A quantitative analysis for geomorphic indices of longitudinal river profile: a case study of the Choushui River,Central Taiwan

Due to the plate movement is considerably slow, the human history record is too short to register landscape change for such a long time scale. However, longitudinal river profile can display watershed landscape characteristics. Therefore, this paper applies a quantitative analysis of geomorphic indices coupled with some mathematical models for the Choushui River and its six tributaries, including the gradient index and slope–area relationship. The abnormally high SL and SL/k values indicated that a decreasing trend from lower- to mid-stream areas and south Lishan fault was higher than north Lishan fault on the upstream areas, and the result of slope–area relationship also indicated that the regression line of the upper and lower steam exhibit an obvious right-shift nearby Lishan fault, could be explained by geodynamic models of active deformation in Taiwan area. This study also found that the abnormally high values of SL/k were affected by river and fault intersecting to form a high angle or perpendicular and the abnormally low values of SL/k were affected by river along with a fault or form a low angle, but the channel of Junda River along with Lishan fault is opposite. Based on quantitative results of these geomorphology indices, this study suggests that the important factor influencing landscape of the Choushui River watershed is tectonic uplift.     

A quantitative analysis of relative tectonic activity classes of Kali river basin, southwest coast of India

The Kali river basin of the southwest coast of India has been investigated to examine the influence of tectonic activity through an analysis of the geomorphic indices that were computed using geographical information system (GIS). Five geomorphic indices—stream length–gradient index, asymmetry factor, hypsometric integral, valley floor width-to-height ratio, and elongation ratio—were used for identification of evidences of tectonic activity. The results obtained from these indices were combined to develop an index of relative tectonic activity classes using GIS. The average of the five measured geomorphic indices was used to evaluate the distribution of relative tectonic activity in the study area. About 18 % of the study area (～726 km²) belongs to class?1; 37 % (～1506 km²) to class?2; and 44 % (～1,762 km²) to class 3. Sub-basins found at the Western Ghat region, relative tectonic activity classes show low and medium values which indicate the higher degree of tectonic activity compared to the upland plateau regions.     

Geomorphic characteristics of a bedrock river inferred from drainage quantification,longitudinal profile,knickzone identification and concavity analysis: a DEM-based study

An examination of river channels has ability to provide substantial information regarding the geomorphic characteristics, control of lithology, tectonic uplift and geomorphic evolution during the geological past of an area. In this paper, a detailed study of geomorphic and structural investigation has been carried out for Pravara basin, Maharashtra, with the help of 90-m resolution SRTM DEM and geospatial techniques. Drainage network analysis performed in this paper demonstrates the general geomorphic characteristics, while the analysis of longitudinal profile synthesises lithological control over Pravara basin. Pravara is a 6th order drainage basin, encompassing an area of 2637 km². Bifurcation ratio reveals low to moderate structural control. Due to the hard rock lithology, the drainage density and stream frequency are low, and it indicates higher permeability in the sub-surface layers. The shape parameters denote that Pravara is highly elongated and it is easier to control floods in this basin. Relief parameters show very steep slope and higher vulnerability to the slope failure in some areas. Upstream of Pravara river has shown that series of breaks and knickzones indicate active erosion and acute lithological control on the channel. Major breaks are observed only in the main channel whereas in two major tributaries, no such breaks found, instead these tributaries are characterised by several knickzones which indicate regional variation in the lithological physiognomies. Different lithological stages on knickpoint and channel incision substantiate rejuvenation of Pravara river in several phases during geological past. The geospatial methodology carried out in this study can be pragmatic elsewhere around this world to recognise the geomorphic appearances and lithological control of a drainage basin.     

青藏高原周边地区河流分形特征与地貌、构造活动耦合关系

青藏高原周边地区的地貌特征与形成演化机制一直是科学界研究的热点。选择青藏高原周边典型地区河流分形特征、地貌特征及构造活动性进行研究,发现喜马拉雅断裂带、龙门山断裂带和阿尔金断裂带控制的区域构造活动性强烈,历史地震记录频繁,大震较多,河流形态与地貌演化特征也非常相似,河流纵剖面变化很快,长波长下凹型,河流坡降比大,地形起伏度大,河流形态变化简单,河流分维值低;青藏高原东北缘构造活动性不强烈,历史地震记录偏低,大震极少,河流纵剖面变化缓慢,近似长波长微振幅上凸型,河流坡降比小,地形起伏度较小,河流形态错综复杂、分维值高;青藏高原东南缘,构造活动性较强烈,历史地震记录频繁,大震较多,但由于该区域平均多年侵蚀速率比较低,同时河流下切深度大,河流纵剖面变化缓慢,也是近似长波长微振幅上凸型,河流坡降比小,河网发育较成熟,河网分维值较高。通过对比发现,降水量的变化对该区域侵蚀速率的影响远小于构造活动性的作用,在分析河网形态特征时可以不考虑降水量空间变化的影响。     

Appraisal of relative tectonic activity along the Kazerun Fault Zone,Zagros Mountains,Iran: insight from spatial analysis of geomorphic indices

This paper investigates the impact of active tectonics on the geomorphic processes and landscape evolution along the Kazerun Fault Zone (KFZ) in the Zagros Mountains of Iran using spatial analysis of geomorphic indices. We document how topography and morphology are influenced by active tectonic deformation. The Zagros fold–thrust belt is an area of active crustal shortening where northwest–southeast oriented fault‐related folds become younger from north to south and from southeast to northwest. This temporal and spatial evolution of the belt was tested using geomorphic indices of active tectonics that include mountain front sinuosity index (Smf), the valley width/height ratio (Vf), drainage basin asymmetry factor, hypsometric integral, drainage basin shape ratio and mean axial slope of the channel. Change in the geomorphic indices is the result of active fold growth and change in the uplift rate. Decreasing Smf and Vf values from north (Smf = 2.01; Vf = 0.5) to south (Smf = 1.12; Vf = 0.2) and from southeast (Smf = 1.84; Vf = 0.8) to northwest (Smf = 1.54; Vf = 0.1) points to a migration of the active crustal shortening towards W–SW. The combined geomorphic (field evidences) and morphometric data (quantitative analysis of geomorphic indices) provide evidence of relative variation in the tectonic activity along the Kazerun Fault Zone and related landforms. The utilization of geomorphic parameters with comparison to the field observations exhibits change in relative tectonic activities mostly corresponding to the change in mechanism of the prominent fault zones in the study area. Copyright © 2014 John Wiley & Sons, Ltd.     

Morphometric analysis of Suketi river basin,Himachal Himalaya,India

Suketi river basin is located in the Mandi district of Himachal Pradesh, India. It encompasses a central inter-montane valley and surrounding mountainous terrain in the Lower Himachal Himalaya. Morphometric analysis of the Suketi river basin was carried out to study its drainage characteristics and overall groundwater resource potential. The entire Suketi river basin has been divided into five sub-basins based on the catchment areas of Suketi trunk stream and its major tributaries. Quantitative assessment of each sub-basin was carried out for its linear, areal, and relief aspects. The analysis reveals that the drainage network of the entire Suketi river basin constitutes a 7th order basin. Out of five sub-basins, Kansa khad sub-basin (KKSB), Gangli khad sub-basin (GKSB) and Ratti khad sub-basin (RKSB) are 5th order sub-basins. The Dadour khad sub-basin (DKSB) is 6th order sub-basin, while Suketi trunk stream sub-basin (STSSB) is a 7th order sub-basin. The entire drainage basin area reflects late youth to early mature stage of development of the fluvial geomorphic cycle, which is dominated by rain and snow fed lower order streams. It has low stream frequency (Fs) and moderate drainage density (Dd) of 2.69 km/km ². Bifurcation ratios (Rb) of various stream orders indicate that streams up to 3rd order are surging through highly dissected mountainous terrain, which facilitates high overland flow and less recharge into the sub-surface resulting in low groundwater potential in the zones of 1st, 2nd, and 3rd order streams of the Suketi river basin. The circulatory ratio (Rc) of 0.65 and elongation ratio (Re) of 0.80 show elongated nature of the Suketi river basin, while infiltration number (If) of 10.66 indicates dominance of relief features and low groundwater potential in the high altitude mountainous terrain. The asymmetry factor (Af) of Suketi river basin indicates that the palaeo-tectonic tilting, at drainage basin scale, was towards the downstream right side of the drainage basin. The slope map of Suketi river basin has been classified into three main zones, which delineate the runoff zone in the mountains, recharge zone in the transition zone between mountains and valley plane, and discharge zone in the plane areas of Balh valley.     

http://www.sciencedirect.com/science/article/pii/S1674987111001265

Landscapes in tectonically active Hindu Kush（NW Pakistan and NE Afghanistan） result from a complex integration of the effects of vertical and horizontal crustal block motions as well as erosion and deposition processes.Active tectonics in this region have greatly influenced the drainage system and geomorphic expressions.The study area is a junction of three important mountain ranges （Hindu Kush-Karakorum-Himalayas） and is thus an ideal natural laboratory to investigate the relative tectonic activity resulting from the India-Eurasia collision.We evaluate active tectonics using DEM derived drainage network and geomorphic indices hypsometric integral（HI）,stream-length gradient （SL）.fractal dimension（FD）.basin asymmetry factor（AF）.basin shape index（B_s）,valley floor width to valley height ratio（Vf） and mountain front sinuosity(S_mf). The results obtained from these indices were combined to yield an index of relative active tectonics （IRAT） using CIS.The average of the seven measured geomorphic indices was used to evaluate the distribution of relative tectonic activity in the study area.We defined four classes to define the degree of relative tectonic activity:class 1 very high（1.0≤IRAT 1.3）;class 2-high（1.3≥IRAT<1.3）:class 3—moderate（1.5≥IRAT<1.8）;and class 4—low（l.8≥1RAT）.In view of the results.we conclude that this combinetl approach allows the identification of the highly deformed areas related to active tectonics.Landsat imagery and held observations also evidence the presence of active tectonics based on the dellected streams,deformed landforms.active mountain fronts and triangular facets.The indicative values of IRAT are consistent with the areas of known relative uplift rates,landforms and geology.     

DEM and GIS analysis of sub-watersheds to evaluate relative tectonic activity. A case study of the North–south axis (Central Tunisia)

Morphotectonic analysis using geomorphic indexes has been developed as a basic tool to identify recent tectonic deformation in specific areas.This study was undertaken to develop an integrated quantitative geomorphic analysis of tectonic activity in the North–south axis, central of Tunisia. Different geomorphic indexes, including elongation ratio (E), drainage basin asymmetry (Af), hypsometric integral (Hi), Valley floor width-to-height ratio (Vf), mountain front sinuosity (Smf), and stream length gradient index (SL) were calculated. The relationships between the calculated indexes, their correlations and their significance (based on p-values) were also investigated.. Using the hierarchical cluster analysis based on Ward’s method, these indexes were classified into three classes describing the relative, different effect of tectonics in each fault segment. The higher deformation is concentrated in the NE-SW Boudinar fault, followed, in order of decreasing activity, by Goubrar, Gouleb, and Majoura normal faults. This pattern of variation in the relative degree of tectonic activity is consistent with field evidence.     

Development of Earthquake Event Detection Technique Based on STA/LTA Algorithm for Seismic Alert System

The drainage basin of the Kalyani river, a tributary of Gomati river has been mapped and delineated using Survey of India toposheets (1:50,000 scale) and remote sensing satellite data. The digitization, slope map preparation and statistical calculations have been carried out with the help of geographical information system (Arc GIS 10). Kalyani a fifth order river exhibits meandering behavior having 2.45 sinuosity index (SI). The Kalyani river basin has about 1235 km²area with NW-SE sloping trend. The total number of first, second, third, and fourth order streams are 373, 71, 12 and 2 respectively, showing dominance of first order streams in the basin. The mean bifurcation ratio (Rb) of the entire basin is 4.8, which indicates that the drainage is not much influenced by geological structures and exhibits dendritic drainage pattern. Relief ratio (Rr) indicates low to medium surface run-off, and low stream power for erosion. The analysis of river bank height ‘r’ (escarpment) and longitudinal profile of the river closely reveals neotectonic activity at some locations in the basin. To prepare a comprehensive watershed development and management plan, it is important to understand the topography and drainage characteristics of the region.     

九龙江北溪流域河流特征及其构造指示意义

本文利用DEM数据,运用基岩河道侵蚀模型提取九龙江北溪流域的河流下凹程度、陡峭指数和蜿蜒度等地貌指数研究北溪流域地质构造活动特点。通过对流域地貌参数的分析发现九龙江北溪流域陡峭指数存在自NW向SE递减的规律,陡峭指数和蜿蜒度有很好的对应关系.排除气候因素和基岩性质等影响因子,认为河道陡峭指数的分布特征揭示了九龙江北溪流域的地壳抬升速率自西北向东南递减的分布特征,此认识与前人采用精密水准资料计算地壳垂直运动速率结果相一致。     

Morphotectonic Appraisal of Yamuna River Basin in Headwater Region: A Relative Active Tectonics Purview

In the present paper integrated appraisals of landform evolution and their geomorphic features, drainage networks across the upper part of Yamuna river basin have been attempted by using various geomorphic indices such as watershed, drainage density (D), drainage texture, stream-gradient index (SL), hypsometric integral (HI), drainage basin asymmetry (AF), mountain front sinuosity (Smf), sinuosity index (SI), valley floor height and width ratio (Vf) and data of historical earthquakes in characterizing the basin in view of relative index of active tectonics (RIAT) on DEM in geographic information systems (GIS) environment to assess the influence of recent tectonics on geomorphologic growth of the basin.The substantiated RIAT classes through some field observations and corroborated by recent seismicity reveal the recent activation of Yamuna tear faults in the basin with delineation of four RIAT classes such as class-1 (inactive 9.8% of the area), class-2 (low active; 16.40% of the area), class-3 (moderately active; 42.38% of the area) and class-4 (very active; 31.62%). The results suggest that the Himalayan frontal thrust (HFT) and Yamuna tear (YT) located in the basin is morphogenic in nature and got activated several times as evidenced by number of seismic activities in the basin and adjoining regions. The incision, and sharp turning of rivers, crenulations and warping of cross beddings/laminations and silt/clay beds and lenses, megascopic and mesoscopic faulting in sediment sequences suggest a very active nature of the HFT and YT till date in association with three prolific microseismogenic weak zones These active discontinuities appear to support the formation and development of different deformational features in sediment sequences which may be indirectly related to subduction and underthrusting of Indian plate under Eurasian plate below the Himalayan mountain chain.     

涪江上游流域盆地地貌特征及构造指示意义

对涪江上游流域盆地地貌特征及成因进行研究,有助于揭示青藏高原东缘晚新生代以来新构造活动的差异性。本文以ArcGIS水文分析模块为技术平台,在研究区域内系统提取涪江上游流域盆地地表水系网络和涪江干流东西两侧36个亚流域盆地,并对亚流域盆地面积、周长、水系总长度、水系分支比、流域盆地演化阶段进行统计分析,结果表明,涪江干流河道东西两侧典型地貌参数存在显著差异。通过对该区域构造运动、岩石抗侵蚀能力、降水特征等几方面因素与河流下切过程相关性的分析可知,降水条件和岩性差异并不是涪江上游亚流域盆地不对称发育的主要影响因素,该区域断裂活动导致的地形不对称分布格局及岩层破碎程度的差异是涪江上游流域地貌差异演化的主控因素。另外,涪江上游干流展布呈现出两个特征:涪江干流河道因雪山断裂、北川-映秀断裂、彭县-灌县断裂的右旋(或左旋)走滑作用而沿断裂发生同步弯曲;涪江干流河道在北川-映秀断裂北侧由西北-东南流向转变为近正南流向,究其原因,主要是龙门山断裂带3条主干断裂的区域性右旋走滑活动驱动该区域物质产生相应右旋运动,从而使长期处于断层右旋作用控制之下的涪江干流河道发生转向。     

Morphometrical analysis of two tropical mountain river basins of contrasting environmental settings, the southern Western Ghats, India

The morphometric analysis of river basins represents a simple procedure to describe hydrologic and geomorphic processes operating on a basin scale. A morphometric analysis was carried out to evaluate the drainage characteristics of two adjoining, mountain river basins of the southern Western Ghats, India, Muthirapuzha River Basin (MRB) in the western slopes and Pambar River Basin (PRB) in the eastern slopes. The basins, forming a part of the Proterozoic, high-grade, Southern Granulite Terrain of the Peninsular India, are carved out of a terrain dominantly made of granite- and hornblende-biotite gneisses. The Western Ghats, forming the basin divide, significantly influences the regional climate (i.e., humid climate in MRB, while semi-arid in PRB). The Survey of India topographic maps (1:50,000) and Shuttle Radar Topographic Mission digital elevation data were used as the base for delineation and analysis. Both river basins are of 6th order and comparable in basin geometry. The drainage patterns and linear alignment of the drainage networks suggest the influence of structural elements. The Rb of either basins failed to highlight the structural controls on drainage organization, which might be a result of the elongated basin shape. The irregular trends in Rb between various stream orders suggest the influence of geology and relief on drainage branching. The Dd values designate the basins as moderate- to well-drained with lower infiltration rates. The overall increasing trend of Rl between successive stream orders suggests a geomorphic maturity of either basins and confirmed by the characteristic I _hyp values. The Re values imply an elongate shape for both MRB and PRB and subsequently lower vulnerability to flash floods and hence, easier flood management. The relatively higher Rr of PRB is an indicative of comparatively steeply sloping terrain and consequently higher intensity of erosion processes. Further, the derivatives of digital elevation data (slope, aspect, topographic wetness index, and stream power index), showing significant differences between MRB and PRB, are useful in soil conservation plans. The study highlighted the variation in morphometric parameters with respect to the dissimilarities in topography and climate.     

Implications of shearing on drainage network development in Achankovil Shear Zone,South India: insights from DEM-based geomorphic indices and longitudinal profile analysis

The Achankovil Shear Zone (AKSZ) in the Southern Granulite Terrain separates the Trivandrum block from the Madurai block. Various geomorphic indices and longitudinal profiles of the river systems in the AKSZ, viz., Achankovil river basin (ARB) and Kallada river basin (KRB), were derived from SRTM DEM to decipher the influence of shearing and deformation on the regional drainage evolution. Although hypsometric analysis of the basins implies old stage of geomorphic evolution, horizontal shifts in the channel plan form are restricted (except in the Tertiary sediments), suggesting the structural controls over the drainage organization, which are also supported by the high topographic sinuosity. The transverse topographic symmetry (T) vectors indicate a southwesterly migration for the upstream channel segments of both ARB and KRB, while the northwesterly migration of the downstream courses can be correlated with the dextral shearing of the AKSZ. Even though the shear zone is considered to be the block boundary between the charnockite of Madurai and khondalite of Trivandrum blocks, the moderate to low profile concavity (θ) values are probably the result of suppressing the effect of the block–boundary interactions by shearing and denudation. The study proposes a model for evolution of drainage network in the AKSZ, where the mainstream of the basins was initially developed along NE–SW direction, and later the upstream and midstream segments were reoriented to the NW–SE trend as a result of intense shearing. Overall, the present study emphasizes the significance of geomorphic indices and longitudinal profile analysis to understand the role of shearing and deformation on drainage evolution in transcrustal shear zones.     

Application of drainage basin morphotectonic analysis for assessment of tectonic activities over two regional structures of the northeast India

The analysis of drainage basin morphotectonic indices is applied in assessment of the influence of tectonic activity on thirteen selected drainage basins of the streams having linear courses and flowing over two very prominent regional structures of northeast India, viz. the Belt of Schuppen and the Dauki fault. Such analysis has been made in order to assess the influence of tectonic activity of these structures on the morphology of the drainage basins of those streams.The different morphotectonic indices considered are: Basin elongation ratio, hypsometric integral, steepness index and profile concavity, drainage basin asymmetry, valley floor width to valley height ratio, longitudinal profiles, stream length gradient index and mountain front sinuosity. Results of the analysis of the morphotectonic indices of the drainage basins infer that morphology of both the streams and drainage basins have been influenced by the regional structures and the present tectonic status of these two structures varies from active to slightly active phase. No significant influence of lithology is seen in the distribution pattern of the anomalous knick points along the longitudinal profiles. The study also reveals that presently the state of tectonic activity is not uniform within the same regional structure and the Belt of Schuppen is relatively more active as compared to the Dauki fault.     

基于DEM的活动构造研究

地形地貌参数指标是分析区域活动构造的有力工具。本文以渭河上游流域的活动构造研究为例,通过提取地貌的参数指标,如面积-高程积分(Hi)、流域盆地不对称度(AF)、山前曲折度(Smf)以及谷底宽度与谷肩高度的比值(Vf)、盆地形状指数(Bs)等,然后对地貌参数指标等级进行算术平均化(S/n),可得到区域的相对构造活动程度(Iat),分为:低、中等、高、较高四类等级。研究认为渭河上游流域的构造活动程度相对高(Iat=1.50),这种方法对探讨整个区域活动构造的差异性具有很好的效果和意义。     

Activity level of tectonic basins,western section of the North Anatolian Fault Zone,Turkey

We employed quantitative techniques to investigate tectonic activity levels and development stages of the Bolu, Yenicaga, Dortdivan, Cerkes, Ilgaz, and Tosya structural basins along the western portions of the main trace of the North Anatolian Fault Zone (NAFZ). Our methodology incorporates six morphometric indices: basin shape (basin elongation and compactness), hypsometric integral, mountain-front sinuosity, stream length gradient index, valley floor width-to-height ratio, and asymmetry factor, obtained from the digital elevation model of the region generated from 1/25,000-scale topographic maps. These indices are integrated within the framework of an analytical hierarchy process to provide relative activity level values of the individual basins. The new analyses indicate that the basins have contrasting tectonic activity characteristics. Judging from the applied indices, the relative increasing order of the tectonic basin activity is Dortdivan, Cerkes, Yenicaga, Ilgaz, Tosya, and Bolu. Among the basins located to the north of the NAFZ, the activity decreases eastwards, whereas to the south of this profound fault zone, it decreases towards the west.     

滇中地块新生代晚期的变形机制:基于构造地貌学分析

滇中地块位于青藏高原东南缘,是研究青藏高原东南缘新生代晚期构造变形机制的理想场所. 滇中地块新生代晚期的变形机制主要有“下地壳流”和“刚性块体挤出”两种模式,前者认为地块构造活动分布较为均匀,后者认为构造活动沿断裂带更为强烈. 由于地貌指数对构造活动非常敏感,为厘定研究区新生代晚期的变形机制,基于30 m分辨率的SRTM?3数字高程模型（DEM）提取了滇中地区319个（亚）流域盆地,通过分析获得了面积高程积分曲线及面积高程积分（HI）、流域形状指数（BS）、流域盆地不对称度（AF）、标准化河流阶梯指数（SLK）、谷底宽度与谷间高度比（VF）这5种地貌指数,综合这五种指数得出相对活动构造指数（I_at）,并利用构造地貌指数（I_at）揭示了研究区的相对构造活动分布特征. 研究表明丽江-小金河断裂带、则木河-小江断裂带、红河断裂带及金沙江两侧的I_at值相对较小,其他部位相对较高,这表明滇中地区的构造活动性强的区域主要集中发育在断裂带附近,与“刚性块体挤出”模式相一致. 滇中地块中部的金沙江两侧I_at值相对较低,表明其地貌活动性较强. 这是由于新生代晚期青藏高原东南缘的隆升及河流重组,导致的金沙江及其支流切割力增强,从而造成金沙江两侧HI值、BS值、SLK值增高和VF值降低,使得金沙江两侧I_at值相对较低.      

Morphometric analysis of Usri River basin,Chhotanagpur Plateau,India, using remote sensing and GIS

A geomorphic unit Usri drainage basin (latitude: 24° 04′00″ N to 24° 34′00″ N and longitude 86°05′00″E to 86°25′00″E) lies in north-eastern parts of Chhotanagpur Plateau, India, has been selected for morphometric analysis. Digital elevation model (DEM) has been generated by Cartosat stereo pair data at 10-m resolution. The morphometric parameters considered for the analysis includes the linear, areal, and relief aspects of the basin. Morphometric analysis of the river network and the basin revealed that the Usri Basin has sixth-order river network with a dendritic drainage pattern. The dendritic drainage pattern indicates that the basin has homogeneous lithology, gentle regional slope, and lack of structural control. The bifurcation ratio between different successive orders varies but the mean ratio is low that suggests the higher permeability and lesser structural control. The low drainage density, poor stream frequency, and moderately coarse drainage texture values of the basin indicate that the terrain has gentle slope, is made up of loose material, and hence has good permeability of sub-surface material and significant recharge of ground water. The shape parameters indicate that the basin is elongated in shape with low relief, high infiltration capacity, and less water flow for shorter duration in basin. The 50 % of the basin has altitude below 300 m and gently sloping towards the southeast direction. All the morphometric parameters and existing erosional landforms indicated mature to early old stage topography.