Chapter 2-Profiles Of Survey Maps 45/D7 and 45/D10PROFILE OF SURVEY MAP 45 D/7DESCRIPTION of the Area covered by Survey Sheet No. 45 D/7 (Gujarat and Rajasthan) District : Banas Kantha and Sirohi Location: Latitude 24 degree 15’ – 240 30’ North Longitude 720 15’ - 720 30’ East This region lies in western India on the borders of Rajasthan and Gujarat at the southern end of the Aravalli Hills, immediately north-east of Sheet 45 D/10. RELIEF : The area is mainly a plain except for: 1. The east central region where the hills rise to almost 500 m., 2. The lower hills of the north-east corner. The slope of the land is from north-east to south-west in the northern half and east to west in the southern portion of the map. (indicated by flow of rivers) DRAINAGE1. The Banas river (not to be confused with the Banas river which is a tributary of the Chambal river to the north) flows into the swampland area of the Little Rann, north-east of the Gulf of Kutch. On this survey sheet it flows westward. It has two main right bank tributaries – Sarod and Arado Nadis and the numerous smaller streams like the one entering the river near Chekla (8192). The only left bank tributary is the Balaram Nadi from the south-east. The Banas river varies in width from 1/4km to over 1 km and has a narrow perennial water course. The dry portion fills in during the rainy seas. 2. The Sipu Nadi is a tributary of the Banas river (the confluence) lying to the west of the area shown. It flows from north-east to south-west withits two main tributaries –Varka and Mahadeviyao Nadis joining the left bank. Both rise in the hilly region to the east. In the region there are numerous other streams that join main rivers. They rise in the higher ground adjacent to the rivers and invariably their courses show large tracts of broken ground indicating soft soil easily eroded by water. SOILS: Map symbols indicate desert conditions, a large part of the plain area being sandy. Soils are soft as shown by excessive erosion causing broken ground near water courses. CLIM ATE: There are three climatic seasons: Summer hot and dry March to June Monsoon hot and wet July to September Winter cool and dry October to February Maximum temperatures in summer are extremely high rising to over 470 C, while minimum temperatures in December/Jan often drops to almost 0 degree C. Because of its location in western India, it receives comparatively less rainfall than other parts of the country. The rainfall which is between 50 to 100 cm annually, falls during the monsoon season. High temperatures cause excessive evaporation. This gives rise to scrub and semi-desert vegetation. NATURAL VEGETATION : Hill areas – dry deciduous forests of small trees Plains – scrub and throny trees where there is no agriculture. IRRIGATION: This region is dependent on the periodic rainfall (Monsoon), tanks, wells for agriculture. There is only one canal in the north-east starting from the reservoir (2222) OCCUPATIONS: Agriculture, rearing of cattle, sheep, camels and horses. CROPS: Winter (Rabi) – Wheat, Barley, Cotton Monsoons (Kharif) – Bajra, Jowar, Maize COMMUNICATIONS: Except for the main line of the Western Railway and the road that runs across the south-east corner of the map through Chitrasani (8923), there are no other important communications. All other settlements are linked by cart tracks. SETTLEMENTS: Except for Chitrasani which is a rail/road centre, all the settlements are small and widely scattered chiefly in the lowland area and are either nucleated or dispersed in pattern. PROFILE OF SURVEY MAP 45 D/10 DESCRIPTION of the Area covered by Survey Sheet No. 45 D/10 (Gujarat and Rajasthan) District : Banas Kantha and Sirohi Location: Latitude 24 degree 30’ – 240 45’ North Longitude 720 30’ - 720 45’ East This region lies in western India on the borders of Rajasthan and Gujarat at the southern end of the Aravalli Hills, immediately north-east of Sheet 45 D/7. RELIEF : The sheet is divided into two distinct physical divisions: 1. The Aravalli Hills rising to a height of over 1400 meters and occupying the south-east corner. The ranges are more or less parallel and run in a NE to SW directon. 2. A large plain covers the remaining portion of the sheet. There are frequent outcrops of rocky ground, some of it rising to over 400 m (i.e. 100 m above the surrounding country side.) DRAINAGE: In the hill area, the drainage is radial. Abu being the highest point of the area is the centre from which the rivers radiate. In the plains, the upper courses of the rivers are dendritic or fan shaped. The main stream Sipu Nadi rises in the hills north of Abu and flows in a south-west direction. It is periodic and seldom exceeds ½ km in width. TRIBUTARIES: Right bank : Sukli Nadi, Unda Wala, Dior Nadi, Left bank: Sukli Nadi, unnamed river flowing past Dhavli, Devengan Nadi and Godua Nadi NOTE: 1. There are three Sukli Nadis in the survey sheet. 2. Because this regions lies close to the desert areas where the soils tend to break up easily, the water courses are numerous and well defined for they are able to cut channels in the soft sandy soils. They are however periodic and rely on the rainy season for the water supply. CLIM ATE: There are three climatic seasons: Summer hot and dry March to June Monsoon hot and wet July to September Winter cool and dry October to February Maximum temperatures in summer are extremely high rising to over 470 C, while minimum temperatures in December/Jan often drops to almost 0 degree C. Because of its location in western India, it receives comparatively less rainfall than other parts of the country. The rainfall which is between 50 to 100 cm annually, falls during the monsoon season. High temperatures cause excessive evaporation. This gives rise to scrub and semi-desert vegetation. NATURAL VEGETATION : Hill areas – dry deciduous forests of small trees Plains – scrub and throny trees where there is no agriculture. IRRIGATION: This region is dependent on the periodic rainfall (Monsoon), tanks, wells for agriculture. There is only one canal in the north-east starting from the reservoir (2222) OCCUPATIONS: Agriculture, rearing of cattle, sheep, camels and horses. CROPS: Winter (Rabi) – Wheat, Barley, Cotton Monsoons (Kharif) – Bajra, Jowar, Maize COMMUNICATIONS: Abu, in the hill area, is linked eastwards by two main roads, which run south-east to Abu Road and north-east to Oriya. In the south of this region the east-west main road links up at Karaunti (0700) with another main road which runs parallel to the foot-hills and connects a number of settlemtns. Many of the smaller settlements are linked by cart tracks. SETTLEMENTS: Abu is a large hill resort, an administrative and an educational centre. In the plains, there are numerous settlements of much smaller size of which Sirori (2023) is the most important. Chapter 3- Interpretation of Topographical Maps STAGE 1 – TYPES OF MAPS There are different types of maps. We will focus now on Topographical Maps. 1. Topographical maps In order to do this, you must be able to:a.Interpret the shape of the ground from a map; b.Definition of relief; and c.Representation of height. CONTOURS •A contour is a line on a map joining two points of equal height, and is the standard method of showing relief on a topographical map. Contours are shown at regular vertical intervals. On a 1:50,000 map the interval is 10 m. INTERPRETATION OF CONTOURS •The shape of the contours indicates the shape of the ground. When contours are further apart, the slope is gentle and when contours are close together the greater the drop. When contours are equal distance apart the slope is uniform: a.Contours are continuous. No matter how far they travel, they always return to where they started. Except for a cliff. b.When spacing of contours down a slope gets close together at the bottom, the slope is convex. c. When spacing is further apart, the slope is concave. STAGE 3 – PLOTTING GRID REFERENCES •A grid is a rectangular square system of lines superimposed on a map, within which any point can be located. Maps are normally printed so that north is on top. •North / South lines are called Eastings because the numbers increase as they go East. •East / West lines are called Northings because the numbers increase as they go North. What are the 3 points in determining height? 1.bench marks; they are often called topo quads or quadrangles. colors can be used to indicate a classification of roads. . These signs are usually explained in the margin of the map. orienteering. and recreational uses such as hiking or. Topographic maps supply a general image of the earth's surface: roads.Easting value first. but historically using a variety of methods.spot height. rivers. is actually a much broader field of study which takes into account all natural and man made features of terrain. Map conventions •The various features shown on the map are represented by conventional signs or symbols.trig points. •The Centre for Topographic Information provides this definition of a topographic map:"A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground. where the primary national series is organized by a strict 7. Uses •Topographic maps have multiple uses in the present day: any type of geographic planning or large-scale architecture. earth sciences and many other geographic disciplines. Traditional definitions require a topographic map to show both natural and man-made features .Northings run – bottom to top. and 2. •A topographic map is a type of map characterized by large-scale detail and quantitative representation of relief.2. buildings.Eastings run – move left to right."Traditionally. or on a separately published characteristic sheet] •Topographic maps are also commonly called contour maps or topo maps." •The study or discipline of topography. What are the two most important things to remember when giving a grid? 1. in particular. often the nature of the vegetation. For example.5 minute grid. mining and other earth-based endeavours. usually using contour lines in modern mapping." •According to Cartographer's Kraak and Ormeling. the relief and the names of the various mapped objects. which uses highly detailed maps in its standard requirements. while interested in relief. and 2. and 3. What is the purpose of a contour line? Joins points of equal heights. In the United States.never round up. What are Eastings and Northings? 1. the main division of maps is into topographic and thematic maps. There are several rules to note when viewing topographic maps: •The rule of V's: sharp-pointed vees usually are in stream valleys. distant contours a shallow slope. INTERPRETATION OF TOPO MAPS AND SURVEY MAPS . and other features and points of interest. •In most cases. to determine differences in elevation between two points. the contour interval. forest cover. •Shows natural features like hills. every point on the marked line of 100 m elevation is 100 m above mean sea level. This is a consequence of erosion. •Today. •These maps usually show not only the contours. Sometimes dashed contour lines are present. railways. Older topographic maps were prepared using traditional surveying instruments. topographic maps are prepared using photogrammetricinterpretation of aerial photography. by means of contour lines. In other words. these represent half the noted contour interval. built-up areas or individual buildings (depending on scale). but also any significantstreams or other bodies of water. buildings. some maps note this by short lines radiating from the inside of the loop. •Spacing of contours: close contours indicate a steep slope. or land contours. •When these joined together. and the innermost loop is the highest area. If a loop instead represents a depression. •Show a variety of landforms with carefully chosen symbols & signs. They•Are based on accurate surveys. must be known. contour intervals are consistent throughout a map. with the vee pointing upstream. bridges and canals. and this is given at the bottom of the map. •Also show man made features like roads. or distance in altitude between two adjacent contour lines. valleys. TOPOSHEETS ARE:•Are prepared on a number of sheets since they are large scale maps. with the drainage channel passing through the point of the vee. Understanding Topographical Maps Understanding of surface depends on the ability to interpret topo maps.•Topographic maps conventionally show topography. waterfalls. •Each sheet gives the details of a part of the whole area. •The rule of O's: closed loops are normally uphill on the inside and downhill on the outside. •Of course. they form a map of the whole area. Two or more contour lines merging indicates a cliff. called "hachures". Contour lines are curves that connect contiguous points of the same altitude (isohypse). Measuring distances and calculating distances 7. each topographical map sheet provides the necessary information in the margin for the users.IT involves ability to follow the symbols portrayed in the map. Glossary of conventional signs and symbols used in survey maps INFORMATION IN THE MARGINS i)The number of the topo sheets: Topo sheets numbers can give an idea as to which part of India is shown on the map. topo sheet . Importance of colours and tints in topographical survey sheets 14.Representation of Relief by contours 5. •Understand the information given in pictorial and written form •Visualize the topography of the original area by interpreting the contour •Spot heights skillfully •Map reading is a practical skill.Reading the Grid reference 3. •Can be developed only by reading topo map very minutely and mentally analyzing the details with the help of conventional signs & symbols given in their conventional colours' •As the conventional symbols cannot cover all the graphical details.Identification of topographical maps 2.Land use and irrigation 11.Directions 6. Inferring occupations 13.Drainage 8. 1.Settlements 12.Means of transport in relation to relief 10.Man-made and natural features 9. Legend 15.Scale (R.F. For example.) 4. . 45D/10 and 45 F/3 show parts of Gujarat and Rajashthan.numbers 45D/7. •Eg. •64P/13 shows a region in north-east Orissa. •45D/7 shows a region of northern Guj. closer to the border of Rajasthan •45D/10 lies in the southern part of Rajasthan close to the border of Gujarat region •45F/3 lies in the western Rajasthan. close to the border of Haryana. the number of latitudes seen on the map decreases. with seasonal rainfall.since all toposheets are from India. But as the scale of the topo map increases. it may be inferred that all the reigons represented by those topo sheets would have a tropical monsoon climate. at least 4 lines of latitude and longitude can be seen. •56D/11 shows a region in north-east Karnataka. •On a 4 degree topographical map. •Western Rajasthan – u may expect scanty rainfall. ii) Latitudinal and Longitudinal extent: These indicate in whichpart of the Earth the area is located. near Jodhpur •53B/7 shows a region in Punjab. .•Knowing the number of toposheet can give us a clue about the general physical relief of the region and its climate which can be confirmed by other information given in the map.a fact which could be verified by the presence of dry river beds and disappearing streams. •The origin of the grid reference lies at a point in the south-west corner of the map. •Vertical lines=Eastings since they are numbered from west to East •Horizontal lines = Northings . ii)Eastings are always read to the East of the origin.GRID REFERENCE •A Grid is a set of lines used to find the exact location of places on a map. •The National Grid Reference is a system of rectangular co-ordinate. •These are sheets most commonly used for various purposes and are of vital practical importance. •It is also identified as the Grid Reference . The reading on the map is always taken with reference to this origin. is called the Grid. READING THE GRID REFERENCE i)Origin is the South –West (SW) corner of the map. •Thus any place on the map can be located by starting its distance east or north of the origin of the grid reference. •Topo maps bear the national grid of squares drawn to the scale of 2 cm=1km with each square having a side measuring 1 km.they are numbered from South to North •Net work of horizontal and vertical lines or the Eastings and Northings . iii)Northings are always read to the North of the origin. followed by Northings .i)The readings are always taken to the right of the Eastings and to the North of the Northings. Eastings are always stated first. ii)While giving a grid reference. a third figure may be added to two-figure eastings and northings. the first two figures are the eastings and the last two are the northings. Six Figure Grid Reference:•For greater accuracy. iv) The crossing point is the location of the reference point.Grid Reference of this picture is 2676 Four Figure Grid Reference:-•In four-figure grid reference. . i) Obtain the four figure reference by using first two digits of eastings and northings. iii) Mark the division of eastings and the division of the northing corresponding to the location. which means that one unit on the map represents 50. 1 cm on the map represents 50. •For example.000 cm on the ground. ii)Then divide each kilometre into ten parts visually.000 is the R.F. 45D/7 •In the map.000 units on the ground. SCALE •Refer to Survey Map No. 1:50. both vertically & horizontally. of the map. plateaus. Distance on the map ____________________________ Distance on the ground In the above map. Representation of Relief on the Map and its Interpretation •Earth’s surface – uneven – made up of hills. lowland which are varying in their elevation or heights from sea level. i)Hachuring ii)Hill shading iii)Form lines .000 This map is referred to as 1:50. •Topographical maps are large-scale maps. R. such as spot heights. contouring.000map and its scale is 2 cm=1km. plains. •Surveying is considered a part of science of map making. •It can be represented on the maps through different methods.F. = 1:50.(Scale of this toposheet is) Scale-2cm:1 km or1:50. •The total terrain is also called physical landscape.•Therefore. etc.F. or Representative Fraction is the ratio between the distance on the map and the corresponding distance on the ground in the same unit.000 •R.F. •In Topographical survey. they show a great deal of details about the relief. actual survey is carried out and different methods are used to represent relief on the map as follows. R. THE DRAINAGE •The term drainage basin describes an area drained collectively by the network of a river along with its tributaries and sub-tributaries of various dimensions. The shadows can be regarded as those which would be cast on an imaginary relief model of the ground when illuminated by parallel rays of light from a selected direction or directions. It can be defined as the addition of shadows to give the optical illusion of a third dimension.on flat grounds they can not be used at all. This method too gives a general idea of relief of the country by it does not give the actual height and that it is difficult to know whether a piece of land is sloping uphill or downhill.For steep slopes . II) HILL SHADING: A method of representing relief on a map by depicting the shadows that would be cast by high ground if light were shining from a certain direction. . it is assumed to be from north west at an angle of 45 degree with the horizon. making hills stand out in relief. •An area drained by a single river is called its Catchment Area. they are drawn closer together than for the gentle slopes. In this map.iv)Spot heights v)Triangulation points vi)Bench markscontours i)Hachuring: are short lines representing directions of a slope. DISADVANTAGE: it gives no indication of the actual height and that both high plateau region and low plain are unshaded The close hachuring of the high mountain regions tends to obscure other details of the map. . •A drainage system as seen in the topographical sheets usually develops a . pattern which is related to the general structure of its basin. 3 distinct patterns can be recognized 1)Dendritic: . •Dendritic systems form in V-shaped valleys. the rock types must be impervious and non-porous . meaning tree.Dendritic drainage patterns are most common. •In a dendritic system there is one main river (like the trunk of a tree). They develop where the river channel follows the slope of the terrain. •Dendritic drainage systems are the most common form of drainage system. which was joined and formed by many smallertributary rivers. due to the resemblance of the system to a tree. as a result. They develop on a land surface where the underlying rock is of u niform resistance to erosion. The term dendritic comes from the Greekword "dendron". •Obsequent streams flow down thedip slope of the escarpments to join the subsequent streams. . •Subsequent streams develop perpendicular to the consequent along softer rock and erode it away. TRELLIS Rectangular drainage patterns develop where linear zones of weakness.2. The main river (the consequent) flows straight down hill. •The consequent river then cuts through the escarpments of harder rock. such as joints or faults cause the streams to cut down along the weak areas in the rock. forming vales. •Trellis systems form in areas of alternating geology. particularly chalk and clay. Prominent surveyed trees are shown in black. river banks. railway lines. Note:. WHITE PATCHES – Uncultivable land 6. Surveyed trees have numbers on their trunks. BLACK – All names. 2. BROWN – Contour lines. The size of the symbol and size and style of letters used give an idea of the size of the settlement. 3. broken ground. heights and their numbering. scattered trees and scrubs. 1. 4. 3. Deserted village cities. lines of latitude and longitude. They serve as landmarks and are not allowed to be cut. settlements. SIGNIFICANCE OF COLOURS IN TOPOSHEETS On toposheets colours are used to show certain features. temporarily occupied huts are also shown. cart tracks. In the case of large cities. telephone and telegraph lines. dry streams. 4. their numbering. Each colour used on a map has significance.3. 7. roads. YELLOW – All cultivated areas are shown with a yellow wash. On a topo map. and sand features such as sand hills and dunes. surveyed trees. RADIAL •Radial drainage patterns develop surrounding areas of high topography where elevation drops from a central high area to surrounding low areas. 5. RED – Grid lines (eastings and northhings) and their numbering. major roads are marked and named. GREEN – All wooded and forested areas. 2. . form lines. all settlements are shown by symbols in RED colour. SETTLEMENTS 1. BLUE – Water features or water bodies that contain water. orchards. huts and buildings. .....5.. 5r. hill or river canal. etc. · Sparse Settlements : forests. forts. 3r. for example . burial grounds. deserts.. dak bungalow.... steep mountain slopes. are indicated by suitable symbols. thick impenetrable forests.. etc then write the answer this way . NOTE – Site is the land on which the settlement (village or town) is built. water towers... post office. embankment. police stations. is .the relative depth of perennial lined well in 3 metres ●5r – the relative height of dry tank is 5 metres NOTE: CHECK THE SYMBOL – if it is tank. OCCUPATION AND MAP FEATURES AGRICULTURE – Level land with yellow wash. meadows.. 8r.... . flood-prone areas.... mountain slopes.. plateaus and hill tops with poor vegetation· Absence of Settlements: Swamps. Dense settlements : Fertile plains and wide river valleys... cement industry near limestone beds) TOURISM – hotels and inns APPROXIMATE OR RELATIVE HEIGHT-is height is not taken from sea level but with respect to the surrounding area. grasslands... presence of road in highland region (sheep) FISHING – Plenty of rivers MINING –Stony wastes. (like making. tank.... dam... EXAMPLE:3r . limestone beds TRADE – Dense settlements near road INDUSTRY – Large settlements near roads and railways. quaries. bridge. many wells LUMBERING: Forests CATTLE REARING – Pastures.. etc.... Places of worship... sand dune or it can be the depth of a well..meters... sandy deserts.the relative height of . marsh land...... It may be the height of a dam. circuit houses. bridge. presence of raw materials. Fundamentals of Maps .Chapter 1 . maps are basically symbolic drawing of visible as well as conceived locational and distributional patterns of whole or a part of the earth. it gives only those details. We are familiar with the maps of the earth surface. Thus. A map gives a picture of one or several of the elements of the earth’s surface and being creation of humans. For example. But it cannot be made large enough to include detailed surface features. • Projection. With the availability of high-speed computers and Global Positioning System (GPS). But it is possible to draw maps of other planets and even the sky when pertinent data becomes available to us. A map is a two-dimensional diagrammatic representation of the whole or part of the earth and its surface features both natural and cultural at a given scale on a flat surface. prismatic compass and theodolite etc. which its maker intends to give. which may not be marked on the ground. Instead of showing the details in their true or visible shape and size. (d) by satellite and radar charts.. However. Only distances and areas are drawn to scale.Fundamentals of Maps THE SPHERICAL earth is best represented bya three-dimensional model of the earth. all that is shown on the map is not drawn to scale. (c) by photographs (ground photographs/aerial photographs). We already have crude maps of the Mars and the Moon. (b) by actual survey with the help of instruments like chain and tape. • Conventional signs and symbols. • Skill of the cartographer. Maps have unique advantage of showing objects or patterns that may be intangible or invisible. All parts of the earth can be shown on it in their true shape. area and location along with correct cardinal directions and distances. it uses symbols that may or may not have similarities with the shape and size of objects represented. • Method of map making. maps are much more useful tool than globes. digital mapping has emerged as an important tool of mapping. and • Requirement of the user. it may show political boundaries or rainfall pattern or crop distribution. There are various ways by which the earth can be mapped: (a) by freehand sketches and diagrams. The amount of information given in a map depends on: • Scale. . called a globe. plane table. the sky or any other heavenly body. Hence. The maps included in this book are also small scale maps. Examples of small scale maps are Atlas and Wall maps.Types of Maps Maps are of different types. The village maps of our country may be cited as an example of large scale maps. varying from 16 cm to a km to 32 cm to a km so as to fill in all possible details. etc. (ii) Chorographical or Atlas Maps: The Atlas maps are drawn on a very small scale and give a highly generalised picture of the natural and cultural aspects such as the physical. continents.000. These maps are drawn on a very large scale. hemispheres. Large Scale : These maps represent small area of the earth on a large size of paper/cloth/plastic sheet with greater details. The scale is smaller than that of topographical maps but larger than atlas maps. there are two broad categories of maps: • Large Scale. and their mode of occurrence and disposition. Maps are broadly classified on two bases: scale and purpose or content .000 scale like the ‘Times Atlas of the World’. and canals. drainage patterns. and • Small Scale. The Registrar General of India brings out C ensus Atlas from time to time. Only a few atlases are prepared on a 1:1. and countries. They are especially prepared by governments to realise land revenue and property taxes. Small Scale : These maps represent large areas on a small sheet of paper. Thematic maps are usually prepared on small scale highlighting specific themes such as relief. plateaus. Based on the scale. (iv) Climate maps show average condition of temperature. (ii) Bathymetric maps show the depth of the oceans and seas. Each map is unique in its design. They show general surface features in detail both natural and cultural. climatic and economic conditions of different regions of the earth. They are also known as charts. Indian toposheets are generally prepared on the scale of 1:50. means of transport and communication like roads and railways. towns. pressure wind and . plains. National Atlas and Thematic Mapping Organisation (NATMO) is a well-known important organisation in our country that publishes all kinds of maps for various purposes depicting different parts of the country. swamps and lakes. The city maps may also be included in this category. temperature. (iii) Geological maps represent rocks that form the crust of the earth.000. According to purpose or theme. These maps broadly show very large areas like world as a whole. drainage. and political divisions. Examples of some of the large scale maps are: (i) Cadastral Maps: The term cadastral is derived from French word cadastre’ meaning register of territorial property. They give only a general picture of the area represented. content and construction and hence. a type by itself. maps could be broadly categorised as follow : (a) Physical or Natural Maps (i) Orographic or relief maps represent features like mountains. buildings. etc. (i) Wall Maps: These maps are generally drawn boldly so that they can be seen from a distance. Principal topographic features depicted on these maps are relief. states and districts.The Cadastral maps are drawn to register the ownership of landed property by demarcating the boundaries of fields. They are used in classrooms and cater to a larger audience. forests. They have fewer details. They are based on precise surveys conducted by the Survey of India. (ii) Topographical Maps: These maps are also prepared on a fairly large scale. villages. Dehradun. which may range from a day to a season. pressure. and lines of transport and communication. However.000 or less are called tactical maps. They help in assessing economic development and potential of the area covered by the map. (iii) Maps with a scale of 1:500. They serve as guides to small units like battalions and patrol units prior to and during movements anywhere near the front line. (iv) Social maps depict elements like language. (v) Land utilisation maps exhibit the character of land use. It may be expressed as a representative fraction (ratio).000 to 1:500. All maps have some common elements. maps are generally classified into large scale and small scale.000. direction. (vii) Weather maps denote the average condition of temperature. (i) Economic maps show distribution of important minerals. (b) Cultural Maps These maps show the man-made features or human aspects.000. (viii) Astronomical maps show the position of stars and planets in the sky. (ii) Political maps show boundaries between different countries and states within countries. It is an important element of a map because it gives relative picture of the ground reality. ethnic groups and religion. What one considers to be large. a line scale or a statement scale. caste. These maps are used for planning concentrated military action. They are used by the Defence Services for general planning purposes. (ii) Maps having scales ranging from 1:1. there is no universally accepted standard for classifying maps according to scale. Scale Scale is the relationship between the distance on a map and the real distance on the earth’s surface.000 upto are classified as large scale maps.000 or more depict only the broad topographical features.000 and 1:1.000 as medium scale maps and those having scales above 1:1. (v) Natural vegetation maps show natural flora of an area or region. (vi) Soil map exhibits various types of soils covering the area. As a matter of convention.000. (iv) Photomap is an air photograph with strategic and tactical data superimposed on it. (c) Military Maps Maps used by Defence Services are called Military maps. Location and distribution of various features and phenomena are depicted using distance. those falling between 1:50. and conventional signs and symbols. wind and precipitation over a short period. As you have read earlier.precipitation of the world or part of it over a long period of time. maps having a scale 1:50.000 are treated as small scale maps. The million sheets of the Survey of India and the National . The same person may consider a map to be of large scale for one purpose but of small scale for another purpose. agricultural and industrial products. (i) General maps on a scale of 1:1. (iii) Historical maps show the past events and facts.000.000 are often classified as strategic maps. may appear to be small or medium for others. As a result of this each specialised group of map users sets up its own standards for classification. 3. It may also be converted into R. this method is not very useful. Scale is the means which enables us to reduce the whole or a part of the earth to a size which is not only convenient and handy but also logical and scientific.): It is also called as numerical scale. For example 1:1. Representative Fraction (R.000.F. The map can be reduced or enlarged without changing the R. the scale will not be the same when the original map is reduced or enlarged. The base is calibrated to express visual equivalents of representative fraction or verbal scale. The scale is written as 1 cm to 1 km. As such.F. For example 1cm on the map represents 1 km on the ground.F as given below. Although it is simple to express in words. it is useful only to those who are familiar with the particular unit of measurement. This means that 1 cm on the map corresponds to 1 km on the ground. A general definition of scale is that it is a ratio between the distance on a map and the corresponding distance on the earth. The advantage of R. Besides. is that it can be used universally irrespective of the local unit of measurement of distance. Linear Scale or Graphical Scale: This scale is expressed as a horizontal or straight line. It is expressed as a ratio of map distance and ground distance.F.000 units of distance on the ground. For example if two points located 10 km apart are shown 1 cm apart on a map. it is difficult for those who are not familiar with the unit of measurement used. Statement: The scale may be indicated in the form of a written statement. then the scale of the map would be 1 cm to 10 km.000 means one unit of distance on the map corresponds to 1. 2. Suppose. The bases are divided into a number of equal parts and are marked to show what these divisions represent on actual ground. The scale has the advantage that it remains true even after reduction or enlargement of the map. 1 cm = 10 KM MAP DISTANCE _______________ GROUND DISTANCE = . Distances on the map are smaller than the corresponding distances on actual ground.000.Atlas of India are considered to be medium scale maps. However. Methods of Expressing Scales The scales can be expressed in three ways: 1. It will give approximate distance. (c) Rotameter is an instrument having a route measuring wheel. Then lift the divider and place it on the calibrated bar scale to get the distance on the ground (b) When the route is zigzag. railway line.000 cm = 1: 1. and canals. coastline etc.000 (Note: 1 km has 100.) Methods of Measuring Linear Distance Linear distance on maps are of two types: (i) Straight lines like roads. the distance can be measured with the help of a divider. showing streams. Distance between two points is measured by allowing the wheel of the rotameter to move along the route. (ii) Curved or Zigzag lines.1 cm _____ 10 km = 1 cm ____________ 10 X 10. It can also be done with the help of a strip of paper. Open a pair of dividers and place one of its legs at one end of the straight distance and the other leg on the other end on the map. place one end of a thread at the starting point and carry the thread along the line. (a) When the line is straight. .000 cm. but the measurement will be less accurate. It can also be measured with the help of a plain divider. as explained earlier.000. After completing the distance stretch the thread and measure the length. North. the line that bisects the angle made by the hour hand with the line joining 12’O clock through the centre of the watch will point to the south. 3. icons. In the northern hemisphere if the watch is held in the horizontal position and turned until its hour hand points to the sun. In between cardinal points one may have several intermediate directions. Legends Every map contains a legend or a key. In how many ways the earth can be mapped and what factors determine the amount of information given in a map? Discuss. east and west are the four major directions. A map must have the base directions represented on it to enable the user to locate different features with respect to each other. south. specific colours show certain area features. This is also a crude method dependent upon the sun . Land use Colour Cultivated area Yellow Forests Dark green Grasslands Light green Built up area Brown Water features Blue . As you know various types of features or phenomena are represented on maps. A rough estimation of direction of the true north can be obtained by the Means of an ordinary watch. alphabets. As a convention. 4. shadings and colours. It lists the features and the signs or symbols used in the map for showing these features. Describe various types of maps and their uses. Review Questions 1. The signs and symbols include lines. A similar exercise in the southern hemisphere will indicate the true north. The line pointing to the north is regarded as the zero direction or base direction line. (iv) What is a cadastral map? (v) What are cardinal points? 2. Answer the following questions: (i) What is a map? What are its advantages? (ii) What is a scale? What purpose does it serve on a map? (iii) What are the small scale maps? Give two examples of small scale maps. 5. Write short notes on: (i) Wall maps (ii) Linear Scale (iii) Base direction line. These are also called cardinal points.Direction Direction has been defined as an imaginary straight line on the map or the ground showing the angular position of various maps with respect to a common base direction. They relate to both land and sea and are shown with the help of conventional signs and symbols. What are the different ways of expressing scale? Explain the merits and limitations of each method giving suitable examples. oceans. lakes. .(Ponds. rivers) You will know about conventional signs in detail in the chapter on study of topographic maps. seas. •During dry season when the stream dries up. Means of Transport in Relation to Relief •Transport always depend on the type of relief and drainage •Eg. spurs. Very high altitudes.difficult to build at such heights •On the map-roads are shown by means of symbols of cart tracks. permanent huts. depresions (Dep). causeways. metalled roads. •Hence town shows well developed. metalled and unmetalled roads. . •Presence of many causeways shows that the area gets seaso nal or scanty rainfall. jungles. contours and pictorial diagrams in conventional colours. shown by contours and their heights.Interpretation of Topographical Maps (Part 2) Man-made and Natural Features •Toposheets shows various details of an area. artificial lakes with embankments. unmetalled roads. •Thus. people make a habit of crossing it. queries.natural and man made features by means of conventional signs(legends).Chapter 4 . unlined wells. footpaths with a bridge. sand features. natural ponds. a footway is formed. •Natural features – rivers. boundaries (national and international). •Main towns. police chowkies and inspection bungalows. cart tracts.well connected by metalled roads show economic devp of the area-is the indication of trade being carried on. physical features like hills. trees. waterfalls. mountaineous areas-only roads and no railway tracks. river valleys and cliffs. post offices. mines. •Causeways are raised platforms across a dry stream. islands (in the exposed river beds). pack tracts. •MAN made features – surveyed trees. broken grounds. pack tracts. streams. . . directions of rivers. •Directions are important for physical as well as urban features. •Urban cities from one another DIRECTION-TO RIVER AND RIVER BANKS .important tool while reading topo map. streams. •Physical features.DIRECTIONS •Directions. dense-mixed jungle. open jungle. Having located the direction of the river. different terms used: •Dense forest. Now to your right is right bank and to your left is the left bank.000 sq m. To calculate the area by grid square method: If there are some incomplete squares. vegetation is shown –green colour along with contours in brown showing elevation. •In the highlands. mixed jungle. Calculation of Area •Area= Length x Breadth •In topo maps.First look at the spot heights to determine the slope of the land 2. one has to locate the source of the river. Reserved Forest (RF). dense mixed .e.•Need to know which direction river flows.To know which side/bank of the river a place is situated. area of each square is 4 sq cm (on the map)= 1 sq km (on the ground) In metres. •REMEMBER THESE STEPS: 1. this can be expressed as Area of each square (i. open-mixed forest. imagine yourself standing at the source of the river facing the main river facing the main river. area can be calcualted as follows: -Note the number of completed squares -Squares covered half are taken as ½ -Squares covering less than half area are taken as 1/3 -Squares covering more than half of the area are taken as 2/3 -All these estimated squares are added together and the sum is multiplied by the scale of the area given out above to obtain the desired area. fairly-mixed jungle. LAND USE •IN topomap location of veg is closely related to relief. •To show density of wooded area. 4 sq cm) = 1000 X 1000 or 1.000. Protected Forest (PF). fairly mixed jungle with bamboo. each grid (square) 2cm X 2cm or 1 km to 1 km as per the scale 2 cm=1 km •Therefore . •A disappearing stream shows a desert or limestone area •Presence of canal. dry ponds. •Rock outcrop – In such region subsoil is exposed and cultivation is not possible. following features are found•Open scrub – scrub land where mostly sheep and goat rearing is practiced •Stony waste – the land which is mostly covered with rock boulders and stones and cultivation is not possible. Because of floods. •Other means of irrigation are canals. •Settlements are generally found on either side of river-wherever irrigation by canals or perennial lined wells is available MEANS OF IRRIGATION •Irrigation largely depends on relief and land use pattern of area (blue) •Hilly region. •The exterior boundaries of areas of Reserved or Protected forest are shown by green ribands . – therefore one can say that the main source of irrigation in such areas are wells and the occupation of people is farming.jungle with bamboo. •Broken ground – developed because of absence of natural vegetation on both the banks of the river.This is formed due to floods which occur during rainy season.no cultivation is possible. THE PLAINS:-•Plains-mainly agriculture. tube wells and tanks indicate use of land for agriculture by means of irrigation •A meandering river shows a flat area •Perennial lined wells indicate a higher water table and are shown by blue dots. SHEET ROCKS:-•Sheet rocks – a region mostly covered with a sheet of rock. wells. uncultivable land. It is common in the desert area and in the areas of gully erosion. one can see blue. artifical lakes withj embankments and river in case it . •In such land. the top soil is washed away developing into bad land which has loose soil and is uncultivable. ponds. •Presence of dry streams. exposed river beds and broken land shown in black indicate an area with scanty rainfall or seasonal rainfall or a desert region. hence there is no need for irrigation •On the flat lands which are coloured yellow.cultivable land is shown in yellow colour •White patch in plain shows bad land or rocky. LOW LANDS:•Plains which are situated at lower level are mostly characterized by a meandering river. round spots which represent perennial lined wells. grasslands. ports. the occupation of the people of an area can be inferred from the following : •Topography of land •Size of settlement •Presence of quarry and mines •Communication network indicating trade REMEMEMBER FEW POINTS: HACHURING: Hachuring are short lines representing directions of a slope. OCCUPATIONS EVIDENCES Forestry. •The following list gives you some information about occupation of the people from a topo-sheet.l akes. •Presence of artificial man-made lake with embankment shows that water is being stored in off season and is used for irrigation through canals. OCCUPATIONS •Occupations have to be inferred from toposheets as there are no symbols to show the occupations of people. etc – dense settlement Entertainment & Cultural devpmnt Gold Courses. lime stone beds Trade Settlement near main roads. certain names like ‘farms’. . rivers. rivers. ‘orchards’ provide some evidence of these occupations. Parks. they cannot be used. etc Tourism Hotels and Inns •Thus.is perennial. •Presence of dry streams and dry ponds with uncultivable lands shown in white indicates that the rainfall in the area is scanty. •Sometimes. pastures Quarrying and mining Mines and Quarries. For steep slopes they are drawn closer together than for the gentle slopes. Rifle Ranges. mines. meadows. etc Industry Factory. However on flat ground. large settlements near roads and railways. presence of raw materials (lime making and cement industry near limestone beds) Fishery Coast. lumbering Forest or Green Patch Agriculture Yellow Patch or orchards with many wells Cattle-grazing or sheep rearing Meadows or Scrub. the dot is enclosed within a triangle and are called the triangulation points. These are represented by a number preceded by a dot. . for example ●340 TRIANGULATION POINTS: When the spot heights are accurately surveyed .SPOT HEIGHTS: Spot heights are used to provide more information about land surfaces between the contours. go through the B corner and C corner and D corner. because two rivers flow towards south west whichis an indication of the slope. Keep a pencil ready to mark few features. read the questions that are asked. Did you spot stony waste (8596)? In the same way. Do you follow? Where do you find the lowest part in the toposheet? The south west corner is the lowest part in the map. North East Corner (B).F. i suppose u understood. can you see the scale? You can see almost near the R. you see river Sipu.F. Rajkot is in grid square 8995 and gangudra is in grid square 8793.F. we can see some spot heights too. You have 15 minutes to read the question paper. R. Can you see R. open scrub. What's the contour interval of the toposheet? Check the contour interval near the scale. I have already explained to you how to write R. For example North west corner (A).F.? You can see at the bottom right. For example what features do you see in the A Corner???First of all. little bit of green forest on top of A corner. you hv to go up which is north and then you have to turn right. The scale is 2cm to 1 km. Imagine you are in Gangudra and you want to go to Rajkot from Gangudra? First of all. which is east direction.For the bigger view of the toposheet.(usually it is 20 metres) What else can you see? Ok. is 1:50. After having a quick glance of thetoposheet. yellow wash. in the earlier lesson. Good.Therefore the comapass direction is north-east from Gangudra. First read the other questions and then come to the toposheet which requires more time to read. . click on top of the picture.000. Can you see a cart track (red line)? We can also see perennial wells (blue). See the features of this toposheet. Contour interval of this toposheet is 20 metres. a few nucleated settlements. Find out what is the directionof Rajkot lie from Gangudra? First of all. let's do the direction which i have explained to you earlier. Divide the toposheet into 4 quarters. Study the each quarter. South West Corner(c) and South East Corner (D). It means 2cm on the map is equal to the 1km on the ground. Make a mental picture of the toposheet with prominent symbols.Interpreting Toposheets Hello. The river or drainage pattern is Rectangular or Trellised. (in blue) several cart tracks. You can see all these in this map. See the settlements on the map: What type of settlement do you find? Ofcourse. they are decreasing towards south west. Let us study the occupation of Bhadli (Jhat) . cart tracks. Go through it again. Study the toposheet closely. you select any two. trees. Can you see them? From this we know that the occupation of the people of that area is cultivation and stone cutting or extraction of limestone. So the people can cross the river during summer. Can you see the shape of the river? Thin lines that join the main river. It is a clustered settlement too. pack tracks. This shows that the area gets seasonal rainfall. Study the river. So the man-made features are temples and permanent huts. the river doesn't have much water in the summer season and so the river dries up. It usually heappens in the area where there is no vegetation/plants. read the text book on settlements and come back to the blog. .Dendritic(Tree like or veins of a leaf) Trellis/Rectangle and Radial. It has a broad sandy riverbed which is exposed. islands in the middle of the river. Identify some spotheights in the map. Therefore. It also has a thin water channel in the middle of the river. So two perennial source of water is the River waters and well irrigation. What kind of rainfal this area gets? check the rivers-we can see broad sandy bed exposed. We can see many cart tracks leading into the village. Read the text book regarding the drainage pattern (if you have not understood) There are three drainage patterns . As I have told you.(it means the river gets water only in the rainy season). Then we also can see the perennial wells.We can see rivers. I had told you about the occupations. perennial wells (Blue dots). they will ask one or two man-made features. So what is broken land? Broken land gives rise to Bad land topography. You will see it in my blog too. Now let's study the natural features . Now let us see the occupation. These are generally found along the banks of a river. Go beyond that.we can see few temples in the toposheets and permanent huts. lined wells. If you dont understand the sandy river bed.We find broken ground there. jungles. Can you see the irrigation facilities or source of water? We can see the river which has narrow blue line which means it is perennial even though the river is seasonal.grid square 8596. What do you notice there? click the toposheet and check. The natural feature is river and forest. Some time a question comes on the comparision of two settlements. Jigol is better off than other settlements.(Grid square 8793) See the drainage pattern around the area-dont see only in the grid square 8793. Broken ground is caused due to erosion during rain when the river is in flood. yellow patch(which means agriculture) and stony waste. perennial wells and the presence of lime kilns. There is a river. go to the text book and looks for the symbos of sandy bed. I couldn't see any post office. It has good transport system in comparision with other villages. my eyes are not very sharp. Let us see the drainage pattern on the map. If you didnt understand. nuclear/compact/clustered. Go and locate that grid square and follow the points that I have told you. This is indicated by the presence of agricultural land ( in yellow colour). you see the sandy beds and cart and pack tracks passing the river.In what two ways does the river bed of Sipu convey that it flows through a region of seasonal rainfall? We did go through that earlier.check the spot heights in the map. Let us study the river bed of Sipu. etc. mines. See the area around the town Gangudra.check corner B . a thin water channel. Do you follow me? Since the river is dry. In the exam. What are the conventional sighs near north east part of the toposheet near open mixed jungle? . Let's study man made features . We also see many cart and pack tracks passing the river. Now let us study the village Jigol (grid square 8590) and other villages. and a pack track. its is A CORNER. Plus it has many lined wells for irrigation purposes. Therefore it is a seasonal river. Sometime they will give a grid square and ask to you to mention one man-made feature and one natural feature. So. let us locate a place using 6-figure grid reference of a temple in the north east of Odhava. Look for the spot heights in the toposheet. First find the square. This is four figure grid reference. now we need 6-figure grid reference. It is in the grid square 8992. Then place the ruler on the vertical line and find the mid point and join these mid points. They flow towards the south west. So the south-west corner of the map exatract is the lowest region. We have done that in the beginning. then u locate the spot in the grid square and if the spot is beoynd the mid point. you will find south west qurater of the map are decreasing towards the south west. When you are asked to locate the 6-digit reference. After locating 4-figure grid reference. get the mid point. divide that square into 4 equal parts. rememeber these points. First take a ruler and place it on the horizontal line of that grid square(.4 figure or 6 figure/digit grid reference. Ok. let us see the 4-figure grid reference. Find four digit grid square is easy but the problem begins when you have to find 6-digit grid reference. Ok. In which quarter of the map extract do you find the lowest area to be? Divide the whole toposheet into 4 corners. then it wil be above 5. NOw you see where is the spot and give the grid reference. if you study the heights. Hope you know how to find grid squares . Now u get 10 X 10 equal squares. Hold the scale vertical and horizontal on that grid square and join them. then u get the mid point of easting and northings.894925 . You can find the exact 6 figure grid reference by dividing grid squares into 10 blocks. See also the river flowing. see various features.. It starts frm the place where the equator and prime meridian meet and is named UA. well connected roads.. It is in northing 94. So four figure grid reference of the triangulated height is 8294....... We locate it in easting 82.. Now let us to to the north-east of the map. Post Office (PO). You will also see Lime Kiln.It is a furnace for baking limestone. The occupation in this area would be sheep or goat rearing..e 0-99 on a toposheet it is written after every 100km.Its presence shows the trade possibilities and the people working in it.. Let us first find out four figure grid reference...Interpreting Toposheets -2 Let us look at this toposheet. etc. Here it is the end of northings.. We have already found out the four figure grid refernce. Now how do you find four figure grid refernce. Under the same fashion the whole world has been divided.It has a police station (PS). Look at the town Panthawada.. perennial wells... What do you see over there? OPEN SCRUB. QC means that there is end of numbering of northing or easting i.. Thus the square is named QC. Let us see the northings. Look at the triangulated height of 224..What does it mean? It indicates desert or semidesert condition... a temple..What is it? According to the international system of location of a place the whole world has been divided into various squares. Let us see the eastings first. Let us look at the Northern part of the toposheeet. You will see the enlarged topomap. Double click on this toposheet. (8294) Let us divide that .. Can you see QC.. Let us study 6 figure grid reference... Can you see the broken ground? (I have marked in the toposheet) What is a broken ground? They are generally found along the banks of a river. . For 6 figure grid reference. So first three figures are 821 and the second part is 941. It usually happens in the area devoid of vegetation. Did you get it? I hope so anyway. Its in first square.square (8294) into 10 equal squares as it is I have done in the toposheet. So you will have 10 equal squares. Broken ground is caused by erosion during rain when the river is in flood. first 3 figures are of eastings and the second part of the 6 figure reference is of northings. you mark one square. Let us now find out the third figure from those small squares. For every 2 cms. So six figure grid reference is 821941 or 822941. Look at it closely. We have already know easting is 82. Revision -Important Toposheet definitions IMPORTANT DEFINITIONS DEFINITIONS FROM TOPO MAPS REPRESENTATIVE FRACTION (RF): It is the ratio between the distances on the map to its corresponding distance on actual ground. TRIANGULATED HEIGHT: It is the height of a place which has been calculated using trigonometry. The RF on this map is 1:50. 3.g.. 2. CONTOUR INTERVAL: The interval between two consecutive contours is called contour interval (*it is a constant 20 mts in your toposheets. 10. SCALE : Scale is the ratio between the distance of any two points on the map and the actual distance of the same points on the ground. The darker lines are called Index Contours. . SPOT HEIGHT: The height of random places between contours shown with a dot. 4. joining all places with the same height above sea level.425 8. It is represented by the height with a small ‘r’ eg –12r. The scale of the given map extract is 2 cm: 1 km or 1:50.) 5. For example at every 100 mts the contour line is made darker. It is written as BM 200 m. 9. represented by a small triangle e.000.000. 7. INDEX CONTOUR: Contour lines are thickened at regular intervals to make it easier to read contours. CONTOUR: Contours are imaginary lines drawn on maps. Eg . 540 6. RELATIVE HEIGHT: Relative height is the height of a feature with reference to the height of the surrounding land and NOT to sea level.Height of a place actually marked on a stone pillar. ROCK OUTCROP: It is a portion of rock jutting above the surface of the earth. rock or shown on a building as a permanent reference. BENCH MARK . 12. 17. (Usually a road used only in the non rainy months. 10. which is totally weathered (exfoliated) due to alternate cooling and heating.11. but show only approximate heights above sea level as they are used to indicate the elevations of the area which are not accessible for proper survey. of 10. 20. 11. BRACKISH: It is a well. DENSE JUNGLE. stones and pebbles.PQ. 21. FORM LINES: Form lines are contour lines. OC. OPEN JUNGLE: A forest where trees are widely scattered. CAUSEWAY: It is a raised road over a small water body. which has been cut in order to make land available for transport routes. (it is indicative of a rocky region) 19. Also made near tanks and rivers to prevent flooding. EMBANKMENT: They are raised rock or soil filled constructions on which roads/railway tracks are built. 16.000 square kms. 15. SHEET ROCK: Large areas of rock where the overlying soil layers have been eroded and removed due to mechanical weathering. The Govt of India has adopted metric system for all measurements. MIXED FOREST: A forest with more than two varieties of trees growing in close proximity to each other.D. Therefore it indicates a dry region. Q. which has water with very high salt content – generally unfit for drinking purposes.C.. 13. 9 STONY WASTE : A large area usually in arid/semi arid regions where the finer sand/soil has blown away leaving a surface covered with boulders. ETC : These are alphabetical codes used to represent the biggest grid sq. : A forest where trees grow very close to each other. OD. All the ordnace survey maps issued by the Survey of India were drawn to the scale . FIRELINE: A cleared pathway in a forest to prevent the spread of forest fires. Hence they are drawn as broken lines and are called 'form lines'. 14.} 18. CUTTING: A portion of land. Q. BROKEN GROUND: A relief feature found mostly in dry regions around rivers and streams. It is land around river. OPEN SCRUB: Scrub is a vegetation found in regions with less than 100 cms of rainfall. 2 cm = 1 km. leaves a hollow or a depression. for example. Hill shading. HILL SHADING: Hill shading resembles a light and shadow effect. however. It is a mapping convention for darker colours to signify greater height. In accordance with this technique. LAYER TINTING: (colouring) While spot heights show the height of the land. Valleys and the sides of mountains appear as though they are cast in shadow. In this system . the thicker the lines are which represent it. This system of map drawing is known as National Grid Reference. While layer tinting is useful. it does not show the detailed shape of the land. OD. Layer tinting is most commonly found on physical maps. LIME KILN OR BRICK KILN: These are open furnaces where limestone is purified or bricks are baked for construction purpose. PG. Layer tinting uses different colours (or shades) to represent different heights. yellow for higher land and brown for the highest land. 26. it gradually began to be replaced since the actual height of the land was not depicted. etc . This is a visually striking method. DEP: It is a depression often found in sandy areas where the wind. While hachuring was initially innovative for its time. OC. When using layer tinting. which is ideal for providing an overall view of the relief of an area. 23. PQ. Hachures use short lines of varying thickness to show the shape and slope of the land. the steeper the slope is. 22. green is often used for low land. does not show height which means that it is no more accurate than hachuring. they only do so at certain points. a technique called layer tinting was developed. having blown away the sand. 24. . the surveyed territory is divided into 100km X 100 km squares. HACHURING: Early cartographers attempted to show surface features on maps by using the technique of hachuring. 25. To provide an overall image which conveyed height. and each square is denoted by English alphabets. Mention any three features seen in the map extract which attract holiday makers. 2. etc)Ans: The region is densely forested. tanks. lakes.Mention ay two features seen in the map extract which indicate the region has seasonal rainfall.. (any two ) 5.. sunset points.( check for any features that is not suitable for human habitation – like dense forest. State two reasons for the absence of human habitation in some region of the map extract. water falls. etc and then write answers) 3.Seasonal streams/ Broken ground/open scrub/seasonal tank/cart track motorable in dry season/narrow perennial channel in the dry bed of the river(after looking for these features. steams and ponds/tanks are dry in nature.. then you can write your answer this way. lakes. steep hills. (look for sandy soil .(look for perennial wells first. many ... Reasons for streams not meeting the main river due to:* presence of sandy soil which is porous * poor rainfall * high rate of evaporation.(look for various tourist destinations like temple. Give one reason to explain why the steams in grid square .. Which is the chief form of irrigation shown in the map extract? Give somE evidences to justify your answer. deserts. 4. select any two features that you find on the topo sheet and write this way) Ans: Open scrub and seasonal streams are two features in the map that indicate the region has seasonal rainfall. For example. Rivers. lack of roads.. rainfall.. etc and give answer. look for these points in the toposheets and can write these answers: 1. park. then the rivers.Some Common Questions Based On Toposheets If you get these questions. if you find the presence of many blue circles in the map. do not join a river. Barren land shown in white colour also indicate tht the region has seasonal rainfall. Presence of blue circles scattered all over the map . open shrubs. etc)Ans.) Ans: The chief form of irrigation is perennial well-irrigation. The region has poor rainfall due to the •Presence of sand dunes •Presence of undefined and disappearing streams •Presence of scrub vegetation •Presence of broken grounds 10. Give two reasons for the presence of only footpaths in the green wash. Give evidence to prove poor rainfall in the region. If you find these features. highlands ii. highlands – collection of forest products ii. or many streams – and then answer according to the features.agriculture 8. * temples are the only destinations in the forested mountain region and hence foot-paths are created by the pilgrims. What will be the main occupation of the people be in i. 6. Lowlands .look for dense jungles.)Ans: The area has dense jungles. steep hills and no important settlement. 9. Expensive to build roads.The reasons for the presence of foot-paths are: * seep and rugged terrain makes construction of roads difficult. then you write the answer this way)Ans. etc. What is the small white patch in the river?Ans: Barren island 7. scrub vegetation. steep hills. Why do so many contour lines so close together in the extract indicate about the topography?(look for steep hills. broken grounds.streams with very steep hills. Why are there no metalled roads in the mapped area?( reasons may be many. or a temple in the . Lowlands?i. or barren land.steams and barren land discourage the building of metalled roads. (look for features like sand dunes disappearing steams. * footpaths may be created by people who depend on forest produce. 11. ... dry tanks.look for these features and then write the answers accordingly -First of all.what type of climate do you find in the particular area . Therefore one must know the colours and what it indicates.) (If you find dry rivers. scanty amount of rainfall can be judged by seeing dry rivers. For example. (if you find dense forests. We can amplify the occupation by inferences provided on the toposheet... scanty vegetation. sand dunes and scrubs and scanty vegetation.jungle and if u find these.. scrubs.. then your answer wil be) The area experiences scanty rainfall or poor rainfall with dry weather. all of you know that yellow colour indicates agricultural land and hence agriculutre can be major occupation.. or dry tanks or sannd dunes. then your answer will be) The area experinces Tropical Monsoon climate.. look for these features.. This gives us a faint idea about the part of the country and the type of climate prevailing there... we cannot know about the occupation of the residents. Directly from a toposheet. Further.. we should try to know which area of the toposheet belongs to.)Ans: Very steep (indicated by close contours) and hilly (indicated by many contours) land. How can we draw a climatic inference from a toposheet? (there may be a question .. What is the occupation of the people of a particular region from an extract of the survey map or toposheet? (When you get a question on the occupation of the people .. Similarly dense forests indicate tropical monsoon climate. Green colour shows forested or wooded area and this . 12.. Questions on occupation 13. then the occupation will be sheep and cattle rearing. show the cultivation of cash or cereal crops. I hope you got me. . a meandering river on the toposheet will indicate a lower or nil gradient. etc. look for these features and write the answer accordingly. Pastures on the slopes may be fit for grazing. etc. indicates that people must be employed in urban services. Dendritic or tree-like drainage pattern would confirm soft surface suitable for agriculure wheras trellised drainage pattern suggests chalk country. 15. when you get a question on the occupation of the people. forestry may be a predominant economic activity in this region. historical monuments indicate occupations like tourism.. then it indicates sheep or cattle rearing. canals. Presence of big towns. industrial area. which is not much suited for cultivation. How can you judge the suitablity of land for agriculture from toposheets? give a good reason. parks. If you locate wells. etc. such a plain area would be suitable for cultivation. Settlement along roadside indicates devp of trade and commerce. symbols of mines. carpentry and bamboo work. Rest houses in hilly areas show devp of tourism. for example if you find grassy area or open shrubs.. recreation. Thus. furniture making. my dear students. lawns. if you find grassy area.indicates that people follow in lumbering. may suggest that some people are employed in mining activities. flat area over plateaus may be used for cultivation. cultural devp. railway station. So. What occupations do the people follow in Highland areas? Ans: High land regions with steep slopes have the following features: most of the slopes are unsuitable for agriculture. tanks. ) 14. etc. ... Silt deposition by rivers is a good sign for agriculture. e.. POINTS TO REMEMEBR REGARDING OCCUPATIONS: If you find KILN . If you find irrigation from wells. if you find STONE QUARRY. perennial wells. etc due to the presence of Kiln in the area. network of canals. then the occupation is quarring. etc. So you write the answer this way: The occupation is drying and baking bricks. A large number of perennial wells present in the area also support this inference. or north. if you find yellow wash. which are the main occupations of the people in this area? give reasons in support of your answer. west or east) which is indicated by green colur which suggests forestry as an important occupation there. Some part of the map shows presence of open jungles. For example. ( if you see yellow wash.kilns on the toposheet. pottery.(mention. tanks and tubewells will indicate intensive use of land for agriculture... then the occupation will be drying and baking bricks. limestone. dams. so look for these features on the toposheet and write accordingly.) Ans: Farming and forestry seem to be the two occupations in this area because a large part of the map has yellow wash which symbolizes cultivated area. presence of kilns shows that lime and brick making is also an occpation of some people.Sand features. presence of broken ground would confirm seasonal flooding. farming is the occupation. barkhans and disappearing streams would indicate the dry conditions with the high temperature. These conditions are unsuitable for agriculture. . your answer will be like this. green colour. south. agriculture is the occupation of the area. canals or tanks.g. pottery. 17.... then the people are dependent on forest products like fruits.. taluqs. there may be primitive agriculture.. so when you write the answer. The line 280 m joins places 280 m above sea-level on the map. if settlement is near the forest(green colour). Closeness of the contours indicates mountainous topography. it means farming is likely to be dependent on rainfall only... trade. nuts. What is the brown line in grid square ... employment can also be in administrative sector because of the presence of large number of offices and organisations... write this way: people are dependent on forest produce or foresty and may practice primitive agriculure. 16. in case they are headquarters of districts.if you dont find any source of irrigation. Second part of the question imagine you see figure 280 m . then fishing is an occupation of that area. then it means 280 m above sea level.. or leaves. They indicate lines joining places having the same height above sea-level. if you find large settlements. services.) Ans: The brown line that we find in grid square is Contour line. called? What does the figure written aong this line indicate? (if it is a brown line . the occupation can also be industries. 17.. esp near the metalled roads. mining is the occupation if you find settlements near mines or quarries. then it is a contour.. so please go through the toposheet properly since one question will be definite on occupation. if you find settlements along the banks of the river. What is a causeway? Why are there so many causeways in the map? Ans: Causeways are land raised across streams for use as metalled . What are the brown lines seen in such abundance? What do they indicate? (same answer as question 16) ans: They are contour lines. What do the following represent in the map? i. The numerous streams crossing the metalled road are likely to flood them. where a colour scheme is used to show relief on the map. Black broken lines indicate disappearing stream and black curved lines indicate broken ground. Explain the term Depression in the map. 19. 20. diagrams and charts. Black curved lines. 21. Name the geographical feature represented by white patches in the middle of the river. . 22. Ans: Depression is a shallow lowland in a sandy region often created by deflation of wind. What is cartography? Cartography is an art and science of drawing maps. What is layer-tinting/colouring? It is a method. Black broken lines ii.road or paths. 23. i. Ans: The geographical feature in the middle of the river represented by white patches is an island or rocks or stores. Name 4 methods by which relief is shown on the map. 18.* Contour lines * Layer Colouring/tinting * Spot height * Hill shading. .. don't write height but the depth) 5r the relative height of dry tank is 5 metres ( if 5r is written near the dry tank symbol) 16r therelative height of sand dune is 16 metres. 6r.... hill.. or it can be depth of a well. tank...... COLOURS: 7 COLOURS are used on toposheets: .....POINTS TO REMEMBER: RELATIVE HEIGHT OR APPROXIMATE HEIGHT: REMEMBER:-This height is not taken from the sea level but with respect to the surrounding area. for example 2r. etc.... It may be height of a dam.... bridge... 3r. Example: ●3r the relative depth of the perennial lined well is 3 metres..... (if 16r is written near the symbol of sand dunes) 8r the relative height of river bank is 8 metres (if 8r is written near the river bank) PLEASE NOTE: you must write the word RELATIVE HEIGHT/DEPTH of .. 5r.. or river canal..(if 3r is written near the symbol of perennial well... sand dune. and the urban cities from one another. scrubs. look at the spot heights to determine the slope of the land. to . telephone. settlement. dry rivers. all sand features like sand dunes. spot heighs are marked this way ●265 ●289 see which spot heights are higher and where it is lower. streams. rivers. form lines. huts and other buildings. first of all. surveyed trees. roads. Having located the direction of the river. then it flows from north-east to south-west. settlements. railway mines. the following steps should be observed. the slope of the land may be from north east to south west. town. river banks. BLACK: Names. orchards iv. their numbering. sand hills. When a question is asked regarding the banks of the river or direction of the river. WHITE PATCHES: uncultivated and barren lands DIRECTIONS Directions are important for physical as well as urban features. broken grounds.i. BLUE: Water bodies containing water like wells. lines of latitudes and longitudes. cart tracks. As you know. scattered trees. and if you see a river . imagine yourself standing at the source of the river f acing the main river. stony waste vii. their numbering. etc)one has to locate the source of the river. the physical features involve the directions of rivers. etc v. GREEN: Forested and wooded areas. and then you will know which way or direction it slopes. telepgraph lines ii. YELLOW: cultivated areas vi. to know on which side or bank of the river a place is situated (a place may be a temple. heights and their numbering. iii. RED: Grid lines (eastings and northings) . BROWN: Contour lines. Shaded Relief. b. Shaded relief is sometimes used in conjunction with contour lines to emphasize these features. However. BOSS!!! when a question is askend on directions with reference to urban cites/settlements.your right is right bank and to your left is left bank. First of all. remember these points. some times the questions are asked on the direction of a city or settlement with a reference to the other. Use the direction arrow and write the direction. Hachures are sometimes used with contour lines. this method does not allow the map user to determine the exact elevation of a specific point—only the range. pay attention to the words 'FROM' a place and 'TO' a place. but are mainly used to show large. They do not represent exact elevations. Relief shading indicates relief by a shadow effect achieved by tone and color that results in the darkening of one side of terrain features. Hachures are short. Each shade of color. or band. A different color is used for each band of elevation. d. broken lines used to show relief. A legend is printed on the map margin to indicate the elevation range represented by each color. SO SIMPLE. Imagine yourself standing on the 'FROM' PLACE and look at the TO PLACE. FEW IMPORTANT TERMS: A. Form lines have no standard elevation and give only a general idea of relief. rocky . c. such as hills and ridges. Form Lines. The darker the shading. the steeper the slope. represents a definite elevation range. Hachures. Layer Tinting: Layer tinting is a method of showing relief by color. Form lines are represented on a map as dashed lines and are never labeled with representative elevations. Form lines are not measured from any datum plane. This number is the elevation of that line. A contour line represents an imaginary line on the ground. Normally. plateaus. such as on fairly level terrain. They show changes in elevation of at least one-half the contour interval. Contour lines are the most common method of showing relief and elevation on a standard topographic map.outcrop areas. The elevation represented by contour lines is the vertical distance above or below sea level. every fifth contour line is a heavier line. Starting at zero elevation or mean sea level. (3) Supplementary. Hachures are used extensively on small-scale maps to show mountain ranges. e. There are normally four intermediate contour lines between index contour lines. Contour Lines. . The contour lines falling between the index contour lines are called intermediate contour lines. These lines are normally found where there is very little change in elevation. All points on the contour line are at the same elevation. (2) Intermediate. These are known as index contour lines. each index contour line is numbered at some point. These lines are finer and do not have their elevations given. These contour lines resemble dashes. (1) Index. above or below sea level. and mountain peaks.