REPORT ON SLOPE, ASPECT AND ALTITUDE OF RANCHI …

RANCHI DISTRICT,JHARKHAND STATE

REPORT ON SLOPE, ASPECT AND ALTITUDE

OF

JHARKHAND SPACE APPLICATIONS CENTER (JSAC)

REMOTE SENSING INSTRUMENTS (An ISO 9001:2008 Company)

Plot#7,Type-I, Industrial Estate, Kukatpally,HYDERABAD-500072

Prepared By

Prepared For

Dept. of Information Technology, Govt. of JharkhandRANCHI - 834004, JHARKHAND

RANCHI DISTRICT,JHARKHAND STATE

REPORT ON

SLOPE, ASPECT AND ALTITUDE OF

JHARKHAND SPACE APPLICATIONS CENTER (JSAC)

REMOTE SENSING INSTRUMENTS (An ISO 9001:2008 Company)

Plot#7,Type-I, Industrial Estate, Kukatpally,HYDERABAD-500072

Prepared By

Prepared For

Dept. of Information Technology, Govt. of JharkhandRANCHI - 834004, JHARKHAND

Report on Slope, Aspect and Altitude of Ranchi District, Jharkhand State

REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. i

ACKNOWLEDGEMENT On behalf of Remote sensing instruments (RSI) Hyderabad, I express my

heartfelt gratitude to Sri A.T. Jeyaseelan, Director, and scientists of JSAC,

Ranchi, for giving opportunity to associate myself and my colleagues in the

valuable endeavor of generating data base on slope under the data base

generation. I am sure that the work done will be useful and fulfill the

requirements. Throughout the study, the officials of JSAC have been very helpful

and offered their valuable suggestions. I am thankful to all of them.

I shall be failing in my duty, if I do not appreciate the help rendered by my

colleagues at RSI worked with great team spirit to complete this project.

for REMOTE SENSING INSTRUMENTS

B.V.RAMANA KUMAR General Manager


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. ii

LIST OF CONTENTS

Chapter

No. Description Page No.

List of Tables iii

List of Figures iii

List of Plates iv

List of Annexure iv

Executive Summary v

How to Use This Report vii

Chapter-1 Introduction 1

Chapter-2 Geographical Setting 3

Chapter-3 Methodology 8

Chapter-4 The Slope, Aspect and Altitude 16

Chapter-5 Impact of Slope on Land Use and Socio Economic

Status 22

Chapter-6 References 24

Annexure 25


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. iii

LIST OF TABLES

Table No. Description Page No. Table-1 Administrative Set-up of Ranchi District 3

Table-2 Distribution of Slope Categories in Ranchi District 16

Table-3 Classification of Slope Categories based on

Slope Percentage 26

Table-4 Contour Spacing for Slope Categories on 1:50,000

Scale Toposheet with 20m Contour Interval 26

Table-5 Attribute Table for Slope 27

Table-6 Structure of the Data Base Table 28

Table-7 Colour Scheme for Slope Map 28

LIST OF FIGURES Figure No. Description Page No.

Figure-1 Flow Chart for Slope Mapping 9

Figure-2 Distribution of Slope Categories in Ranchi District 17


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. iv

LIST OF PLATES

Plate No. Description Page No. Plate-1 Location Map of Ranchi District 4

Plate-2 Base Map of Ranchi District 7

Plate-3 Toposheet Index of Ranchi District 10

Plate-4 Slope Map of Ranchi District 18

Plate-5 Altitudinal Zonal Map of Ranchi District 20

Plate-6 Slope, Aspect and Altitude Map of Ranchi Toposheet

(73 A/11) 21

Plate-7 IRS P-6 LISS III Satellite Imagery of Ranchi District 23

LIST OF ANNEXURE Serial No. Description Page No.

1 Tables of Technical Guidelines 25


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. v

EXECUTIVE SUMMARY

Remote Sensing Intruments (RSI), Hyderabad carried out Slope

mapping of Ranchi district under the “Slope Analysis and Creation of GIS Database on Slope” programme at the instance of Jharkhand Space

Applications Center (JSAC), Ranchi. Ranchi district is located in the South

Chotanagpur division of Jharkhand State, between 22052” to 23043” north latitude

and between 84051” to 85055” east longitude, covering an area of 5025Km2 in the

tribal belt of Chotanagpur Plateau. Slope mapping of this district has been carried

out by visual interpretation of Survey of India Toposheets numbering 73A/14,

73A/15, 73A/16, 73E/2, 73E/3, 73E/4, 73E/6, 73E/7, 73E/8, 73E/10, 73E/11,

73E/12, 73E/15, 73E/16, 73F/9 and 73F/13 on 1:50,000 scale. The Slope

categories have been delineated on quality tracing films with precision and

accuracy by the visual analysis of the contour spacing on Survey of India

Toposheets on 1:50,000 scale. In addition to slope categories, aspect, altitudinal

zones and base details like settlements, major roads, railway lines and major

water bodies are also mapped, from those toposheets. These visually interpreted

and mapped features are validated by limited field checks carried out by the

subject specialists. Quality checking has been carried out by the subject experts

for each toposheet, at different stages of mapping. Boundary matching with

adjacent sheets has been carried out such that the slope categories should be

continuous in side-by-side toposheet/ district / commissionaries. The interpreted

tracing films have been scanned, geo-referenced, digitized, brought into GIS

environment and database has been created to each and every feature. Finally

district wise and toposheet wise Slope, Aspect and Altitude maps have been

generated in the GIS environment. .

The entire information is compiled in the form of a report and presented in

the next few Chapters. The information compiled would be very useful in


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. vi

assessing the existing slope categories and helpful for management and

developmental practices.

The salient findings of this study are:

1. More than 2/3 part (i.e., 69.86%) of the Ranchi district is covered by

nearly level (0-1% slope) and very gently sloping (1-3% slope) ground.

2. Moderately sloping (5-10% slope) ground is located in the central part

of the district.

3. Strongly sloping to very steep sloping (>10% slope) ground is located

mostly along northern and southern boundaries and in the eastern part

of the district.

4. Major part of the district is in the altitudinal zone of 200-800m.

5. A minor part of the district is in the altitudinal zones of 100-200m and

800-1100m. The altitudinal zone of 100-200m is located in two patches

along the eastern boundary of the district and 800-1100m zone is

mostly along the boundary of this district.

6. Ranchi City is located in the altitudinal zone of 600m to 700m.

The entire data is presented in this report, in the form of text, tables,

figures and plates.

The report and maps will provide exhaustive information and could be

efficiently used for evolving Management and Developmental plans of the

available resources.


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA. vii

HOW TO USE THIS REPORT

• From the list of contents, tables, figures, plates and annexure, what data is

available and where it is located.

• Brief methodology and salient findings of this study are given in the

Executive Summary.

• The necessary of slope mapping and scope of the work is mentioned

under Chapter-1 (Introduction).

• The location, extent, area, administrative setup, physiography, drainage,

geology, climate and transport network is mentioned under Chapter-2

(Geographical Setting).

• The detailed methodology of slope mapping and creation of database on

slope is mentioned under Chapter-3 (Methodology) with flow chart.

• Findings of this study are given in the Chapter-4 (The slope, aspect and

altitude).

• Classification of slope categories and distribution of slope categories in

Ranchi district with area and percentage are given in the form of tables

and figures.

• Location map, toposheet index, base map, soil map and altitudinal zonal

map of Ranchi district and slope, aspect and altitude map of one

toposheet are shown in plates.

• Impact of slope on land use and socio economic status is mentioned in

Chapter-5.

• Field photographs are provided in appendix.


REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.REMOTE SENSING INSTRUMENTSHYDERABAD, INDIA.

1

CHAPTER – 1

INTRODUCTION Jharkhand is a prosperous state with rich natural resources and extensive

variability in terrain characteristics and associated ecosystems. The state

extends over a geographical area of 79,714sq.km and currently supporting a

projected human population of 2,69,09,428. The state frequently faces natural

calamities such as drought, floods besides the local-specific hazards of industrial

emissions and pollutants, epidemics, fires, accidents etc. The hazards/disasters,

which occur often, though confronted and managed, but needs proper planning,

organisation and implementation strategy. Such situations can certainly be

improved if cause and effect relationships are analysed and understood properly

for gearing up the administration and the infrastructure for drawing appropriate

action plan. This calls for a critical evaluation of the existing situation in terms of

status of the natural resources and its spatial distribution in relation to socio-

economic conditions.

In order to assess the implications of occurrence of natural hazards, one

needs a critical analysis of the situation for which an information base is

essential. Such information base should comprise both spatial and non-spatial

data related to natural resources, infrastructure and the associated socio-

economic parameters. The creation of database would involve generation,

compilation, storage and retrieval facilities, which have, direct and indirect

bearing on the disaster under study.

The generation of spatial information on natural resources has become

handy with the advent of satellite remote sensing which coupled with GIS

technology has enhanced the data storage, retrieval and data analysis. Further,

creation of computerized data base adds a new dimension to the dissemination



2

of information in the form of networking for the free flow of data and information

exchange for speeding up implementation programmes.

In view of the fact that the modern information technology such as Remote

Sensing and Geographic Information System (GIS) have a prominent role to play

in terms of data collection, formatting, storage, manipulation, transmission,

updating, analysis and query development and network / communication link-

age, The Government of Jharkhand has entrusted Jharkhand Space Applications

Center (JSAC), Ranchi, the task of “Slope Analysis and Creation of GIS Database on Slope” for the state. The database thus generated would be

extremely useful to the district authorities for planning and decision-making.

For ‘Slope Analysis and Creation of GIS Database on Slope’, Jharkhand

Space Applications Center (JSAC), Ranchi has identified the different vendors

who are recognised by the Department of Space, Government of India. One of

the vendors is Remote Sensing Instruments (RSI), Hyderabad. South

Chotanagpur Commissionaire covering districts of Lohardaga, Gumla, Simdega,

Khunti and Ranchi has been assigned to Remote Sensing Instruments (RSI),

Hyderabad.

Scope of work: The scope of the work is

• Visual interpretation of Survey of India Toposheets for generation of

Slope, Aspect and Altitude Maps on 1;50,000 scale.

• The interpreted toposheets should be validated by limited field checks.

• Boundary matching of individual toposheet/ district / commissionaries and

state.

• GIS database creation for Slope, Aspect and Altitude.

• Generation of district wise brief reports on Slope, Aspect and Altitude.



3

CHAPTER – 2

GEOGRAPHICAL SETTING

Location & Extent: Ranchi district is one of the oldest districts. It is situated in

the central portion of the Jharkhand state and surrounded by Chatra, Hazaribagh

and Ramgarh districts in the north, West Bengal and Saraikela district in the east,

Khunti and Saraikela districts in the south and Latehar, Lohardaga and Gumla

districts in the west. It is located in the South Chotanagpur division of Jharkhand

State, between 22052” to 23043” north latitude and between 84051” to 85055” east

longitude, covering an area of 5025Km2 in the tribal belt of Chotanagpur Plateau.

Location map of Ranchi district is shown as Plate-1.

Administrative Set-up: Ranchi district is divided into Ranchi and Bundu

subdivisions and each subdivision is further divided into blocks. The details of

the blocks are shown in the Table-1

Table-1 Administrative Set-up of Ranchi District

Subdivision Block

Ranchi

1 Kanke 2 Ratu 3 Chanho 4 Mandar 5 Lapung 6 Burmu 7 Bero 8 Namkum 9 Ormanjhi

10 Angara 11 Silli

Bundu 1 Bundu 2 Sonahatu 3 Tamar



4

Plate-1 Location Map of Ranchi District



5

Ranchi district contains 1319 villages spread over in 298 Gram

Panchayats. Ranchi is the only city and municipal corporation in the district.

Ranchi city is the capital of Jharkhand state and head quarter of the district.

Physiography: The landscape of the district is formed of hills and undulating

terrain of Ranchi Plateau. Ranchi plateau is the largest plateau in Jharkhand.

The uplands of this plateau are known as Tanrs and the lowlands are locally

known as Dons. These lowlands have a number of small hill blocks covered with

forests.

Drainage: Swarnrekha river originates near Ratu. It flows in eastern direction

until it descends at Hundru fall, then it enters into the Singhbhum district. Sankh

river originates in the northwestern part of the district near the Rajadera plateau.

South Koel rises near Mandar and flows towards north in Ranchi district.

Geology: Geologically Ranchi district is comprised with Chotanagpur Gneissic

Complex of Archaean system. Granite gneiss constitutes the geological

formation to a major extent of the district.

The most important mineral occurs in the district is bauxite. Other minerals

which are found in the district are limestone and manazite.

Climate: The climate of Ranchi district comes under subtropical semi-arid type.

The mean annual temperature is 24.50C. The temperature varies from 20.60C to

37.20C in summer and 10.30C to 22.90C in winter. The mean summer

temperature is 280C and the mean winter temperature is 190C. The district

receives annual average rainfall of 1530 mm with the maximum rainfall occurring

in the months of July-August and the minimum in the month of March.



6

Transport Network: Ranchi district is well connected with good network of

communication facilities. National Highway No. 23 and 33 passes through the

district and Ranchi city. Ranchi district is having a railway network. Ranchi city is

connected by rail with Dhanbad and Rourkela, which are located on main rail

lines. Birsa Munda Airport is located at Ranchi. Ranchi is also connected by air

with Patna, Kolkota, Delhi and Mumbai. Base map of Ranchi district is shown as

Plate-2.



7

Plate-2



8

CHAPTER – 3

METHODOLOGY

Slope is an important parameter in planning developmental activities, soil

conservation measures and in disaster mitigation studies. Slope is an indicator of

relief energy because it helps in the formation of erosional as well as depositional

features. Slope is also an important indicator to understand the amount of

precipitation that goes as runoff, land capability and land irrigability of the area

and also to understand the vulnerability to natural hazards like landslides and

floods.

Slope mapping of Ranchi district has been carried out by visual

interpretation of Survey of India Toposheets on 1:50,000 scale. The methodology

followed for the preparation of slope Maps is given in the flow chart as Figure – 1

and the same has been described below.

Identification of Required Toposheets: Toposheets pertaining to Ranchi district have been identified by overlaying

district boundary on the toposheet grid. Those are 16 toposheets viz., 73A/14,

73A/15, 73A/16, 73E/2, 73E/3, 73E/4, 73E/6, 73E/7, 73E/8, 73E/10, 73E/11,

73E/12, 73E/15, 73E/16, 73F/9 and 73F/13. Toposheet index of the district is

shown in the Plate-3.

Procurement of Toposheets:

Toposheets pertaining to Ranchi district have been procured from the

Survey of India. These toposheets are with contour interval of 20m on

1:50,000scale and are surveyed in different years.



9

Figure-1 Flow Chart for Slope Mapping



10

Plate-3 Toposheet Index of Ranchi District

Delineation of Slope Categories by Visual Interpretation: Slope is a measurement of gradient of steepness between two places or points

on land surface. Slope is measured as ratio of vertical interval and horizontal

distance of a given surface. The vertical drop can be estimated / measured from

the contour intervals and the horizontal distance in between the contours can be

measured from maps by multiplying the map distance with the scale factor. Slope

is expressed in percentage or degrees.

Contour interval in meters

Slope Percentage = -------------------------------------------------------------------------- X 100 Distance between the contours in meters x Scale factor



11

Slope has been classified into seven categories based on the percent of

slope. Jharkhand State Remote Sensing Application Centre (JSAC), Ranchi, has

provided the classification system and is given in the annexure as Table-3.

The contour spacing for each slope category has been calculated on

1:50,000scale toposheet with 20m contour interval and their details are given in

the annexure as Table-4.

Based on the contour spacing, slope categories have been delineated on

good quality tracing films with precision and accuracy by the visual analysis of

Survey of India Toposheets on 1:50,000 scale with 20m contour interval.

Demarcation of Aspect Direction: Slope aspect is the direction toward which

the surface of the earth faces. It has a bearing on precipitation of rainfall and

vegetation type, growth and conditions. It is also very important to know the slope

direction in order to understand certain features like soil erosion and vulnerability

to land slide.

The direction (slope aspect) is expressed as an angle between 0 degree

and 360 degrees (measured clockwise from true north) or as a compass point

such as east or north-northwest.

Aspect is directly derived from the toposheet and marked on the slope map

for the categories having more than 15 percent of slope. Aspect is marked in

arrow symbol facing four directions such as

• north for north, northeast and northwest facing slopes

• east for east facing slopes

• south for south, southeast and southwest facing slopes and

• west for west facing slopes



12

Demarcation of Altitudinal Zones: Contour lines with 100m interval have been

derived from the toposheet and marked on the slope map, for generating

altitudinal zones.

Ground Truth: The limited ground truth has been carried out by the subject specialists to

verify the accuracy of slope categories. The actual slope on the ground has been

measured with the instruments like Abney level, Clinometers etc., and the details

have been noted in the field dairies. Representative photographs for each slope

category have been taken with their precise location, recorded through handheld

GPS receivers. Then all the slope categories of each map have been finalized by

incorporating necessary modifications collected in the field.

Quality Checking: Internal quality checking has been carried out by the subject experts for

each toposheet, at different stages of mapping. Then necessary modifications

have been incorporated in each map as suggested in the quality checking.

Boundary Matching: After finalizing of the interpreted slope map, boundary matching with

adjacent sheets has been carried out, such that the slope categories and

altitudinal zones are continuous, in side-by-side toposheet/ district /

commissionaries.

Quality Assurance and Standardization: External quality checking of the slope, aspect and altitudinal zones on

tracing films have been carried out, for each toposheet, by the Quality Assurance

and Standardization (QAS) team, constituted by the Director, JSAC, Ranchi.

Then necessary modifications have been incorporated in each map as per the

QAS report.



13

Scanning: The tracing films containing the finalized slope polygons, aspect and

altitudinal zones have been scanned in grey scale at 150 DPI resolution and

converted into Tiff format (in soft copy) .

Geo-Referencing: Correlating data to the real world co-ordinates with a specific projection

and specified units is called geo-referencing. There is no correlation between

Survey of India grid and scanned data (Tiff file). The feature on the Tiff file

doesn’t have any reference to real world co-ordinates. Unless until, Tiff files are

geo-referenced, they cannot be arranged sequentially or overlaid one upon

another for any further analysis. Correlation of the image to user specified

referencing system, with projection has been taken up. Each tiff file of the scanned slope maps has been Geo-referenced with the

co-ordinates of its respective toposheet with UTM (Universal Transverse

coordinate Mercator) projection system by using Erdas Imagine software. Zone 5

is used for the Jharkhand state of 840 E to 940 E extent with 870 E as Central

meridian, WGS8 as Datum and WGS84 as Spheroid.

Digitization: Digitization is the process of capturing the point, line and polygon features

as vectors. The manual digitization method is followed for vectorization of visually

interpreted slope maps. The scanned interpreted slope sheet has been displayed

in the background; the required environment settings for digitization are set and

the required features like slope polygons, aspect symbols, altitudinal zones and

base details like major roads, railway lines, rivers, lakes, reservoirs and

settlements have been captured into different layers. Topology was built between

different polygons and the overshoots and undershoots have been edited.



14

During the digitization, care has been taken that the vector lines, points,

polygons sit exactly on top of the scanned raster data, without any shift between

raster and vector data, on scale of digitization.

GIS Data Base Creation: Attributions like slope category, altitudinal zone value, aspect direction,

settlement name, water body etc., details have been added to the digitized vector

data. During this process care has been taken that there is no miss matching

between vector data and respective raster data and all the attributes are tagged

correctly and complete.

Then prescribed attribute table has been attached to the vector data in Arc

GIS environment. The attribute table for slope and structure of the data base

table are provided by the JSAC and they are shown in the annexure as Table-5

and Table-6.

Map Composition: Map composition of the slope, aspect and altitude map has been carried

out for each toposheet and district mosaic in MXD format in Arc GIS environment

as per the prescribed MOCK-UP provided by JSAC. Colour scheme provided by

JSAC for slope map is shown in the annexure as Table-7. Each map comprises

of map elements like slope theme, aspect direction, altitudinal zones, overlay of

base map features like major settlements, major roads, railway line and water

bodies, legend, index map, location map, sources of data, toposheet number,

commisionarie name, district name, theme title, scale bar and north arrow. A

sample map covering Ranchi town is shown as Plate-6.

Care has been taken that all the information shown in the map layout is

complete and perfect with respect to Mock-up prescribed by the JSAC. After



15

internal quality checking of the each map layout, they have been converted into

pdf format.

Quality Assurance and Standardization: External quality checking of the slope, aspect and altitude maps in pdf

format, has been carried out for each toposheet and district mosaic, by the

Quality Assurance and Standardization (QAS) team, constituted by the Director,

JSAC, Ranchi. Then necessary modifications have been incorporated in the map

layout as per the QAS2 report.

Generation of Maps: After incorporating the modifications as per QAS2 report, hard copies of

toposheet wise and district mosaic maps of slope, aspect and altitude have been

generated on coated paper. District wise report on slope, aspect and altitude has

been prepared as per the format provided by JSAC.



16

CHAPTER – 4

THE SLOPE, ASPECT AND ALTITUDE

Slope: More than 2/3 part (i.e., 69.86%) of the Ranchi district is covered by nearly

level and very gently sloping ground. Moderately sloping area is located in the

central part of the district. Strongly sloping to very steep sloping ground is located

mostly along northern and southern boundaries and in the eastern part of the

district. The distribution of the slope categories, in this district, with their area and

percentages are shown in the Table -2 and Figure-2. The slope map of Ranchi

district is shown as Plate-4. Toposheet wise map covering Ranchi city, with slope

details, is shown as Plate-6.

Table-2 Distribution of Slope Categories in Ranchi District

Serial No. Slope Category Area

(in sq.km) Percentage

(%) 1 Nearly Level (0-1%) 768.02 15.28

2 Very Gently Sloping (1-3%) 2742.83 54.57

3 Gently Sloping (3-5%) 282.51 5.62

4 Moderately Sloping (5-10%) 420.85 8.37

5 Strongly Sloping (10-15%) 331.50 6.60

6 Moderately Steep to Steeply

Sloping (15-35%) 306.61 6.10

7 Very Steeply Sloping (>35%) 173.49 3.45

Total 5025.82 100.00



17

Figure-2

15.28%

54.57%

5.62%

8.37%

6.60%

6.10%3.45%

Distribution of Slope Categories in Ranchi District

Nearly Level (0‐1%)

Very Gently Sloping (1‐3%)

Gently Sloping (3‐5%)

Moderately Sloping (5‐10%)

Strongly Sloping (10‐15%)

Moderately Steep to Steeply Sloping (15‐35%)

Very Steeply Sloping (>35%)



18

Plate-4



19

Aspect: Aspect direction changes from place to place in this district. Toposheet

wise map covering Ranchi City, with aspect symbols, is shown as Plate-6.

Altitude: Ranchi district is located in the altitudinal zone of 100m to 1100m. In it,

major part of the district is in 200-800m zone and a minor part is in 100-200m

and 800-1100m zones. 100-200m zone is in two patches along the eastern

boundary of the district. 800-1100m zone is also located mostly along the

boundary of this district. Ranchi city is located in the altitudinal zone of 600m to

700m. Altitudinal zonal map of Ranchi district is shown as Plate-5. Toposheet

wise map covering Ranchi city, with altitudes, is shown as Plate-6.



20

Plate-5



21

Plate-6 Slope, Aspect and Altitude Map of Ranchi Toposheet (73 E/7)



22

CHAPTER – 5

IMPACT OF SLOPE ON LAND USE AND SOCIO ECONOMIC STATUS

Land use/land cover of the district is mainly agriculture and forestry. By

comparing the slope map (Plate-4) and IRS P-6 LISS III satellite imagery (Plate-

7) of Ranchi district, it is evident that, strongly sloping to very steep sloping

(>10% slope) ground is covered by forest. So, there is a direct impact of slope on

the land use of the district. In the same way, where ever the nearly level to very

gently sloping (0-3% slope) ground is there in the slope map (Plate-4),

agricultural development is observed in the IRS P-6 LISS III satellite image

(Plate-7).

In Ranchi district, 74% of the population lives in the villages and totally

depend on agriculture and related activities. Agriculture is practiced mainly in

plains. However, cultivation is also taken up to some extent in gently sloping

areas and in moderately steeply sloping areas. There is a scarcity of sufficient

and dependable source of irrigation. There are no irrigation projects in this

district, may be due to erratic rain and other unfavorable conditions. Due to lack

of good irrigational facilities, the farmers are not able to grow enough food grains

to meet their requirement. The main crop grown in the district is rice followed by

maize, bajra, pulses, wheat, oil seeds (til and mustard) and vegetables. Around

50% of the households of this district are below poverty line. For want of

irrigational facilities the farmers are traditionally been doing mono cropping,

resulting in poor economy. In the larger interest of the rural economy, agriculture

needs to be strengthened and one of its most important inputs ie, irrigation

facilities needs to be given due priority.



23

Plate-7 IRS P-6 LISS III, Satellite Imagery of Ranchi District



24

CHAPTER – 6

REFERENCES

1. Unpublished technical reports on slope mapping.

2. Technical guidelines for execution of slope analysis and creation of GIS

database on slope, Jharkhand Space Applications Center (JSAC), Govt.

of Jharkhand, Ranchi.

3. Jharkhand.nic.in

4. Singh, Sunil (2005). Inside Jharkhand, Crown Publications, Ranchi,

Jharkhand.



25

ANNEXURE

Tables of Technical Guidelines



26

Table-3 Classification of Slope Categories based on Slope Percentage

Serial No. Slope Category Slope % 1 Nearly Level 0 - 1

2 Very gently Sloping 1 - 3

3 Gently Sloping 3 - 5

4 Moderately Sloping 5 - 10

5 Strongly Sloping 10 - 15

6 Moderately Steep to Steeply Sloping 15 - 35

7 Very steeply Sloping > 35

Table-4

Contour Spacing for Slope Categories on 1:50,000 Scale Toposheet with 20m Contour Interval

Slope Category

Lower and Upper Limit of Slope Percent

Lower and Upper Limit of Contour Spacing

1 0 – 1 percent More than 4 cm

2 More than 1 percent and

up to 3 percent

More than 1.33cm and

up to 4cm


up to 5 percent

More than 0.8cm and up

to 1.33cm


up to 10 percent

More than 0.4cm and up

to 0.8cm


up to 15 percent


up to 0.4cm


up to 35 percent


up to 0.26cm

7 More than 35 percent 0.11cm and less



27

Table-5 Attribute Table for Slope

SLP-CODE Slope % Aspect

01-00 0 - 1

02-00 1 - 3

03-00 3 - 5

04-00 5 - 10

05-00 10 - 15

06-00 15 - 35

06-01 North (NE&NW)

06-02 South (SE&SW)

06-03 East

06-04 West

07-00 > 35

07-01 North (NE&NW)

07-02 South (SE&SW)

07-03 East

07-04 West

98-98 Habitation

99-9 Water Body



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Table-6 Structure of the Data Base Table

Field Name Field Type Key Y/N Remarks

SLP-CODE 4,4,C Y Feature Code

SLOPE 30,30,C N Slope in Percent

ASPECT 20,20,C N Aspect Direction

Table-7 Colour Scheme for Slope Map

Serial No. Slope Category Colour Scheme

1 Nearly Level Yellow

2 Very gently Sloping Yellow

3 Gently Sloping Yellow

4 Moderately Sloping Yellow

5 Strongly Sloping Orange

6 Moderately Steep to Steeply Sloping Brown

7 Very steeply Sloping Red

Documents

REPORT ON SLOPE, ASPECT AND ALTITUDE OF RANCHI …