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Abstract

ABSTRACT

Landscape features owe their origin to a combination of tectonic and climatic forces. Tectonic forces displace the land, changing the elevation locally as well as on a regional scale, affecting the altitude dependent surface processes, which in turn shape the landscape. Tectonic and geomorphic processes are therefore intimately interrelated. Quantitative assessment of landscape features has traditionally been based on calculation of geomorphic indices using elevation data derived from topographic maps, aerial photographs and field work. In recent years ASTER derived digital elevation data and advances in GIS technologies have been extensively used to determine the morphometric properties of tectonically active regions. The results of several indicesof active tectonics such as Hypsometric integral by Strahler (1952), Asymmetry Factor by Cox (1994), Stream length-gradient index developed by Hack (1973), Mountain front sinuosity developed by Bull and Mc Fadden (1977),Ratio of valley floor width to valley height can be combined to highlight tectonic activity and to provide an assessment of the relative degree of tectonic activity in an area. The objective of this research is to develop a remotely sensed approach in investigation of active tectonics in Ramganga basin, Eastern Kumaon Himalayas and to access the current degree of tectonic activity in the basin at sub basin level based on various geomorphic indices and generate tectonic activity maps based on these indices, depicting relative uplift and tilt in the study area

For the present study, Ramganga River constituting a right bank tributary of the Kali River transecting the Himalayan orogen in a NE-SW direction was considered an ideal location to test the relationship of landforms and active tectonics, and to predict relative tectonic activity on a basis of area rather than a single valley or mountain front. The study area has variable rates of active tectonics resulting from the uplift of the Kali River anticline oriented transverse to the primary structural grain of the Himalayan range, superimposed on the nearly 1.0 m/ky uplift of the orogen in response to the collision of India with Asia that produced linear WNW-ESE anticlinal forms. We test the hypothesis that areas of relatively high rates of active tectonics in the Himalaya are associated with courses of trans-Himalayan rivers predating the Himalayan orogeny.

Abstract

Digital elevation model datasets of the Advance Spaceborne Thermal Emission Radiometer (ASTER) were used for channel network and watershed delineation. The stereo images of L1b data have been used for the production ASTER DEM and data provided from ASTER represents a significant improvement in quality as 30 meter spatial resolution. Channel network extraction and watershed delineation were carried out using TauDEM (Terrain Analysis Using Digital Elevation Models), a plugin for ArcGIS 9.3. A total of 26 sub-basins were delineated in the Ramganga river basin. The main channel of the watershed is a fifth order Stream.Lower order streams mostly dominate the basin. The drainage patterns of the sub-basins are dendritic and parallel. It appears that the development of stream segments in the basin was largely influenced by local geology and structures.

We present an assessment of active tectonics based on: Mountain front sinuosity (Smf), Asymmetry factor (AF), Transverse topographic symmetry (T), Hypsometric Integral (HI), Channel sinuosity (S), Valley floor width to height ratio (Vf), Stream length-gradient index (SL),and Basin elongation ratio (Re).

Mountain front sinuosity (Smf) is defined by dividing the length of mountain front and straight line length along the mountain front. It is derived by the following formula:

Smf = Lmf/Ls

Where, Smf is the Mountain front sinuosity index, Lmf is the total length of the mountain front and Ls is the straight line length of the mountain front.

Channel Sinuosity (Cs) is derived by dividing the length of stream segment and length of valley along the stream length.

S = SL / VL

Where SL is the stream length and VL is the valley length.

Basin elongation (Re) is defined by the ratio of the diameter of a circle of the same area as the basin to the maximum basin length. It is derived by following formula:

Re = (2√A: √π)/L

Where A is the area of the basin and L is the length of the basin.

Abstract

Values of Re close to 1.0 are typical of regions of low relief and basins close to this range are oval to circular in shape.

Another index is the valley floor width to height ratio. This index reflects the differences between the V-shaped valleys down cutting in response to active uplift, where the stream is governed by the influence of a base level fall at some point downstream that indicates a relatively high tectonic activity, and the U-shaped broad- floored valleys with principally lateral erosion into the adjacent hill slopes in response to relative base level stability or tectonic quiescence that signifies a relatively low tectonic activity. The Vf index is calculated by the following equation:

Vf= 2Vfw/ {(Eld-Esc) + (Erd-Esc)}

Where Vfw is width of the valley floor and Esc is elevation of valley floor. Erd and Eld are the elevations of right and left valley divides respectively.

Theoretically U-shaped valleys are indicative of the less tectonic activity and V- shaped valleys, as a response to uplift, are associated with high tectonic activity. The Vf indices of all sub-basins in the Ramganga basin are less than 1.0, indicating a generally high level of tectonic activity.

The channel sinuosity index (Cs), which is a measure of the deviation of a river from a straight line course, is usually derived by dividing the length of a reach as measured along a channel by the length as measured along the valley. Whereas the high sinuosity of a river in plane areas may be attributed to very low angles of the ground slope, in hilly terrains the sinuosity of channels may be strongly influenced by tectono-structural features.

Results of the channel sinuosity in 26 sub basins ranges between 1.1 and 1.7. Sinuosity of the trunk stream of the Ramganga River showing moderate sinuosity (1.27) while for some reaches this index increases upto 1.91. In general high sinuosity found in the old stage of the river while in the Ramganga river basin, values more than 1.4 are indicating strong sinuosity that corresponds to the prevailing tectonic activity in the form of tectonic structures viz: Vaikrita Thrust, Munisiari Thrust (MCT), Bhujpatri Gad Fault, Darun Fault, ramganga Fault and Askot Thrust and number minor thrust and faults.

Abstract

Drainage basin asymmetry (AF), an indicator of possible ground tilting due to inequilibrium between incision and uplift, indicates neotectonic activity. Basin asymmetry is estimates by:

AF= 100 (Ar/At)

Where Ar is area of the right of the basin (looking downstream) and At is the total area of the basin. In a stable tectonic environment or when the uplift is uniform throughout the region under consideration, the AF is 50, suggesting no tilt. Values more/less than 50 are suggestive of a tilt perpendicular to the main channel. The degree of asymmetry and the elongation directions of sub-basins of the Ramganga were translated into vectors which give the variation in the direction and amount of tilt over the study area. On the basis of AF, the Ramganga basin, particularly the thrust-bound central sector is tilting in a South-west direction.

The hypsometric curve, created by plotting the proportion of total basin height (h/H = relative height) against the proportion of total basin area (a/A = relative area) describes the distribution of elevations across an area. A simple way to characterize the shape of the hypsometric curve is to calculate its hypsometric integral (HI). The integral is defined as the area under the hypsometric curve. One way to calculate the integral for a given curve is as follows:

Hi = (Mean elevation – min elevation) / (Max elevation – Min elevation)

Results of the Hypsometric Integral (HI) suggest that the Ramganga river basin in particular is a youthful basin while within the basin it shows great variation. Sub basins present in the Northern and North-Eastern part of the Ramganga basin except the basin no.5 (Tejam) are showing the values between 0.3 and 0.45, which is eroded and showing the late mature to mature stage of the basin. Basin no.5 (Tejam) has the value 0.3 which indicates the old stage of the basin. But in the real sense these basins are in this stage are not because of the maturity of the basin but because of the presence of the tectonic forces and fluvial influences on these basins.

On the basis of this study it may be suggested that the Ramganga river basin in particular and the eastern Kumaon Himalaya in general, are one of the highly tectonically active sector of the Himalayan orogen.

The Kali River, of which the Ramganga is an important tributary, appears to be a site of rapid erosion and uplift, promoting the formation of an anticlinal structure with its 4

Abstract axis transverse to the main trend of the Himalaya. Results of the present study viz., high tectonic activity and the westward tilting of the eastern Kumaon sector lend credence to the hypothesis that areas of relatively high rates of active tectonics in the Himalaya are associated with courses of trans-Himalayan rivers predating the Himalayan orogeny.

DEPARTMENT OF GEOLOGY ALIGARH MUSLIM UNIVERSITY, ALIGARH-202002, INDIA

ANNEXURE-1 CANDIDATE’S DECLARATION

I, Indu Sharma, Department of Geology certify that the work embodied in this Ph.D. thesis is my own bonafied work carried out by me under the supervision of Dr. Shahid Farooq (Professor) at Aligarh Muslim University, Aligarh. The matter embodied in this Ph.D. thesis has not been submitted for the award of any other degree.

I declare that I have faithfully acknowledge, given credit to and referred to the research workers whenever their works have been cited in the text and the body of the thesis. I further certify that I have not willfully lifted up some other’s work, para, text, data, result, etc. reported in the journals, book magazines, reports, dissertations theses, etc., or available at web-sites and included them in this Ph.D. thesis and cited as my own work.

Date: Signature of candidate

………………………………………………………………... Certificate from the Supervisor This is to certify that the above statement made by the candidate is correct to the best of my knowledge.

Research Supervisor Dr. Shahid Farooq (Professor) Department of Geology Aligarh Muslim University Signature of the Chairman

Department of Geology, Aligarh Muslim University, Aligarh-202002, India

Dr. Shahid Farooq Tel: +91-571-2700615 (O) ( Professor ) Fax: +91-571-2700528 (F)

CERTIFICATE

This is to certify that the work presented in the Ph.D. thesis entitled, “Investigation of Active tectonics in the Ramganga Basin, Eastern Kumaon Himalaya, using geomorphic Indices derived from Digital Elevation Models” submitted by Miss. Indu Sharma (Research Scholor) has been carried out and completed under my supervision. The work is an original contribution to the existing knowledge of the subject and has not been submitted earlier.

She is allowed to submit the work for the award of the Ph.D. degree in Geology of the Aligarh Muslim University, Aligarh.

Date: (Dr. Shahid Farooq) Supervisor

DEPARTMENT OF GEOLOGY ALIGARH MUSLIM UNIVERSITY, ALIGARH-202002, INDIA

ANNEXURE-II

COURSE/COMPREHENSIVE EXAMINATION/PRE-SUBMISSION

SEMINAR COMPLETION CERTIFICATE

This is to certify that Miss. Indu Sharma, Department of Geology, Aligarh Muslim University, Aligarh has satisfactorily completed the course work/comprehensive examination and pre-submission seminar requirement which is part of her Ph.D. programme.

Date: (Signature of the Chairman )

Department of Geology, Aligarh Muslim University, Aligarh-202002, India

ANNEXURE-III COPYRIGHT TRANSFER CERTIFICATE

Title of the Thesis : “Investigation of Active tectonics in the Ramganga Basin, Eastern Kumaon Himalaya, using geomorphic Indices derived from Digital Elevation Models ”.

Candidate’s Name : Indu Sharma

The undersigned hereby assigns to the Aligarh Muslim University, Aligrh copyright that may exist in and for the above thesis submitted for the award of the Ph.D. degree.

(Signature of the Candidate)

Note: However, the author may reproduce or authorize others to reproduce material extracted verbatim from the thesis or derivative of the thesis for author’s personal use provide that the source and the University’s copyright notice are indicated.

Dedicated To My Beloved Parents & Husband ACKNOWLEDGEMENTS

First of all, I would like to thank the Almighty for bestowing his mercy and blessings upon me. “When every hope is gone and helps flee: assistance comes from where I know not,” this is the essence of ALLAH. My very special thanks to my beloved mother and my beloved mother in law, because without their kind support it could not be possible for me to complete this work. My sincere thanks to Lt. Gen. Zameer Uddin Shah, Vice Chancellor, AMU, Aligarh India, and Brig. Syed Ahmad Ali Pro-Vice Chancellor AMU, Aligarh India for recommending me to undergo Degree of Doctorate in Geology, at Aligarh Muslim University, Aligarh, India. My sincere thanksto Dr.Rahimullah Khan, Chairman, Department of Geology, Aligarh Muslim University. I would like to express my special appreciation and deepest admiration for the finest guidance of my supervisor Dr. Shahid Farooq (Professor), Department of Geology, Aligarh Muslim University, Aligarh for the continuous support of my study, for his motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. Who inspired and guided me with his keen observation throughout my research. I am also grateful to all of my batch mates, especially Dr. Himanshu Govil and Mr. Mohammad Nazish Khan for their kind support and whose company was very enjoyable and memorable for me.

I would like to express thanks to my dear friends who at every step of my work encouraged me and let me to achieve the success, especially my beloved friend Mr. Shamshad Ahmad, Naqeebul Islam, Mr.Saad Rahaman, Ruchi Agarwal, Priyanka Sharma, Nazrarna Mohammadi and Haseeb Khan. Last but not the least, I would like to thank to all my family members specially Sangeeta Sharma, Rajneesh Sharma, Muskan, Tamanna, Ishita, Shaurya and Divyanh for their loving presence, encouragement, support and attention for me.

Indu Sharma CONTENTS

Acknowledgements

List of Figures

List of Tables

CHAPTER-I INTRODUCTION 1-9

CHAPTER-II REGIONAL GEOLOGY 10-21

CHAPTER-III DATA AND METHODOLOGY 22-44

CHAPTER-IV GEOMORPHIC INDICES OF

ACTIVE TECTONICS 45- 66

CHAPTER-V RESULTS AND DISCUSSIONS 67-123

CHAPTER-VI CONCLUSION AND RECOMMENDATIONS 124-127

REFERCENCES 128-137 LIST OF FIGURES

Fig. 1: Location map of the study area. Fig 2.1: Map showing the longitudinal divisions of the Himalaya (After Valdiya, 1980). Fig. 2.2: Geological map of the Ramganga river basin after Valdiya (1980). Fig 2.3: Map showing the lithology present in different Groups and Formations of the Ramganga Basin. Fig 2.4 Major tectonic structures present in the study area.

Fig 3.1: (a) Digital Elevation Model of the Ramganga basin Fig 3.1: (b) Map showing detailed drainage network of the Ramganga basin. Fig 3.2: (a) Stream ordering of the Ramganga basin. Fig 3.2: (b) Numbering of sub basins in the Ramganga basin. Fig 3.3: (a) Satellite image of the Ramganga basin. Fig 3.3: (b) Land use and land cover classification of the Ramganga basin. Fig 3.4 Map Showing Slope of the Ramganga Basin. Fig 3.5 Showing Aspect map of the Ramganga Basin. Figure 4.1 (a).Calculating mountain front sinuosity (Smf) index (Modified from Keller and Pinter 2002, figure 4.14, p. 137). Figure 4.1 (b): Showing total length of mountain front (Lmf) and straight line length (Ls) of the mountain front. Figure 4.2: Block diagram shows the effect of an asymmetry factor with a left side tilt on tributaries lengths (From Keller and Pinter 2002, figure 4.3, p. 125). Figure 4.3: (a) Solid line showing the trend of the river channel Figure 4.3: (b) arrow showing the direction of the migration of the river channel. Figure 4.4: (a) Showing Da and Dd of the basin. Figure 4.4: (b) Arrow showing direction of migration of the channel from the midline of the basin Figure 4.5: Calculating valley floor width to height ratio (Keller and Pinter 2002, figure 4.15, p. 139. Fig 4.6 Map showing the valley profile of a basin (Generated in Global mapper). Figure 4.7: Diagram shows the process of calculating the Stream Length-Gradient Index (SL) for a given creek (Keller and Pinter 2002, figure, 4.6, p. 128). Figure 5.1 Map showing tectonic activity based on Smf and their relation with tectonic structures. Figure 5.2 Map showing tectonic activity based on Smf in 26 sub basins of the Ramganga basin. Fig 5.3: Map showing the Mountain fronts in the whole Ramganga river basin.

Fig 5.4 Map showing the results of Asymmetry Factor with tectonic structures. Fig 5.5 Map showing the Asymmetry in 26 sub basins of the Ramganga basin. Fig 5.6 Lined portion are showing the relative uplift in the Ramganga basin. Figure 5.7 Arrow showing direction of the migration of the channel in different sub basins of the Ramganga basin. Figure 5.8 Arrows showing the direction of migration in Ramganga basin. Fig 5.9 Direction of the arrow showing the tectonic tilting in the Ramganga river basin. Figure 5.10 Map showing erosional status in 26 sub basins of the Ramganga basin. Figure 5.11 Relation of the tectonic structures with erosional status of the sub basins. Figure 5.12 Map showing the sinuosity of the river channel in 26 sub basins of the Ramganga river basin.

Fig 5.13 Abrupt change in the sinuosity of the River channel (in circle). Fig 5.14 Abrupt change in the sinuosity of the River channel (in circle). Figure 5.15 Map showing the values of Vf in 26 sub basins of the Ramganga river basin. Figure 5.16 Relation of Vf with tectonic structures. Fig 5.17 Graph showing the river profile in the basin Figure 5.18 Map showing the elongation ratio of the 26 sub basins of the Ramganga river basin.

LIST OF TABLES

Table 3.1. ASTER GDEM Characteristics.

Table 4.1 Showing the shape of the Basin on the Basis of Basin Elongation Ratio.

Table-5.1: Table showing Different Classes of Tectonic Activity.

Table 5.2: Showing the Smf values in 26 sub basins of the Ramganga river basin.

Table 5.3: Showing Asymmetry Factor in 26 sub basins of the Ramganga basin.

Table 5.4: Table showing the Transverse topographic symmetry in 26 sub basins of the Ramganga basin.

Table 5.5 Showing erosional stages of the basin.

Table 5.6: This table illustrates the geological stages of 26 sub basins of the Ramganga river basin based on the results (After Omvir Singh et al, 2008).

Table 5.7 Showing the HI values in 26 sub basins of the Ramganga basin.

Table 5.8 Showing the values of Channel sinuosity in 26 sub basins of the Ramganga basin.

Table 5.9 Showing different classes based on Vf.

Table 5.10 Showing result of Vf in 26 sub basins of the Ramganga Basin

Table- 5.11 Showing SL values in 26 sub basins of the Ramganga basin.

Table 5.12 Table showing the values of Re in 26 sub basins of the Ramganga basin. Table-5.13: Table shows the values of different geomorphic indices at micro- watershed level in Ramganga river basin.

Introduction

Chapter-1

INTRODUCTION

1.1 Introduction:

Continent-continent collision, giving rise to most of the world’s mountain chains, is a recurrent event in the history of the earth. The most spectacular collision that we can witness is that of India with Asia which began some 55 m.y. ago, resulting in the uplift of the formidable Himalaya, which continues even to this day (Gansser 1964; Nakata 1972; Molnar and Tapponnier 1975; Valdiya 1980). These mountains, where many of the world’s highest peaks are located, are perhaps the most active of all mountain chains in the world. The Himalayas are mainly young folded mountains. It is about 2400 km in length from Afgahnistan- Pakistan in the west and Namcha Barwa in the east. It varies in width from 250 to 300 km along its length. The mountain range is arc-shaped, convex southwards with syntaxial bends at the western and eastern ends (Wadia 1931; Valdiya 1980; Ahmad 2011). Recent GPS surveys have indicated that the Indian plate is moving northwards at rates ranging from 5 to 22±2 mm/yr. This northward movement of the Indian plate results in complex folding of the sedimentary sequences along with the crystalline basement, and repeated splitting by thrusting and faulting which give rise to seismicity in the region. The Indus Suture Zone (ISZ) lying north of the main Himalayan ranges represents the junction between the Indian and Asian landmasses. From north to south, regional scale faults/thrusts, accounting for more than a thousand kilometers of crustal shortening in the Himalaya are: the Trans Himadri Fault (THF), the Main Central Thrust (MCT), the Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust (HFT).

It is common knowledge that the deepest and the most powerful earthquakes occur at convergent plate boundaries or collision (or subduction) zones. It is not surprising that 2500 km long and 400 km wide Himalayan sector is one of the world’s most seismically active regions.

The term active tectonics refers to those tectonic processes that produce deformation of the earth’s crust on a time scale of significance to human society. Plate tectonics is the continual slow movement of the tectonic plates, the outermost part of the earth. This motion is what causes earthquakes and volcanoes and has created most of the

1 Chapter-1 spectacular scenery around the world. Earthquakes, landslides, volcanoes, tsunami etc. are the result of the movement of the tectonic plates. These natural disasters affect our social and economic life directly and indirectly. Himalaya is the tectonically most active zone in the world and natural disasters such as earthquakes, landslides, cloudburst, and flash floods frequently occurs almost every region of the Himalaya.

Tectonics plays a very important role in the geomorphic evolution of a drainage basin and is well reflected in fluvial processes and morphometric indices of drainage basins. Assessment of active tectonics is facilitated by the use of morphotectonic indices. These indices are reflective of an interaction of tectonic processes, climate change, rock resistance and influence of structural and resulting into landscape evolution(Bhatt, Litoria et al. 2008).

Morphometry is defined as quantitative measurement of landscape shape. At the simplest level, landforms can be characterized in terms of their size, elevation and slope. Quantitative measurements allow geomorphologists to compare different landforms and to calculate less straightforward parameters (geomorphic indices) that may be useful for identifying a particular characteristic of an area (its level of tectonic activity).

In the present thesis an attempt has been made to decipher active tectonics in the Ramganga river basin using geomorphic indices such as Mountain front sinuosity (Smf), Asymmetry factor (AF), Hypsometric integral (HI), channel sinuosity (S), Valley floor width to height ratio (Vf), Stream length gradient index (SL) and Basin elongation ratio (Re) with the help of the remote sensing and GIS, which plays a significant role in providing spatial information needed for computation of these indices.

2 Chapter-1

1.2 Nature of problem:

Ramganga river basin is situated in the the Lesser Himalaya which is delimited by the Main Boundary Thrust (MBT) to its south and Main Central Thrust (MCT) to its north, displays the terrain rejuvenation (Valdiya 1964; Valdiya 1976; Valdiya 1980; Pant, Goel et al. 1992; Valdiya 2001; Valdiya 2003; Thakur 2004). Kumaon Himalaya is located near the central part of the Himalayan orogen and is, therefore, a critical area for studying the typical characteristics of the Himalayan tectonics. Seismotectonically, this is a very active segment of the Himalayan arc in contrast to the areas in close proximity to NE and NW- syntaxes where complications arise due to complex tectonics (Valdiya and Pant 1986; Valdiya and Kotlia 2001; Valdiya 2001; Paul and Pant 2003; Valdiya 2003; Kotlia and Rawat 2004; Valdiya 2005; Luirei, Pant et al. 2006; Patel, Adlakha et al. 2011). A number of recent and young landforms produced in the central part of the Himalayan orogen by the tectonic movements along the boundary thrusts and transverse faults suggest recent tectonic events (Greisbach 1891; Valdiya and Kotlia 2001; Valdiya 2001; Valdiya 2003; Valdiya 2005; Pant, Kothyari et al. 2007; KOTHYARI and PANT 2008). There is a strong relationship between the active faulting and the earthquakes. Many studies around the world confirmed the strong relationship between active faults and earthquakes and the usefulness of remote sensing techniques to recognize and analyze that relationship (Suzen and Toprak 1998; Dreger and Kaverina 2000).

Investigations carried out on the basis of seismic data recorded in the eastern Kumaon Himalaya indicate that the North and South Almora Thrusts, and various local thrusts and faults running parallel or transverse to the structural grain of the Himalaya are neotectonically active. Various geomorphic features viz., unpaired river terraces, ponding of rivers, paleochannels, paleolake deposits, uplifted potholes, deep gorges with convex walls, extensive landslides, and stream offsets are cited as indicators of neotectonic activity (Farooq, Sharma et al. 2015). Most investigators surmise that the Himalayan sector is accumulating strain energy which might be released in the form of destructive earthquakes. Be that as it may, these tectonic forces also result in a slow and steady deformation in the form of folding, uplift, warping and tilting of various rock units. Therefore, there is an urgent need to monitor active tectonics in the region for a better understanding and management of prospective natural calamities and disasters (Farooq, Sharma et al. 2015). Assessment of active tectonics of a region is an essential prerequisite to many developmental activities, for

3 Chapter-1 such assessments help in the mitigation and management of natural hazards, and help in deciding where to site structures so that they serve their purposes most effectively. Evaluation of active tectonics and associated hazards requires knowledge of the rates, styles, and patterns of tectonic processes. The patterns of tectonic activity leading to catastrophic events are difficult to predict on the basis of observations spanning a few years, or even by all events recorded in history. Assessments of active tectonics based on geomorphic indices of landscapes have provided insights into specific areas or sites in a region that are adjusting to relatively rapid rates of tectonic deformation.

This thesis deals with the studies of geological hazards viz. earthquakes, landslides, and river erosion etc. in sub-basins of the Ramganga River basin in Eastern Kumaun Himalaya in relation to zones of active deformation. The physiographic setting of the terrain is characterized by conspicuous WNW-ESE trending ridges with high relief and paralleling the major tectonic features of the region. Geological formations exposed in the area are the Almora and Garhwal Group of rocks. The Almora Group generally compnses of gneisses and migmatites, high- to low-grade schists, slates and phyllites, while the Garhwal Group is generally represented by an assemblage of interbedded quartzites, shales, imestones, dolomites and phyllites (Farooq 1985).

The proposed study would help in the investigation of the tectonic status in the Ramganga river basin, Eastern Kumaon Himalaya with the help of the geomorphic indices such as Mountain front sinuosity, Asymmetry factor, Hypsometric integral, Valley floor width to height ratio etc. These geomorphic indices are key tool to evaluate the areas on the basis of tectonic activity.

1.3 Research objectives:

The objective of this research is to develop a remotely sensed approach in investigation of active tectonics in Ramganga basin, Eastern Kumaon Himalayas and to access the current degree of tectonic activity in the basin at sub basin level based on various geomorphic indices and generate tectonic activity maps based on these indices, depicting relative uplift and tilt in the study area.

4 Chapter-1

1.4 Research questions:

(i) Are geomorphic Indices helpful in identifying areas on the basis of tectonic activity?

(ii) In Asymmetry Factor and Transverse topographic symmetry which method is suitable for the identification of the River migration?

(iii) Erosion promoted the uplift in the Ramganga basin?

(iv) In which direction Ramganga basin is uplifting?

(v) Which part of the Ramganga basin is highly prone to the natural hazards such as landslides, erosion and flash floods?

(vi) How active tectonic processes together with geological, geomorphological and climatic conditions help in finding solutions for reducing human misery and enhancing the quality of life?

1.5 Justification of the study:

Present study is believed to be the first attempt to apply different geomorphic indices to decipher the relative tectonic activity present in the Ramganga river basin at 26 sub watershed level. These geomorphic indices are proposed by different authors as an indicator of seismic activity. Mountain front Sinuosity (Smf) and Valley floor width to valley height ratio (Vf) proposed by Bull and Mc Fadden in 1977, Asymmetry factor (AF) is proposed by Cox in 1994, Hypsometric integral (HI) is proposed by Strahler in 1952, Channel sinuosity (S) is proposed by Muller in 1968 and Basin elongation ratio by S.A. Schumn in 1956. Values of these indices were calculated manually with the help of their simple mathematical formulas using ASTER DEM data processed in the GIS environment. In the present research, a new methodology is applied using digital approach including satellite imagery, multiple layers of geographic data and digitized calculations of the given geomorphic indices of seismic potential to achieve more precise determinations.

The aim of present study is to decipher the relative tectonic activity present in different 26 sub basins of the Ramganga river basin. On the basis of the Asymmetry factor, we can assess the area on the basis of the relative upliftment or tilting.

5 Chapter-1

Hypsometric integral is helpful in the assessment of the erosional status of the basin. Mountain front sinuosity and valley floor width to height ratio are the key indicators of the recent tectonic activity. Basin elongation ratio provides the information about the shape of the basin by which we can easily categorize the basins on the basis of the flood prone areas.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery will be the main source of Digital Elevation Models (DEMs) and an input to other digital data. Morphometric analysis is being utilized because the results of this method have proven to be reliable and relatively accurate in the assessment of tectonic activity of largescale regional analysis of natural geomorphic forms. In addition, this approach is easy, does not require expensive equipment, and can be remotely performed without conducting field measurements (Ata 2008).

1.6 Study area:

The present study is confined to the Ramganga river basin which extends over an area of 1360 sq. km. in eastern Kumaon Himalaya and has a perimeter of 237 km. The river originates from the Namik glacier (3600 m. elevation) in Pithoragarh district of Uttarakhand state (Fig.1). Lying between the Kali River in the east and Sutlej in the west, the Kumaon region includes a 320 km stretch of mountainous terrain. The Ramganga Basin lies in the Lesser Himalayan zone which is bounded by the Main Central Thrust (Collective term used to describe the broad fault zone separating the Lesser Himalayan Sequence and Greater Himalayan Complex) in the north and Main Boundary Thrust in the south. The Ramganga River flows in N-S direction for about 78.6 km. The basin lies between 29⁰31'23''and 30⁰14'11'' N latitudes and 80⁰06'12''and 80⁰06'49'' E longitudes and is 26.5 km at its widest. The Ramganga is fed by numerous small and large tributaries from the east and west and finally joins the Saryu River at Rameshwar near Ghat in Pithoragarh.

6 Chapter-1

Fig. 1: Location map of the study area.

1.7 Geomorphology and landforms of the study area:

The Ramganga River originates in the north of Pithoragarh district and flows southwards for about 105km before it confluences with the Sarju River at Rameshwar. The headwaters of this perennial river come from the Namik glacier which is surrounded by three lofty peaks – Nanda Devi (7850 m), Nanda Kot (6860 m) and Trishuli (7120 m). Other sources that feed the Ramganga are more than a dozen spring-fed streams flowing in a general E-W direction before they confluence with the Ramganga. The highest and lowest elevations in the basin are 6004.3 m and 479.1 m respectively.

7 Chapter-1

The northern part of the basin is glaciated. The most prominent geomorphic features of the Ramganga basin appear to be the NNW-SSE trending streams and gorges with relatively straight mountain fronts, fault scarps and steep cliffs in the middle and upper parts of the basin. Other geomorphic features include rock benches, waterfalls and stream offsets. Of minor importance are streams aligned in a NNE-SSW direction. This alignment of geomorphic features suggests a structural control over the development of landforms in the area. The rocks exposed in and around the Ramganga basin trend in a WNW-ESE direction and include meta-sedimentaries viz., phyllites, schists, micaceousquartzites, amphibolites and granitic gneisses. Terraces formed by sediments laid down by the river are found on both banks.

The investigated area receives an average annual rainfall of 497.6 mm mostly restricted to the monsoon months of July to September. Sudden cloud bursts with a very heavy rainfall (150–200 mm/day) are occasional phenomenon in this terrain. Vegetation in the catchment varies from Alpine meadows in the upper reaches to temperate and sub-tropical coniferous and deciduous forests in the lower reaches. This area experiences frequent landslides and an alarming rate of erosion.

The 3-D models of the terrain obtained by draping satellite imageries over ASTER DEMs have provided an opportunity to visualize the landforms of the Ramganga Basin. The area is characterized by large scale landform features in the form of elongated valleys and ridges which have a striking parallelism. The prominent geomorphic features include elongated ridges, valleys and mountain fronts. The sub- parallel disposition of linear ridges and valleys is considered a first indication of faulting, shearing in the area. A higher rate of erosion of the softer, broken and sheared rock finds expression as narrow, elongated valleys. Differential erosion of various rock types juxtaposed due to fault movement will also influence the landscape. The area is also characterized by small-scale geomorphic features known to have their origin in vertical and lateral shuffling of fault-bound sectors like linear gullies, shutter ridges, sag ponds, deflected and offset stream channels, linear benches along valley walls, offset terraces, scarps, fault controlled drainage and folds. A small part of the northern slopes of the Ramganga are snow-bound during the winter months.

8 Chapter-1

1.8 Data and software used:

The following datasets and software have been used in the present study.

1.8.1 Datasets used:

 Toposheet

 Geological map

 ASTER DEM data

 Landsat 8 data

1.8.2 Software used:

 Arc GIS 9.3  Global mapper 11  Map maker 3  Erdas imagine 9  Microdem

Regional geology

Chapter -II

Regional Geology

2.1 Introduction:

The Himalayas is the highest and one of the youngest mountain ranges in the world. The Himalayan arc extends ~2400 km from Nanga Parbat (8138 m) in the west to Namche Barwa (7756 m) in the east. This region includes the independent kingdoms of Nepal and Bhutan as well as parts of Pakistan, India, and China. This Orogeny forms a sharp transition between the average ~5 km-high, arid Tibetan plateau and the warmer, wetter Indian lowlands, and is comprised of roughly parallel, crustal-scale fault systems that bound distinctive lithologic units along strike. The magnificent heights to which the Himalayas have been uplifted must have been a result of several orogenic movements. The tectonic history of the Himalayas is a much debated subject. Some workers have recognized five phases of deformation on the basis of small scale shortening structures. Others have deciphered four major tectonic movements, the earliest dating back to the Precambrian or Lower Paleozoic, while the other three postdating the Permian. A few workers however, recognise only three episodes of orogenic activity, post-dating the Cretaceous. The first phase of Himalayasn orogeny - the Daling event (Precambrian or Lower Paleozoic) is marked by medium grade metamorphism but intense deformation accompanied by both acid and basic igneous intrusives. The second phase of orogeny known as the Ladakh phase involved the beginning of earth movements which were responsible for the major uplift of the Himalayas. It is during this phase that the Indian plate is believed to have collided with the Asian plate. This caused a shallowing of seas, emplacement of ophiolites along the Indus Suture zone, granitic intrusions, palingenesis, and granitization. Patches of Eocene rocks over the Tal (Jurassic), Krols (Permo-Trias), Simla Slates, and Deoban rocks indicate folding and erosion of these sedimentary basins before transgression of the sea in Eocene period, and subsequent deposition of Eocene sediments. This phase of the Himalayan orogeny was active from Late Cretaceous to early Eocene times. The third and most vigorous of all orogenic movements is termed the Dharamsala phase which culminated in the Middle Miocene. The consequent compression due to under-thrusting of the Indian plate beneath the Tibetan (=Asian) plate caused large scale isoclinal and recumbent folding of the Precambrian crystalline rocks. This resulted in the thrusting of huge blocks of these

10 Chapter -II rocks that moved southwards, and came to rest upon the younger sedimentaries. Most of the thrust sheets of the Lesser Himalayas and widespread regional metamorphism and acid igneous activity are associated with this phase. Due to the great uplifting, a foredeep was created in front of the rising Himalayas into which the Siwalik molasse sediments were deposited. The fourth phase of Himalayasn orogeny is the Siwalik phase. This phase was very active from the Late Pliocene to Middle Pliestocene period. Most of the present structures of the Himalayas developed during this phase. The Siwalik sediments were also uplifted. Tectonic creep along some of the thrust faults of the Himalayas, translation of upper Siwalik rocks over the subrecent gravel beds, and seismicity in the region strongly suggest that this phase has not yet ceased (Farooq 1985).

The Kumaon Himalaya, seismo-tectonically an active region of Himalayan arc, shows development of all the major five litho-tectonic units bounded by the boundary thrusts. Longitudinally, these divisions are-

1. The great Himalaya

2. The Inner Himalaya or Lesser Himalaya

3. The Sub-Himalayan foot hills and the adjacent Tarai and Duar plain.

2.1.1. Great Himalaya:

The Greater or higher Himalaya is limited by the Main Central Thrust (MCT) to its south and Tethyan Detachment Fault (TDF) to its north. It comprises high grade Precambrian crystallines, cambro-ordovician (500±50 Ma) granites/orthogneisses and Tertiary leucogranites. The great Himalayan sequence shows progressive regional metamorphism ranging from greenschist to upper amphibolite facies (Thakur 1992). The granites frequently intrude the medium to high grade metamorphic sequences of meta sedimentary rocks. The MCT, marking the southern boundary of the great Himalaya, is one of the most important tectonic elements associated with the Himalayan orogenesis and it separates the high grade metamorphic rocks of the higher Himalaya (hanging wall) in the north from the weakly metamorphosed rocks of the lesser Himalaya (foot wall) (Gansser 1974; Valdiya 1980).

11 Chapter -II

2.1.2 Inner Himalaya or Lesser Himalaya:

The Lesser Himalayan zone is bounded the Main Central Thrust (MCT) in the north and Main Boundary Thrust (MBT) to the south and consists of the late Proterozoic to early Cambrian sediments intruded by some granites and acid volcanics (Valdiya 1980; Srikantia and Bhargava 1982). It mainly comprises the marine sequences of late Proterozoic to early Cambrian age and some sedimentary record of transgressing shallow sea during Permian and late cretaceous to early Eocene periods. The predominant rock types are quartzites, siltstone, shale and carbonates. There are zone of phyllite, schists with subordinate impure marbles, metamorphosed mafic rocks and augen orthogneisses (Valdiya 1980).

Fig 2.1: Map showing the longitudinal divisions of the Himalaya (After Valdiya, 1980).

2.1.3 Sub-Himalaya:

The sub Himalaya or outer Himalaya forms low altitude foot hills between the Himalayan Frontal Fault (HFF) to its south and Main Boundary Thrust to its north. It preserves the record of the post collision sediments produced by weathering and erosion of the debris of the rising Himalayan front. These sediments were carried and deposited in the foreland basin, the Himalayan foreland basin (HFB). It consists of the

12 Chapter -II lower tertiary sediments (Paleocene to early Miocene) comprising Subathu, Dagshai and Kasauli formation which are marine to brakish water sediments and the upper Tertiary sediments (middle Miocene to middle Pleistocene) consisting of the Siwalik group fluvial deposits, along with the late orogenic intermontane deposits and alluvium. The HFF separates the Siwalik sediments in the north from the Indo- Gangetic sediments towards south (Erlewein 2013; Grumbine and Pandit 2013).

2.2 Tectonic Features:

2.2.1 Trans - Himadri Fault

Trans – Himadri fault also known as Malari thrust fault (in northern Kumaon Himalaya), South Tibetan detachment thrust (in Nepal), Zanskar shear zone (in Himachal Pradesh) is the tectonic boundary between the great Himalayan crystalline complex and its thick late Proterozoic to late cretaceous sedimentary cover of the Tethys terrain, representing the distal continental margin of the Indian shield and having an extremely rugged physiography. The Tethyan terrain ends against the Indus – Tsangpo Suture zone that marks the junction of the Indian and Asian continental masses (Valdiya 2002). The detachment of the tethyan sedimentary cover from its foundation (the Himadri basement complex) along the trans-himadri fault was accompanied by east-west extension, which took place in the 19-22 Ma period in the Nepalese Tethyan terrain (Burchfiel and Royden 1985; Pêcher 1991) and in the period 20-25 Ma in the Zanskar range in Himachal Pradesh (Inger 1998; Vance and Harris 1999)- that is, in the early Miocene at about 22 Ma.

The basement complex comprises high grade metamorphic rocks intruded by 550 ± 25 Ma old porphyritic granites. The basement complex was thrust up almost synchronously along and in between the MCT and T-HF as a stupendous lithotectonic slab, giving rise to the Great Himalaya or Himadri. Repeated and strong movements along these delimiting faults are evident from the wide zones of shearing and pronounced mylonitization of rocks that occur as overlapping sheets characterized by a multiplicity of planes of gliding and sliding (Valdiya 2002).

2.2.2 Main Central Thrust

This thrust fault was first described by Heim and Gansser (1939) when they noted a contact between terrigenous carbonate rocks and thick overlying metamorphic rocks,

13 Chapter -II micaschists and gneiss (Sinha 1987). The main central fault marks the boundary between the higher and lesser Himalayan Mountains. It is a longitudinal thrust fault and in many places is marked by a several kilometre thick zone of deformed rocks with varying degrees of shearing and imbrication (Sorkhabi, Stump et al. 1999). Mylonitization and retrograde metamorphic assemblages also occur here. The MCT is the actual suture between Gondwanaland (India) and the Proto-Tethys micro continent to the north. Movement along the fault has brought crystalline rock from the Higher Himalayan zone on top of lesser Paleozoic sediments in the form of klippen in synclines (Erlewein 2013; Grumbine and Pandit 2013).

2.2.3 Main Boundary Fault

The main boundary fault is a major structural plane traceable throughout the length of the Himalaya. The irregularity and sinuosity of the fault trace is evidence of a gently inclined plane. The older rocks of the lesser Himalayas are thrust over the Siwaliks along a series of more or less parallel thrust planes. The main boundary fault is a reverse fault with large scale movements and still very active. Measurements demonstrate that the present day movement is of the order of 0.92 cm/year (Valdiya 1978).

2.3 Geology of the Lesser Kumaon Himalaya:

The Kumaon Himalaya, lying between the Kali river in the east and Sutlej in the west, include a stretch of 320 km. of mountaneous terrain. Kumaun is one of the two regions and administrative divisions of Uttarakhand, a mountainous state of northern India, the other being Garhwal. It includes the districts of Almora, Bageshwar, Champawat, Nainital, Pithoragarh, and Udham Singh Nagar. It is bounded on the north by Tibet, on the east by Nepal, on the south by the state of Uttar Pradesh, and on the west by the Garhwal region.

The Lesser or Lower Himalaya is limited by the Main Boundary Thrust (MBT) to its south and MCT to its north and consists of the late Proterozoic to early Cambrian sediments intruded by some granites and acid volcanics (Valdiya 1980; Srikantia and Bhargava 1982). It mainly comprises the marine sequences of late Proterozoic to early Cambrian age and some sedimentary record of transgressing shallow sea during Permian and late Cretaceous to early Eocene periods. The predominant rock types are

14 Chapter -II quartzites, siltstone, shale and carbonates. There are zone of Phyllite, schist with subordinate impure marbles, metamorphosed mafic rocks and augen orthogneisses (Valdiya 1980). The MBT separates the northern Lesser Himalayan sediments (hanging wall) from the sediments of the sub-Himalaya (footwall) to the south.

In spite of a lot of good work by many generations of geologists in the Lesser Kumaon Himalaya, many structural and stratigraphic interpretations remain inadequate because of the meagre fossil record. Geological correlation is based almost entirely on stratigraphic evidence. Most workers postulate the existence of regional inversion of sedimentary sequences in the form of two elongated tectonic belts of sedimentary/metasedimentary rocks separated by an ENE-WSW trending zone of metamorphic rocks – the Almora-Dudhatoli Crystalline Zone. The southern sedimentary belt which occurs south of the Almora-Dudhatoli Crystallines and is called the Outer Sedimentary Belt. The northern sedimentary belt occurring north of the Crystallines is the Inner Sedimentary Belt, which has also been referred to as the Deoban-Tejam Zone (Gansser 1964) or the Jaunsar-Berinag Nappe (Valdiya 1978). The Crystalline zone representing the divide between the two sedimentary belts constituting the Kumaon Lesser Himalaya is itself an inverted sequence of low to very high grade older metamorphic thrust over the younger sedimentaries from the Central Axial Crystalline Zone during the main Himalayan orogeny.

A generalized tectonic sequence for the Lesser Kumaon Himalaya (Valdiya, 1978) is tabulated below:

Vaikrita Group ------Vaikrita Thrust ------Munsiari Formation ------Main Central Thrust ------Almora-Dudhatoli Nappe (with Askot, Baijnath, Chiplakot and Satpuli Klinne) ------Almora Thrust ------Outer Sedimentary Belt Inner Sedimentary Belt ------Main Boundary Fault ------Siwalik Group

15 Chapter -II

2.4 Geology of the Ramganga River Basin:

Ramganga river basin lies in the Inner Sedimentary Belt of the Kumaon Lesser Himalaya extend from the Garhwal region in the west to beyond the Kali River marking the eastern boundary of the Kumaon Himalaya.

2.4.1 Rameshwar Formation:

The oldest rock unit of this belt is termed the Rameshwar Formation (Ahmad 1978) and consists of slate, siltstone, greywacke, protoquartzite, limestone and phyllite. This formation is correlated with the Rautgara Quartzites (Valdiya 1964) and Hatsila Formation (Misra and Bhattacharya 1972).

2.4.2 Pithoragarh Formation:

The Pithoragarh Formation, overlying the Rameshwar Formation include stromatolite bearing dolomitic limestone with magnesite, talc, chert, pebble beds with some slate and calcareous slates. Three rock units constitute the Pithoragarh Formation namely thalkedar limestone, sor slates and massive gangolihat dolomites.

Fig. 2.2: Geological map of the Ramganga river basin after Valdiya (1980).

16 Chapter -II

2.4.3 Thalkedar Limestone

The Thalkedar Limestone constituting the lowermost unit consists of thinly bedded limestone with minor grey shale/slate.

2.4.4 Sor Slates

The Sor Slates overlying this unit consist of grey slate and shale with minor dolomitic bands.

2.4.5 Gangolihat Dolomite

The topmost unit of the Pithoragarh Formation are the massive Gangolihat Dolomites with stromatolites. These are, in places, phosphatic, and are interbedded with magnesite and talc schists. This zone is apparently the same as the main calcareous unit of the Calc Zone of Pithoragarh (Valdiya 1962; Valdiya 1969), the Calc Zone of Tejam (Heim and Gansser 1939; Gansser 1964), and the Kotaga Banali of Saklani (1971, 1978), as well as the Doya Dolomite (Misra and Bhattacharya, 1972) of Pugar valley and the Jhatkwali Formation.

2.4.6 Kanalichina Formation:

This formation is characterized by the phyllite with interbedded arenaceous and calcareous bands with an approximate 960m thickness. These rocks are the same as, or directly correlatable with the Sailing formation (Bhattacharya 1980) of the Pithoragarh district and the Betalghat Formation (Raina and Dungrakoti 1975) of the Bhimtal-Bhowali area in Nainital district (Farooq 1985).

2.4.7 Berinag Formation:

The Berinag Formation constituting the topmost horizon of the Inner Sedimentary Belt is seen surrounding the crystalline masses of the Almora, Askote, and Baijnath units. The rock types consists of fine to coarse grained massive quartzite, often sericitic and schistose, with pebble beds, chlorite beds, and interbedded metabasites. (Sharma and Kumar 1978) has correlated the Berinag Formation with the Kaimur Formation of Upper Vindhyans. The rock formations constituting the Inner Sedimentary Belt have been tightly folded into a few E-W to

17 Chapter -II

ESE-WNW trending folds. At places there is strong evidence of thrusting and dislocation by a number of faults. Based on field evidences, some workers (Valdiya 1962; Valdiya 1964; Misra and Kumar 1968; Valdiya 1969; Saklani 1971; Misra and Bhattacharya 1972) are of the opinion that a thrust plane separates the Berinag Formation from the underlying units, and that this sedimentary sequence is inverted. Other workers (Heim and Gansser, 1939; Gansser, 1964; Mehdi et al., 1972; Banerjee and Bisaria, 1975; Kumar, 1978; and Bhattacharya, 1980) maintain that the entire sedimentary pile is in a normal position except for locally inverted sequences.

2.4.8 Almora-Dudhatoli and Related Crystallines:

One of the most prominent and typical feature, occurring in the Kumaon and Garhwal Himalaya is the presence of the Crystallines rocks in the form of nappe and klippe. These are Askot crystallines, Chiplakot crystallines, Baijnath crystallines, Satpuli crystallines and the biggest among them Almora Dudhatoli Crystallines. Naming of these crystallines is based on the local name.

There are two opinions regarding the crystalline occurrence in the lower Himalaya. One group of researchers (Heim and Gansser 1939; Gansser 1964; Ghose, Chakraborti et al. 1974; Misra and Bhattacharya 1976; Bhanot, Pandey et al. 1977) believe that these crystalline are the remnant of the Central Axial Crystallines Zone of the Higher Himalaya, which were pushed southwards over the younger sedimentaries of the Lesser Himalayas in the past orogenic movement. Another group of researchers (Misra and Sharma 1972; Misra, Sharma et al. 1973; Saxena 1974; Saxena and Rao 1975; Bhattacharya 1980) believe that these crystallines are not the remnant of the Higher Himalaya instead these are autochthonous in nature with their root zone in the North Almora thrust.

The Central Crystalline Zone of the Greater Himalaya can, in a generalized way, be described to be the representative of basement rocks in the Himalayan domain. Typically, the foliation of these massive pile of metamorphic rocks show moderate dips northwards (Bhattacharya 2008).

18 Chapter -II

2.4.9 Tethys sediments:

The Tethys Himalayan sedimentary zone is one of the major tectonic domains within the Himalayan orogen. The Tethys Himalaya contains a complete record of fossiliferous sediments from Cambrian to Tertiary. The nature of the Tethyan Fault is described differently by different workers. The contact with the overlying metasedimentary and sedimentary sequence of rocks was earlier described as either conformable or as thrust, at different places () but now it is described as a normal fault (Gansser 1964; Herren 1987).

Table 1: Composite litho-tectonic column of Inner Lesser Himalayan belt of Garhwal and Kumaon after Ahmad, 1975 (modified after Valdiya, 1962 and Mehdi et. al. 1972)

Age Stratigraphic Lithology Thickness units

LATE Askot Gneisses; augen gneisses, PRECAMBRIAN Crystalline streaky gneisses, chlorite TO PALEOZOIC schists, granite with lenses of quartzite and amphibolite. (Garhwal Group) Fault

Berinag Quartzite; white to cream 2350m Formation coloured massive to gritty often sericite and schistose with interbeds of chlorite schist and basic rocks.

Kanalichina Mainly phyllite with 960m Formation or interbededarenaceous and sailing calcareous bands formation

Pithoragarh Gangolihat Member (B): 425m Formation or Stromatolitic dolomite with kapkot beds of magnesite and talc formation schist

Gangolihat Member (A): 400m Massive dolomites often stromatolitic with minor interbeds of grey slate

Sor Slate: Dark grey slates with 2400m few bends of dolomitic

19 Chapter -II

limestone

Thalkedar limestone: Thinly 700m bedded limestone with interbeds of dolomites and grey calcareous shales/slate

Rameshwar Interbeded white/purple 426m Formation or quartzite and phyllite with hatsila subordinate calcareous beds formation basic rocks and intraformational conglomerate

(Base not exposed) ------NORTH ALMORA THRUST------

Fig 2.3: Map showing the lithology present in different Groups and Formations of the Ramganga Basin.

20 Chapter -II

Fig 2.4 Major tectonic structures present in the study area.

Data and methodology

Chapter -III

Data and Methodology

3.1 Introduction:

This chapter provides the details of the methods and procedure to collect the data for the present study which includes the data acquisition, preparation, processing of the digital data and morphometric analyses. This chapter also provides the methodology of the delineation of the basin and sub basin boundaries and their stream networks. It also explains the digitization of the mountain fronts in the Ramganga river basin, calculation of the hypsometric integral, basin elongation ratio, channel sinuosity and digitization of the valley profiles at different places in the Ramganga river basin. In order to observe the geomorphological changes in the Ramganga river basin, remotely sensed data from a number of sources have been utilized. Due to the inaccessible nature of both regions and associated problems with access, remote sensing is the only feasible source of data on topography, drainage networks, vegetation patterns and land use. The quality of information extracted from these datasets will depend on a number of factors, including spatial resolution and inconsistencies between data sets captured at different times because of anthropogenic modification and natural landscape evolution. All data are transformed to conform to a common projection and datum viz., the Universal Transverse Mercator (UTM) and WGS84. The digitization of geological and other information is carried out in Map Maker 3 and Arc GIS 9.3 software.

3.2 Software Used:

3.2.1 Arc GIS 9.3 with TauDEM:

TauDEM is a plugin tool with ArcGIS software, developed by (Tarboton 2005) of the Utah State University. It provides the capability of pit removal, calculation of flow paths and slopes, calculation of contributing area using single and multiple flow direction methods, methods of delineation of steam networks and delineation of watersheds and sub watersheds from the Digital Elevation Models. With the help of this plugin, basin boundary of the Ramganga river basin and its 26 sub basins have delineated from the ASTER DEM with 30 m spatial resolution.

22 Chapter -III

ArcMap is one of the components of Esri's ArcGIS suite of geospatial processing programs, and is used primarily for viewing, editing, createing, and analyzing geospatial data. ArcMap allows the user to explore data within a data set, symbolize features accordingly, and create maps.

ArcMap is useful in creating and manipulating data sets to include a variety of information. For example, the maps produced in ArcMap generally include features such as north arrows, scale bars, titles, legends, etc. The software package includes a style-set of these features. ArcInfo is the highest level of licensing, allow users access to such extensions as 3D Analyst, Spatial Analyst, and the Geostatistical Analyst. Upon completion of the map, ArcMap allows saving, printing, and export maps in PDF format.

3.2.2 Map Maker:

Map Maker is a Geographical Information Systems (GIS) application available for use with Microsoft Windows. Map Maker software developed by Eric Dudley of Map Maker Ltd in Scotland. It allows drawing and editing of basic maps, and linking them to databases. It has powerful GIS functions such as thematic mapping and data interrogation, and offers a host of functions for manipulating vector, raster, 3D, and GPS data. Tasks such as dividing and joining polygons, that are complex in many other programs, are simple in Map Maker. The program can be used both with vector and raster data and produces high quality, accurately scaled print outs. It is compatible with a wide range of map data formats - e.g. tif, .jpg, ecw, shp, emf, dxf, gml etc. It is fully functional map production programs which produce accurately scaled maps on any true windows compatible printer. It also supports multi-sheet printing of large maps.

3.2.3 Global Mapper:

Global Mapper is a geographic information system (GIS) software package originally developed by the United States Geological Survey and followed up since 1998 by Blue Marble Geographics. For the present study, Global Mapper version 11 was used. It handles vector, raster, and elevation data and provides visualization, conversion, and other general GIS functionalities. It has built in functionality for watershed

23 Chapter -III delineation, terrain layer comparison, and triangulation and gridding of 3D point data, contour generation from surface data, view shed analysis, distance and area calculations, raster blending, feathering, spectral analysis, elevation querying, line of sight calculations, cut-and-fill volume calculations, as well as advanced capabilities like image rectification.

In the present study, Global Mapper was used to calculate various features of the Ramganga river basin like area, perimeter, stream length, stream numbers, and relief, creation of buffers around structures etc. as well as the various sub-basins of the Ramganga river basin. Global Mapper supports direct access to the free online data in the USGS' Spatial Data Transfer Standard (SDTS) through the software interface.

3.2.4 Microdem:

MicroDEM is a program that works with digital elevation models (DEMs), and includes other non-DEM related features. It contains many interesting and useful tools and is particularly useful for its terrain visualization and analysis capabilities. MicroDEM was created, and is still maintained and constantly upgraded, by Peter Guth, professor of Oceanography at the US Naval Academy. The main install program is updated every month or so, while new releases of both the executable and help file (with bug fixes and new features) come out somewhat more frequently, usually several times a week. Some slope maps and aspect maps of different sub basins of the Ramganga river basin were created in this software.

3.2.5 Topographic Maps:

For the present study, topographic maps of the area published by the Army Map Service, Corps of Engineers, U. S. Army were used. The Army Map Service is responsible for the publication and distribution of military topographic maps for use by U.S. military forces. One of the objectives of the Army Map Service is to collect, catalogue, and store foreign and domestic maps and map information required by the War Department, and to compile and reproduce maps required for initial operations of US military forces.

Topographic maps of the study area on a 1:250,000 scales were downloaded from the Perry-Castañeda Library of the University of Texas at Austin. The Perry-Castañeda Library Map Collection is an extensive map collection owned by the Perry-Castañeda

24 Chapter -III

Library at The University of Texas at Austin. Many of the maps in the collection have been scanned and are available online, and most of these maps are public domain.

The maps were georeferenced to the UTM projection and WGS84 datum to conform to other spatial datasets used in this investigation using Global Mapper. The georeferenced topographic maps were used for vectorizing the locations of villages and small towns in the watershed, as also for comparing the accuracies of DEM derived drainage network and watershed boundaries.

3.2.6 ASTER GDEM:

For this study, digital elevation models derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used. The ASTER instrument was built by the Ministry of Economy, Trade and Industry (METI) of Japan and launched onboard NASA‟s Terra spacecraft in December 1999. ASTER acquires spectral data in 14 bands using three separate telescopes and sensor systems. These include three visible and near-infrared (VNIR) bands with a spatial resolution of 15 m, six short-wave-infrared (SWIR) bands with a spatial resolution of 30m, and five thermal infrared (TIR) bands that have a spatial resolution of 90 m. Each ASTER scene corresponds to about 60 X 60 km ground area. VNIR Band 3 is also acquired by a backward-looking telescope, providing an along-track stereo coverage with a base- to-height ratio of 1:6, from which high-quality global digital elevation model (GDEM) is generated. One of the advantages of the along track data acquisition system is that the images constituting the stereo pair are obtained a few second apart under consistent lighting and environmental conditions, producing a homogenous quality that is suitable for generating DEMs employing automated stereo correlation techniques.

ASTER Global Digital Elevation Model (GDEM) was jointly developed by the Ministry of Economy, Trade and Industry (METI) of Japan, and the United States National Aeronautics and Space Administration (NASA). The ASTER-GDEM was contributed by METI and NASA to the Global Earth Observation System of Systems (GEOSS), and is available to the global user community via electronic download from

25 Chapter -III the Earth Remote Sensing Data Analysis Center (ERSDAC) of Japan and USGS- NASA‟s Land Processes Distributed Active Archive Centre (LPDAAC).

The ASTER GDEM is available in 1°-by-1°tilesand covers land surfaces between 83°N and 83°S. The ASTER GDEM is in GeoTiff format with geographic lat/long coordinates and a 1 arc-second (approximately 30 m) grid. It is referenced to the WGS84/EGM96 geoid. Table 1 summarizes the basic characteristics of the ASTERGDEM.

Table 3.1. ASTER GDEM Characteristics

Tile Size 3601 x 3601 (1°-by-1°)

Posting Interval 1 arc-second

Geographic Geographic latitude and longitude coordinates

DEM output format GeoTIFF, signed 16 bits, and 1 m/DN

Referenced to the WGS84/EGM96 geoid

Special DN values -9999 for void pixels, and 0 for sea water body

Coverage North 83° to south 83°, 22,600 tiles for Version 1

Pre-production estimated accuracies were 20 m at 95 % confidence for vertical data and 30 m at 95 % confidence for horizontal data. Table 1 summarizes the basic characteristics of the ASTER GDEM. Studies conducted by a large group of international investigators, working under the joint leadership of U.S and Japan ASTER Project participants conclude that the overall accuracy of ASTER GDEM, on a global basis, can be taken to be approximately 20 meters at 95 % confidence (ASTER Validation Team, 2009). Based on a set of geodetic ground control points over Western Australia, Hirt et al. (2010) have assessed the horizontal accuracy of ASTER GDEM to be ~30 m and the vertical ~15 m. Notwithstanding these limitations, ASTER GDEM ver1 is considered to be research-grade (ASTER Validation Team 2009). Hall and Tragheim (2010) while comparing the accuracy of

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ASTER DEMs with the British NEXT Map data demonstrated that ASTER DEMs, if generated with adequate ground control, can have a level of accuracy which is suitable for fulfilling much geological and mapping application in international projects.

Dataset used for the present study (ASTGTM_N29E080) was downloaded from the website of Earth Remote Sensing Data Analysis Center (http://gdem.ersdac. jspacesystems.or.jp/). ERSDAC has since merged with the Institute for Unmanned Space Experiment Free Flyer (USEF) and Japan Resources Observation System and Space Utilization Organization (JAROS) to form a new organization called “Japan Space Systems”, but continues to dispense ASTER GDEM data.

3.2.7 LANDSAT 8

Multispectral data used for land cover classification of the study area is a scene acquired by the Operational Land Imager on board the LANDSAT 8. Landsat 8 was launched on February 11, 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. It carries two instruments – the Operational Land Imager (OLI) which includes the same bands as its predecessor (the ETM+), along with three new bands: a deep blue band for coastal/aerosol studies, a shortwave infrared band for cirrus detection, and a Quality Assessment band and the Thermal Infrared Sensor (TIRS) sensor which provides two thermal bands. These sensors both provide improved signal-to-noise (SNR) radiometric performance quantized over a 12-bit dynamic range. Improved signal to noise performance enable better characterization of land cover state and condition.

The objectives of calibrating remote sensing data are to remove the effects of the atmosphere (scattering and absorption) and to convert from radiance values received at the sensor to reflectance values of the land surface. Figure 1a shows a sample radiance spectrum from an imaging spectrometer. The overall level and shape of this radiance spectrum is strongly a function of the solar illumination and absorption by atmospheric gases. Thus, greater confidence may be placed in the maps of derived from calibrated reflectance data, in which errors may be viewed to arise from problems in interpretation rather than incorrect input data.

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The following table shows the band identification:

Band Band # Band Description Centre (nm)

1 Coastal Aerosol (Operational Land Imager (OLI)) 433

2 Blue (OLI) 482

3 Green (OLI) 562

4 Red (OLI) 655

5 Near-Infrared (NIR) (OLI) 865

6 Short Wavelength Infrared (SWIR) 1 (OLI) 1610

7 SWIR 2 (OLI) 2200

8 Panchromatic (OLI) 590

9 Cirrus (OLI) 1375

10 Thermal Infrared Sensor (TIRS) 1 10800

11 TIRS 2 12000

The scene ID of the data used for this study is LC81450392014321LGN00, downloaded from the website of the US Geological Survey at http://earthexplorer.usgs.gov/. The data was acquired on November 17, 2014 at about 10:30 local time. Although the scene has a cloud cover of 6.2 %, areas representing the study area are 100 % cloud free. Each of the multispectral and thermal bands consists of 7861 lines and 7711 samples. The panchromatic band consists of 15721 lines and 15421 samples. The multispectral bands (1-7 & 9) have aspatial resolution of 30 meters, the panchromatic band (8) has a resolution of 15 meters, and the TIRS

28 Chapter -III bands (10-11) collected at 100 meters are resampled to 30 meters to match OLI multispectral bands.

The dataset used for land cover classification is processed to Level 1T (L1T), and is orthorectified, consisting of radiometrically corrected image data derived from L0 data scaled to at-aperture spectral radiance or reflectance. The dataset is resampled for registration to the WGS 84 cartographic projection. The L1T product is also corrected for terrain relief. The geometric corrections have used observatory ephemeris data and ground control points; DEM data has been used to correct for terrain relief. The dataset thus incorporates systematic radiometric accuracy. Geometric accuracy is incorporated by using ground control points, while topographic accuracy is obtained by employing a Digital Elevation Model (DEM). Geodetic accuracy of the product depends on the accuracy of the ground control points and the resolution of the DEM used.

3.2.8 Geological Data:

Geological data in respect of lithology, major tectonic features like thrusts and dislocations and minor faults, joints and shears were extracted mainly from the geological map of Kumaon Himalaya compiled from various sources and modified after Valdiya (1980). The map was georeferenced to the UTM projection and WGS84 datum to conform to ASTER DEM and multispectral data used in this study.

3.2.9 Earthquake Database:

Earthquakes are the most direct evidence of active tectonics. To assess the tectonic activity in the area of investigation on the basis of seismicity, historical earthquake data available from the United States Geological Survey‟s (USGS) Earthquake Hazards Program was used. The USGS Earthquake Hazards Program (EHP) which is a part of the National Earthquake Hazards Reduction Program (NEHRP) monitors and reports earthquakes on a global scale, assesses earthquake impacts and hazards, and researches the causes and effects of earthquakes. The EHP provides and applies relevant earthquake science information and knowledge for reducing deaths, injuries, and property damage from earthquakes through understanding of their characteristics and effects and by providing the information and knowledge needed to mitigate these

29 Chapter -III losses. The earthquake database in respect of the event, date, time, location and depths of foci in a 200 km radius around the Ramganga river basin for the last 115 years was downloaded from the USGS-EHP website at: (http://earthquake. usgs. gov/ earthquakes/search/).

3.3 METHODOLOGY:

3.3.1 Watershed delineation

Automated watershed delineation is playing crucial role in the geomorphic studies as well as in the other disciplines. Delineation is part of the process known as watershed segmentation into optimum number of sub watershed, requires for the analyzing watershed behavior. It provides clue about running processes and forms.

Watershed Delineation Using TauDEM:

TauDEM (Terrain Analysis Using Digital Elevation Models) is a set of tools for the analysis of terrain using digital elevation models. It incorporates programs digital elevation model (DEM) analysis functions developed by David Tarboton over several years of research with support from a variety of sponsors. tauDEM is currently packacged as an extendable component (toolbar plugin) to ESRI ArcGIS 9.3.

You will get this dialog box on the TauDEM toolbar from the Grid Analysis menu.

Select the DEM file and click ok to go on further instructions. Next dialog will open “fillpits” click ok and wait couple of minutes.

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Check at the dialog that opens that the input grid is 'ned' and the output one 'nedfel'. Ignore the Flow Path Grid items. (The flow path grid items are used if you want to impose existing flow directions along a channel network).

Click on Compute and wait for a few minutes (or more) for the job to complete. Time is proportional to the size DEM as size increase, time increase.

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After this you have to follow top to bottom sequence in input commands. The program automatically suggest file names for the outputs that follow the convention described in the documentation and you can just click compute at each dialog and have the command execute.

In another way, here we will shortcut running each command by selecting the „Do all preprocessing‟ command from the „Grid Processing‟ menu to have all results generated without any interruption. Processing of this will take 10-15 minutes for the Ramganga DEM. You should answer OK to the prompt to overwrite the existing „Ramfel‟ file that you created above. A number of output layers will be added to the map. The name suffixes designate the contents according to the file naming convention in the documentation. Examine these grid layers to understand their contents.

To proceed further and delineate watersheds a shapefile containing outlet points to be created. Open „ArcCatalog‟ right click on the folder „Ramganga‟ and select „New /Shapefile.. set the name „outlet‟ and set the feature class to the point.

Add the shapefile „outlet.shp‟ to ArcMap. It has no data. Display the editor toolbar and start editing and use to create new feature button and carefully locate a point at the outlet of Ramganga river near south corner of the domain. After locating a point right click on the editor toolbar and save edit then stop editing. This step is finished now.

Now select TauDEM utility/ Network Delineation/ select outlet.shp file… browse to select shapefile and click open and OK. Now select TauDEM/ Do All Network and Watershed delineation steps. Here at this point, a desired threshold to produce desired number of watersheds and stream network have to give. After few seconds of running operation, a small popup bling on the screen “delete exixsting dataset.src” delete it. The same file is being recreated for writing the grid raster only for drainage network to the outlet. A channel network and watersheds are delineated the TauDEM default settings that automatically does a constant drop test using an upwards curved drainage area thresholds to delineate channels.

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The Network delineation/ River Network Raster Upstream command provides a dialog box that allows selecting the different thresholds and algorithms to make river network and watersheds at required thresholds for the purpose of study.

This dialog provides a number of ways and algorithms to made watershed delineation task convenient for the different purposes.

TauDEM utility naming concept:

Table shows default naming convention suggested and used by the TauDEM software plugin.

No Elevation data. Application suffix. fel Pit filled elevation data. produced by Fill pits and non-draining hollows p D8 drainage directions. produced by D8 flow directions sd8 D8 slopes. produced by D8 flow directions

33 Chapter -III ad8 D8 contributing area’s, units produced by D8 drainage area are number of grid cells. slp Dinf slopes. produced by Dinf flow directions ang Dinf flow directions. produced by Dinf flow directions sca Dinf contributing area, units are produced by Dinf drainage area specific catchment area, i.e. number of grid cells times cell size. plen Longest path length to each grid point produced by Grid network order, along D8 directions. Upslope total flow length, Upslope longest path length function tlen Total path length to each grid point produced by Grid network order, along D8 directions. Upslope total flow length, Upslope longest path length function gord Strahler order for grid network produced by Grid network order, defined from D8 flow directions. Upslope total flow length, Upslope longest path length function src Network mask based on channel produced by River Network Raster source rules. ord Grid with Strahler order for mapped produced by River Network Raster stream network. w Subbasins mapped using produced Create Network and Sub- subbasinsetup. Watersheds fdr Flow directions enforced to follow the produced by Convert Connected existing stream network Reach Network to Forced Flow Direction Grid fdrn Flow directions enforced to follow the produced by flood when forced flow existing stream network after cleaning directions are used to remove any loops

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Fig 3.1: (a) Digital Elevation Model of the Ramganga basin

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Fig 3.1: (b) Map showing detailed drainage network of the Ramganga basin.

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Fig 3.2: (a) Stream ordering of the Ramganga basin.

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Fig 3.2: (b) Numbering of sub basins in the Ramganga basin.

3.3.2 Method of Image Classification:

A false colour composite of the scene displaying bands 5, 4 and 3 as RGB was used as a guide to classification. This image can be considered as an equivalent of a false

38 Chapter -III color infrared photograph. Even in this simple three-band image, it was easy to see that there are areas that have similar spectral characteristics. Bright red areas in the image represent high infrared reflectance, usually corresponding to healthy vegetation, either under cultivation, or along rivers. Slightly darker red areas typically represent native vegetation, in this case in slightly more rugged terrain, primarily corresponding to coniferous trees. Several distinct landcover classes regolith, surface water and ice are also readily apparent.

The cursor Location/Value option was used to preview image values in the displayed spectral bands. The image was examined for data values at specific locations. ENVI‟s integrated spectral profiling capability was used to examine the spectral characteristics of different land cover types.

A supervised classification approach was used to cluster pixels in the Landsat scene into five classes corresponding to pre-defined training areas viz., dense forest, sparse vegetation, regolith, ice and snow, and surface water. This classification type required the selection of training areas for use as the basis for classification. ENVI provides various comparison methods to determine if a specific pixel qualifies as a class member. It provides a broad range of supervised classification methods, including parallelepiped, minimum distance, mahalanobis distance, maximum likelihood, spectral angle mapper, binary encoding, and neural net. For the present investigation the maximum likelihood method was used. Training sets were selected using regions of interest (ROI) as described in the ENVI Tutorial. ENVI allows defining regions of interest which are used to extract statistics for classification, masking and other operations.

Maximum likelihood classification assumes that the statistics for each class in each band are normally distributed and calculates the probability that a given pixel belongs to a specific class. Unless a probability threshold is selected, all pixels are classified. Each pixel is assigned to the class that has the highest probability (i.e., the maximum likelihood). The classification was performed using the default parameters and various probability thresholds. Image linking and dynamic overlay was used to compare this classification to the color composite image and previous unsupervised and supervised classifications to arrive at optimized results.

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Classified images require post-processing to evaluate classification accuracy and to generalize classes for export to imagemaps and vector GIS. There are a number of approaches to post-processing of classified images viz., classification of rule images; calculation of class statistics and confusion matrices; applying majority or minority analysis to classification images; for clumping, sieving, and combining classes; for overlaying classes on an image; for calculating buffer zone images; for calculating segmentation images; and to output classes to vector layers. In the present case, class statistics were extracted were extracted from the image used to produce the classification. Separate statistics were calculated for each class selected.

ENVI‟s confusion matrix function was used to compare the classified image and the RIOs. Clump and Sieve functions were used to generalize the classified image. Sieve was run first to remove the isolated pixels based on a size (number of pixels) threshold, then clump was run to add spatial coherence to existing classes by combining adjacent similar classified areas. The Overlay Classes function was used to overlay the classified image as a colour overlay over the 5,4,3 image to allow a visual inspection of classification results.

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Fig 3.3: (a) Satellite image of the Ramganga basin.

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Fig 3.3: (b) Land use and land cover classification of the Ramganga basin.

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Fig 3.4 Map Showing Slope of the Ramganga Basin.

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Fig 3.5 Showing Aspect map of the Ramganga Basin.

Geomorphic indices of active tectonics

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Geomorphic Indices of Active Tectonics

4.1 Introduction

Morphometry is defined as quantitative measurement of landscape shape. At the simplest level, landforms can be characterized in terms of their size, elevation and slope. Quantitative measurements allow geomorphologists objectively to compare different landforms and to calculate less straightforward parameters (geomorphic indices) that may be useful for identifying a particular characteristic of an area (its level of tectonic activity).

Some geomorphic indices have been developed as basic reconnaissance tools to identify areas experiencing rapid tectonic deformation. This information is used for planning research to obtain detailed information about active tectonics. Other indices were developed to quantify description of landscape. Geomorphic indices are particularly useful in tectonic studies because they can be used for rapid evaluation of large areas and the necessary data often can be obtained easily from topographic maps and aerial photographs. Some of the geomorphic indices most useful in studies of active tectonics such as Hypsometric integral by Strahler (1952), Asymmetry Factor by Cox (1994), Stream length-gradient index developed by Hack (1973), Mountain front sinuosity developed by Bull and Mc Fadden (1977), Ratio of valley floor width to valley height etc. (Keller and Pinter 2002). Mountain front, valley, sinuosity of the channels is surface features that construct the arid to semiarid landscape and exists at large or small scales. To understand the way landforms evolve, it is essential to study the underlying geology. In general, landform development implies deep structures of the earth; therefore there is always a strong relationship between landscape and the geologic environment (Keller and Pinter 2002). Morphotectonics has been considered as a tool to determine the intensity of tectonic activity in the tectonically active areas (Wells, Bullard et al. 1988; Merritts and Vincent 1989; Rhea 1993).

4.2 Remote sensing and GIS uses in geomorphology:

In recent years, the advancements in computer technologies and digital data acquisition/processing has led to the improvement of the knowledge of geomorphic processes and the development of the use of predictive models and quantitative measurements to analyze, monitor, and understand landform changes. This

45 Chapter -IV advancement has allowed geographers, geologists, and geomorphologists to explore human/land interaction utilizing modelling and systems analysis in their geomorphological studies that relied on sophisticated hardware and software tools (Ata 2008).

Earth-observing satellites, airborne sensor systems and aerial and space photography have nearly complete coverage of the Earth’s surface that provides images of different formats and various scales. This permits not only interpretation of landscape evolution, but rather offers the opportunity to integrate observation of a variety of processes over a large region. Geomorphic analysis from space has the advantage of allowing the use of quantitative methods for both data gathering and information extraction. Thus, satellite images are becoming useful and necessary in geomorphology, especially in obtaining quantitative measurements and performing geomorphic analyses (Hayden 1986).

Geographic Information Systems (GIS) have enhanced the applicability of geologic mapping when integrated with data obtained by remote sensing using a wide range of formats and scales. In addition, advancement in image analysis provides geologists opportunity to enhance, manipulate, and combine digital remotely-sensed data with several types of geographic information that in turn increases the amount of extracted information related to topographic and geologic features (Horsby and Harris 1992).

Digital enhancement of satellite images yields much information about image features. GIS techniques enable the integration and analysis of multi spatial and non- spatial data that have the same georeferencing scheme. Therefore, the integration of GIS and remotely sensed data could be more informative and results would be more applicable to image interpretation (Ehlers 1992; Horsby and Harris 1992; Saraf and Choudhury 1998). Within the context of GIS, surface geomorphology is most commonly represented in Digital Elevation Models (DEMs) especially when quantitative measurement using geomorphometry is necessary. DEMs are generally defined as a regular two dimensional array of heights sampled above some datum that describes a surface (Wood 1996).

Below is a brief description of the most common geomorphic indices used in active tectonic studies. The description includes the index definition/explanation, mathematical formula, and tectonic geomorphological application.

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4.3 Geomorphic Indices:

4.3.1. Mountain front sinuosity (Smf)

Mountain front sinuosity is a widely used reconnaissance tool to identify areas on the basis of the tectonic activity. Smf index reflects a balance between the tendency of streams and slope processes to produce an irregular (sinuous) mountain front and vertical active tectonics that tends to produce a prominent straight front (Bull and Fadden 1977). A mountain front generated by faulting is a zone on which fluvial system can adjust themselves to local base-level processes (Shaoping and Guizhi 1999). Such relative adjustment can be examined by the morphometric analysis which includes several useful geomorphological indices and Smf index is one of them.

Bull and Mc Fadden in 1977 proposed the degree of tectonic activity and erosional modifications of tectonic structures can be measured by this index. Mountain front sinuosity (Smf) is the ratio of the total length of the mountain front as measured along the prominent break in slope along the foot of a mountain and the straight line length of the mountain front. And it is expressed by the following formula-

Smf = Lmf/Ls

Where, Smf is the Mountain front sinuosity index, Lmf is the total length of the mountain front and Ls is the straight line length of the mountain front.

Studies analysing the mountain front sinuosity from different regions, such as the SW USA (Bull and Fadden 1977; Rockwell, Keller et al. 1985; Costa 1987; Wells, Bullard et al. 1988; Rhea 1993; Silva, Goy et al. 2003) suggest that mountain fronts with low values of Smf (<1.6) are categorized as active fronts (Malik and Mohanty 2007).

Thus, mountain fronts associated with active uplift are relatively straight, but if the rate of uplift is reduced or ceases, erosional processes will begin to form a sinuous fronts that become more irregular with time. Lower values of the mountain front sinuosity indicates straight mountain front while higher values shows that front is irregular.

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Mapping of mountain front and its sinuosity

The Smf index is particularly attractive because it can be quickly and easily measured from aerial photographs, satellite or other high altitude imagery or topographic maps.

Values of Smf depend on image scale, small scale topographic maps (1:250,000) produce only a rough estimate to mountain front sinuosity (Keller and Pinter 2002).

Mountain fronts can be measured manually from the high resolution satellite images and topographic maps. For measurement of mountain front sinuosity in the ramganga river basin, digital elevation models (DEMs) generated by stereo image bands 3N and 3B of ASTER were used. 3-D surfaces using DEMs were generated in Global Mapper (version 11). The mountain fronts were traced by supervised navigation of the 3-d surfaces. For this purpose, Selection of the mountain front is also a main task. Ramganga river basin has been divided into 26 sub basins and in each sub basin many fronts has been traced and measured, depending on the area of the basin. After calculating of smf in each sub basin, the mean of the values calculated and used as representative value of that basin. Smf index is unitless (Bull and Fadden 1977) (Rockwell, Keller et al. 1985; Keller and Pinter 2002). Mountain front can be calculated as one major front divided into segments of many fronts of same length or several continuous fronts of various lengths (Bull 1984; Wells, Bullard et al. 1988; Silva, Goy et al. 2003). In this study, later approach is adopted because this method was more suitable for the present research. And with this method we achieve better results about the tectonics of the area.

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Figure 4.1 (a).Calculating mountain front sinuosity (Smf) index (Modified from Keller and Pinter 2002, figure 4.14, p. 137).

Figure 4.1 (b): Showing total length of mountain front (Lmf) and straight line length (Ls) of the mountain front.

4.3.2. Drainage basin asymmetry

The geometry of stream networks can be described in several ways, both qualitatively and quantitatively. Different drainage pattern reflects different structural control as well as their tectonic settings also. If drainage pattern develops in the presence of active tectonic deformation, the network often has a distinct pattern and geometry.

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Drainage basin asymmetry depicts that in which direction river migrate and how much a basin is asymmetric. In other words we can say that we calculate tectonic tilting of the basin and their direction and how much tilting is taking place in comparison to other basin. Here we are discussing two parameters for deciphering asymmetry of the basin.

To decipher the possible pattern of ground tilting in the study area we used two quantitative morphometric parameters namely, Asymmetric factor and Transverse topographic symmetry (T-vector).

(a) Asymmetry factor (AF):

The asymmetry factor was developed to detect tectonic tilting transverse to flow at drainage basin or larger scale. The asymmetry factor is defined as

AF = 100 (Ar/At)

Where, Ar is the area of the basin to the right (facing downstream) of the trunk stream. And At is the total area of the drainage basin. For most of the stream networks that formed and continue to flow in stable setting, AF should equal about 50. The AF is sensitive to tilting perpendicular to the trend of the trunk stream. Values of AF significantly greater or less than 50 may suggest tilt.

So with the help of this simple formula we can easily calculate the tilting of the basin. If AF is 50, it suggest stable setting and there is no tilt in the basin and if AF is more or less 50, may suggest tilt and it indicates that basin is tectonically active and still uplifting (Keller and Pinter 2002).

Any drainage basin with a flowing trunk stream that was subjected to a tectonic rotation will most likely have an effect on the tributaries lengths. Assuming the tectonic activity caused a left dipping to the drainage basin, the tributaries to the left of the main stream will be shorter compared to the ones to the right side of the stream with an asymmetry factor greater than 50, and vice versa (Hare and Gardner 1985; Keller and Pinter 2002), as shown in following figure (fig 3).

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Figure 4.2: Block diagram shows the effect of an asymmetry factor with a left side tilt on tributaries lengths (From Keller and Pinter 2002, figure 4.3, p. 125).

Procedure for calculating AF in GIS environment:

To calculate the Asymmetry factor (AF) in the Ramganga basin we found out the general trend of the main stream of the basin. First, we took the main stream of the basin and plotted the number of points depending on the length of the stream. After this we assigned the latitude and longitude of those points and created a scatter plot in Arc GIS and calculate the general trend of the stream using this scatter plot. After this process we draw an arrow perpendicular on the general trend of the stream. Direction of that arrow is showing the direction of tilting of the river channel of that basin.

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Figure 4.3: (a) Solid line showing the trend of the river channel

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Figure 4.3: (b) Arrow showing the direction of the migration of the river channel.

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(b) Transverse topographic symmetry factor (T-vector)

Another quantitative index to evaluate basin asymmetry is the transverse topographic symmetry following the basic technique presented in (Cox 1994; Cox, Arsdale et al. 2001). This index is calculated with the formula-

T= Da/Dd

Where,

Da= the distance from the midline of the drainage basin to the midline of the active meander belt.

Dd= the distance from the basin midline to the basin divide.

Values of T=0 indicates perfectly symmetric basin as asymmetry increases; T increases and approaches a value of 1.

Migration of the channel from the midline of the basin is an indication of the ground tilting in the direction of migration. Thus T is a vector which has magnitude from 0 to 1 and direction. Values of T are calculated for different segments of the valley and indicate preferred migration of stream perpendicular to the drainage-basin axis.

Procedure for plotting midline of the basin (Temme 2010):

Plotting of midline is followed by number of steps as-

1. Find lowest cell of watershed means outlet of the basin.

2. Find the cell from the same watershed that is furthest from this lowest cell.

3. Draw a straight line between the lowest and furthest cell (called stepline).

4. In case where this straight line is not insight the watershed (imagine a banana- shaped watershed), the line is pushed sideways to cover the edge of the watershed (called sidestepline).

5. Draw a perpendicular to the stepline in both directions from sidestepline to find the watershed boundaries (these lines are called looklines).

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6. Finally halfway points are calculated from the pair of distances and the lines formed by the joining of the mid points are called the midline of the basin.

Procedure of measuring Da and Dd-

Da is the distance from the stream channel to the midline of its drainage basin (measured perpendicular to a straight line segment fit to the channel) and Dd is the distance from the basin margin (divide) to the midline of the basin (Tsodoulos, Koukouvelas et al. ; Salvany 2004)

Figure 4.4: (a) Photograph Showing Da and Dd of the basin.

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Figure 4.4: (b) Arrow showing direction of migration of the channel from the midline of the basin.

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Calculation of T-vector:

In order to calculate the T- index, Ramganga river watershed is divided into 26 sub watersheds. And in each sub watersheds T index is calculated for each segment of the river channel in which it migrates from the mid of the basin and it represents as a two dimensional vector. The length of the vector is equivalent to the ratio Da/Dd, and its direction is perpendicular to the segment of the stream. Statistical analysis of the calculated vectors was used to estimate the most prominent direction of stream migration, in a set of vectors, the most dominant direction can be found by calculating the resultant vector (Davis 2002). The direction of the resultant vector is the mean direction of all the calculated vectors. The length of the resultant vector divided by the number of the calculated vectors gives the mean resultant length (R), which is a measure of dispersion (Davis 2002). The mean resultant vector length ranges from 0 to 1. Values of the mean resultant length near 1 indicate small dispersion, while values near 0 indicate that vectors are widely dispersed.

4.3.3. Hypsometric integral (HI)

In tectonic geomorphology, morphometric analysis is the key tool to evaluate the area on the basis of the tectonic activity. The distribution of the elevations within a region provides information on the balance between external processes (which tend to lower the landscape) and internal processes (which tend to create relief). One of the most useful parameter that describe and analyze the distribution of elevations in an area is Hypsometry (Pena, Azanon et al. 2009).

Hypsometric integral, a dimensionless parameter, is proposed by Strahler in 1952. The advantage of the HI is that we calculate and compare different basins of different areas irrespective of scale. According to Strahler, Hypsometric analysis (or area- altitude analysis) is the study of the distribution of horizontal cross-sectional area of a landmass with respect to elevation. Classically, hypsometric analysis has been used to differentiate between erosional landforms at different stages during their evolution (Strahler 1952; Schumm 1956). HI thus helps in explaining the erosion that had taken place in the watershed during the geological time scale due to hydrologic processes and land degradation factors (P.Bishop, ShroderJr. et al. 2003). The HI is also an indication of the cycle of erosion(Strahler 1952). The cycle of erosion is defined as the total time required for reduction of a land topological unit to the base

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level that is the lowest level. The entire period or the cycle of erosion can be divided into three stages viz. monadnock (old) stage, in which watershed is fully stabilized characterized by a landscape near base level with subdued relief; equilibrium stage or mature stage, where many geographic processes operate in approximate equilibrium and inequilibrium or young stage, in which the watershed is highly susceptible to erosion (Strahler 1952; Sarangi, Bhattacharya et al. 2001). which is characterized by deep incision and rugged relief. Strahler (1952) found that the HI was inversely correlated with total relief, slope steepness, drainage density and channel gradients. HI is expressed as a percentage, and is indicator of the remnant of the present volume as compared to the original volume of the basin (Ritter, Kochel et al. 2002).

HI is calculated by the following formula-

HI = mean elevation – minimum elevation / maximum elevation – minimum elevation

Value of HI ranges from 0 to 1.High hypsometric integral values indicate that most of the topography is high relative to the mean representing a youthful topography stage. Intermediate to low hypsometric integral values represent more evenly dissected drainage basins, indicating a mature stage of development (Strahler 1952; Mayer 1990; Keller and Pinter 2002).

How to calculate Hypsometric Integral?:

Calculating the hypsometric integral (HI) is achieve by deriving the maximum and minimum elevation directly from a topographic map. The mean elevation is calculated by obtaining the mean of at least 50 elevation values in the basin using point sampling on a grid (Pike and Wilson 1971; Keller and Pinter 2002) It can also be evaluated directly from the digital elevation model (DEM) of the basin (Pike and Wilson 1971; Keller and Pinter 2002; Luo 2002; Luo and Howard 2005).

Method adopting for extraction of HI values in the Ramganga river basin:

In Ramganga river basin HI values were obtained automatically from ASTER DEM of 30m resolution which was processed in Arc GIS 9.3 environment. For detailed study of the HI in the Ramganga river basin, we crop the DEM data for individual 26

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sub basins. For this, in Global Mapper 11, we put the ASTER digital elevation model of the Ramganga river basin and overlay the shape file of 26 sub basins. With the help of the digitizer tool, select the shape file of the each sub basin and export DEM with the function of the “Export raster and elevation data” and save them in desired location. After this process, open the DEM data of each sub basin in the Arc GIS 9.3 environment and go to the properties of the opened DEM file and found the maximum elevation, minimum elevation and mean elevation and put these values in the mathematical formula of the hypsometric integral.

Keller and Pinter (2002) described the values of HI on the basis of the erosional status of the basin-

If, HI ≤ 0.3 (old stage), it means watershed is fully stabilized.

0.3 ≤ HI ≤ 0.6 (equilibrium or mature stage) indicate watershed is susceptible to erosion.

HI ≥ 0.6 (inequilibrium or young stage) indicate watershed is highly susceptible to erosion.

Their susceptibility of erosion is also an indicator of the tectonic conditions of the basin. Basin with high susceptibility of erosion is tectonically active and old stage of the basin is less active. Strahler (1952) found that the hypsometric integral was inversely correlated with total relief, slope steepness, drainage density and channel gradients.

So, to decipher the tectonic status in 26 sub basins of Ramganga, we have categorized the values as-

0-0.3 (less active)

0.3-0.45 (active)

0.45-0.6 (highly active).

4.3.4. Channel sinuosity (S)

Channel sinuosity is a significant quantitative index for interpreting the significance of streams in the evolution of landscapes and beneficial for Geo morphologists,

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Hydrologists and Geologists. Sinuosity deals with the pattern of channel of a drainage basin(Pareta and Pareta 2011). (Muller 1968)defined channel sinuosity as it is the ratio of channel length and river valley length. In practice no river follows straight course from source to mouth. Sinuosity of the river helps in understanding the role of the tectonics. The index value of 1 indicates straight river course. Values between 1.0 and 1.5 indicate sinuous river whereas channel sinuosity more than 1.5 represents meandering course (Wolman and P.Miller 1964; Bhatt, Chopra et al. 2007; Rawat, Tiwari et al. 2011)

To find out the channel sinuosity index we measure the total length of the river channel and divide it by the straight line length of that river channel. And it is calculated as-

S= SL/VL

Where, S is the channel sinuosity, SL is the stream length and VL is the valley length.

Sinuosity of the river channel depends on many factors such as underlying rock type, structures present on that region, climate, vegetation, hydrological factor, deposition of the sediments in river course, time etc.

Sinuosity or meandering usually occurs on those regions where relief is very low. Those river channels which flow on the mountainous region and on steeper slopes follow straight course.

In Ramganga river basin values of channel sinuosity ranges from 1.1 to 1.7 means it indicates sinuosity of the river channel. Sinuosity of the river channel varied from one sub basin to the other. Sinusity of the river channel ranged 1.7 in two sub basins namely Bansbagad (sub basin 3) and Bhakuna (sub basin 10). In this case, high sinuosity is not due to the absence of steeper slope and high elevation but because of the structures present in underlying rock types. These two sub basins are present in the close association of the Main Central Thrust, Bhujpatri Gad fault and Darun fault.

To assess the relative tectonic activity in the Ramganga river basin values are classified as-

1.1 – 1.2 (tectonically more active)

60 Chapter -IV

1.2 – 1.4 (less active)

1.4 – 1.7 (inactive settings)

4.3.5. The ratio of valley floor width to valley height (Vf)

The valley floor width to valley height ratio (Vf) is another index to assess the area on the basis of the tectonic activity. This index reflects the differences between the V- shaped valleys down cutting in response to active uplift, where the stream is governed by the influence of a base level fall at some point downstream that indicates a relatively high tectonic activity, and the U-shaped broad-floored valleys with principally lateral erosion into the adjacent hill slopes in response to relative base level stability or tectonic quiescence that signifies a relatively low tectonic activity. Therefore, this index uses one vertical and one horizontal dimension at a given point along the stream in the erosional system. The ratio of valley floor width to valley height is defined as:

Where, Vfw is the width of the valley floor, Esc is the elevation of the valley floor or stream channel, and Eld and Erd are the elevations of the left and right valley divides respectively.

Similar to the Smf index, lower values of the Vf index indicate relatively active mountain fronts and reflect deep valleys with active incision related to uplift, whereas higher Vf index values are associated with relatively moderate to less active mountain fronts that represent low uplift rates (Bull 1977a, 1978, (Bull and Fadden 1977; Burbank and Anderson 2001) (Rockwell, Keller et al. 1985; Wells, Bullard et al. 1988; Keller and Pinter 2002; Silva, Goy et al. 2003)

Theoretically U-shaped valleys are indicative of the less tectonic activity and V- shaped valleys, as a response to uplift, are associated with high tectonic activity (Bull and Fadden 1977; Burbank and Anderson 2001; Keller and Pinter 2002).

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Figure 4.5: Calculating valley floor width to height ratio (Keller and Pinter 2002, figure 4.15, p. 139.

Digitizing valley profiles and measuring elevations and valleys’ widths:

The digitization of valley profiles will serve the purpose of calculating the four unknown elevations of Eld, Erd, Esc and Vfw values in order to calculate the Vf values of each individual valley. Towards this, all the valley profiles will be converted into three dimensional profiles by using the 3D path profile/line of sight tool and viewed in the global mapper to measure the elevation values of each valley individually. Valley profile is oriented at the right angle to the valley of the basin. For example, if the valley is oriented in the north-south direction, as a result, the valley profile will be in the east-west direction. Therefore, during the calculation of the Vf values, east end elevation of the valley will represent the left valley elevation of the valley divide (Eld) while the west end will represent the right valley elevation divide (Erd). Width of the valley floor (Vfw) and elevation of the valley floor (Esc) is calculated directly from the reading of the 3D profile of the basin.

62 Chapter -IV

Fig 4.6 Map showing the valley profile of a basin (Generated in Global mapper).

4.3.6. Stream length- gradient index (SL)

The Stream Length-Gradient Index (SL) is calculated along a river and used to evaluate the erosional resistance of the available rocks and relative intensity of active tectonics. The SL index has sensitivity to channel slope changes, which makes it a good evaluation tool for the relationship between potential tectonic activity, rock resistance, topography, and length of the stream (Hack 1973; Azor, Keller et al. 2002; Keller and Pinter 2002). The stream length-gradient index (or SL index) proposed by Hack (1973) calculated for a particular reach of interest and defined as-

SL = (ΔH/ΔL) / L

Where SL is stream length gradient, ∆H/∆L is the channel slope or gradient of particular reach, ∆H is the change in elevation of the reach and ∆L is the length of the reach and L is the total length from midpoint of the reach of interest upstream to the highest point on the channel.

The stream length-gradient index (SL) correlates to the total stream power, available at particular reach of channel is an important hydrologic variable, because it is related to ability of a stream to erode its bed and transport sediment.

Total available stream power is the product of the slope of the water surface and discharge. Slope of water surface generally measured by its slope of the channel bed.

The SL index is sensitive to change in slope and this sensitivity allows the evaluation of relationship among the possible tectonic activity, rock resistance and topography.

63 Chapter -IV

Index value will be significantly lower in softer strata; rock types are shale, siltstone and carbonate rocks and increases, where the stream crosses the relatively hard rocks.

In landscape evolution, the adjustment of stream profiles to rock resistance is assumed fairly quickly. Therefore, the SL index is used to identify recent tectonic activity by identifying anomalously high index values on a particular type. For example, an area of high index values on softer rock may indicate recent tectonic activity. Anomalously low values of the index also may represent tectonic activity, along linear valleys produced by strike slip faulting, indicates valleys is crushed by fault movement.

The SL index over a region can be computed from small-scale topographic maps. The index could also be computed from analyses of elevation data stored in computer systems. Therefore, in theory, large regions may be evaluated quickly, although interpretation of the index will remain crude because it may be difficult to separate effects of rock resistance from active tectonics. Nevertheless, the SL index is a valuable reconnaissance tool useful in isolating smaller areas for detailed work.

Figure 4.7: Diagram shows the process of calculating the Stream Length-Gradient Index (SL) for a given creek (Keller and Pinter 2002, figure, 4.6, p. 128).

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4.3.7. Basin elongation ratio (Re)

(Schumn 1956) defined the basin elongation ratio as the ratio of the diameter of a circle of the same area as the basin to the maximum basin length. Elongation ratio indicates how the shape of the basin deviates from a circle and this index tells about the shape of the basin. The varying slopes of watershed can be classified with the help of the index of elongation ratio (Pareta and Pareta 2011). According to (Suresh 2000) this ratio runs between 0.6 and 1.0 over a wide variety of climatic and geologic types. The variation of the elongated shape of the basins is due to the guiding effect of thrusting and faulting in the basin. Values close to 1.0 are typical of regions of low relief whereas values in the range 0.6-0.8 are usually associated with high relief and steep ground slope (Strahler 1964). High Re values indicate that the areas are having high infiltration capacity and low runoff (Sreedevi, Owais et al. 2009). And is derived by following formula-

Re = (2√A: √π)/L

Where, Re is basin elongation ratio; A is the area of the basin; L is the length of the basin.

A value of basin elongation ratio on the basis of the shape of the basin is described by different researchers (Pareta and Pareta 2011; Rawat, Tiwari et al. 2011; Sethupathi, Narasimhan et al. 2011) and grouped as -

Circular (0.9 to 1.0),

Oval (0.8 to 0.9),

Less elongated (0.7 to 0.8) and

Elongated (<0.7)

Values of basin elongation ratio in 26 sub basins ranged from 0.56 to 0.9. Lower values of the basin elongation ratio indicates the elongated shape of the basin while higher values indicates the oval to circular or near circular shape of the basin. Elongated to highly elongated basins are less flood prone areas whereas circular to near circular basins are highly susceptible to the flood.

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Minimum value (0.56) found in Namik (sub basin 1) and maximum value 0.9 found in Sirtoli (sub basin 14) respectively.

Values near to 1.0 are typical of regions of very low relief (Strahler 1964) with circular in shape and are efficient in the discharge of runoff than elongated basin because concentration time is less in circular basins. Thus Re values help in flood forecasting. The elongation ratio and shape of basin are given below.

Table 4.1 Showing the shape of the Basin on the Basis of Basin Elongation Ratio.

Elongation ratio Shape of the basin

Circular 0.9 to 1.0

Oval 0.8 to 0.9

Less elongated 0.7 to 0.8

Elongated < 0.7

The basin elongation ratio (Re) proposed by Bull and Mc Fadden (1977) is one of the proxy indicators of recent tectonic activity (Cuong and Zuchiwicz, 2001). And in terms of tectonic activity, they categorized the values of basin elongation ratio as-

Re < 0.50, Tectonically Active

Re = 0.50-0.75, Slightly Active

Re > 0.75, Inactive Setting

Results and discussions

Chapter -V

Results and Discussion:

1. Mountain front sinuosity (Smf)

A number of different mountain fronts were analysed in 26 sub basins of the Ramganga river basin. Mountain front analysis shows the lowest result as 1.001 in Thal (basin no.9) and highest result as 1.23 in Naini (basin no.23). Out of 26 sub basins, 11 basins have values 1.01, 8 basins have 1.02, 3 basins have 1.03, 2 basins have 1.04 and 1 basin has lowest value 1.001 and 1 basin has highest value as 1.26. Therefore, on the basis of derived results, all the mountain fronts in 26 sub basins of the Ramganga basin fall in „tectonically active front‟ category.

Although all mountain fronts present in different sub basins are highly tectonically active but to decipher the relative tectonic activity in sub-basins we categorized the Smf values into three classes as-

Table-5.1: Table showing Different Classes of Tectonic Activity.

Class Value Tectonic activity

1 < 1.02 Extremely active

2 >1.02- 1.04 Moderately active

3 >1.04 Active

Analysis revealed that those mountain fronts which are closely associated of the tectonic structures such as Munsiari thrust, Vaikrita thrust, Bhujpatri gad fault, Darun fault, Darmoli fault and some other minor faults and thrusts have relatively straight mountain fronts and shows extremely high tectonic activity in the basin (Basin no.1 to basin no. 13, basin 15, basin 18, basin 21, basin 22, basin 24, basin 25, basin 26). These basins are present in whole Northern, some basins in south- Eastern and southern portion of the Ramganga river basin. In these basins influence of the tectonic structures are more pronounced. Those mountain fronts which are present relatively far from these structures are showing relatively sinuous mountain fronts (basin no. 23) and showing the less tectonic activity in the basin. Basin no. 14, basin no. 16, basin

67 Chapter -V no. 17, basin no. 19, basin no. 20 is showing the moderate tectonic activity. Theses basins constitute lithotectonic contacts include Berinag formation, Thalkedar limestone, Gangolihat dolomite and Almora-Dudhatoli and related crystallines. Contacts of these lithological contacts are the more suitable sites of erosion. In these basins erosional forces are dominant on the tectonic forces and thus showing the relatively sinuous fronts.

Figure 5.1 Map showing tectonic activity based on Smf and their relation with tectonic structures.

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Figure 5.2 Map showing tectonic activity based on Smf in 26 sub basins of the Ramganga basin.

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Fig 5.3: Map showing the Mountain fronts in the whole Ramganga river basin.

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Table 5.2: Showing the Smf values in 26 sub basins of the Ramganga river basin.

Entity Sub basin Total Straight Smf values(km) Mean 1 length(km) line values length(km)

Namik a 1.653 1.6238 1.01798251 1.02

b 2.784 2.69 1.034944238

c 3.037 3.0002 1.012265849

d 1.78 1.7613 1.010617158

e 2.61 2.5914 1.007177587

f 2.942 2.8327 1.038585095

g 2.263 2.2285 1.015481265

h 1.114 1.1002 1.012543174

Girgaon sub basin 2

a 1.432 1.397 1.025053686 1.02

b 2.349 2.2954 1.02335105

c 2.522 2.4667 1.022418616

Bansbagad sub basin 3

a 1.578 1.5359 1.027410639 1.02

b 2.723 2.7123 1.003944991

c 1.869 1.8437 1.013722406

d 3.136 3.0186 1.038892202

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Dhanyar sub basin 4

a 0.963 0.936 1.028846154 1.02

b 2.126 2.086 1.019175455

c 3.488 3.47 1.00518732

d 2.389 2.358 1.013146735

e 3.394 3.318 1.022905365

Tejam sub basin 5

a 0.864 0.862 1.002320186 1.01

b 0.809 0.807 1.002478315

c 0.847 0.837 1.011947431

Muhari sub basin 6

a 0.876 0.873 1.003436426 1.01

b 0.968 0.964 1.004149378

c 1.702 1.662 1.024067389

d 6.473 6.415 1.009041309

Dhalkot sub basin 7

a 2.637 2.596 1.015793529 1.01

b 1.797 1.782 1.008417508

Naulara sub basin 8

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a 0.791 0.786 1.006361323 1.01

b 1.058 1.056 1.001893939

c 1.169 1.157 1.010371651

Thal sub basin 9

a 0.969 0.968 1.001033058 1.001

b 0.55 0.549 1.001821494

Bhakuna sub basin 10

a 0.847 0.834 1.01558753 1.02

b 1.387 1.363 1.017608217

c 1.007 0.974 1.033880903

d 1.568 1.516 1.034300792

e 1.41 1.384 1.018786127

Chamoli sub basin 11

a 0.948 0.936 1.012820513 1.02

b 1.477 1.465 1.008191126

c 1.527 1.506 1.013944223

d 1.357 1.301 1.043043812

Chaukori sub basin 12

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a 4.393 4.298 1.022103304 1.01

b 1.763 1.754 1.005131129

c 1.389 1.388 1.000720461

d 2.213 2.15 1.029302326

Amtar sub basin 13

a 1.952 1.913 1.020386827 1.02

Sirtoli sub basin 14

a 1.658 1.553 1.067611075 1.04

b 0.794 0.781 1.016645327

Kukroli sub basin 15

a 1.106 1.099 1.006369427 1.01

b 2.981 2.942 1.013256288

Raitoli sub basin 16

a 2.331 2.228 1.046229803 1.03

b 1.21 1.199 1.009174312

c 2.15 2.084 1.031669866

Nagaur sub basin

74 Chapter -V

a 1.265 1.25 1.012 1.03

b 1.408 1.321 1.065859198

c 1.64 1.619 1.01297097

Dhanigaon sub basin 18

a 0.989 0.982 1.00712831 1.01

b 1.157 1.123 1.030276046

c 1.028 1.017 1.010816126

d 2.07 2.064 1.002906977

Simali sub basin 19

a 2.303 2.244 1.026292335 1.04

b 1.633 1.528 1.068717277

c 1.506 1.505 1.000664452

d 1.529 1.462 1.045827633

Takulia sub basin 20

a 1.505 1.472 1.022418478 1.03

b 1.996 1.952 1.022540984

c 0.87 0.831 1.046931408

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d 1.378 1.367 1.008046818

Kanalchhi sub basin na 21

a 2.108 2.003 1.052421368 1.02

b 1.829 1.808 1.011615044

c 1.366 1.362 1.002936858

Gangolihat sub basin 22

a 4.256 4.217 1.009248281 1.01

Naini sub basin 23

a 1.156 2.599 0.444786456 1.26

b 2.657 1.146 2.318499127

c 1.567 1.562 1.003201024

Batala sub basin 24

a 1.786 1.736 1.028801843 1.01

b 0.836 0.829 1.008443908

c 0.991 0.985 1.006091371

Chaukyala sub basin gaon 25

76 Chapter -V

a 1.686 1.655 1.018731118 1.01

b 1.688 1.676 1.007159905

Damta sub basin 26

a 1.345 1.327 1.013564431 1.01

b 1.109 1.096 1.011861314

c 0.979 0.972 1.007201646

d 1.437 1.414 1.016265912

2. Drainage basin asymmetry-

Asymmetry factor and Transverse topographic symmetry are two important parameters to decipher the relative upliftment or tilting of the area.

(i) Asymmetry Factor:

This index has been calculated for 26 sub basins. Results of the drainage basin asymmetry ranges between 23 and 87, clearly suggest strong asymmetry. Derived results express spatial variation of tectonic tilting at one side due to in-equilibrium between incision and uplift. Ideally tectonically stable region should express the values 50, suggest no tilting and incision. Values of drainage asymmetry greater or less than 50 suggest tilting of the basin. It is interpreted as values greater than 50 indicates that main river channel is shifted towards the left side of the basin looking downstream while values less than 50 indicates that the main river channel is shifting towards right side of the basin looking downstream. The rate of uplift and tectonic activity can also vary locally within a region. Among geomorphic indices, drainage systems are very sensitive to active deformation especially in the folded and thrusted regions.

Drainage basin asymmetry of the Ramganga river basin suggest high asymmetry in the north eastern and south eastern part of the basin, resulting main stream channel is

77 Chapter -V shifting towards southwest in general. And in particular, Dhalkot (basin no.7), Naulara (basin no.8), Thal (basin no.9), Sirtoli (basin no.14), Nagaur (basin no.17) and Simali (basin no.19) are showing high asymmetric values.

Effects of the tectonic structures on the basins are more influenced. Tectonic tilting is also directly influenced by the erosional status of the basin. Those basins in which high erosion is taking place are also experiencing upliftment of the basin. Results of the hypsometric integral support my hypothesis. Sub basins of the Ramganga basin showing the eroded stages are showing the upliftment. Drainage basin asymmetry describes that the sub basins in the close proximity of faults and thrusts having relatively higher values while sub basins transect with the main river channel and increasing distance from the major structures suggest relatively symmetric drainage system.

Fig 5.4 Map showing the results of Asymmetry Factor with tectonic structures.

78 Chapter -V

Fig 5.5 Map showing the Asymmetry in 26 sub basins of the Ramganga basin.

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Table 5.3: Showing Asymmetry Factor in 26 sub basins of the Ramganga basin.

S.no. Entity Area(km²)or At Ar 100(Ar/At) AF

1 Namik 250.98 141.94 56.55430712 57

2 Girgaon 112.88 52.62 46.61587527 47

3 Bansbagad 153 75.05 49.05228758 49

4 Dhanyar 78.55 41.12 52.34882241 52

5 Tejam 15.14 6.19 40.88507266 41

6 Muhari 67.91 35.45 52.20144309 52

7 Dhalkot 18.3 14.73 80.49180328 80

8 Naulara 14.2 11.65 82.04225352 82

9 Thal 11.7 7.25 61.96581197 62

10 Bhakuna 37.53 17.67 47.08233413 47

11 Chamoli 38.24 16.92 44.24686192 44

12 Chaukori 50.77 28.07 55.28855623 55

13 Amtar 7.1 1.6 22.53521127 23

14 Sirtoli 5.09 3.84 75.44204322 75

15 Kukroli 25.18 7.54 29.94440032 30

16 Raitoli 31.67 21.99 69.43479634 69

17 Nagaur 34.64 30 86.60508083 87

18 Dhanigaon 54.85 24.92 45.43299909 45

19 Simali 33.32 26.28 78.87154862 79

20 Takulia 48.35 12.6 26.05997932 26

80 Chapter -V

21 Kanalchhina 35.02 14.39 41.09080525 41

22 Gangolihat 36.78 19.53 53.0995106 53

23 Naini 47.37 15.38 32.46780663 32

24 Batala 39.59 14.18 35.81712554 36

25 Chaukyalagaon 31.05 18.98 61.12721417 61

26 Damta 80.69 39.63 49.11389268 49

Fig 5.6 Lined portion are showing the relative uplift in the Ramganga basin.

81 Chapter -V

(ii) Transverse topographic symmetry:

Transverse topographic symmetry analyzed in 26 sub basins of the Ramganga basin. Values of Da and Dd were calculated at different places in each basin with their main stream. Results show that in each sub basin main channel not follow the midline of the basin, it flows either left or right sight of the main channel. The deviation of the channel from their midway suggests tilting of the basin. To decipher the precise calculation of the tilting present in the basin we calculated the T at several places in each basin depending on the length of the basin and after the calculation of the T in several places we calculated the mean value of that basin. This mean value of T is taking as the representation value of that basin. Each basin of the Ramganga basin is showing own result of the migration of the channel (Figxx). In the Ramganga basin there are various geomorphic features are present such as the NNW-SSE trending streams and gorges with relatively straight mountain fronts, fault scarps and steep cliffs in the middle and upper parts of the basin. Other geomorphic features include rock benches, waterfalls and stream offsets etc. In the study area these geomorphic features have great influence for the migration of the channel from their midway. Varying slope, underlying lithology, presence of different categories of the landcover, tectonic structures have also influenced the migration of the channel. Analysis of the T for the whole Ramganga river basin showing that tectonic tilting is present in the South-West direction.

82 Chapter -V

Figure 5.7 Arrow showing direction of the migration of the channel in different sub basins of the Ramganga basin.

83 Chapter -V

Figure 5.8 Arrows showing the direction of migration in Ramganga basin.

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Fig 5.9 Direction of the arrow showing the tectonic tilting in the Ramganga river basin.

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Table 5.4: Table showing the Transverse topographic symmetry in 26 sub basins of the Ramganga basin.

Basi Entity Distance from midline to distance from Da/Dd(k Avera n no. active channel(Da) midline to basin m.) ge divide(Dd) value

1 Namik 0.9 1.7 0.52 0.14

0.4 3.1 0.12

0.2 4.1 0.04

0.3 4.6 0.06

0.5 4.7 0.10

0.3 4.7 0.06

0.2 4.9 0.04

0.3 4.6 0.06

0.2 4.8 0.04

0.7 4.5 0.15

0.8 4.5 0.17

1 4.9 0.20

1 4.5 0.22

0.8 4 0.2

0.6 3.3 0.18

0.4 3 0.13

0.08 2.4 0.03

0.5 1.7 0.29

86 Chapter -V

2 Girgaon 0.2 2 0.1 0.15

0.2 2.5 0.08

0.5 3 0.16

0.5 3.8 0.13

0.4 4.2 0.09

0.4 3.6 0.11

1.4 3.3 0.42

3 Bansbag 0.14 2 0.07 0.12 ad

0.5 2 0.25

0.12 3.5 0.03

0.04 5 0.008

0.3 5 0.06

1.7 4.5 0.37

0.9 5.7 0.15

0.3 5.8 0.05

4 Dhanyar 0.1 0.9 0.11 0.18

0.2 1.8 0.11

87 Chapter -V

0.8 4.6 0.17

0.5 4.2 0.11

0.4 3.6 0.11

0.3 3.2 0.09

0.5 2.6 0.19

0.6 1.5 0.4

0.06 0.9 0.06

0.5 1.08 0.46

5 Tejam 0.2 1.1 0.18 0.15

0.1 1.8 0.05

0.2 1.8 0.11

0.2 1.4 0.14

0.4 1.5 0.26

0.3 1.2 0.25

0.06 0.9 0.06

0.07 0.4 0.175

6 Muhari 0.6 3.1 0.19 0.21

1.2 3.9 0.30

0.8 3.5 0.22

0.5 2.9 0.17

88 Chapter -V

0.9 2.9 0.31

0.2 2.8 0.07

0.4 2.6 0.15

0.6 2.1 0.28

7 Dhalkot 0.47 0.94 0.5 0.35

0.56 1.29 0.43

0.36 1.37 0.26

0.2 0.98 0.20

8 Naulara 1.2 1.5 0.8 0.63

1.7 2.6 0.65

2 3 0.66

1.8 3 0.6

1.4 2.7 0.51

1.3 2.4 0.54

9 Thal 0.2 0.6 0.33 0.24

0.3 1.5 0.2

0.4 2.7 0.14

0.8 2.8 0.28

89 Chapter -V

10 Bhakun 0.3 1.7 0.17 0.35 a

0.9 2.1 0.42

1.6 2.1 0.76

0.9 1.9 0.47

0.9 1.8 0.5

0.8 2.2 0.36

1.3 2.2 0.59

0.6 2.1 0.28

0.12 2.1 0.05

0.3 2 0.15

0.2 1.7 0.11

0.8 2.1 0.38

11 Chamoli 0.02 0.8 0.025 0.09

0.7 1.7 0.41

0.3 2.1 0.14

0.03 2 0.015

0.2 2 0.1

0.05 2.9 0.01

0.04 3.3 0.01

0.05 3.2 0.01

90 Chapter -V

12 Chaukor 0.1 0.8 0.12 0.14 i

0.2 1.7 0.11

0.5 2.5 0.2

0.9 2.5 0.36

0.6 2.6 0.23

0.5 2.5 0.2

0.4 3.2 0.12

0.2 3.2 0.062

0.1 2.5 0.04

0.05 2.1 0.02

0.1 1.7 0.05

13 Amtar 0.7 1.8 0.38 0.45

0.6 1.4 0.42

0.6 1.08 0.55

14 Sirtoli 0.9 1.2 0.75

0.8 1.2 0.66

0.3 1.2 0.25

91 Chapter -V

15 Kukroli 0.5 1.4 0.35 0.40

0.6 1.5 0.4

0.7 1.9 0.36

1.3 2.2 0.59

1 2.4 0.41

0.9 2 0.45

0.6 1.6 0.37

0.3 1 0.3

16 Raitoli 1.3 2.2 0.59 0.39

1.4 2.9 0.48

1.6 3.3 0.48

1.8 5 0.36

1.5 5.3 0.28

0.6 3.3 0.18

17 Nagaur 3.7 4.8 0.77 0.66

3 4.7 0.63

3.4 5 0.68

2.6 4.7 0.55

18 Dhaniga 0.4 1.6 0.25 0.13

92 Chapter -V

0.2 2.2 0.09

0.2 1.8 0.11

0.2 1.6 0.12

0.6 2 0.3

0.4 2 0.2

0.2 2.2 0.09

0.3 3.1 0.09

0.2 2.4 0.08

0.2 3.3 0.06

0.4 4.1 0.09

0.2 5.2 0.03

0.7 2.8 0.25

19 Simali 1 1.3 0.76 0.58

0.9 1.8 0.5

1.4 2 0.7

1.2 2 0.6

1 2.2 0.45

1 2.6 0.38

1.2 2.1 0.57

1 1.4 0.71

93 Chapter -V

0.3 0.5 0.6

20 Takulia 2.3 3.4 0.67 0.52

2.7 4 0.67

2.3 5.3 0.43

1.9 6 0.31

21 Kanalch 1.8 2.2 0.81 0.31 hina

1.2 2.6 0.46

0.66 3.7 0.17

0.72 3.5 0.20

0.43 2.9 0.14

0.3 3.2 0.09

22 Gangoli 0.06 0.6 0.1 0.11 hat

0.15 0.86 0.17

0.13 1.1 0.11

0.2 1.5 0.13

0 0 0

0.4 3 0.13

94 Chapter -V

0.4 3.3 0.12

0.3 4 0.075

0.4 3.3 0.12

0.5 2.5 0.2

23 Naini 0.4 1.8 0.22 0.25

0.9 4.3 0.20

1.2 5.3 0.22

2.2 5.8 0.37

24 Batala 0.3 0.8 0.37 0.28

0.9 2 0.45

0.8 2.3 0.34

0.8 3.1 0.25

1 3.2 0.31

0.54 3 0.18

0.1 2.8 0.035

0.8 2.8 0.28

25 Chauky 0.32 1.2 0.26 0.26 alagaon

0.3 1.8 0.16

95 Chapter -V

0.09 2.9 0.031

0.9 3.2 0.28

1.5 3.3 0.45

0.8 3.3 0.24

0.9 2.3 0.39

0.4 1.4 0.28

26 Damta 2.4 5.1 0.47 0.20

0.4 4.2 0.09

1.9 5.2 0.36

0.8 5.5 0.14

0.8 4.5 0.17

0.1 2.3 0.04

0.04 2.1 0.01

0.6 1.8 0.33

96 Chapter -V

3. Hypsometric integral (HI)-

Hypsometric Integral have been calculated in the 26 sub basins of the Ramganga river basin and summarized in table xx. In 26 sub basins, values of HI ranged from 0.30 to 0.58. To decipher the relative tectonic activity we categorized the values into three classes-

Table 5.5 Showing erosional stages of the basin.

Class Value Stages of the basin

1 0 – 0.3 Indicates old stage of the basin means basin is fully stabilized.

2 0.3 – 0.45 Basins of this range is susceptible to erosion means mature stage of the basin.

3 0.45 – 0.58 Youth stage of the basin.

In the present study the Ramganga river basin has been subdivided into 26 sub basins so that variation of tectonic activity can be assessed more accurately.

Results of the Hypsometric Integral (HI) suggest that the Ramganga river basin in particular is a youthful basin while within the basin it shows great variation. Values of HI with their erosional stages and tectonic status are summarized in table xxx.

Sub basins present in the Northern and North-Eastern part of the Ramganga basin except the basin no.5 (Tejam) are showing the values between 0.3 and 0.45, which is eroded and showing the late mature to mature stage of the basin. Basin no.5 (Tejam) has the value 0.3 which indicates the old stage of the basin. But in the real sense these basins are in this stage are not because of the maturity of the basin but because of the presence of the tectonic forces and fluvial influences on these basins. Area of the Tejam basin is relatively less than the other surrounding basins and it also suffering from various tectonic structures. Cumulative effect of the structures, size of the basin, high river discharge and underlying lithology are responsible for the high erosion in this sub basin. Those basins which are present in and around tectonic structures or tectonic structures passing through the basins have lowered the HI values. Along with

97 Chapter -V these forces flow of the streams is also influential parameters to erosion of the basin. Although these basins are in the youthful stage but cumulative effect of these forces result in the erosion of the basin. Simali (basin 19), Gangolihat (basin 22), Naini (basin 23) and Batala (basin 24) are the basins showing the higher values of HI which means youth stage of the basin. High rate of erosion positively correlates with uplift. As the river erode its bed, resulting uplift of the basin to established equilibrium between tectonic and hydraulic forces.

High erosion in the basins is responsible for the upliftment of the area. So, those basins which have high erosion also experiencing the upliftment of the area.

Table 5.6: This table illustrates the geological stages of 26 sub basins of the Ramganga river basin based on the results (After Omvir Singh et al, 2008).

Basin no. H.I. values Geological stages Tectonic status 1 0.35 late mature Active 2 0.41 mature Active 3 0.36 late mature Active 4 0.39 late mature Active 5 0.3 old Less active 6 0.49 mature Highly active 7 0.44 mature Active 8 0.32 late mature Active 9 0.31 late mature Active 10 0.42 mature Active 11 0.41 mature Active 12 0.49 mature Highly active 13 0.36 late mature Active 14 0.43 mature Active 15 0.42 mature Active 16 0.39 late mature Active 17 0.43 mature Active 18 0.44 mature Active 19 0.46 mature Highly active 20 0.38 late mature Active 21 0.37 late mature Active 22 0.58 late youthful Highly active 23 0.48 mature Highly active 24 0.46 mature Highly active 25 0.4 mature Active 26 0.43 mature Active

98 Chapter -V

Figure 5.10 Map showing erosional status in 26 sub basins of the Ramganga basin.

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Figure 5.11 Relation of the tectonic structures with erosional status of the sub basins.

100 Chapter -V

Table 5.7 Showing the HI values in 26 sub basins of the Ramganga basin.

S.no. Entity min. elevation max. elevation mean elevation mean-min max-min H.I.

1 Namik 965.3 6004.2 2778.56 1813.26 5038.9 0.35

2 Girgaon 976.6 4130.8 2284.85 1308.25 3154.2 0.41

3 Bansbagad 874.8 3696.8 1894.35 1019.55 2822 0.36

4 Dhanyar 867.8 2698 1593.6 725.8 1830.2 0.39

5 Tejam 874.9 2183.9 1268.98 394.08 1309 0.3

6 Muhari 788.2 2297.7 1542.62 754.42 1509.5 0.49

7 Dhalkot 844 2197.1 1447.21 603.21 1353.1 0.44

8 Naulara 812 2187.6 1263.23 451.23 1375.6 0.32

9 Thal 774.5 1924.7 1137.43 362.93 1150.2 0.31

10 Bhakuna 863.2 2529.1 1578.22 715.02 1665.9 0.42

11 Chamoli 809.3 2315.5 1439.39 630.09 1506.2 0.41

12 Chaukori 785.6 2030.6 1405 619.4 1245 0.49

13 Amtar 773.4 1610.6 1081.43 308.03 837.2 0.36

14 Sirtoli 751.1 1332.5 1001.3 250.2 581.4 0.43

15 Kukroli 776.2 2298.2 1420.6 644.4 1522 0.42

16 Raitoli 722.9 1791.2 1144.21 421.31 1068.3 0.39

17 Nagaur 698.1 1810 1182.11 484.01 1111.9 0.43

18 Dhanigaon 725.3 2320 1439.62 714.32 1594.7 0.44

19 Simali 705.2 2334.7 1457.9 752.7 1629.5 0.46

20 Takulia 657.2 1984.6 1174.21 517.01 1327.4 0.38

21 Kanalchhina 1047.3 2319.5 1529.19 481.89 1272.2 0.37

22 Gangolihat 616.3 2132.1 1500.55 884.25 1515.8 0.58

23 Naini 599.1 2095.2 1331.88 732.78 1496.1 0.48

24 Batala 661.7 2091.4 1331.6 669.9 1429.7 0.46

101 Chapter -V

25 Chaukyalagaon 1046.4 2452.9 1609.4 563 1406.5 0.4

26 Damta 479.1 2134.9 1201.55 722.45 1655.8 0.43

4. Channel sinuosity (S)

Channel sinuosity has been calculated for the whole Ramganga river basin to assess the significance of sinuosity in understanding the role of neotectonic activity that shifts the channels into a direction for a considerable distance. It also provides clues about interactions of different forms and processes that are running within the basin. In this study, the entire Ramganga river basin has been divided into 26 sub basins. These sub basins have been used for calculating channel sinuosity, by selecting a representative reach in each basin. Results of the channel sinuosity in 26 sub basins ranges between 1.1 and 1.7. Sinuosity of the trunk stream of the Ramganga River showing moderate sinuosity (1.27) while for some reaches this index increases upto 1.91. In general high sinuosity found in the old stage of the river while in the Ramganga river basin, values more than 1.4 are indicating strong sinuosity that corresponds to the prevailing tectonic activity in the form of tectonic structures viz: Vaikrita Thrust, Munisiari Thrust (MCT), Bhujpatri Gad Fault, Darun Fault, ramganga Fault and Askot Thrust and number minor thrust and faults.

Derived results reveal some facts that the sub basin bansbagad (basin 3) and Bhakuna (basin 10) showing the values of sinuosity 1.7, while others sub basins of the Ramganga basin ranges the value between 1.1 and 1.4. High values of the sinuosity index in two basins are the result of the offset of the stream due to the close proximity of the MCT and the Vaikrita thrust, bhujpatri Gad Fault. Fig xxx showing the relation of the main streams of the sub basins with the tectonic structures.

In general scenario high sinuosity occurs in the relatively low slopes and mature topography but in the present case these two basins have slope ranges between 30 and 50 degree and have the young stage of the basin. On the basis of the derived results it has be proven that high sinusity in these two basins (basin 3 and basin 10) are totally controlled by the tectonic structures and suffering the relatively high tectonic activity that the other part of the basin.

102 Chapter -V

Figure 5.12 Map showing the sinuosity of the river channel in 26 sub basins of the Ramganga river basin.

103 Chapter -V

Fig 5.13 Abrupt change in the sinuosity of the River channel (in circle).

104 Chapter -V

Fig 5.14 Abrupt change in the sinuosity of the River channel (in circle).

105 Chapter -V

Table 5.8 Showing the values of Channel sinuosity in 26 sub basins of the Ramganga basin.

S.no. Entity stream valley Channel length(km) length(km) sinuosity 1 Namik 37.85 30.87 1.2 2 Girgaon 21.53 18.91 1.1 3 Bansbagad 27.96 16.8 1.7 4 Dhanyar 16.83 14.2 1.2 5 Tejam 7.4 6 1.2 6 Muhari 16.11 13.4 1.2 7 Dhalkot 3.1 2.7 1.2 8 Naulara 4.2 3.2 1.3 9 Thal 3.2 2.9 1.1 10 Bhakuna 14.3 8.6 1.7 11 Chamoli 10.6 8.7 1.2 12 Chaukori 13.1 10.5 1.2 13 Amtar 2.6 2.3 1.1 14 Sirtoli 2.2 1.9 1.2 15 Kukroli 8.8 7.2 1.2 16 Raitoli 5.8 4.8 1.2 17 Nagaur 4.8 3.4 1.4 18 Dhanigaon 13.1 9.4 1.4 19 Simali 11.1 9.1 1.2 20 Takulia 8.2 6 1.4 21 Kanalchhina 7.6 6 1.3 22 Gangolihat 10 8.2 1.2 23 Naini 7 5.2 1.4 24 Batala 11 8.1 1.4 25 Chaukyalagaon 9.2 6.9 1.3 26 Damta 13.75 11.48 1.2

106 Chapter -V

5. Valley floor width to height ratio (Vf)-

Vf is calculated in 26 valleys of the Ramganga river basin. For precise calculation of the basin floor width and valley height, we analysed Vf in different places of each valley and analysis revealed that lowest value of Vf is 0.05 (in basin no.1, 3, 21, 22) and highest value is 0.4 (in basin no.16) of the Ramganga river basin. Values are classified into three classes as-

Table 5.9 Showing different classes based on Vf.

Class Values Shape of the Valley

1 0.05 – 0.12 indicates less eroded basin and v-shaped valleys

2 0.12 – 0.24 indicates eroded basin

3 0.24 – 0.4 indicates highly eroded basin and U-shaped valleys

Majority of the V-shaped valleys are in the upper portion of the Ramganga river basin and U-shaped valleys are in the lower- Middle Western part of the basin.

V-shaped valleys are mainly influenced by tectonic structures (Munsiari thrust, main central thrust, Bhujpatri gad fault, Darun fault, Darmoli fault and Tejam anticline etc. which are passing through the upper portion of the Ramganga basin. Those basins which have close proximity of the structures but have U-shaped valleys have influenced by erosion of the main river channel.

The low values are confined to those regions having deep incised valleys and deep gorges. Sub basins aligned nearly perpendicular to the trunk stream indicates relatively higher values. Those segments confined to the trunk stream of the sub basins or Ramganga river basin having relatively higher values suggest high rate of erosion in the valley than the surrounding basins. Along the Ramganga river basin, mostly sub basins suggest low values, indicative of v-shaped and deep valleys. Ramganga River is eroding its bed and incised deeply, resulting upliftment due to

107 Chapter -V isostatic balance. It means the area is highly active in general and presently in the upliftment phase.

Northerly basins are showing the “V” shaped valleys except Tejam (basin 5). This basin is influenced by the tectonic structures passing through it. Tejam basim showing the erosion of the basin and have nearly “U” shaped basin which is the indication of the less tectonic activity. But whole northern part of the Ramganga river basin is experiencing the high tectonic activity including the Tejam basin. In the Southern portion of the Ramganga basin some basins are showing the high values while some are showing the low values. Low values are due to the presence of the active incision of the trunk stream of the basin, presence of the structures etc.

Figure 5.15 Map showing the values of Vf in 26 sub basins of the Ramganga river basin.

108 Chapter -V

Figure 5.16 Relation of Vf with tectonic structures.

109 Chapter -V

Table 5.10 Showing result of Vf in 26 sub basins of the Ramganga Basin

Entity S.basins right ele(Erd) left ele(Eld) floor ele(Esc) floor width(Vw) Vf Mean value

Namik 1 4250 4080 3030 84 0.074 0.046

3650 3500 2330 26 0.02

2600 2570 2000 20 0.034

2500 2850 1700 25 0.025

2050 2000 1325 40 0.057

2250 2000 1150 62 0.063

Girgaon 2 3050 3160 2700 24 0.059 0.08

2750 3050 2000 33 0.036

2400 2580 1535 50 0.052

1560 1860 1300 63 0.153

1950 1630 1130 66 0.1

Bansbagad 3 2050 2190 1680 30 0.068 0.05

2630 2850 1450 21 0.016

2200 2380 1200 37 0.033

1375 1480 1050 38 0.1

1850 1625 950 41 0.052

Dhanyar 4 1725 1625 1340 30 0.089 0.07

1625 1800 1100 46 0.075

1700 1820 910 40 0.047

Tejam 5 2000 1500 950 120 0.15 0.18

1650 1625 900 175 0.237

1360 1480 900 80 0.153

Muhari 6 1210 1350 850 60 0.139 0.07

110 Chapter -V

1460 1300 900 30 0.062

1720 2050 1000 35 0.039

1850 2050 1200 26 0.034

1940 2050 1275 31 0.043

2000 1500 1375 33 0.088

Dhalkot 7 1600 1250 900 60 0.114 0.1

1450 1650 870 61 0.089

1450 1390 870 54 0.098

Naulara 8 1200 1280 880 30 0.083 0.11

980 1150 850 31 0.144

Thal 9 1160 1600 780 78 0.13 0.1

1700 1625 780 58 0.065

1330 1410 800 61 0.107

Bhakuna 10 2150 2100 1375 72 0.096 0.076

1900 1800 1250 44 0.073

1500 2270 1080 31 0.038

1260 1625 1050 35 0.089

1380 1220 920 33 0.086

Chamoli 11 1440 1500 1150 30 0.093 0.16

1400 1170 1000 48 0.168

1250 1350 930 60 0.162

1125 1320 860 80 0.22

Chaukori 12 1525 1530 1400 98 0.768 0.26

1635 1650 1025 58 0.093

1460 1600 975 60 0.108

111 Chapter -V

1270 1550 900 55 0.107

1070 1090 860 50 0.227

Amtar 13 1290 1460 800 95 0.165 0.18

1000 1380 780 82 0.2

Sirtoli 14 1220 1160 800 65 0.166 0.24

1180 960 760 100 0.322

Kukroli 15 1710 2050 1375 48 0.095 0.094

1680 1850 1200 43 0.076

1480 1750 1090 29 0.055

1310 1410 930 36 0.083

1100 1250 850 52 0.16

Raitoli 16 960 910 750 110 0.594 0.41

1060 960 750 75 0.288

1100 930 750 89 0.335

Nagaur 17 910 990 730 100 0.454 0.33

1000 1060 720 81 0.261

1250 1000 700 119 0.28

Dhanigaon 18 1620 1330 1280 26 0.133 0.14

1480 1400 1130 32 0.103

1260 1375 980 89 0.263

1440 1375 840 51 0.089

950 1080 780 25 0.106

Simali 19 1625 1460 1350 153 0.794 0.39

1675 1390 1140 57 0.145

112 Chapter -V

1240 1210 980 116 0.473

1060 1170 900 66 0.306

1250 900 800 63 0.229

Takulia 20 900 970 700 66 0.28 0.28

830 870 660 79 0.415

1140 1160 700 59 0.131

Kanalchhina 21 1770 1800 1400 15 0.038 0.048

1560 1490 1350 13 0.074

1540 1900 1180 16 0.029

1470 1470 1080 19 0.048

Gangolihat 22 1490 1700 1300 15 0.05 0.046

1470 1570 1125 15 0.037

1875 1500 990 9 0.012

1300 1100 850 12 0.034

900 1000 700 24 0.096

Naini 23 1800 1700 630 59 0.052 0.12

1300 1200 620 88 0.139

925 1250 600 83 0.17

Batala 24 1325 1340 1000 44 0.132 0.18

1200 1470 900 56 0.128

970 1040 850 50 0.322

885 1375 720 55 0.134

Chaukyalagaon 25 1800 1775 1125 55 0.083 0.35

1660 1850 1220 28 0.052

1370 1500 1320 30 0.26

113 Chapter -V

1870 1900 1800 86 1.011

Damta 26 1540 1560 550 110 0.11 0.14

1360 1170 550 66 0.092

870 1050 500 104 0.226

Stream length gradient index

Stream Length gradient index is calculated for the many reaches of the sub watersheds in the Ramganga river basin. The study has been carried out for 26 sub basins of the Ramganga river basin and derived results are presented in the Table xx. In the each sub basin three reaches have been chosen to calculate SL index that express the power of stream to erode its bed and to transport sediments. After calculating the SL index for different reaches of the sub basins, the average of the values also have been calculated to obtain a representative value for the whole sub basin. Obtained average value ranges between 1532 and 42916 in Damta (basin 26) and Sirtoli (basin 14) respectively, have been considered in drawing inferences. The calculated SL index expresses its sensitivity to change in channel slope and this sensitivity allows the evaluation of relationship among possible tectonic activity, rock resistance and topography. In the ramganga river basin, sub basins showing low stream length gradient corresponds to the higher rate of erosion. It means main stream erode its river bed at very fast rate.

Results show great variation in the Ramganga river valley clearly suggest about complexity of the area. It indicates that river channel in the Ramganga valley responding against combination of the climatic, lithologic and structural variables. Stream length gradient index correlates to the total stream power, available at particular reach of channel and shows the ability of stream to erode its bed and transport sediment. High values of SL index suggest high power of stream to erode the valley and transport the sediments while low values indicate lower the stream power. Ramganga River originates from the Namik glacier from the height of 3600 m and after 78.6 km run it confluence with Saryu at Rameshwar. River profile shows the very high power. During the passage, Ramganga River passes through number of geological regimes. These geological environments determine the rate of erosion.

114 Chapter -V

Some rock types are resistance to erosion while some are easy to erode. In less resistant geological regimes, values of the SL index will be lower. So it may be interpreted as geology of the study area has much influence on the stream power.

In the ramganga river basin suggests that along the main river channel values are correspondingly low while in the sub basins which are distant from the main stream, having significantly high values. Such circumstances can be interpreted as high rate of erosion in the main valley and availability of water for the whole duration. Second thing is that along the main channel high rate of erosion and high rate of uplift in the surrounding basins.

Basin elongation ratio (Re)- In Ramganga river basin, values of elongation ratio ranged from 0.56 to 0.93 which indicates the highly elongated to near circular shape of the basins respectively. Majority of the elongated basins are present in the northwest and less elongated basins are present in the north-east part of the study area. Some oval shape basins are in the south-east side of the study area and some oval to near circular basins are present in the central part of the Ramganga river basin.

115 Chapter -V

Fig 5.17 Graph showing the river profile in the basin.

116 Chapter -V

Table- 5.11 Showing SL values in 26 sub basins of the Ramganga basin. basin Max Min (ΔL) (L) max-min (Δh)/(Δ (Δh)/(ΔL) / L Avg. no. elevation elevation elevation (Δh) L) (Km) value (m)

1 1188.79 1048.4 4.8 30.5 140.39 29.247 0.9589 1960.7

1384.96 1180.32 4.8 25.8 204.64 42.633 1.6524

1716.22 1384.96 4.8 21.1 331.26 69.012 3.2707

2 1230 1075.15 3 17.05 154.85 51.616 3.0273 5276.8

1384.8 1230 3.1 13.95 154.8 49.935 3.5796

1695 1384.77 3.1 10.85 310.23 100.074 9.2234

3 986.86 922.64 2.7 23.5 64.22 23.785 1.0121 1732.1

1045.7 982.67 2.7 20.5 63.03 23.344 1.1387

1189.2 1045.3 2.7 17.5 143.9 53.296 3.0455

4 940.49 915.66 1.65 14.25 24.83 15.048 1.0560 1574.2

968.45 940.49 1.69 12.59 27.96 16.544 1.3140

1011.06 968.45 1.66 10.91 42.61 25.668 2.3527

5 907.77 892.52 0.94 7.24 15.25 16.223 2.2408 1749.0

907.45 898 0.94 7.14 9.45 10.053 1.4080

915.17 904.69 0.93 7.05 10.48 11.268 1.5984

6 893.82 848.3 1.62 13.7 45.52 28.098 2.0510 3406.3

940 893.82 1.6 12.1 46.18 28.862 2.3853

1040.76 939.9 1.7 10.26 100.86 59.329 5.7825

7 859.6 849.2 0.3 2.55 10.4 34.666 13.5947 11217.2

854.3 846.3 0.3 2.25 8 26.666 11.8518

859.1 854.3 0.3 1.95 4.8 16 8.2051

8 827.4 820.8 0.54 3.4 6.6 12.222 3.5947 3956.1

117 Chapter -V

832.14 822.9 0.49 2.9 9.24 18.857 6.5024

833.65 831.5 0.51 2.38 2.15 4.215 1.7712

9 784.2 779.4 0.41 2.6 4.8 11.707 4.50281 7927.8

793.68 783.17 0.41 2.2 10.51 25.634 11.6518

798.26 792.63 0.41 1.8 5.63 13.731 7.6287

10 1012.49 952.4 1.45 12.13 60.09 41.441 3.4164 3180.2

1032.6 1004.9 1.47 10.67 27.7 18.843 1.7660

1089.32 1032.6 1.41 9.23 56.72 40.226 4.3582

11 879.44 856 1.04 9.02 23.44 22.538 2.4987 4220.3

906.64 879.3 1.07 7.96 27.34 25.551 3.2099

955.62 905.25 1.05 6.9 50.37 47.971 6.9523

12 874 856 1.3 11.05 18 13.846 1.2530 3436.5

911.4 870.8 1.3 9.75 40.6 31.230 3.2031

975.7 911.4 1.3 8.45 64.3 49.461 5.8534

13 797.6 789.3 0.3 2.15 8.3 27.666 12.8682 12963.2

789.3 781.9 0.3 1.85 7.4 24.666 13.3333

788.3 782.4 0.3 1.55 5.9 19.666 12.6881

14 762 753.4 0.4 1.6 8.6 21.5 13.4375 42916.6

764.9 754.4 0.4 1.2 10.5 26.25 21.875

794.8 764.9 0.4 0.8 29.9 74.75 93.4375

15 866 820 0.88 7.51 46 52.272 6.9604 11098.6

916.8 866 0.88 6.63 50.8 57.727 8.7069

1006 916.8 0.88 5.75 89.2 101.363 17.628

16 745.5 735.1 0.73 4.7 10.4 14.246 3.0311 5306.5

748.6 730.3 0.71 4 18.3 25.774 6.4436

118 Chapter -V

745.4 730.3 0.71 3.3 15.1 21.267 6.4447

17 723.6 709.4 0.48 4.08 14.2 29.583 7.2508 5265.6

714.5 711.6 0.47 3.6 2.9 6.170 1.7139

722 712.1 0.46 3.15 9.9 21.521 6.8322

18 824.2 777.1 1.1 11.45 47.1 42.818 3.7395 3443.1

853.4 815.3 1.1 10.35 38.1 34.636 3.3465

881.7 848.7 1.1 9.25 33 30 3.2432

19 848.6 780.3 1.1 9.45 68.3 62.090 6.5704 7486.5

909.2 848.6 1.1 8.35 60.6 55.090 6.5977

983.3 909.2 1.1 7.25 74.1 67.363 9.2915

20 700.6 667.8 0.8 6.9 32.8 41 5.9420 8026.8

712.9 670 0.82 6.2 42.9 52.317 8.4382

713.2 669.2 0.84 5.4 44 52.380 9.7001

21 1123.2 1086.9 0.73 4.9 36.3 49.726 10.1481 25919.2

1201.4 1123.2 0.75 4.2 78.2 104.266 24.8253

1310.5 1201.4 0.75 3.4 109.1 145.466 42.7843

22 827.8 767.6 1 8.5 60.2 60.2 7.0823 10947.4

917.5 827.8 1 7.5 89.7 89.7 11.96

1007.2 917.5 1 6.5 89.7 89.7 13.8

23 610.75 600.3 0.7 5.95 10.45 14.928 2.5090 4229.7

625.5 600.3 0.7 5.25 25.2 36 6.8571

617.7 607 0.7 4.6 10.7 15.285 3.3229

24 775.5 717.5 1.1 9.35 58 52.727 5.6392 5650.3

850 775.5 1.1 8.25 74.5 67.727 8.2093

874.4 850 1.1 7.15 24.4 22.181 3.1023

119 Chapter -V

25 1118.2 1086.5 0.92 7.82 31.7 34.456 4.4062 5709.1

1146.8 1118.2 0.93 6.9 28.6 30.752 4.4569

1193.1 1146.8 0.94 5.96 46.3 49.255 8.2643

26 506.6 484.9 1.4 11.6 21.7 15.5 1.3362 1532.4

522.6 501.3 1.4 10.2 21.3 15.214 1.4915

525 503.2 1.4 8.8 21.8 15.571 1.7694

There are varieties of different rock types and small and major thrust and faults are present in the Ramganga basin. Of which most of faults and thrusts are passes across the main channel of the river. Those basins which are present almost parallel of the thrust and faults have elongated shape and those basins which present across the faults deviate their shape from elongation and attain oval to nearly circular shape. In Ramganga basin elongation of the basin is mainly influenced by the tectonic structures.

120 Chapter -V

Figure 5.18 Map showing the elongation ratio of the 26 sub basins of the Ramganga river basin. Table 5.12 Table showing the values of Re in 26 sub basins of the Ramganga basin. S.no. Entity Area(km2) Basin length(km) (2√A:√π) Re

1 Namik 250.98 31.441 17.9 0.56

2 Girgaon 112.88 20.219 12 0.59

3 Bansbagad 153 18.678 13.97 0.74

4 Dhanyar 78.55 15.337 10.01 0.64

5 Tejam 15.14 6.197 4.39 0.7

6 Muhari 67.91 14.191 9.31 0.65

7 Dhalkot 18.3 7.362 4.83 0.65

8 Naulara 14.2 4.786 4.26 0.89

9 Thal 11.7 4.515 3.87 0.85

121 Chapter -V

10 Bhakuna 37.53 10.372 6.92 0.66

11 Chamoli 38.24 9.522 6.98 0.73

12 Chaukori 50.77 11.392 8.05 0.7

13 Amtar 7.1 3.927 3.01 0.76

14 Sirtoli 5.09 2.73 2.55 0.9

15 Kukroli 25.18 7.978 5.67 0.71

16 Raitoli 31.67 8.378 6.36 0.75

17 Nagaur 34.64 9.932 6.65 0.66

18 Dhanigaon 54.85 11.346 8.37 0.73

19 Simali 33.32 9.758 6.52 0.66

20 Takulia 48.35 9.126 7.86 0.86

21 Kanalchhina 35.02 7.659 6.69 0.87

22 Gangolihat 36.78 9.324 6.85 0.73

23 Naini 47.37 8.737 7.78 0.89

24 Batala 39.59 8.501 7.11 0.83

25 Chaukyalagaon 31.05 8.135 6.29 0.77

26 Damta 80.69 12.833 10.15 0.79

122 Chapter -V

Table-5.13: Table shows the values of different geomorphic indices at micro- watershed level in Ramganga river basin.

S. No. Entity Smf AF HI S Vf Re

1 Namik 1.02 57 0.35 1.2 0.05 0.56

2 Girgaon 1.02 47 0.41 1.1 0.08 0.59

3 Bansbagad 1.02 49 0.36 1.7 0.05 0.74

4 Dhanyar 1.02 52 0.39 1.2 0.07 0.64

5 Tejam 1.01 41 0.3 1.2 0.18 0.7

6 Muhari 1.01 52 0.49 1.2 0.06 0.65

7 Dhalkot 1.01 80 0.44 1.2 0.1 0.65

8 Naulara 1.01 82 0.32 1.3 0.11 0.89

9 Thal 1.001 62 0.31 1.1 0.1 0.85

10 Bhakuna 1.02 47 0.42 1.7 0.08 0.66

11 Chamoli 1.02 44 0.41 1.2 0.16 0.73

12 Chaukori 1.01 55 0.49 1.2 0.26 0.7

13 Amtar 1.02 23 0.36 1.1 0.18 0.76

14 Sirtoli 1.04 75 0.43 1.2 0.24 0.9

15 Kukroli 1.01 30 0.42 1.2 0.09 0.71

16 Raitoli 1.03 69 0.39 1.2 0.4 0.75

17 Nagaur 1.03 87 0.43 1.4 0.33 0.66

18 Dhanigaon 1.01 45 0.44 1.4 0.14 0.73

19 Simali 1.04 79 0.46 1.2 0.39 0.66

20 Takulia 1.03 26 0.38 1.4 0.28 0.86

21 Kanalchhina 1.02 41 0.37 1.3 0.05 0.87

22 Gangolihat 1.01 53 0.58 1.2 0.05 0.73

23 Naini 1.26 32 0.48 1.4 0.12 0.89

24 Batala 1.01 36 0.46 1.4 0.18 0.83

25 Chaukyalagaon 1.01 61 0.4 1.3 0.35 0.77

26 Damta 1.01 49 0.43 1.2 0.14 0.79

123

Conclusion and recommendations

Chapter -VI

CONCLUSIONS AND RECOMMENDATIONS

In this research, different geomorphic indices such as mountain front sinuosity, Asymmetry factor, transverse topographic symmetry, Hypsometric integral, channel sinuosity, Valley floor width to height ratio, stream length gradient index and Basin elongation ratio have been investigated in the Ramganga river basin to decipher the relative tectonic activity present in the study area by using satellite remotely sensed datasets.

26 sub basins have been selected for the detailed and precise study of these indices. Different geomorphic indices are showing different results in these sub basins. On the basis of the results each basin considered as a zone of tectonic activity. Ramganga basin is easily classified in different tectonic zones based on the sub basins.

At the initial level of this research work some research questions were formulated for justification. Point wise justification of these questions has been given below.

(i) Are geomorphic Indices helpful in identifying areas on the basis of tectonic activity?

Based on the results of Mountain front sinuosity (Smf), Channel sinuosity (S), Valley floor width to height ratio (vf) have proven that geomorphic indices are very helpful in identifying areas on the basis of the tectonic activity. Result of Smf showing that although whole Ramganga basin is tectonically active but basins present in the Northern, North-Eastern, North-Western and Southern portion are extremely active while some basins present in the Western side in the lower portion of the Ramganga basin are tectonically less active.

Results of Channel sinuosity indicates that sinuosity in the basins are the results of the tectonic activity. Two basins (basin 3 and basin 10) are showing the meandering of the channel. Meandering of the channel in these two basins is controlled by the tectonic structures. Vaikrita, Munsiari thrusts and other small scale thrust and faults influenced these basins. Main stream of the Ramganga basin is flowing in the North- South direction but at some reaches it deflected in the NW-SE direction and then after some distances it again deflected in the NE-SW direction and in the lower portion it

124 Chapter -VI again maintained their original path. Close examination of this sinuosity has proven that basin is experiencing tectonic activity. Meandering of the channels are showing the extreme tectonic activity in the Basin 3 and basin 10 while other basins experiencing high to moderate tectonic activity.

Results of Valley floor width to height ratio indicates that basins present in the Northern portion of the Ramganga basin are extremely active while at the lower portion of the Ramganga basin high to moderate tectonic activity is present. High tectonic activity is associated with the tectonic structures. Those basins which are present far from these tectonic structures are less active. These less active basins are present in the western portion of the Ramganga basin and some basins are present in the southern and Suth-Eastern part of the Ramganga basin.

(ii) In Asymmetry Factor and Transverse topographic symmetry which method is suitable for the identification of the River migration?

These two parameters are showing the drainage basin asymmetry present in the Ramganga basin. On the basis of the results of Asymmetry factor it is concluded that Eastern, North-Eastern and South-Eastern part of the Ramganga basin is uplifting while Western and North-Western part of the Ramganga basin is tilting. But the results of the Transverse topographic symmetry are showing the direction of the migration of the river channel in each sub basins and whole Ramganga basin. On the sub basin level there are many direction of the migration of the channel because of many causative factors acted on them. Analyses of the main river channel of the basin are showing the direction of the migration of the channel in the South-West direction.

So, based on the results of these two parameters it has been proven that Transverse topographic symmetry is best describes the migration of the river channel.

(iii) Erosion promoted the uplift in the Ramganga basin?

Hypsometric Integral describes the answer of this question. Analysis of the results of the sub basin has shown that the erosion is present in those basins which are present in the North, north-east, East portion of the Ramganga basin. Less eroded basins are

125 Chapter -VI present in the western and Southern part of the Ramganga basin. Erosion means, unloading of the sediments from the basin and to remain in the isostatic balance upliftment is present in those basins which have high erosion. Result of this upliftment is supported by the result of the drainage basin asymmetry.

(iv) In which direction Ramganga basin is uplifting?

Based on the results of the Drainage basin asymmetry and the Hypsometric Integral it has been concluded that basin is uplifting in the N- NE direction.

(v) Which part of the Ramganga basin is highly prone to the natural hazards such as landslides, erosion and flash floods?

Results of the basin elongation ratio depicts that highly elongated basin are present in the Western and North-Western portion of the Ramganga basin. Moderately elongated basins are present in the Eastern and Southern part of the Ramganga basin. Oval to near circular basins are present in the middle and lower portion of the Ramganga basin. Erosion is also pronounced in these ovals to circular and less elongated basins and the possibility of flash floods are more in these basins as compare to the elongated basins. So, on the basis of the results it is concluded that middle and lower portion of the Ramganga basin is highly prone to the natural hazards. Soft and friable rocks with high slope are present in the upper portion of the Ramganga basin which is highly prone to the landslides.

(vi) How active tectonic processes together with geological, geomorphological and climatic conditions help in finding solutions for reducing human misery and enhancing the quality of life?

With the help of the tectonic activity maps based on different geomorphic indices with the information of the lithology, geomorphic features present in the area we can classify the Ramganga river basin on the basis of highly hazardous and less hazardous zones. On the basis of this study we can relocate those hamlets, villages and other

126 Chapter -VI settlements which are situated in the highly hazardous areas in the Ramganga basin and can reduce human misery and enhancing the quality of life.

Recommendations:

 Areas identified on the basis of tectonic activity and as prone to flash floods must be avoided for settlement and other developmental activities. Villages and hamlets already located in these zones need to be relocated.

 areas with no vegetation and slope excess of 40°

 Be taken up for plantation if they are within forest limits.

 Be used for cultivation and/or horticulture purpose after terracing.

127

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137 Publications

PAPER PUBLICATION

2015 S. Farooq, Indu Sharma and M. Nazish Khan (2015) “Geomorphic evidence of Active Tectonics in Eastern Kumaon Himalaya as deciphered from the Morphometry of Ramganga River Basin.” International Journal of Advancement in Earth and Environmental Sciences. Vol.3, No.1, 24-33.

2015 S. Farooq, M. Nazish Khan & Indu Sharma (2015)“Assessment of Active Tectonics in Eastern Kumaon Himalaya on the Basis of Morphometric Parameters of Goriganga River Basin.” International Journal of Advancement in Earth and Environmental Sciences. Vol.3, No.1, 16-23.