Semi-Automated Cartographic Techniques to Analyse the - - PowerPoint PPT Presentation

Semi-Automated Cartographic Techniques to Analyse the Geomorphometric Parameters in High Altitude Glacierised Terrain using SRTM DEM Data

• M. TAMIL SELVAN

Remote Sensing and GIS Centre Jawaharlal Nehru University, New Delhi, India mtselvan@jnu.ac.in

Third Pole

Drainage map of the Himalayan Rivers

Tista Basin

Himalayan Glaciers

Principal Glacier Fed River System of Himalayas

Major river system Name of river/ tributary Catchment area (sq. km) covered by Percentage Glaciation Mountains Glaciers Indus 268,482 8,790 3.3 33,670 170 5.0 27,195 2,944 10.0 8,029 206 2.5 47,915 1,295 2.7 14,504 638 4.4 Ganga Yamuna 11,655 125 1.1 23,051 2,312 10.0 Ramganga 6,734 3 0.04 Kali 16,317 997 6.01 Karnali 53,354 1,543 2.9 Gandak 37,814 1,845 4.9 Brahmaputra Kosi 61,901 1,318 2.1 Tista 12,432 495 4.0 Raidak 26,418 195 0.7 Manas 31,080 528 1.7 Subansiri 18,130 725 4.0 256,928 1,080 0.4 Dibang 12,950 90 0.7 Lohit 20,720 425 2.01 Gross 10,01,294 25,724 2.6

Drainage map of the Himalayan Rivers

Bhagirathi Alaknanda Chhota shigri Tista Basin

Himalayan Glaciers

Location Map of Uttarkashi District in Uttaranchal State

• Rajasthan

Gujarat Maharashtra Orissa Karnataka Madhya Pradesh Bihar Uttar Pradesh Andhra Pradesh Jammu & Kashmir Tamil Nadu Assam Jharkhand Punjab Chattisgarh Kerala West Bengal Haryana Uttaranchal Arunachal Prades Himachal Pradesh Manipur Mizoram Meghalaya Nagaland Tripura Sikkim Goa Delhi

Location Map of Uttaranchal State in India

Chamoli Uttarkashi Pithoragarh Garhwal Almora Nainital Tehri Garhwal Dehradun Hardwar Bageshwar Udhamsingh Nagar Rudraprayag Champawat

Location Map of Uttarkashi District in Uttaranchal State

13

Wah Sar Mon Ran Osla Sola Kuwa Rama Doni Asna Purga Angar Barsu Agora Dunda Dewar Naini Salra Kulni Datmir Harsil Salang Pilang Thalan Chakon Thalan Saundi Hadhan Barkot Purola Jakhol Lewani Balcha Nellang Jadhang Chirbas Gaumukh Chholmi Kharsal Kanatal Sunagar Uprikot Bharkot Margaon Bangaon Shrikot Kandani Naugaon Sarnoul Jarmola Naitwar Harkidun Gangotri Yamnotri Bhatwari Rajgarhi Gaurikund Pujargaon Gainchwan UTTARKASHI Syana Chatti Shaptrishi Kund

HIMACHAL PRADESH

CHINA

Tehri Garhwal Dehradun Rudra Prayag Chamoli Figure 1.3: Uttarkashi District Map

B H A G I R A T H I R I V E R

• Legend

Rivers Glacier Area Major Roads Major Towns

International Boundary

79°12'0"E 79°12'0"E 79°0'0"E 79°0'0"E 78°48'0"E 78°48'0"E 78°36'0"E 78°36'0"E 78°24'0"E 78°24'0"E 78°12'0"E 78°12'0"E 78°0'0"E 78°0'0"E 77°48'0"E 77°48'0"E 31°24'0"N 31°24'0"N 31°12'0"N 31°12'0"N 31°0'0"N 31°0'0"N 30°48'0"N 30°48'0"N 30°36'0"N 30°36'0"N 30°24'0"N 30°24'0"N

20 40 10 Kilometers

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Bhilangna Ganga Kaldi Basin

KU Bhu Uta Stab Sari Pahi Mana Tara Meru Kiark Kamar Jamak Barsu Wodar Diara Sonam Angor Mendi Sumla Namti Khogu Lanka Mahla Okhla Jaurah Pilang Solang Tongua Neland Dadera Deoban Korcha Dhomka Misosa Spring Khorgu Mukhba Harsil Jaonli Kopang Riattal Chaurun Karkoti Dosumdu Jadhang Shastru Din Gad Pagaria Son Gad Jadhang Tirpani Karmoli Namuche Misohra Rig Tal Tel Gad Tel Gad Dakhani Gaumukh Chirbas Dee Gad Bhujbas Bhujkot Lod Gad Son Gad Bhatwari Gantrara Mana Gad Guli Gad Gani Gad Sian Gad Dhumdhar Lamkhaga Lamathot Chor Gad Nokurcha Dudhpani Dudu Gad Kot Dhar Gangotri Srikanta Multhata Kamar Gad Ghora Gad Bambi Gad Guli Dhar Pagun Gad Ghatu Gad Nahal Gad Mardhalan Pipe Line Khera Gad Bhela Gad Satopanth Gaurikund Akhorthat Nandanban Rudugaira Po Ki Gad Bhela Gad Kedarnath Satopanth Kiarki Gad Jodh Ganga Sonam Dhar Sarup Dhar Ghora Dhar Mana Bamak Gawar Dhar Ruriakanda Sian Bamak Jodh Ganga Miyana Gad Mangla Chu Lanka Dhar Karcha Gad Shong Dhar Darani Gad Shingmoche Tilga Nala Sartia Gad Mana Bamak Hodas Dhar Kakora Gad Manj Kanda Awani Dhar Bhu Tharar Chaukhamba Meru Bamak Jadhang Gad Jungti Dhar Sri Kailash Shastra Tal Rancha Dhar Chaling Gad Mechha Dhar Mana Parvat Matri Bamak Bhandargaon Bhrigupanth Patang Dhar Kedar Ganga Kedar Bamak Jogin Group Khargu Dhar (Badrinath) Kirti Bamak Kharchakund Nilapani Gad Surali Bamak Mana Glacier Deogad Bamak Goni Glacier Amlaoki Dhar Bensaru Khat Jelandli Gad Rohlia Bamak Rongmach Gad Kalapani Gad Jaonli Bamak Kalindi Khat Seta Glacier Kirti Stambh Nilapani Dhar Kailash Bamak Dehigad Bamak Guligad Bamak Choro ki Dhar Miyana Kharak Chaudar Bamak Dudhpani Nala Democha Bamak Chaling Bamak Bhrigu Parbat Manda Glacier Rudugaira Gad Chhalan Bamak Sumeru Parbat Vasuki Parbat Khurmuche Dhar Nilapani Bamak Bambigad Bamak Chirbas Parbat Lamkhaga Bamak Bareguddar Gad Kalapani Bamak Dokriani Bamak Raktvarn Bamak Pilapani Bamak Nilambar Bamak Swetvarn Bamak Khankhu Udiyar Koleon Glacier Mandani Parpat Chandra Parpat Vasuki Glacier Dhongar ki Dhar Thandapani Nala Phating Pithwar Dadapokhri Dhar Rudugaira Bamak Malandi Glacier Kalindi Glacier Tinktia Changdum Thandapani Bamak Ghanohim Glacier Swachand Glacier Chaturang Bhamak Gangotri Glacier Andharban ki Dhar Bartiakhunt Bamak Jhalalu ki Jaonli Bhagirathi Parbat Chorgad Uttari Bamak Chorgad Bichli Bamak Chorgad Dakhni Bamak Harsil Reserve Forest Bhagirath Kharak Bank Gangotri Group of Glaciers 78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

Legend

Locations Roads Streams

Map No. 2.4: Bhagirathi Sub-Basins with River Network

10 20 5 Kilometers

• Base Map of the Bhagirathi River Basin

Chaukhamba peak Shivling Peak

Different Group of Peaks

Gaumukh, Snout of the Bhagirathi River Flow of Bhagirathi River

Debris / Ice Cover in the Gangotri Glacier

1817 1889 1935 1966 1971 1991 2008

Snout positions of the Gangotri Glacier since 1817 to 1971

Retreat of the Gangotri Glacier by Earth Observatory, NASA, 2004

• Measurement and calculation of surface modifying natural factors and their impact

zonation considering coverage area. Tectonic forces originating deep below the surface

• f earth are capable of changing surface configuration, increase or reduce the rate of

surface intensity.

• Understanding the role of surface agents which tends to modify the face of earth
• surface. These agents and their activities are distributed in various intensities, forms

and continuously modify the Earth’s surface.

• Therefore, it becomes imperative to discuss the distribution of these processes and

their forming agents. In the present theme, the surface processes are analysed through the morphometric analysis techniques.

• Morphomteric analysis are applied in character as well as integrated in the approach. It

provides a clear picture of the physiography of a region.

• For any demarcation based on divide a region into certain homogenous regions, such

analysis becomes an essential ingredient. Morphomteric analysis are applied in character as well as integrated in approach. It provides a clear picture of the physiography of a region.

Physiographic Impacts on the Hydro-Geomorphology

• The basin morphometry constitutes three types of properties such as areal,

linear and relief. For the purpose of this study, areal properties such as stream frequency, drainage texture, drainage density and relief properties such as average relief, relative relief, dissection index and ruggedness index have been analysed.

• A quantitative approach is adopted here for showing the morphometric

characteristics and spatial variations in the region. The database for this purpose is generated with the help of sources such as satellite imagery, SRTM data and toposheet.

• For morphometric analysis, contour intervals at 30 meters has been used.

Contours are generated at 30 meter intervals and verified and modified with SOI toposheets.

• The study area is divided into 6,392 square grids of 1km x 1km and detailed

statistics calculated for each grid is done.

GEOMORPHOLOGICAL ANALYSIS

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

Map No. : Stream Order map of Bhagirathi Basin

10 20 5 Kilometers

• Legend

1st Order 2nd Order 3rd Order 4th Order 5th Order 6th Order

Stream Order Map of the Bhagirathi Basin

78°24'0"E 78°24'0"E 78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 79°36'0"E 79°36'0"E 30°40'0"N 30°40'0"N 30°50'0"N 30°50'0"N 31°0'0"N 31°0'0"N 31°10'0"N 31°10'0"N 31°20'0"N 31°20'0"N 31°30'0"N 31°30'0"N

• Map No. Grid Map of the Bhagirathi Basin with Streams( 1km by 1km)

20 40 10 Kilometers

( Grid of 1km by 1km)

Grid Map of the Bhagirathi Basin with streams

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0 30°48'0"N 30°48'0 30°54'0"N 30°54'0 31°0'0"N 31°0'0" 31°6'0"N 31°6'0" 31°12'0"N 31°12'0 31°18'0"N 31°18'0 31°24'0"N 31°24'0

Map No. : Digital Elevation Model map of the Bhagirathi Basin

10 20 5 Kilometers

• Digital Elevation Model(DEM) of the Bhagirathi Basin

(in metres) <

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Slope Map of the Bhagirathi Basin with Streams

Legend

80.474 - 89.991 89.991 - 89.992 89.992 - 89.993 89.993 - 89.994 89.994 - 89.995 89.995 - 89.996 89.996 - 89.997 89.997 - 89.998 89.998 - 89.999

Slope Map of the Bhagirathi Basin with streams (in degree)

(in degree)

Surface Plot of the Bhagirathi Basin

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Stream Frequency Map of the Bhagirathi Basin with Streams

Legend

0 - 0.4 0.4 - 0.8 0.8 - 1.2 1.2 - 2.0 2.0 - 10.4

Stream Frequency (Number of Streams/Sq.km.)

Stream frequency (S.F.) = ∑ N / A Where ∑ N total number of stream segments S.No. Classes Frequency classes % of Area Covered 1 Very high 2.01-5.83 3.26 2 High 1.21-2.0 11.51 3 Moderate 0.81-1.2 19.40 4 Low 0.41-0.8 19.43 5 Very low 0.01-0.4 46.40

High to very high stream frequency is found in the Bhagirathi and Jahnvi sub-basins. Moderate frequency found in other basins

• equally. The reason may be due to the

numerous seasonal streams coming out of these basins.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Drainage Density Map of the Bhagirathi Basin with Streams

Legend

0 - 0.2 0.2 - 0.4 0.4 - 0.7 0.7 - 1.0 1.0 - 1.6

Drainage Density (Length of Streams/Sq.km.)

Drainage density (DD) = ∑ L /A Where ∑L is total length of stream segments, in km. and A is the unit area in sq. km. S.No. Classes Frequency classes % of Area Covered 1 Very high 1.0-1.6 1.44 2 High 0.7-1.0 9.01 3 Moderate 0.4-0.7 21.42 4 Low 0.2-0.4 18.93 5 Very low 0.01-0.2 49.19

Shows equal drainage density for all most all the basins. Jahnvi and Bhagirathi sub-basins are dominating, may be due to large area of coverage and more number of glaciers available.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Drainage Texture Map of the Bhagirathi Basin with Streams

Legend

0 - 0.1 0.1 - 0.4 0.4 - 0.8 0.8 - 1.0 1.0 - 5.14

Drainage Texture (No. of Streams/km)

S.No. Classes Frequency classes % of Area Covered 1 Very high 1.0-5.14 9.93 2 High 0.8-1.0 7.19 3 Moderate 0.4-0.8 22.51 4 Low 0.1-0.4 30.33 5 Very low 0.01-0.1 30.04 Dt = AS = Where, Dt = Drainage Texture, AS = Average spacing between two streams t = t1, t2 = Number of intersections between the stream Network and grid square diagonal And,

to = Number of intersections between the stream

Network and grid square edges. p =

High to very high drainage texture is found along Bhagirathi sub-basin due to dip- controlled slope. Maximum area is covered by moderate to very low drainage texture.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Absolute Relief Map of the Bhagirathi Basin with Streams

Legend

245 - 2,500 2,500 - 3,500 3,500 - 4,500 4,500 - 5,500 5,500 - 6,792

Absolute Relief in Metres

S.No. Classes Frequency classes % of Area Covered 1 Very high 5500-6792 35.25 2 High 4500-5500 31.29 3 Moderate 3500-4500 13.99 4 Low 2500-3500 16.85 5 Very low < 2500 2.62

Absolute relief gives the elevation of any area above the sea level in exact figure. Absolute relief high in all glacierised area of the basin. The upper part is made up of high level fan deposits and the central part acts as a water divide. The whole region is equally well distributed among the five classes. Among them maximum area is

• ccupied by the very high frequency

class that is between 5500 to 6792 meters.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Relative Relief Map of the Bhagirathi Basin with Streams Legend

0.5 - 200 200 - 400 400 - 550 550 - 700 700 - 1,260

Relative Relief (in Meters)

S.No. Classes Frequency classes % of Area Covered 1 Very high 700-1260 11.33 2 High 550-700 26.47 3 Moderate 400-550 32.88 4 Low 200-400 27.22 5 Very low 0.5-200 2.10 Relative Relief (RR) = highest contour value - lowest contour value

High relative relief in Jalandhri Basin and small patch of Jahnvi Basin. The moderate frequency classes have maximum occurrence. The zero relative relief does not found any where in the

• region. The values and the figure clearly

indicate that it is more or less flat valley.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Disection Index Map of the Bhagirathi Basin with Streams Legend

0 - 0.05 0.05 - 0.1 0.1 - 0.15 0.15 - 0.2 0.2 - 0.36

Dissection Index

Dissection index (DI) = Relative relief (RR)/ Absolute relief (AR). S.No. Classes Frequency classes % of Area Covered 1 Very high 0.20-0.36 17.06 2 High 0.15-0.20 21.22 3 Moderate 0.10-0.15 32.74 4 Low 0.05-0.10 24.10 5 Very low 0.01-0.05 4.88

Moderate to low frequency class of dissection index occurs in major part of the basin. High and very high frequency class of dissection index is shown less part of the basin in the south-western part. The reason behind it is that it is having low relative relief.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Kaldi Basin Bhilangna Ganga

79°40'0"E 79°40'0"E 79°30'0"E 79°30'0"E 79°20'0"E 79°20'0"E 79°10'0"E 79°10'0"E 79°0'0"E 79°0'0"E 78°50'0"E 78°50'0"E 78°40'0"E 78°40'0"E 78°30'0"E 78°30'0"E 31°30'0"N 31°30'0"N 31°20'0"N 31°20'0"N 31°10'0"N 31°10'0"N 31°0'0"N 31°0'0"N 30°50'0"N 30°50'0"N 30°40'0"N 30°40'0"N

• 10

20 5 Kilometers

Map No. : Ruggedness Index Map of the Bhagirathi Basin with Streams

Legend

0 - 0.1 0.1 - 0.2 0.2 - 0.3 0.3 - 0.4 0.4 - 1.0

Ruggedness Index

S.No. Classes Frequency classes % of Area Covered 1 Very high 0.40-1.00 55.45 2 High 0.30-0.40 20.45 3 Moderate 0.20-0.30 13.08 4 Low 0.10-0.20 6.64 5 Very low 0.01-0.10 4.38 Ruggedness index (RI) = relative relief (RR) * drainage density / 1000(constant)

Moderate to very high frequency classes of ruggedness index generally at the region where it is having high relative relief and dissection index, but the moderate value of frequency classes also occur towards valley area and also towards in some patches in the north and eastern part which shows that it is also dependent on drainage density. But, as the value of relative relief are very high compared to the value of drainage density that is why the figure of ruggedness index is more alike to the figure relative relief etc. It clearly shows that high values of dissection index are found in Jahnvi and Jalandhri Basins. Very low value frequency classes of dissection index is found in almost whole valley.

Jahnvi Ganga Basin Bhagirathi Ganga Pilang Basin Jalandhri Gad Basin Bhilangna Ganga Kaldi Basin

bhg9 bhg8 bhg6 bhg5 bhg3 bhg2 bhg1 jah9 jah8 jah7 jah6 jah5 jah4 jah2 jah1 jal9 jal8 jal7 jal6 jal5 jal4 jal3 jal2 jal1 pil9 pil8 pil6 pil5 pil2 pil1 bhi9 bhi8 bhi7 bhi6 bhi5 bhi4 bhi3 bhi2 bhi1 bhg78 bhg77 bhg74 bhg72 bhg71 bhg70 bhg69 bhg68 bhg66 bhg65 bhg64 bhg63 bhg62 bhg61 bhg57 bhg56 bhg43 bhg37 bhg36 bhg35 bhg34 bhg33 bhg32 bhg31 bhg30 bhg29 bhg28 bhg27 bhg26 bhg25 bhg24 bhg22 bhg21 bhg20 bhg19 bhg18 bhg17 bhg16 bhg15 bhg14 bhg13 bhg12 bhg11 bhg10 jah60 jah58 jah57 jah56 jah54 jah52 jah50 jah49 jah48 jah45 jah44 jah43 jah41 jah39 jah38 jah37 jah36 jah33 jah32 jah31 jah30 jah29 jah28 jah26 jah25 jah24 jah22 jah19 jah18 jah16 jah15 jah13 jah12 jah11 jal64 jal63 jal62 jal61 jal60 jal59 jal58 jal57 jal56 jal55 jal54 jal53 jal52 jal51 jal48 jal47 jal45 jal44 jal41 jal40 jal38 jal37 jal36 jal35 jal34 jal33 jal28 jal27 jal26 jal24 jal23 jal22 jal21 jal20 jal18 jal17 jal16 jal15 jal13 jal12 jal11 jal10 pil23 pil21 pil20 pil19 pil18 pil17 pil16 pil15 pil14 bhi12 bhi11 bhi10

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

Legend

Glacier Locations Roads Streams

Map No. 2.3: Bhagirathi Sub-Basins with River Network

10 20 5 Kilometers

• and Glacier Locations

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

Map No. : Classified Image of the Bhagirathi Basin for the year 1980

10 20 5 Kilometers

• Source: MSS Imagery of December 1980

Legend

Vegetation Open Rocks Debris covered Ice Snow Sub-basin Boundary Streams

Figure 6.33: Classified Image of the Bhagirathi River basin for the year 1980

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

10 20 5 Kilometers

• Map No. 3.2: Classified Image of the Bhagirathi Basin for the year 1990

Source: TM Imagery of October 1990

Legend

Vegetation Open Rocks Debris covered Ice Snow Sub-basin Boundary Streams

Figure 6.34: Classified Image of the Bhagirathi River basin for the year 1990

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

10 20 5 Kilometers

• Source: ETM+ Imagery of October 2000

Map No. 3.3: Classified Image of the Bhagirathi Basin for the year 2000

Legend

Vegetation Open Rocks Debris covered Ice Snow Sub-basin Boundary Streams

Figure 6.35: Classified Image of the Bhagirathi River basin for the year 2000

78°30'0"E 78°30'0"E 78°36'0"E 78°36'0"E 78°42'0"E 78°42'0"E 78°48'0"E 78°48'0"E 78°54'0"E 78°54'0"E 79°0'0"E 79°0'0"E 79°6'0"E 79°6'0"E 79°12'0"E 79°12'0"E 79°18'0"E 79°18'0"E 79°24'0"E 79°24'0"E 79°30'0"E 79°30'0"E 30°42'0"N 30°42'0"N 30°48'0"N 30°48'0"N 30°54'0"N 30°54'0"N 31°0'0"N 31°0'0"N 31°6'0"N 31°6'0"N 31°12'0"N 31°12'0"N 31°18'0"N 31°18'0"N 31°24'0"N 31°24'0"N

10 20 5 Kilometers

• Map No. 3.4: Classified Image of the Bhagirathi Basin for the year 2006

Source: IRSP6-LISS-III of October 2006

Legend

Vegetation Open Rocks Debris covered Ice Snow Sub-basin Boundary Streams

Figure 6.36: Classified Image of the Bhagirathi River Basin for the year 2006

Hypsometric Analysis

• Hypsometric analysis (or area-altitude analysis) is the study of the distribution
• f horizontal cross-sectional area of a landmass with respect to elevation

(Strahler, 1952).

• Classically, hypsometric analysis has been used to differentiate between

erosional landforms at different stages during their evolution

• Hypsometric curves and integrals can be interpreted in terms of degree of

basin dissection and relative landform age: Convex-up curves with high integrals are typical for youth, undissected (disequilibrium stage) landscapes; smooth, s- shaped curves crossing the center of the diagram characterize mature (equilibrium stage) landscapes, and concave-up with low integrals typify old and deeply dissected landscapes.

• Hypsometric data were derived for the entire basin from the 50m DEM data.

The percentage hypsometric method used here relates the area enclosed between a given contour and the basal plane of the analyzed area to the height of that contour above the basal plane.

Percentage Hypsometric Curve of the entire Bhagirathi River Basin Percentage Hypsometric Curve of the Gangotri Basin

• The resulting hypsometric curve permits comparison of areas of different

sizes and elevations. It expresses the manner in which the volume above the basal plane is distributed from base to top. Hypsometric curves always

• riginate in the lower left-hand corner and reach the upper right-hand
• corner. It may, however, take any one of a variety of paths between these

points, depending upon the distribution of the landmass from base to top.

• As these two results one is for Bhagirathi River Basin and another is for

Gangotri Basin are clearly shows that Hypsometric curve starts from top in the shape of the concave and in the middle in changes and it become convex shape and ends.

• This kind of shape is clearly shows that the basin is very dynamic and

disequilibrium stage in nature.

• It shows that the basin is vulnerable to the land slide, land erosion or any
• ther natural phenomena.

Conclusion