphometric analysis of Mogamureru river basin at the YSR Kadapa District, Andhra Pradesh, India using GIS and remote sensing

Water availability and scarcity are impacted by geomorphological changes that occur within a catchment. As a result, determining the influence of geomorphological processes on the catchment’s hydrology requires a quantitative study of the catchment geometry. Approaches based on remote sensing (RS) and geographic information systems (GIS) have grown in popularity in recent years because they assist strategists and decision-makers in making accurate and effective choices and plans. For this research, the Mogamureru River basin was chosen. The study shows that GIS and RS data can be used to analyse and approximate the period and erosional operations’ risk in a Mogamureru river basin for better design and maintenance. The quickest and most economical method of displaying the hydrologic and physiographic features of the Mogamureru river basin is to assess the morphometric parameters. All of the following parameters such as: linear (7) areal (5), relief (5), and drainage texture (5) characteristics were obtained with hypsometric curve for the Mogamureru river basin utilizing the Shuttle Radar Topography Mission (SRTM) images. According to the linear parameter values, the majority of streams (82 %) belong to the first order, Statistical analysis shows that there is a good relationship between stream order and stream length, as well as stream order and stream number. The circularity ratio (0.55) depicts the young, elongated topography. The basin as a whole is in the mature stage of formation, with good to moderate potential, according to the hypsometric index (0.46). Due to land deterioration, Pulivendula and Vemula have had the most soil loss. This study concludes that morphometric analysis based on GIS & remote sensing techniques is a competent tool for hydrological studies. The research findings will help policymakers for integrated river basin management, agricultural development, and water management. In addition, researchers of morph hydrological, geological and climatological research will be beneficiary.

Tectonic analysis of the Mula River Basin, Kirthar fold belt, Pakistan, using hypsometric index

The Mula River Basin is in an active tectonic region of the Kirthar fold fault belt in the Western Himalayas. The presence of numerous major faults like Chaman Fault, Kirthar Frontal Fault, and Bannh Fault near the study suggests complex tectonic processes in the region. The seismic record of the study area also indicates that this area is tectonically active. This makes the study area an ideal site to measure tectonic activity through geomorphic indices like hypsometric integrals (HI). For tectonic analysis of the Mula River Basin, we divided the study area into 309 subbasins. The results obtained from the HI calculations for the subbasins led us to the classification of the study area into three classes, i.e., class 1 (0.51–0.78), class 2 (0.37–0.50), and class 3 ([Formula: see text]), where class 1 is for the highest tectonic activity, class 2 responds to moderate, and class 3 is for the lowest tectonic activity. We calculated the hypsometric curves to understand the geomorphological cycle of the Mula River Basin. We quantified the subbasins of the Mula River Basin inside the highly active tectonic zone of Kirthar fold and fault zone as per their tectonic activity and found that a major portion of the study area indicates low tectonic activity (44.33%), medium tectonically active, and high tectonically active subbasins are 37.86% and 17.79%, respectively. These findings are supported by the presence of high-relief areas and known faults in the study area.

Application of GIS and remote sensing in morphometric analysis of river basin at the south-western part of great Ganges delta, Bangladesh

Abstract Analysing the morphometric parameters is the most expedient and parsimonious way of representing the hydrologic and physiographic attributes of river basins. The present study attempts to measure the morphometric parameters for assessing the understanding of morphological, hydrological, and physiographic properties of the south-western part of the Ganges delta. Parameters were analysed from Shuttle Radar Topography Mission's (SRTM) maps and total of eight linear, six areal, eight relief, and five drainage texture parameters have taken with hypsometric analysis for the four major rivers and two tributary river basins. The values of linear parameter denote that most of the streams (82%) fall in first order, and other orders have homogeneous underline materials. The aerial parameters represent low peak discharge and the upper region is less vulnerable to flood. The relief parameter values show that the entire basin has low surface runoff and they are less erosional (slope < 3.97°). The drainage density indicates the coarser nature and circularity ratio (0.08) represents the elongated shape. The southern portion of the basin has a greater flood potential and hypsometric index (0.49) shows the entire basin is in mature stage of formation. These results would be helpful for reckoning the watersheds for drainage management and environmental planning for ecological management and sustainable development.

GIS-Analysis for Active Tectonics Assessment of Wadi Al-Arish, Egypt

In this paper, we apply an effective method to evaluate relative tectonic activity by applying several morph-tectonic indices that are useful in evaluating topography and tectonics. These indices include stream length-gradient, asymmetric factor, hypsometric index, hypsometric curves, valley floor width to valley height ratio, drainage basin shape, and mountain front sinuosity. The study region of Wadi Al-Arish in northern Sinai Peninsula in northern Egypt is a natural laboratory to examine relative tectonic activity levels for calculating morpho-tectonic indices of several catchments and sub-catchments rather than an individual catchment. Northern Sinai, comprising the Waid Al-Arish area, is characterized by several large inversion anticline folds. The cumulative results extracted from morpho-tectonic indices ae presented as a new index, namely relative tectonic activity level (RTAL), which we classified into four levels: low, moderate, high, and very high relative tectonic activity. Therefore, the study region provides different levels of relative tectonic activity resulting from fault patterns affecting the northern Sinai inversion forms. The paper examines the concept that regions with various levels of tectonic activity are associated with specific values of RTAL.

On the disequilibrium response and climate change vulnerability of the mass-balance glaciers in the Alps

AbstractGlaciers in the Alps and several other regions in the world have experienced strong negative mass balances over the past few decades. Some of them are disappearing, undergoing exceptionally negative mass balances that impact the mean regional value, and require replacement. In this study, we analyse the geomorphometric characteristics of 46 mass-balance glaciers in the Alps and the long-term mass-balance time series for a subset of nine reference glaciers. We identify regime shifts in the mass-balance time series (when non-climatic controls started impacting) and develop a glacier vulnerability index (GVI) as a proxy for their possible future development, based on criteria such as hypsometric index, breaks in slope, thickness distribution and elevation change pattern. We found that the subset of 46 mass-balance glaciers reflects the characteristics of the total glacier sample very well and identified a region-specific variability of the mass balance. As the GVI is strongly related to cumulative glacier mass balances, it can be used as a pre-selector of future mass-balance glaciers. We conclude that measurements on rapidly shrinking glaciers should be continued as long as possible to identify regime shifts in hind-cast and better understand the impacts of climatic variability on such glaciers.

A Quantitative Evaluation of Hyperpycnal Flow Occurrence in a Temperate Coastal Zone: The Example of the Salerno Gulf (Southern Italy)

The inner continental shelf is regarded as a repository of hyperpycnal flow (HF) deposits the analysis of which may contribute to hydrogeological risk assessment in coastal areas. In line with the source to sink paradigm, we examined the dynamics of the coastal watersheds facing the Salerno Gulf (Southern Tyrrhenian Sea) in generating hyperpycnal flows and investigated the shallow marine sediment record to verify their possible occurrence in the recent past. Thus, the morphometric properties (hypsometric integral, hypsometric skewness, hypsometric kurtosis, density skewness and density kurtosis) of the watersheds together with the potential rivers’ discharge and sediment concentration, calculated by applying altitude- and extent -based experimental relations, allowed to detect the rivers that were prone to producing HFs. In the shallow marine environment record of the last 2 kyr, anomalous sedimentation, possibly linked to HF events, was identified by comparing the sand-mud ratio (S/M) down-core —at three sites off the main river mouths — to the expected S/M calculated by applying the relation governing the present-day distribution of sand at the seabed in the Salerno Gulf. A return period of major HF events ≤ 0.1 kyr can be inferred for rivers which fall into the category “dirty rivers”. In these cases, the watersheds have a hypsometric index ranging between 0.2 and 0.3, coastal plains not exceeding 30% of the entire catchment area and a maximum topographic height ≥1000 m. A return period of about 0.3 kyr has been inferred for the “moderately dirty rivers”. In these other cases, about 50% of the watersheds develop into a low gradient coastal plain and have a hypsometric index ranging between 0.09 and 0.2. The observations on land and offshore have been complemented to reach a more comprehensive vision of the coastal area dynamics. The method here proposed corroborates the effectiveness of the source to sink approach and is applicable to analogous sediment records in temperate continental shelves which encompass the last 3 kyr, a time interval in which the oscillations of relative sea level can be overlooked.

Landscape expressions of tectonics in the Zagros fold-and-thrust belt

This study uses geomorphic indices, including normalized channel steepness index (ksn), integrated relief and hypsometric index (HI), to investigate how landscape responds to tectonic and climatic drivers in the Zagros fold-and-thrust belt, and show how geomorphology can be a sensitive indicator of tectonic processes. There is a broad association of relatively high ksn values (>50 m0.9) with the upper elevation limit for seismogenic thrusting, which occurs regionally at the 1250 m topographic contour. Higher ksn values occur beyond this seismicity cut-off in the Bakhtyari Culmination, but are rare in the Fars region. We measured HI values for 17,380 third order river basins across the Zagros. In many areas the low/high HI transition (0.3) is typically at the elevation limit of seismogenic thrusting. There are two important exceptions. In the Dezful Embayment/Bakhtyari Culmination the low/high HI transition lies at higher elevations than the thrust seismicity cut-off. In the Fars region, the HI transition lies at lower elevations than the seismicity cut-off. We explain these differences by the different climates of the two areas: wetter conditions and vigorous drainage systems in the Dezful/Bakhtyari region retard orogenic plateau growth; drier climate and low power rivers in the Fars region promote plateau growth. Orographic precipitation may itself have a tectonic control; regional basement strength variations have caused intense thrusting and high relief in the Bakhtyari Culmination. Integrated relief of five across-strike Zagros topographic swath profiles is in the range 2.2–2.8 108 m2. We argue that this consistency within ~25% relates to the comparable strain rates across different sectors of the Zagros, regardless of local structural, drainage network or climatic variations.

An assessment of landform composition and functioning with the first proglacial systems dataset of the central European Alps

Proglacial systems are enlarging as glacier masses decline. They are in a transitory state from glacier-dominated to hillslope and fluvially-dominated geomorphological processes. They are a very important meltwater, sediment and solute source. This study makes the first quantitative, systematic and regional assessment of landform composition and functioning within proglacial systems that have developed in the short term since the Little Ice Age (LIA). Proglacial system extent was thus defined as the area between the LIA moraine ridges and the contemporary glacier. We achieved this assessment via a series of topographic analyses of 10 m resolution digital elevation models (DEMs) covering the central European Alps, specifically of Austria and Switzerland. Across the 2812 proglacial systems that have a combined area of 933 km2, the mean proportional area of each proglacial system that is directly affected by glacial meltwater is 37%. However, there are examples where there is no glacial meltwater influence whatsoever due to complete disappearance of glaciers since the LIA, and there are examples where >90% of the proglacial area is probably affected by glacial meltwater. In all of the major drainage basins; the Inn, Drava, Venetian Coast, Po, Rhine, Rhone and Danube, the proportions of the combined land area belonging to each landform class is remarkably similar, with >10% fluvial, ~35% alluvial and debris fans, ~50% moraine ridges and talus/scree, and ~10% bedrock, which will be very helpful for considering estimates of regional sediment yield and denudation rates. We find groupings of the relationship between proglacial system hypsometric index and lithology, and of a slope threshold discriminating between hillslope and fluvial-dominated terrain, both of which we interpret to be due to grain size. We estimate of contemporary total volume loss from all of these proglacial systems of 44 M m3a−1, which equates to a mean of 0.3 mm·a−1 contemporary surface lowering. Overall, these first quantifications of proglacial landform and landscape evolution will be an important basis for inter- and intra-catchment considerations of climate change effects on proglacial systems such as land stability, and changing water, sediment and solute source fluxes. Our datasets are made freely available.

Using unsupervised classification techniques and the hypsometric index to identify anthropogenic landscapes throughout American Samoa

Aerial LiDAR data offers a valuable tool in locating ancient anthropogenic landscapes around the world. This technology is particularly ideal in places where thick vegetation obscures the ground surface, reducing the utility of satellite imagery. On the islands of American Samoa, many interior anthropogenic landscapes remain unsurveyed, largely because the terrain makes it difficult and there is only general knowledge of where the anthropogenic modification may have existed. Aerial LiDAR flown in 2012 is proving to be a valuable tool in locating these prehistoric anthropogenic areas, yet improvements can be made on the methodology. This paper provides an unsupervised classification method to identify anthropogenic landscapes based on slope and hypsometric index: a topographic measure of roughness. Areas of American Samoa with known anthropogenic modifications were used to develop the classification techniques, which were then extended to areas where anthropogenic landscapes are undocumented and unexplored. The findings presented here suggest that interior anthropogenic patterns may be strongly dependent on island topography.

Overprint of neotectonism along the course of River Chel, North Bengal, India

This paper aims to unveil neotectonic imprints in topography, drainage and sediments in the 46.25 km long course of the River Chel from its source down to its alluvial fan at the base of the Himalayan Mountain Front in the Darjeeling–Jalpaiguri districts of India. A semi-circular ridge delimits its primary catchment. Within confinement of this watershed basin the drainage pattern is composite being convergent along the periphery and divergent on a butte inside. All these geomorphic neotectonic imprints are accompanied by ramp and flat structures and spectacular mylonitization of rocks.High hypsometric index and convex shape of the hypsometric curve derived from the central near-straight course of the river between the primary catchment and the Main Frontal Thrust (MFT) also reflects tectonic youthfulness of the river course. It is well manifested also in widely variable stream index and stream gradient index ratios (SL/K) often exceeding 2. In response to neotectonism, this river course as a whole shifted westward between 1962 and 2007. Maximum reduction of the stream gradient on top of the MFT is eloquent enough about recent uplift of the thrust ridge. The high average slope gradient of canyon wall about 45.68° is well consistent with this uplift. Very low channel-width/valley-height ratio along the river further corroborates the uplift.The alluvial fan system of the River Chel is comprised of five morphogenetic fans stacked one above another with a tendency to shrink and shift progressively upslope. They differ from each other in terms of tilt, axial orientation, primary depositional surface gradient and convexity in transverse section and thus present a writ of ongoing tectonism. Progressive upward increase in the share of distal crystalline rocks in clast composition within alluvial fan package is a clear proxy for southerly advancement of the MFT. Concomitant increase in maximum clast size is in good agreement with sediment source uplift. All the five fans are, however, dormant now. Present-day River Chel deeply incises through all of them and suggests further basement uplift in the context of frequent evidences of neotectonism all around, although the role of climate remains uncertain in absence of adequate data.

Geomorphic evidences and chronology of multiple neotectonic events in a cratonic area: Results from the Gavilgarh Fault Zone, central India

The ENE–WSW trending Gavilgarh Fault Zone (GFZ) is an important tectonic lineament within the Central Indian shield. Geomorphological mapping and spatial analyses of rivers were carried out to elucidate the imprints of active tectonics on the fluvial systems of this region. The sinuosity index, width–depth ratio of river valleys, longitudinal profile, S–L index and hypsometric index of the rivers flowing from north to south across the GFZ lineament suggest that the northern side of GFZ was tectonically uplifted. Luminescence dating of sediments from river terraces and calculation of knickpoint migration rates in the rivers indicate occurrence of multiple neotectonic events in GFZ at ca. 65–80ka, ca. 50ka, ca. 30–40ka, and ca. 14ka. Evidences of neotectonic activity, presence of active geothermal springs, and occurrence of recent earthquakes along GFZ suggest that this lineament is tectonically active and there is a need for proper seismic monitoring of this fault zone.

Neotectonic Activities in Northern Saurashtra Peninsula Bordering Gulf of Kachchh

This study points out the evidences of neotectonics and possible existence of active fault in northern part of Saurashtra Peninsula. The methodology used for the detection of neotectonism are: a) analysis of numerical data obtained from Digital Elevation Model (DEM) and its derivatives (morphometric indices), b) study of geomorphic markers and c) correlation of seismic & palaeoseismic data and geomorphology with structural lineaments. Morphometric indices such as drainage density, stream frequency, bifurcation ratio, basin length, basin relief, relief ratio, elongation ratio, stream gradient index, hypsometric index and sinuosity ratio have been used to assess the tectonic signatures. Morphometric indices suggest that Aji river basin is tectonically active, whereas Und and Sasoi river basins show some of the parameters in active tectonic range. Regional study using remotely sensed data (Landsat OLI multispectral) has helped to show a) about 100° dextral rotation of Aji river trunk channel near the Gulf coast and b) dextral deflection of both Aji and Und river about 25 km from the coast. Study of a segment of Aji river basin near Ranjitpura- Balamba proved upliftment and tilting of land resulting a) narrowing of trunk channel towards sea, b) development of new sets of channels over tilted river terrace, c) development of beheaded channels, d) presence of palaeo-channels and palaeo-delta in different directions with the present ones and e) formation of estuary with definite geometric shape. Occurrence of earthquake epicentres, in conformity with predicted lineaments in addition to paleoseismic records supports the existence of the fault. On the basis of integrated evidences it has been established that the Saurashtra coast along the Gulf of Kachchh is tectonically active with the existence of a dextral strike slip fault (ENE-WSW trending) with a rotational component manifesting tilting of the northern block towards east.

Recent tectonic activity of the Gafsa fault through morphometric analysis: Southern Atlas of Tunisia

This article focuses on the neotectonics of the southern Atlas of Tunisia based on morphometric analyses. Five major relevant morphometric parameters were processed and analyzed: residual topography, hypsometric index, drainage anomalies, maximum vertical curvature, and terrain roughness, and compared to the structural and tectonics of the study area. These are relevant to describe the topographic changes, and therefore suggest possible neotectonic activity.The analysis of these morphometric indices reveals that two structures in the study area (Jebels Ben Younes and Bou Ramli) are distinguished by a specific morphometric footprint: high residual topography, high hypsometric integral value of some watersheds (HI > 0.6), high frequency of drainage anomalies, high maximum vertical curvature, and high roughness index. The correlation of these geomorphic indices with the structural pattern of the study area confirms the neotectonic reactivation (dating from the Quaternary) and the dextral strike-slip component of the Gafsa fault (the major tectonic feature in the southern Atlas of Tunisia). Thus, the morphometric analysis of the Digital Elevation Model and the drainage network provide a more accurate insight into the morphodynamics of the study area.

How fast is the denudation of the Taiwan mountain belt? Perspectives from in situ cosmogenic 10Be

Quantifying denudation rates in a wide range of climatic and tectonic settings at various time and space scales is a critical step in calibrating and validating landscape evolution models. Focusing on Taiwan, we quantified centennial rates of denudation at the scale of the whole orogen, using in situ 10Be concentrations measured in stream sediments collected at the outlets of major rivers. To assess denudation rates that are statistically significant, we applied both the mean square weighted deviation approach and the bootstrap technique. For the central segment of the belt, where the collision is considered to be near mature, the orogen-scale pattern of denudation shows a two-fold pattern: (1) higher denudation values on the order of 4–5mm/yr characterize the eastern side of the belt (i.e., retro-wedge), with a slight increase towards the south and (2) lower denudation values on the order of 1–3mm/yr on the western side of the belt (pro-wedge) with a minimum value centered on the main recess of the deformation front. To the north and to the south of the central segment, the denudation rates converge towards lower values on the order of 2–3mm/yr. At the scale of the mountain belt, drainage basin metrics such as relief, hypsometric index and slope values seem to explain the observed variance in the data population, conversely to the first-order average precipitation pattern, suggesting a strong tectonic control on the regional pattern of denudation rates. Applied to the whole orogen, such field-based approach thus provides important input data to validate and calibrate the parameters to be supplied to landscape evolution models.

Changes in Clemenceau Icefield and Chaba Group glaciers, Canada, related to hypsometry, tributary detachment, length–slope and area–aspect relations

AbstractWe compiled a detailed glacier inventory of 176 glaciers in the Clemenceau Icefield Group (CIG) and adjacent Chaba Group (CH), Canada, based on 2001 Landsat 7 and 2000–03 ASTER satellite imagery and Natural Resources Canada digital elevation models. We used this inventory to measure length and mass-balance changes and their possible controls. A classification of glacier hypsometry in the form of a hypsometric index was used to assess the sensitivity of different glacier systems to a unit rise in snowline. The altitude and AAR of possible steady-state ELAs was derived using several methods, and was compared to late-summer snowlines of 2001 .We further compared planar glacier area to slope-corrected area, and compared the effects on the shape of the hypsometric curves, on the total glacier area and on the aspect–area distribution. In 2001, CIG had a glaciated area of 271 km2 and had lost 42 km2 since the mid-1980s. CH had a total area of 69 km2 and had lost 28 km2. Average retreat rates are 14 ma–1 for the period 1850–2001 (n=39) and 21 ma–1 for 1986/87–2001 (n=23), indicating accelerated retreat. Larger glaciers and those that experience tributary detachment tend to retreat faster. The difference between planar and slope-corrected glacier areas ranges from 5% to 20%, with a 6% increase for the entire CIG/CH region. The area increase does not change the shape of the hypsometric curves.

Magnitude and frequency of debris flows

Debris flows periodically result in the loss of lives and property. Engineering structures designed to control debris flows are often inadequate because of lack of knowledge of the magnitude of debris events. The objective of this study was to develop a method that could be used to estimate the magnitude and frequency of debris flows. The data base for the study included 29 watersheds in the Los Angeles area, with drainage areas < 3 mile 2. Assuming a log-normal distribution, prediction equations for 2-, 5-, 10-, 25-, 50-, and 100-year return periods were developed as a function of relief ratio, hypsometric index, the interval between burns, and drainage area. Principal components and correlation analyses were used to select the predictor variables. Numerical optimization was used to calibrate the model. The prediction equations can be used to estimate the magnitude of debris flows for ungaged watersheds where estimates are required for debris basin and channel design, protection of culverts and roads, land use planning, and zoning and establishing insurance rates.