- Relief refers to the height, slope, and shape of land such as mountains, plains, and plateaus.
- Landforms have three dimensions—length, breadth, and height.
- Maps are two-dimensional, showing only length and breadth.
- Special methods are used to show height and slope on maps.
- The main methods of relief representation are hachures, hill shading, form-lines, and contours.
Key Points
Key Points: Map Reading
- Map reading means understanding and interpreting physical and man-made features shown on a map.
- It helps in studying the relationship between natural features and human activities.
- Natural features include relief, rivers, valleys, waterfalls, vegetation, and wells shown using contours.
- Man-made features include roads, houses, places of worship, quarries, tunnels, and artificial lakes.
- Most features on topo maps are shown using conventional signs and symbols.
Key Points: Primary Information or Marginal Information
- Marginal (primary) information is the important information printed on the margins of a topo-sheet.
- It includes the sheet number, which shows the area of India represented on the map.
- Latitude–longitude lines and Eastings–Northings help in locating places and estimating areas.
- The map scale and contour interval show distance relationships and vertical height differences.
- Margins also show true and magnetic north, legend (symbols), and year of survey/publication.
Key Points: Representation of Relief Features
Key Points: Relationship Between Physical Features and Human Activities
- Physical features control human activities like land use, settlements, occupations, transport, and irrigation.
- Relief and drainage decide land use: plains support agriculture, mountains suit grazing/forests, and floodplains are highly fertile.
- Drainage patterns indicate conditions: dendritic = good for farming, trellis/limestone = poor farming, radial = highlands, disappearing streams = dry areas.
- Settlement distribution and type depend on relief and resources: dense in fertile plains, sparse in hills, forests, and deserts; types include linear, dispersed, radial, and nucleated.
- Occupations and transport are inferred from map features like mines, quarries, farms, roads, railways, rivers, and communication networks.
Key Points: Analysis of Topo-sheet No. G43S7
- Location: G43S7 lies on the Rajasthan–Gujarat border (Banaskantha & Sirohi).
- Relief: Aravalli hills, piedmont plains, and saline sandy west.
- Drainage: Banas river system; mostly seasonal streams.
- Climate & Vegetation: Hot, low rainfall, scrub and dry deciduous forests.
- Human activities: Rain-fed farming, animal rearing, settlements in lowlands.
Key Points: Analysis of Topo-sheet No. G43S10
- Location: Lies on the Rajasthan–Gujarat border (Sirohi & Banaskantha), near the Aravalli hills.
- Relief: Hilly region with Mt. Abu in the north and semi-desert plains in the west.
- Drainage: Sipu nadi system; radial pattern in hills and dendritic pattern in plains.
- Climate & Vegetation: Hot, low rainfall (50–100 cm); dry deciduous forests in hills and scrub in plains.
- Human activities: Agriculture in plains, animal rearing in hills, tourism at Mt. Abu, good road connectivity (NH-168).
Important Questions [3]
- Study the extract of the Survey of India Map sheet No. G43S7 and answer the following question: Mention two man made features seen in grid square 2706.
- Study the extract of the Survey of India Map sheet No. G43S7 and answer the following question: Mention two natural features seen in grid square 2905.
- Study the extract of the Survey of India Map sheet No. G43S7 and answer the following question: Calculate the area in kilometre square of the region enclosed between Easting 26 to 29
