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: Lati tude 24 degree 15’ – 240 30’ North Longitude 720 15’ - 720 30’ East This region lies in we stern India on the borders of Rajasthan and Gujarat at the southern end of the A ravalli Hills, immediately north-east of Sheet 45 D/10. RELIEF : The area is mai nly a plain except for: 1. The east central region where the hills rise to almos t 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 south ern 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 ri ver to the north) flows into the swampland area of the Little Rann, north-east o f the Gulf of Kutch. On this survey sheet it flows westward. It has two main rig ht 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 t he 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 d uring the rainy seas. 2. The Sipu Nadi is a tributary of the Banas river (the co nfluence) 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 b ank. 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 indi cating soft soil easily eroded by water. SOILS: Map symbols indicate desert cond itions, a large part of the plain area being sandy. Soils are soft as shown by e xcessive erosion causing broken ground near water courses. CLIM ATE: There are t hree climatic seasons: Summer hot and dry March to June Monsoon hot and wet July to September Winter cool and dry October to February Ma ximum temperatures in summer are extremely high rising to over 470 C, while mini mum temperatures in December/Jan often drops to almost 0 degree C. Because of it s 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 i s no agriculture. IRRIGATION: This region is dependent on the periodic rainfall (Monsoon), tanks, wells for agriculture. There is only one canal in the north-ea st starting from the reservoir (2222) OCCUPATIONS: Agriculture, rearing of cattl e, sheep, camels and horses. CROPS: Winter (Rabi) – Wheat, Barley, Cotton Monsoons (Kharif) – Bajra, Jowar, Maize COMMUNICATIONS: Except for the main line of the We stern Railway and the road that runs across the south-east corner of the map thr ough Chitrasani (8923), there are no other important communications. All other s ettlements are linked by cart tracks. SETTLEMENTS: Except for Chitrasani which i s 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 Rajasth an) District : Banas Kantha and Sirohi Location: Latitude 24 degree 30’ – 240 45’ Nort h 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. REL IEF : 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 corne r. The ranges are more or less parallel and run in a NE to SW directon. 2. A lar ge 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 surroundi ng 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 th e 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 direc tion. It is periodic and seldom exceeds ½ km in width. TRIBUTARIES: Right bank : S ukli Nadi, Unda Wala, Dior Nadi, Left bank: Sukli Nadi, unnamed river flowing pa st 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 t he soils tend to break up easily, the water courses are numerous and well define d for they are able to cut channels in the soft sandy soils. They are however pe riodic and rely on the rainy season for the water supply. CLIM ATE: There are th ree 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 sum mer are extremely high rising to over 470 C, while minimum temperatures in Decem ber/Jan often drops to almost 0 degree C. Because of its location in western Ind ia, 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 seaso n. High temperatures cause excessive evaporation. This gives rise to scrub and s emi-desert vegetation. NATURAL VEGETATION : Hill areas – dry deciduous forests of small trees Plains – scrub and throny trees where there is no agriculture. IRRIGATION: This re gion is dependent on the periodic rainfall (Monsoon), tanks, wells for agricultu re. There is only one canal in the north-east starting from the reservoir (2222) OCCUPATIONS: Agriculture, rearing of cattle, sheep, camels and horses. CROPS: W inter (Rabi) – Wheat, Barley, Cotton Monsoons (Kharif) – Bajra, Jowar, Maize COMMUNI CATIONS: 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 ru ns parallel to the foot-hills and connects a number of settlemtns. Many of the s maller settlements are linked by cart tracks. SETTLEMENTS: Abu is a large hill r esort, an administrative and an educational centre. In the plains, there are num erous settlements of much smaller size of which Sirori (2023) is the most import ant. Chapter 3- Interpretation of Topographical Maps STAGE 1 – TYPES OF MAPS There are different types of maps. We will focus now on To pographical 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.R epresentation 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 topographica l map. Contours are shown at regular vertical intervals. On a 1:50,000 map the i nterval is 10 m. INTERPRETATION OF CONTOURS •The shape of the contours indicates t he 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 fa r they travel, they always return to where they started. Except for a cliff. b.W hen spacing of contours down a slope gets close together at the bottom, the slop e is convex. c. When spacing is further apart, the slope is concave. STAGE 3 – PLO TTING 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 t hat 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 numb ers increase as they go North. What are the 3 points in determining height? 1.be nch marks; they are often called topo quads or quadrangles .trig points. where the primary national series is organi zed by a strict 7. For example.Eastings ru n – move left to right. . What are the two most i mportant things to remember when giving a grid? 1. is actually a much broader field of study which takes into account all natural and man made features of terrain. •A topographic map is a type of map characterized by large-scale detail and qua ntitative representation of relief. Uses •Topographic maps have multiple uses in the present day: any type of geographic planning or large-scale architecture. rivers." •The study or discipline of topography. usually using contour lines in modern mappin g. while interested in relief. and recreational uses such as hiking or.Northings run – bottom to top. and 3. Map conventions •The various features shown on the map are represented by conventional signs or symb ols. buildings . colors can be used to indicate a classification of roads. orienteering. Thes e signs are usually explained in the margin of the map. the main division of maps is into topographic and thematic maps.spot height." •According to Cartographer s Kraak and Ormeling. and 2. mining and other earth-based en deavours. in particular. In the United States. or on a separately publi shed characteristic sheet] •Topographic maps are also commonly called contour maps or topo maps. often the nature of the vegetation.5 minute grid.Easting value first. and 2. •The Centre for Top ographic Information provides this definition of a topographic map:"A topographi c map is a detailed and accurate graphic representation of cultural and natural features on the ground.2. earth sciences and many other geographic disciplines. What is the purpose of a contour line? Joins points of equal height s. Topograp hic maps supply a general image of the earth s surface: roads. but historically using a variety of methods.nev er round up."Traditio nally. Traditional definitions require a topographic map to show both natural and man-made features . What are Eastings and Northings? 1. the relief and the names of the various ma pped objects. which uses highly detailed maps in its standard requirements. This is a consequence of erosion. waterfalls. •Shows natural features like hills. som e maps note this by short lines radiating from the inside of the loop. Older topographic maps were prepared u sing traditional surveying instruments. •In most cases. •When these joined together. they form a map of the whole area. must be known. the contour inte rval. or distance in altitude between two adjacent contour lines. and the in nermost loop is the highest area. with the vee pointing upstream. TOPOSHEETS ARE:•Are prep ared on a number of sheets since they are large scale maps. •These maps usually show not only the contours. •Spacing of contours: close contours indicate a steep slope. every point on the marked line of 100 m el evation is 100 m above mean sea level. •Today. distant con tours a shallow slope. INTERPRETATION OF TOPO MAPS AND SURVEY MAPS . and other featur es and points of interest. by means of co ntour lines. with the drainage channel passing through the point of the vee. They•Are based on a ccurate surveys. In other words. Two or more contour lines merging indicates a cliff. •Also show man made feat ures like roads. called "h achures". Sometimes dashed contour lines are present. railways. forest cove r.•Topographic maps conventionally show topography. topographic maps are prepared using photogramme tricinterpretation of aerial photography. built-up areas or individual buildings (depending on scale). Contour lines are curves that connect contiguous points of the same altitude (isohypse). buildings. •Show a variety of landforms with carefully chosen symbols & sign s. or land contours. •The rule of O s: closed loops are normally uphill on the inside and downhill on the outside. but also any significantstreams or other bodies of water. contour intervals are cons istent throughout a map. these repre sent half the noted contour interval. •Each sheet gives the details of a part of the whole area. valleys. If a loop instead represents a depression. •Of co urse. Understanding Topographical Maps Understan ding of surface depends on the ability to interpret topo maps. to determine differences in elevation between two points. bridges and canals. and this is given at the bottom of the map. There are several rules to note when view ing topographic maps: •The rule of V s: sharp-pointed vees usually are in stream v alleys. •Can be developed only by reading topo map very minutely and mental ly analyzing the details with the help of conventional signs & symbols given in their conventional colours •As the conventional symbols cannot cover all the grap hical details.Identification of topographical maps 2.Reading the Grid reference 3. •Understand the in formation given in pictorial and written form •Visualize the topography of the ori ginal area by interpreting the contour •Spot heights skillfully •Map reading is a pr actical skill.Means of transport in relation to relief 10.IT involves ability to follow the symbols portrayed in the map.Drainage 8. each topographical map sheet provides the necessary information i n the margin for the users.Measuring distances and calculating distances 7.) 4. Inferring occupations 13. Importance of colours and tints in topographical survey sheets 14. 1. Glossary of conventional signs an d 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 whic h part of India is shown on the map.Settlements 12.Land use and irrigat ion 11.Directio ns 6.Representation of Relief by contours 5.Man-made and nat ural features 9. For example.Scale (R. Legend 15. topo sheet .F. .numbers 45D/7. 45D/10 and 45 F/3 show parts of Gujarat and Rajashthan. •On a 4 degree topograph ical map. the number of latitudes seen on the map decreases. •56D/11 shows a region in north-east Karnataka. •Western Rajasthan – u may expec t scanty rainfall.a fact which could be verified by the presence of dry river b eds and disappearing streams. . •45D/7 shows a region of northern Guj. closer to the border of Rajasthan •45D/10 lie s in the southern part of Rajasthan close to the border of Gujarat region •45F/3 l ies in the western Rajasthan. •Eg. near Jodhpur •53B/7 shows a region in Punjab. close to the border of Haryana. with seasonal rainfall. •64P/13 sh ows a region in north-east Orissa. ii) Latitudinal and Longitudinal extent: Thes e indicate in whichpart of the Earth the area is located.•Knowing the number of toposheet can give us a clue about the general physical rel ief of the region and its climate which can be confirmed by other information given in the map. at least 4 lines of latitude and longitude can be seen. But as the sca le of the topo map increases. it m ay be inferred that all the reigons represented by those topo sheets would have a tropical monsoon climate.since all toposheets are from India. The reading on the map is alwa ys taken with reference to this origin. •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. ii)Eastings are always read to the East of the origin. •V ertical lines=Eastings since they are numbered from west to East •Horizontal lines = Northings . iii)Northings are always read to the North of the origin. •The origin of the grid reference lies at a point in the south-west corner of the map.GRID REFERENCE •A Grid is a set of lines used to find the exact location of places on a map. •It is al so identified as the Grid Reference . •These are sheets most commonly used for various purposes and are of vital practical importance. •The N ational Grid Reference is a system of rectangular co-ordinate.they are numbered from South to North •Net work of horizontal and v ertical lines or the Eastings and Northings . is called the Grid. READING THE GRID REFERENCE i)Origin is the South –West (SW) corner of the map. •Thus any plac e on the map can be located by starting its distance east or north of the origin of the grid reference. i)The readings are always taken to the right of the Eastings and to the North of the Northings. ii)While giving a grid reference. Eastings are always stated fir st. followed by Northings . 000 un its on the ground. 1 cm on the map represents 50.000 i s the R. 45D/7 •In the map.000 cm on the groun d. 1:50. iii) Mark the division of eastings and the division of the northing corresponding to the location. •For example. which means that one unit on the map represents 50. a third figure may be added to two-figure eastings and north ings. i) Obtain the four figure reference by using first two digits of eastings and northings. . SCALE •Refer to Survey Map No. the first two figures are the eastings and the last two are the northings.Grid Reference of this picture is 2676 Four Figure Grid Reference:-•In four-figure grid reference. both verti cally & horizontally. iv) The crossing point is the location of the reference point. of the map.F. ii)Then divide each kilometre into ten parts visually. Six Figure Grid Reference:•Fo r greater accuracy. i)Hachuring ii)Hill shading iii)Form lines .F. actual survey is carried out and different methods are used to represe nt relief on the map as follows. or Representative Fra ction is the ratio between the distance on the map and the corresponding distanc e on the ground in the same unit. etc.000map and its scale is 2 cm=1km.000 •R. •The total terrain is also called physical landscape. plateaus.F. such as spot heights. •In Topographica l survey. •It can be represented on the maps through different methods.000 This m ap is referred to as 1:50. = 1:50. lowland which are varying in their elevation or heights from sea level. contouring. R. they show a great deal of details about the relief. pla ins. R. •Topographical maps are larg e-scale maps. •Sur veying is considered a part of science of map making.F. Representation of Re lief on the Map and its Interpretation •Earth’s surface – uneven – made up of hills. Distance on the map ____________ ________________ Distance on the ground In the above map.(Scale of this toposheet is) Scale-2cm:1 km or1:50.•Therefore. .iv)Spot heights v)Triangulation points vi)Bench markscontours i)Hachuring: are s hort lines representing directions of a slope. THE DRAINAGE •The term drainage basin describes an area d rained collectively by the network of a river along with its tributaries and sub -tributaries of various dimensions. In this map.on flat grounds they can not be used at all. •An area drained by a single river is called i ts Catchment Area. II) HILL SHADIN G: 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. 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 . it is assumed to be from north west at an angle of 45 degree with the horizon. .For steep slopes . making hills stand out in relief. Thi s method too gives a general idea of relief of the country by it does not give t he actual height and that it is difficult to know whether a piece of land is slo ping uphill or downhill. It can be defined as the addition of shadows to give the optical illusion of a third dime nsion. they are dra wn closer together than for the gentle slopes. The shadows can be regarded as those wh ich would be cast on an imaginary relief model of the ground when illuminated by parallel rays of light from a selected direction or directions. 3 distinct patterns can be recognized 1)Dendritic: .pattern which is related to the general structure of its basin. They develop on a land surface wher e the underlying rock is of u niform resistance to erosion. The term dendritic comes from the Greekword "dendron". They develop where the river channel follows the slope of the terrain. mean ing tree. t he rock types must be impervious and non-porous . due to the resemblance of the system to a tree. which was joined and formed b y many smallertributary rivers. •Dendritic systems form in V-shaped valleys. •In a dendritic system t here is one main river (like the trunk of a tree). as a result.Dendritic drainage patterns are most common. •Dendritic drainage systems are the most common form of drainage system. particularly chalk and clay. •Ob sequent streams flow down thedip slope of the escarpments to join the subsequent streams. .2. The main river (the consequent) flows straight down hill. •Subsequent streams dev elop perpendicular to the consequent along softer rock and erode it away. TRELLIS Rectangular drainage patterns develop where linear zones of weakness. •The consequent river then cuts through the escarpments of harder rock. such as jo ints or faults cause the streams to cut down along the weak areas in the rock. •Tr ellis systems form in areas of alternating geology. formin g vales. 2. SETTLEMENTS 1. railway lines. BLACK – All names. Th ey serve as landmarks and are not allowed to be cut. al l settlements are shown by symbols in RED colour. Each colour used on a map has significance. their numbering. BLUE – Water features or water bodies that contain water. major roads are marked and named. GREEN – All wood ed and forested areas. and sand features such as sand hills a nd dunes. . RED – Grid lines (eastings and northhings) and their numbering. BROWN – Co ntour lines.3. form lines. settlements. 3. lines of latitude and longitu de. YELLOW – All cultivated ar eas are shown with a yellow wash. temporarily occupied huts are also shown. Surveyed trees have numbers on their trunks. huts and buildings. r iver banks. 1. telephone and telegraph lines. Deserted village cities. surveyed trees. WHITE PATCHES – Uncultivable land 6. broken ground. In the case of large cities. 7. heights and their number ing. cart tracks. SIGNIFICANCE OF COLOURS IN TOPOSHEETS On toposheets colours are used to show cer tain features. scattered trees and scrubs. The size of the symbol and size and style of letters used give an idea of the size of the settlement. 5. 4.Prominent su rveyed trees are shown in black. 2. Note:. orchards. On a topo map. dry streams. RADIAL •Radial drainage patterns develop surrounding areas of high topography where eleva tion drops from a central high area to surrounding low areas. 3. roads . 4. fl ood-prone areas. Dense s ettlements : Fertile plains and wide river valleys.... is ... forts. police stations. sand dune or it can be the depth of a well... 8r. thick impenetrable forests. etc..meters. bridge.... · Sparse Settlements : forests ..... post office... plateaus and hill tops with poor vegetation· Absence o f Settlements: Swamps.. 5r. etc.. circuit houses.. sandy deserts. .. tank.. marsh land. presence of raw materials. bridge.. 3r... steep mountain slopes. many wells LUMBERING: Forests CATTLE REARING – Pastur es.. for example ... etc then write the answer this way .. It may be the height of a dam. cement industry near limestone beds) TOURISM – hotels and inns APPROXIMATE OR RELATIVE HEIGHT-is height is not taken from sea level but w ith respect to the surrounding area. (like making. grasslands.. N OTE – Site is the land on which the settlement (village or town) is built... OCCUPATION AND MAP FEATURES AGRICULTURE – Level land with yellow wash.... limestone beds TRADE – Dense settlement s near road INDUSTRY – Large settlements near roads and railways. EXAMPLE:3r . hill or river canal... Places of worship. burial grounds... quaries. dam... presence of road in highland region (sheep) FISHING – Ple nty of rivers MINING –Stony wastes.the relative depth of perennial lined well in 3 m etres ●5r – the relative height of dry tank is 5 metres NOTE: CHECK THE SYMBOL – if it is tank..the rela tive height of . deserts. mountain slopes.5. are indicated by suitable symbols... water towers. meadows. embankment. dak bungalow. Chapter 1 .Fundamentals of Maps . Fundamentals of Maps THE SPHERICAL earth is best represented bya three-dimensional model of the earth . it gives only those details. called a globe. But it cannot be made large enough to include detailed surface features. prismatic compass and theodolite etc. W e are familiar with the maps of the earth surface. (d) by satellite and radar charts. all that is shown on the map is not drawn to scale. The amount of information given in a map depends on: • Scale. We already have crude maps of the Mars and the Moon. plane table. (c) by photographs (g round photographs/aerial photographs). it uses symbols that may or may not have similarities with the shape and size of objects represented. area and location along with correct cardinal directions and distances. Ma ps have unique advantage of showing objects or patterns that may be intangible o r invisible. the sky or any other heavenly body . and • Req uirement of the user. it may show political boundaries or rainfall pattern o r crop distribution. . But it is possible to draw ma ps of other planets and even the sky when pertinent data becomes available to us . Only distances and areas are drawn to scale. which its maker intends to give. A map gives a picture of one or several of the elements of the earth’s surface and being creation of humans . • Projection. A map is a two-dimensional diagrammatic rep resentation of the whole or part of the earth and its surface features both natu ral and cultural at a given scale on a flat surface. maps ar e much more useful tool than globes. dig ital mapping has emerged as an important tool of mapping. Thus. Hence. (b) by actual survey with the help of instruments like chain and tape. With t he availability of high-speed computers and Global Positioning System (GPS). • Method of map making. All parts of the earth can be shown on it in their true shape. maps are basic ally symbolic drawing of visible as well as conceived locational and distributio nal patterns of whole or a part of the earth.. There are various ways by which the earth can be mapped: (a) by freehand sketche s and diagrams. However. • Skill of the cartographer. which may not be marked on the ground. For example. • Conventi onal signs and symbols. Instead of showi ng the details in their true or visible shape and size. They have fewer details. temperature. hemispheres. The maps included in this book are also small scale maps . Large Scale : These maps r epresent small area of the earth on a large size of paper/cloth/plastic sheet wi th greater details. Th ematic maps are usually prepared on small scale highlighting specific themes suc h as relief. and political divisions. and canals. swamps and lakes. and countries. Examples of small scale maps a re Atlas and Wall maps. plateaus. maps could be broadly categorised as follow : (a) Physical or Natural Maps (i) Orographic or relief maps represent features like mountains. buildings. Indian toposheets are generally prep ared on the scale of 1:50. and their mode of occurrence and disposition. Only a few atlases are prepared on a 1:1. They show general surface features in detail both natural and cultural. These maps are drawn on a very large scale. a type by itself. forests. They are used in classrooms and cater to a larger audience. (ii) Bathymetric maps show the depth of the oceans and s eas. continents. The Registrar General of India brings out C ensus Atlas from time to time. They ar e especially prepared by governments to realise land revenue and property taxes. The scale is smaller than that of topographical maps but la rger than atlas maps. etc.000. villages. They are also known as charts. and • Small Scale. They give only a general picture of the area represented. drainage patterns. s tates and districts. Each map is unique in its design. (iii) Geological maps represent rocks that f orm the crust of the earth. towns. climatic and economic conditions of diff erent regions of the earth. These maps broadly show v ery large areas like world as a whole.Types of Maps Maps are of different types. plains. Based on the scale. Dehradun. The city maps may also be includ ed in this category. (iv) C limate maps show average condition of temperature. (ii) Topographical Maps: These maps are also prepared on a fairly large scale. (ii) Chorographical or Atlas Maps: The Atlas maps are draw n on a very small scale and give a highly generalised picture of the natural and cultural aspects such as the physical. means of transport and communi cation like roads and railways.000 sca le like the ‘Times Atlas of the World’. varying from 16 cm to a km to 32 cm to a km so as to fill in all possible details. drai nage. etc. Principal topographic features depicted on these maps are relief. con tent and construction and hence.000. They are based on precise surveys conducted by the Survey of India. According to purpose or theme . Small Scale : These maps represent large areas on a small sheet of paper. (i) Wall Maps: These maps are generally drawn boldly so that they can be seen from a distance. there are two br oad categories of maps: • Large Scale. Maps are broadly classified o n two bases: scale and purpose or content . pressure wind and . The village maps of our country may be cited as an example of large scale maps. 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. 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.The Cadastral maps are drawn to register the ownership of landed property by demarcating the boundaries of fields. 000 or more depict only the broad topographical features . As a result of this each specialised group of map users s ets up its own standards for classification. (i) General map s on a scale of 1:1. (iv) Social maps depict elements like language. maps hav ing a scale 1:50. which may range from a day to a season. direction. All maps have some common elements. They are used by the Defence Services for general planning purposes. (v) Land utilisation maps exhibit the character of land use. those falling betw een 1:50. (i) Economic maps show distribution of important minerals.000 are often classified as str ategic maps. and conventional signs and symbols.000 and 1:1. wind and precipitation over a short period.000 or less are called tactical maps. (iii ) Maps with a scale of 1:500. (ii) Political maps show boundaries between different countr ies and states within countries. ethnic groups and religion. The same person may consider a map to be of large scale for one purpose but of small scal e for another purpose.precipitation of the world or part of it over a long period of time. As a matter of convention. They serve as guides to small units like battalions and patrol units prior to and during move ments anywhere near the front line.000 are treated as small scale maps.000. caste. (vii) Weather maps denote the average condition of temperature. (viii) Astronomical maps show the posit ion of stars and planets in the sky. (v) Natural vegetation maps show natural flora of an area or region.000 upto are classified as large scale maps. It is an important element of a map becau se it gives relative picture of the ground reality. (iv) Photomap is an air photograph with stra tegic and tactical data superimposed on it. (ii) Maps having scales ranging from 1:1. ma ps are generally classified into large scale and small scale. They help in assessing economic development and potential of the area covered by the map. As you have read earlier. Scale Scale is the relationship between the distance on a map and the real dista nce on the earth’s surface. may appear to be small or medium for others. What o ne considers to be large. there is no universally accepted standard for classifying maps according to scale. (vi) Soil map exhibits various types of soils covering the area.000. However. and lines of transport and commu nication. It may be expressed as a representative fraction (rati o). Location and distribution of various features and phenomena are depicted using d istance.000 as medium scale maps and those having scales above 1:1. agricultural and industrial products. (iii) Historical maps show the past events and facts. The million sheets of the Survey of India and the National . (c) Milit ary Maps Maps used by Defence Services are called Military maps.000. a line scale or a statement scale. pressure.000. These maps are used for planning concentrated military action. (b) Cultural Maps These maps show the man-m ade features or human aspects.000 to 1:500. then the scale of the map would be 1 cm to 10 km. However. The scale has the advantage that it remains true even after reduction or enlargement of the map. The map can be reduced or enlarged without chang ing the R. For example if two points lo cated 10 km apart are shown 1 cm apart on a map.Atlas of India are considered to be medium scale maps. it is useful only to those who are familiar wit h the particular unit of measurement. Besides. As such. Methods of Expressing Sca les The scales can be expressed in three ways: 1.F. the scale will not be the same when the original map is red uced or enlarged. 1 cm = 10 KM MAP DISTANCE _______________ GROUND DISTANCE = . This means that 1 cm on the map corresponds to 1 km on the ground.F as given below. Suppose. 3. 2. is that it can be used universally irrespective of the local u nit of measurement of distance. The bases are divided into a number of equal parts and are marked to show what these divisions represent on actual g round. For example 1:1.000 units of distance on the ground.F. The scale is written as 1 cm to 1 km. The advantage of R.000 means one unit of di stance on the map corresponds to 1. this method is not very useful. A general definition of scale is that it is a ratio between the distance on a map and the corresponding distance on the earth. Statement: The scale may be in dicated in the form of a written statement.000. The base is calibrated to express visual equivalents of representative fraction or verbal scale. it is difficult for those who are not familiar with the unit of measur ement used. It is expressed as a ratio o f map distance and ground distance. Distances on the map are smaller than the corresponding distances on actual grou nd. Linear Scale or Graphical Scale: This scale is expressed as a ho rizontal or straight line. Scale is the means which enables us to reduce the whole or a part of the ear th to a size which is not only convenient and handy but also logical and scienti fic. It may also be converted into R. Although it is simple to express in words. For example 1cm on the map represent s 1 km on the ground.000.F.): It is also called as numerical scale. Representative Fra ction (R. place one end o f a thread at the starting point and carry the thread along the line. as e xplained earlier.) Methods of Measuring Linear Distance Linear distance on maps are of two types: ( i) Straight lines like roads. but the measurement will be less accurate. . It can also be done with the help of a strip of paper. 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. It will give appr oximate distance. and canals. showing streams. (c) Rotameter is an instrument having a route measuring wheel. coastline etc. It can also be measured with the help of a plain divider. (ii) Curved or Zigzag li nes. Open a pair of dividers and place o ne of its legs at one end of the straight distance and the other leg on the othe r end on the map.000 cm = 1: 1. the distance can be measured with the help of a divider. (a) When the line is straight.000 (Note: 1 km has 100. After comp leting the distance stretch the thread and measure the length. Distance between two points is measured by allowing the wheel of the rotameter to move along the route.1 cm _____ 10 km = 1 cm ____________ 10 X 10.000.000 cm. railway line. A map must have the base directions represented on it to enable the user to locate different features with respect to each other. Review Question s 1. Write short notes on: (i) Wall maps (ii) Linear Scale (iii) Base direction line. A rough estimation of direction of the true north can be obtained by the Means o f an ordinary watch. (iv) What is a cadastral map? (v) What are cardinal points? 2. south.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 commo n base direction. east and west are the four major directions. 3. The signs and symbols include lines. The line pointing to the north is regarded as the zero directi on or base direction line. A similar exercise in the southe rn hemisphere will indicate the true north. In between cardinal points one may have several intermediate dire ctions. 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 s mall scale maps? Give two examples of small scale maps. In the northern hemisphere if the watch is held in the hori zontal position and turned until its hour hand points to the sun. 4. Nor th. This is also a crude method dependen t upon the sun . Land use Colour Cultivated area Yellow Forests Dark green Gr asslands Light green Built up area Brown Water features Blue . shadings and colour s. Legends Every map contains a legend or a key. As a convention. 5. Describe various types of maps and their uses. specific colours show certain area features. What are the different wa ys of expressing scale? Explain the merits and limitations of each method giving suitable examples. As you know various types of features or phenomena are represented on maps. In how many ways the earth can be map ped and what factors determine the amount of information given in a map? Discuss . the line that bisects the angle made by the hour hand with the line joining 12’O clock through t he centre of the watch will point to the south. They relat e to both land and sea and are shown with the help of conventional signs and sym bols. These are also called ca rdinal points. It lists the feat ures and the signs or symbols used in the map for showing these features. icons. alphabets. (Ponds. lakes. oceans. seas. . rivers) You will know about conventional signs in d etail in the chapter on study of topographic maps. •Hence town shows well developed. broken ground s.natural and man made features by mea ns of conventional signs(legends). pack tra cts. •Causeways are raised plat forms across a dry stream. people mak e a habit of crossing it. islands (in the expo sed river beds). •Presence of many causeways sh ows that the area gets seaso nal or scanty rainfall. trees. mines. queries. unlined wells. Means of Transport in Relation to Relief •Transport always depend on the type of relief and drainage •Eg. natural ponds. unmetalled roads. depresions (Dep). shown by contours and their heights. permanent huts. streams. a footway is formed. contours and pictorial diagrams in convention al colours. waterfalls. •Main towns. mountaineous areas-only roads and no railway tracks. physical features like hills. post offices. •During dry season when the stream dries up. Very high altitudes . jungles. metalled roads. cart tracts. •Thus.difficult to build at suc h heights •On the map-roads are shown by means of symbols of cart tracks. causeways. boundaries (national an d international). pack tracts. spurs.Interpretation of Topographical Maps (Part 2) Man-made and Natural F eatures •Toposheets shows various details of an area. footpaths with a bridge. •MAN made features – surveyed trees .Chapter 4 . •Natural features – rivers. artificial lakes with embankments. . police chowkies and inspection bungalows. metalled and unmetalled roads. sand features. river valleys and cliffs.well connected by metalled roads show economic devp of the area-is the indication of trade being carried on. . . •Directions are important for ph ysical as well as urban features. stream s.important tool while reading topo map. •Urban cities from one another DIRECTION-TO RIVER AND RIVER BANKS .directions of rivers.DIRECTIONS •Directions. •Physical features. one has to locate the source of the river. Protected Forest (PF). Having located the direction of the river. dense mixed . Reserved Fores t (RF). each grid (square) 2cm X 2cm or 1 km to 1 km as per the scale 2 cm=1 km •Therefore . open-mixed forest. different terms used: •Dense forest.e.•Need to know which direction river flows. area can be calcualted as follows: -Note t he number of completed squares -Squares covered half are taken as ½ -Squares cover ing 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 s um is multiplied by the scale of the area given out above to obtain the desired area.000. fairly-mixed jungle.First look at th e spot heights to determine the slope of the land 2. this can be expressed as Area of each squa re (i. •To show density of wooded area. Calculation of Area •Area= Length x Breadth •In topo maps.000 sq m. mixed jungle. LAND USE •IN topomap location of veg is closely related to relief. imagine yourself standing at the source of t he river facing the main river facing the main river. fairly mixed jungle with bamboo. •REMEMBER THESE STEPS: 1.To know which side/bank of t he river a place is situated. area of each square is 4 sq cm (on the map )= 1 sq km (on the ground) In metres. dense-mixed jungle. •In the highlands. 4 sq cm) = 1000 X 1000 or 1. Now to your right is right bank and to your left is the left bank. vegetat ion is shown –green colour along with contours in brown showing elevation. To calculate the area by grid square method: If there are some incomplete squares. op en jungle. no cultivation is possible. dry ponds. ponds.cultivable land is shown in yellow colour •White patch in plain shows bad land or rocky. artifical lakes withj embankments and river in cas e it . exposed river beds and broken land shown in b lack indicate an area with scanty rainfall or seasonal rainfall or a desert regi on.jungle with bamboo. SHEET ROCKS:-•Sheet rocks – a region mostly covered with a sheet of rock. It is common in the desert area and in the areas of gully erosion . hence there is no need for irrigation •On the fla t lands which are coloured yellow.This is formed due to floods which occur during rainy season. •Br oken ground – developed because of absence of natural vegetation on both the banks of the river. – therefore one can say that the main source of irrigation in such areas are wells and the occupation of people is farming. uncultivable land. the top soil is washed away developing into bad land which has loose soil and is uncultivable. THE PLAINS:-•Plains-mainly agriculture. •A disappearing stream shows a desert or limestone area •Presence of canal. round spots which represent perennial lined wells. fol lowing features are found•Open scrub – scrub land where mostly sheep and goat rearin g is practiced •Stony waste – the land which is mostly covered with rock boulders an d stones and cultivation is not possible. •Other means of irrigation are canals. •In such land. •Settlements are generally found on either side of river-wherever irrigation b y canals or perennial lined wells is available MEANS OF IRRIGATION •Irrigation largely depends on relief and land use pattern of area (blue) •Hilly reg ion. •Rock outcrop – In such region subsoil is exposed and cultivation is not possible. tube wells and tanks indicate use of land for agriculture by me ans of irrigation •A meandering river shows a flat area •Perennial lined wells indic ate a higher water table and are shown by blue dots. •The exterior boundaries of areas of Reserved or Protected for est are shown by green ribands . LOW LANDS:•Plains which are situated at lower level are mostly characterized by a meandering river. wells. one can see blue. •Presence of dry streams. Because of floods . l arge settlements near roads and railways. ports. . grasslands. 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: Ha churing are short lines representing directions of a slope. etc – dense settlement Entertainment & Cu ltural devpmnt Gold Courses. etc Industry Factory. certain names like ‘farms’. Rifle Ranges. For steep slopes the y are drawn closer together than for the gentle slopes. ‘orchards’ p rovide some evidence of these occupations. lime stone beds Trade Se ttlement near main roads. •Presence of dry streams and dry ponds with uncultivable lands shown in white indicates that the rainfall in the area is scanty. pastures Quarrying and mining Mines and Quarries. OCCUPATIONS •Occupations have to be inferred from toposheets as there are no symbo ls to show the occupations of people. etc Tour ism Hotels and Inns •Thus. rivers. •The following list gives you some info rmation about occupation of the people from a topo-sheet. mines. rivers. However on flat ground. presence of raw materials (lime making and cement industry near limestone beds) Fishery Coast. they cannot be used. •Sometimes. OCCUPATIONS EVIDENCES Forestry.l akes. Parks. lumbering Forest or Green Patch Agriculture Yellow Patch or orchards w ith many wells Cattle-grazing or sheep rearing Meadows or Scrub. mea dows.is perennial. •Presence of artifici al man-made lake with embankment shows that water is being stored in off season and is used for irrigation through canals. . f or example ●340 TRIANGULATION POINTS: When the spot heights are accurately surveyed . the dot is enclosed within a triangle and are called the triangulatio n points. These are represented by a number preceded by a dot.SPOT HEIGHTS: Spot heights are used to provide more information about land surfa ces between the contours. i suppose u understood. After having a quick glance of thetoposheet. you see river Sipu. Can you see R. we can see some spot heights too. Make a mental picture of th e toposheet with prominent symbols. Can you see a cart track (red line)? We can a lso see perennial wells (blue).Interpreting Toposheets Hello. Divide the toposheet into 4 quarters.F.Therefore the comapass direction is north-east from Gangudra. Contour interval of this topos heet is 20 metres.F. Keep a pencil ready to mark few features. yellow wash. What s the contour interval of the topo sheet? Check the contour interval near the scale. For example what features do you see in the A Corner???First of all.F. little bit of green forest on top of A corner. Good.For the bigger view of the toposheet. go through the B corner and C corner and D corner. Rajkot is in grid square 8995 and gangudra is in grid square 8793. It means 2cm on the map is equal to the 1km on t he ground. For example North west corner (A). The scale is 2cm to 1 km. click on top of the picture. Did you spot stony waste (8596)? In the same way . . open scrub.F.000. Study the each quarter.? You can see at the bottom right. First read the other questions and then come to the toposheet which requires more time to read. See the features of this toposheet.(usually it is 20 metres) What else can you see? Ok. is 1:50. let s do the direction which i have explained to you earlier. I have already explained to you how to writ e R. Imagine you are in Gangudra and you want to go to Rajkot from Gangudra? First of all. in the earlier lesson. which is east direction. read the questions that are asked. R. a few nucleated sett lements. North East Corner (B ). South West Corner(c) and South East Corner (D). Find out what is the direct ionof Rajkot lie from Gangudra? First of all. can you see the scale? You can see almost near the R. You have 15 minutes to read the question pap er. because two rivers flow towards south west whichis an indication of the slope. you hv to go up which is north and then y ou have to turn right. Do you follow? Where do you find the lowest part in the toposheet? The south west corner is the lowest part in the map. Go through it again. Can you see the shape of the river? Thin lines that join the main river. pack tracks. Read the text book regarding the dra inage pattern (if you have not understood) There are three drainage patterns . Plus it has many lined wells for irrigation purposes. cart tracks. its is A CORNER. Broken ground is caused due to e rosion during rain when the river is in flood. What kind of ra infal this area gets? check the rivers-we can see broad sandy bed exposed. So the man-made features are temples and permanent huts. It has a broad sandy riverbed which is exposed. jungles. trees. So. In the exam. Go and locate that grid square and follo w the points that I have told you. Can you see the irrigat ion facilities or source of water? We can see the river which has narrow blue li ne which means it is perennial even though the river is seasonal. Can y ou see them? From this we know that the occupation of the people of that area is cultivation and stone cutting or extraction of limestone. It usually heappens in the area w here there is no vegetation/plants. So the people can cross the river durin g summer. We also see many cart and pack tracks passing the river. Then we also c an see the perennial wells. If you didnt understa nd. T herefore. Jigol is better off than other settlements. It is a clustered settlement too. lined wells.check the spot heights in the map. (in blue) several cart tracks. It also has a thin water channel in the middle of the river. nuclear/compact/clustered. So what is broken land? Broken land gives rise to Bad land topography. perennial wells (Blue dots). Let us study the occupation of Bhadli (Jhat) . a thi n water channel. go to the text book and looks for the symbos of sa ndy bed. We can see many cart tracks leading into the village. You will see it in my blog too. Sometime they will give a grid square and ask to you to mention one ma n-made feature and one natural feature. The rive r or drainage pattern is Rectangular or Trellised.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. These are generally found along the banks of a river. perennial wells and the p resence of lime kilns. you see the sandy beds and cart and pack tracks passing the river. You can se e all these in this map. See the settlements on the map: What type of se ttlement do you find? Ofcourse. S ee the area around the town Gangudra. they are decreasing towards south west. and a pack track. the river doesn t have much water in the summer season and so the rive r dries up. my eyes are not very sharp.we can see few temples in the toposheets and permanent huts. As I have tol d you. There is a river. islands in the middle of t he river. Therefore it is a seasonal river. Let us see the drainage pattern on the map. This shows tha t the area gets seasonal rainfall. read the text book on settlements and come back to the blog. Some time a question comes on the comparisio n of two settlements.We find broken ground ther e. Now let s s tudy the natural features . Let us stud y the river bed of Sipu. you select any two. Now let us study the village Jigol (grid square 8590) and other villages. Now let us see the occupation. The natural feature is river an d forest.check corner B . What are the conventional sighs near north east part of the toposheet near open mixed jungle? . Study the topo sheet closely. Let s study man made features .We can see rivers. I couldn t see any post office. This is indicated by the presence of agricultural land ( in yellow colour). mines. etc.grid square 8596. Study the river. I had told you about the occupations. What do you notice th ere? click the toposheet and check. Go beyond that.(Grid square 8793) See the drainage pattern around the area-dont see only in the grid square 8793. yellow patch(which means agriculture) and stony waste. Ident ify some spotheights in the map. It has good transpor t system in comparision with other villages.D endritic(Tree like or veins of a leaf) Trellis/Rectangle and Radial. Do you follow me? Since the river is dry.(it means the river gets water only i n the rainy season). . So two perennial source of water is the River waters and well irrigation. If you dont un derstand the sandy river bed. they will ask one or two man-mad e features. NOw you see whe re is the spot and give the grid reference. Hold the scale vertical and horizontal on that grid square and join them. Now u get 10 X 10 equal squares. you will find south west qurater of the map are decreasing towards the south west. This is four figure grid reference. Ok. So the south-west corner of the map exatract is the lowest region. Find four digit grid square is easy but the problem begins when you have to find 6-digit grid reference. get the mid point. We have done that in the beginning. Hope you know how to find grid squares . First take a ruler and place it on the horizontal line of that grid square(. When you are asked to locate the 6-digit reference. rememeber these points. let us see the 4-figure grid reference. Then place the ruler on the vertical line and find the mid p oint and join these mid points.4 figur e or 6 figure/digit grid reference. divide that square into 4 equal par ts. You can find the exact 6 figure grid reference by dividing grid squares into 10 blocks. After locating 4-figure grid reference. then it wil be above 5. now we need 6-figure grid refere nce. Ok. if you study the heights. then u get the mid point of easting and northing s. It is in the grid s quare 8992. First find the square. then u locate the spot in the grid square and if the spot is beoynd the mid p oint. They flow towards the south west.894925 . See also the rive r flowing. Look for t he spot heights in the toposheet. let us locate a place using 6-figure grid reference of a temple in the north east of Odhava. In which quarter of the map extract do you find the lowest area to be? Divide th e whole toposheet into 4 corners. Let us see the eastings first.. Now l et us to to the north-east of the map..It has a police station (PS ).see variou s features. a temple.e 0-99 on a toposheet it is written after every 100km. We have already found out the four figure grid refernce. Let us see the northings. Double click on this toposheet. Under the same fashion the whole world has been divided.. It starts frm the place where the equator and prime meridian meet and is named UA.. Now how do you find four figure grid refernce. It is in northing 94. etc.. The occupation in this area would be sheep or goat rearing.. Let us look at the Northern part of the toposheeet. You will also see Lime Kiln.. . Look at the town Panthawada.. Post Office (PO).. Here it i s the end of northings..Its presence shows the trade possibilities and the people working in it.W hat does it mean? It indicates desert or semidesert condition.. Can you see QC. We locate it in easting 82... Look at the triangul ated height of 224. well connected roads. QC means that there is end of numbering of northi ng or easting i..It is a furnace for baking limestone... (8294) Let us divide that . Thus the square is named QC.. So four figure grid reference of the triangulated height is 829 4. Let us study 6 figure grid reference.Interpreting Toposheets -2 Let us look at this toposheet. Let us first find out four figure grid reference... You will see the enlarged topomap..What is it? According to the international system o f location of a place the whole world has been divided into various squares..... What do you see over there? OPEN SCRUB.. perennial wells. Its in fi rst square. you mark one square. Can y ou see the broken ground? (I have marked in the toposheet) What is a broken grou nd? They are generally found along the banks of a river. .square (8294) into 10 equal squares as it is I have done in the toposheet. So first three figures are 821 and the second part is 941. For 6 figure grid reference. For every 2 cms. So six fi gure grid reference is 821941 or 822941. It usually happens in the ar ea devoid of vegetation. first 3 figures are of eastings and the sec ond part of the 6 figure reference is of northings. We have already know easting is 82. Broken ground is caused by erosion during rain when the river is in flood. Let us now find out the third figure from those small squares. So you will have 10 equal s quares. Look at it closely. Did you get it? I hope so anyway. 4. 3.000. BENCH MARK .g. 9 . For example at every 100 mts the contour line is made darker.000. CONTO UR INTERVAL: The interval between two consecutive contours is called contour int erval (*it is a constant 20 mts in your toposheets. SPOT HEIGHT: The height of random places between contours shown with a dot.. It is represented by th e height with a small ‘r’ eg –12r. joining all places with the same height above sea level. 10. 7.Height of a place actually marked on a stone pillar. The darker lines are c alled Index Contours. The RF on this map is 1:50. SCALE : Scale is the ratio between the distance of any two points on the map a nd the actual distance of the same points on the ground.) 5. E g .425 8. 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. . 2 . ROCK OUTCROP: It is a portion of rock jutting a bove the surface of the earth. The scale of the given map extract is 2 cm: 1 km or 1:50. represented by a small triangle e.Revision -Important Toposheet definitions IMPORTANT DEFINITIONS DEFINITIONS FROM TOPO MAPS REPRESENTATIVE FRACTION (RF): It is the ratio between the distances on the map t o its corresponding distance on actual ground. CONTOUR: Contours are imaginary lines drawn on maps. TRIANGULATED HEIGHT: It is the height of a place whi ch has been calculated using trigonometry. INDEX CONTOUR: Contour l ines are thickened at regular intervals to make it easier to read contours. It is written as BM 200 m. ro ck or shown on a building as a permanent reference. OD. FORM LINES: Form lines are contour lines. 20. All the or dnace survey maps issued by the Survey of India were drawn to the scale . 10. DENSE JUNGLE. SHEET ROCK: Large areas of rock where the overlying soil layers have been er oded and removed due to mechanical weathering. 16. Therefore it indicates a dry region. Q. 15. BROKEN GROUND: A relief feature found mostly in dry regions around rivers and streams. CUTTING: A portion of land. 14. 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. (it is indicative of a rocky region) 19. : A forest where trees grow very close to each other. The Govt of India has adopted metric system for all measurements. It is land around river. Hence they are drawn as broken lines and are called form lines . OC. 17. OPEN SCRUB: Scrub is a vegetation found in regions with less than 10 0 cms of rainfall. 11. CAUSEWAY: It is a raised road over a small water body. EMBANKMENT: They are raised rock or soil filled construc tions on which roads/railway tracks are built.. 12. which is totally weathered (exfoliated) due to alternate cooling and hea ting. Q.PQ. stones and pebbles. of 10. FIRELINE: A cleared pathway in a forest to prevent the spread of fores t fires. 13. Also made near tanks and rivers t o prevent flooding. MIXED FOREST: A forest with more than two varieties of trees growin g in close proximity to each other. ETC : These are alphabetical codes used to represent the biggest grid sq. 9 STONY WASTE : A large area usua lly in arid/semi arid regions where the finer sand/soil has blown away leaving a surface covered with boulders.} 18. (Usually a roa d used only in the non rainy months. OPEN JUNGLE: A forest where trees are wi dely scattered. 21.C.000 square k ms.11. which has been cut in order to make land available for transport routes. BRACKISH: It is a we ll. which has water with very high salt content – generally unfit for drinking pur poses.D. a technique called layer tinting was developed. the surveyed territory is divided into 100km X 100 km squares. DEP: It is a depre ssion often found in sandy areas where the wind. 26. HACHURING: Early cartographers attempted to sh ow surface features on maps by using the technique of hachuring. which is i deal for providing an overall view of the relief of an area. PQ. This system of map drawing is known as National Grid Reference. they only do so at certain points. lea ves a hollow or a depression. HILL SHADING: Hill shading resembles a light and shadow effect. OC. 23. howev er. Hill shading. Hachures use sh ort lines of varying thickness to show the shape and slope of the land. it does not show the detailed shape of the land. This is a visually striking method. To provide an overall image which conveyed he ight. When using layer tinting. Layer tinting is most commonly found on physical maps. While layer tinting is useful. LAYER TINTING: (colouring) While spot heights show the height of the land. the steeper the slope is. Layer tinting uses differe nt colours (or shades) to represent different heights. In accor dance with this technique. the thicker the lines are w hich represent it. LIME KILN OR BRICK KILN: These are open furnaces where limestone is purifi ed or bricks are baked for construction purpose. PG. and each square is denoted by English alphabets. for example. . green is often used for low land. etc . It is a mapping conventio n for darker colours to signify greater height. In this system . 24. having blown away the sand.2 cm = 1 km. While hachuring was initially innovative for its time. it gra dually began to be replaced since the actual height of the land was not depicted . does not show height which means that it is no more accurate than hachuring. Valleys and the sides of mountains appear a s though they are cast in shadow. 22. yellow for higher land and brown for the highest lan d. O D. 25. .) Ans: The chief form of irrigation is perennial well-irrigation. tanks. (look for sandy soil . many .. Barren land shown in white colour also indicate tht the region has seasonal rainfall. Give one reason to explain wh y the steams in grid square . park. lakes.Mention ay two features seen in the map extract which indicat e the region has seasonal rainfall. water falls. Rivers. Presen ce of blue circles scattered all over the map .(look for various t ourist destinations like temple.. et c)Ans: The region is densely forested. rainfall.. deserts. then the rivers. sunset points. then you can write your answer t his way. lack of roads. select any two features th at you find on the topo sheet and write this way) Ans: Open scrub and seasonal s treams are two features in the map that indicate the region has seasonal rainfal l. lakes. etc an d then write answers) 3.. do not join a river. steep hills.Mention any three f eatures seen in the map extract which attract holiday makers. For example. etc)Ans..Seasonal streams/ Broken ground/open scrub/se asonal tank/cart track motorable in dry season/narrow perennial channel in the d ry bed of the river(after looking for these features. 2. Reasons for streams not meeting the main river due to:* pre sence of sandy soil which is porous * poor rainfall * high rate of evaporation.. open shrubs. State two reasons for the absence of human habitation in some regi on of the map extract.( check for any features that is not suitable for human ha bitation – like dense forest. 4.. if you fin d the presence of many blue circles in the map. look for these points in the toposheets and can writ e these answers: 1. Which is the chief form of irrigation shown in the map extract? Give somE evidences to justify your answer. (any two ) 5. etc and give answer. steams and ponds/tanks are dry in nature.(look for perennial wells fi rst.Some Common Questions Based On Toposheets If you get these questions. 11.loo k for dense jungles. 9. What will be the main occupation of the people be in i. (look for features like s and dunes disappearing steams. broken grounds.)Ans: The area has dense jungles. The region has poor ra infall due to the •Presence of sand dunes •Presence of undefined and disappearing st reams •Presence of scrub vegetation •Presence of broken grounds 10. or many streams – and then answe r according to the features. * temples are the only destinations in the forested mountain region and h ence foot-paths are created by the pilgrims. steep hills and no important settlement. If you fin d these features. Why are there no metalled roads in the mapped area?( reasons may be many. Lowland s?i.The reasons for the presen ce of foot-paths are: * seep and rugged terrain makes construction of roads diff icult. or barren land.steams and barren land discourage the building of metalle d roads. * footpaths may be created by peopl e who depend on forest produce. or a temp le in the .streams with very steep hills. highlands ii. Why do so many contour lines so close togeth er in the extract indicate about the topography?(look for steep hills. 6.agriculture 8. scrub vegetation. Expensive to build roads. Lowlands . Give evidence to prove poor rainfall in the region. then you write the answer this way)Ans. etc. steep hills. Give two reasons for the presence of only footpaths in the green wash. What is the small wh ite patch in the river?Ans: Barren island 7. highlands – collection of forest products ii. .what type of climate do you find in the particular area .)Ans: Very steep (indicated by close contours) and hilly (indicated by many contours) land.. 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 .. we cannot know about the occupation of the residents. scanty v egetation.. sand dunes and scrubs and scanty vegetation. This gives us a faint idea about the part of the country and the type of climate prevailing there. (if you find dense forests. or dry tanks or sannd dunes.. How can we draw a climatic inference from a toposheet? (there may be a quest ion . 12. scrubs. then your answer will be ) The area experinces Tropical Monsoon climate... look for these features.. dry tanks. Directly from a topo sheet. Therefore one must know the colours and what it indicates. Further.. all of you know that yellow colour i ndicates agricultural land and hence agriculutre can be major occupation.. We can amplify the occupation by inferences provided on the toposheet..jungle and if u find these..) (If you find dry rivers... For example. we should try to k now which area of the toposheet belongs to. Similarly dense forests indicate tropical monsoon climate.. scanty a mount of rainfall can be judged by seeing dry rivers.look for these f eatures and then write the answers accordingly -First of all. then your answer wil be) The area experiences scanty rainfall or poor rainfall with dry weather. Green colour shows forested or wooded area and this . Questions on occupation 13.. . indi cates that people must be employed in urban services. look for these features and write the answer according ly. my dear students. which is not much s uited for cultivation. How can you judge the suitablity of land for agriculture from toposheets? gi ve a good reason. forestry may be a predominant economic activity in this region .. Thus. railway station. industrial area. etc. parks. a meandering river on the toposheet will indicate a lower or n il gradient. then the occupation will be sheep and cattle rearing. for example if you find grassy area or open shrubs. What occupations do the people follow in Highland areas? Ans: High land regi ons with steep slopes have the following features: most of the slopes are unsuitable for agriculture. if you find grassy area. Rest houses in hilly areas show devp of tourism.. recre ation. etc. tanks. cultural devp. Pastures on the slopes may be fit for grazing. lawns. Settlement along roadside indicates devp of trade and commerce. historical monuments indicate occupations like tourism. such a plain area would be suitable for cultivation. Dendriti c or tree-like drainage pattern would confirm soft surface suitable for agriculu re wheras trellised drainage pattern suggests chalk country. flat area over plateaus may be used for cultivation. etc. when you get a question on the occupation of the people.indicates that people follow in lumbering. So. ) 14. carpentry and bambo o work. If you locate wells. show the cultivation of cash or cereal cr ops. then it indicates sheep or cat tle rearing. furniture making. 15. etc. may suggest that some people are employ ed in mining activities. Presence of big towns. symbols of mines. I hope you got me. canals. (mention. limestone.. Silt deposition b y rivers is a good sign for agriculture. etc due to th e presence of Kiln in the area. your answer will be like this. network of canals. south. if you find yellow wash. etc. agriculture is the occupation of the area. These conditions are unsuitable for agricultu re.. If you find irrigation from wells.) Ans: Farming and forestry seem to be the two occupations in this area because a large part of th e map has yellow wash which symbolizes cultivated area.. green colour. pottery. POINTS TO REMEMEBR REGARDING OCCUPATIONS: If you find KILN . then the occupation is quarring. canals or tanks. which are the main occupations of the people in this area? give rea sons in support of your answer. so look for these fea tures on the toposheet and write accordingly. A large number of perenn ial wells present in the area also support this inference. perennial wells.g..kilns on the toposheet. farming is the oc cupation. or north. For example.Sand features. then the occupation will be drying and baking bricks. dams. west or east) wh ich is indicated by green colur which suggests forestry as an important occupati on there. pottery. presence of kilns shows that lime and brick making is also an occpatio n of some people. ( if you see yellow wash. barkhans and disappearing streams would indicate the dry con ditions with the high temperature. tanks and tube wells will indicate intensive use of land for agriculture. if you find STONE QUARRY. Some part of the map shows presence of open jungles. presence of broken ground would confirm seasonal flooding. .. So you write the ans wer this way: The occupation is drying and baking bricks. e.. there may be primitive agriculture. Second part of the question imagine you see figure 280 m . if you find large settlements. then fish ing is an occupation of that area. What are the brown lines seen in such abundance? What do they indicate? (same answer as question 16) ans: They are contour lines.. if you find settlements along the banks of the river.. then the people are dependent on forest products like fruits. in case they are headquarters o f districts. 17. What is the brown line in grid square . or leaves . Closeness of the contours indicates moun tainous topography.if you dont find any source of irrigation.. if settlement is near the forest(green colour ). services.... mining is the occupation if you find settlements near mi nes or quarries. employment can also be in administrative sector because of the presence of large number of offices and organisations... esp near the metalled roads.) Ans: The brown line that we find in grid square is Conto ur line. then it is a cont our. the occ upation can also be industries.. 16. taluqs. write this w ay: people are dependent on forest produce or foresty and may practice primitive agriculure. What is a causeway? Why are there so many causeways in t he map? Ans: Causeways are land raised across streams for use as metalled . so when you write the answer.. it means farming is likely to be depe ndent on rainfall only. then it means 280 m above sea level... so please go through the toposheet properly since one question will be definite on occupation. They indicate lines joining places having the same height above sea-level.. nuts. The line 280 m joins places 280 m above sea-level on the map. 17. trade.. called? What does the fi gure written aong this line indicate? (if it is a brown line . * Contour lines * Layer C olouring/tinting * Spot height * Hill shading.road or paths. 22. . Name the geo graphical feature represented by white patches in the middle of the river. 21. What is cartography? Cartography is an art and science of drawing maps. Black broken lines indicate d isappearing stream and black curved lines indicate broken ground. What do the following represent in the map ? i. i. Ans: Depression is a shallo w lowland in a sandy region often created by deflation of wind. Black curved lines. Name 4 methods by which relief is shown on the map. 20. 19. What is layer-tinting/colouri ng? It is a method. The numerous streams crossing the metalled road are likely to flo od them. Explain the term Depression in the map. where a colour scheme is used to show relief on the map. 23. 18. Ans: The geographical feature in the middle of the river represented by white patches is an island or rocks or stores. Black broken lines ii. diagram s and charts. . hill. bridge.. 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.... f or example 2r. or river canal.. COLOURS: 7 COLOURS are used on toposheets: ..(if 3r is written near the symbol of perennial well.. 6r..... or it can be depth of a well. 3r. sand dune..POINTS TO REMEMBER: RELATIVE HEIGHT OR APPROXIMATE HEIGHT: REMEMBER:-This height is not taken from t he sea level but with respect to the surrounding area. .. It may be height of a dam .... tank...... (if 16r is written near the symbol of sand dunes) 8r the relative hei ght 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 .. Example: ●3r the relative depth of the perennial l ined well is 3 metres........ etc.. 5r. cart tracks. and then you will know which way or direction it slopes. stony waste vii. BROWN: Contour lines. settlements. WHITE PATCHES: uncultivated and barren lands DIRECTIONS Directions are important for physical as well as urban features. railway mines. their number ing. their numbering. the physical fe atures involve the directions of rivers. GREEN: Fore sted and wooded areas. broken grounds. settlement. etc v. imagine yourself st anding at the source of the river f acing the main river. huts and other buildings. telepgraph lines ii. As you know. surveyed trees. form lines. river banks. BLACK: Names. and if you see a river . etc)one has to locate the sou rce of the river. Having located the direction of the river. dry rivers. and the urban cities from one another. scattered trees. town. orchards iv. heights and their numbering. spot heighs are ma rked this way ●265 ●289 see which spot heights are higher and where it is lower. roads. the slope of the land may be from north east to south west. streams. first of all. rivers. lines of latitudes and longitudes. look at the spot heights to determine the slope of the land.i. scrubs. the following steps should be observed. to . RED: Grid lines (eastings and northings) . s and hills. all sand features like sand dunes. BLUE: Water bodies containing water like wells. iii. telepho ne. When a question is asked regarding the banks of the river or direction of the river. then it flows from no rth-east to south-west. to know on which side or bank of the river a place is si tuated (a place may be a temple. YELLOW: cultivated areas vi. A legend is printed on the map margin to indi cate the elevation range represented by each color. FEW IMPORTANT TERMS: A. some times the questions are asked on the direction of a ci ty or settlement with a reference to the other. SO SIMPLE. this method does no t allow the map user to determine the exact elevation of a specific point—only the range. Shaded Relief.your right is right bank and to your left is left bank. but a re mainly used to show large. Form lines are not measured from any datum plane. Form Lines. the steeper the slope. However. pay attention to t he words FROM a place and TO a place. Shaded r elief is sometimes used in conjunction with contour lines to emphasize these fea tures. d. b. broken lines used to show relief. A differ ent color is used for each band of elevation. Form line s are represented on a map as dashed lines and are never labeled with representa tive elevations. or band. Form li nes have no standard elevation and give only a general idea of relief. rocky . Imagine yourself standing on the FROM PLACE and look at the TO PLACE. First of all. Layer Tinting: Layer tinting is a method of showing relief by color. BOSS!!! when a question is askend on directions with reference to urban cites/settlements. They do not represent exact elevations. Hachures are sometimes used with contour lines. re member these points. Hachures are short. Relief shading indicates relief by a shadow effect achieved by tone and color that results in the darkening of one side of terrain features. repr esents a definite elevation range. c. Each shade of color. Hachures. Use the direction arrow and write the directio n. s uch as hills and ridges. The darker the shading. These lines are finer and do not have th eir elevations given. All points on the contour line ar e at the same elevation. plateaus. . (3) Supplementary. (2) Intermediate. The contour lines falling between the index contour lines are called intermediate contour lines. such as o n fairly level terrain. and mountain peaks. Starting at zero elevation or mean sea level. each inde x contour line is numbered at some point. These li nes are normally found where there is very little change in elevation. These are known as index contour lines. every fifth contour lin e is a heavier line. e. Contour Lines. above or below sea level. Contour lines are the most common method of showing relief and elevation on a standard topographic map. Normally. The elevation represented by contour lines is the verti cal distance above or below sea level. These contour lines resemble dashes. Th ey show changes in elevation of at least one-half the contour interval. A contour line represents an imaginary line on the ground. (1) Index. This number is the elevation of that l ine.outcrop areas. There are normally four intermediate contour lines between index contour lines. Hachures are used extensively on small-scale maps to show mountai n ranges.