मराठी

Revision: Practical Work and Project Report >> Study and Interpretation of Topographical Maps Geography ISC (Arts) Class 12 CISCE

Define transport.

Transport is the movement of people, animals and things from one place to another.

Key Points: Conventional Signs and Symbols used in Topographical Maps

Conventional signs and symbols are standard signs used to show features on topographical maps.
Colours have fixed meanings: red–man-made, blue–water, green–vegetation, yellow–cultivation, brown–relief, black–names and boundaries.
Buildings and settlements are shown by specific symbols such as huts, temples, mosques, churches, and tombs.
Transport features like roads, railways, bridges, passes, and causeways have separate symbols.
Important facilities such as post offices, hospitals, police stations, power lines, and quarries are shown using symbols.

Key Points: Interpretation of Topographical Maps

Introduction: Gives marginal details like sheet number, scale, year and grid reference.
Relief: Shown by contour lines; wide spacing = plains, close spacing = mountains.
Drainage: Shows rivers, lakes and drainage patterns (dendritic, radial, etc.).
Vegetation & Climate: Type of forests helps to guess rainfall and climate.
Population & Settlements: Size and pattern of settlements show population density.
Transport & Irrigation: Roads, railways and canals show development and farming support.
Occupation & Future: Land use tells main occupation; transport and industries show future growth.

Key Points: Development of Topographical Maps in India

Beginning – Scientific topographical mapping in India began in the 18th century. The Survey of India was established in 1767.
Triangulation Survey – Systematic mapping started with the Great Trigonometrical Survey under William Lambton and Sir George Everest.
Survey of India – Headquartered at Dehradun, it expanded mapping work across the country and produced detailed topographical maps.
Indian & Adjacent Countries Series – Maps drawn on 1:1,000,000 scale; each sheet covers 4° latitude and 4° longitude.
International Series – Based on 1:1,000,000 scale under International Map Projection; covers large parts of the world including India.
World Aeronautical Charts – Prepared for aviation purposes on 1:1,000,000 scale.
State & General Maps – After 1956, Survey of India prepared state maps (1:1 million scale) and other general maps like road, rail and tourism maps.

Key Points: Nomenclature and Numbering of Topographical Sheets

Base Series – Topographical sheets are based on the India and Adjacent Countries Series (1:1,000,000 scale). Each sheet covers 4° latitude × 4° longitude and is given an index number.
Quarter Inch / Degree Sheet (1:250,000) – Each 4° × 4° sheet is divided into 16 parts (1° × 1° each). These are called degree sheets.
Half Inch / Half Degree Sheet (1:125,000) – Each degree sheet is further divided into 4 equal parts.
One Inch / Quarter Degree Sheet (1:50,000) – Each degree sheet is divided into 16 smaller parts (15′ × 15′). These are called 1:50,000 topo-sheets.
New Series (1:25,000) – Introduced later; each 1:50,000 sheet is divided into 4 parts. These maps show greater detail and have smaller contour intervals.

Key Points: Conventional Signs

Conventional signs are symbols used on topo-sheets to represent different natural and man-made features on the ground.
These signs are not drawn to scale. They are only symbolic and help in giving clear and quick information.
Conventional signs are internationally accepted and make maps easy to read and understand.
Different colours are used to show land use:
Yellow – Cultivated land
Dark Green – Forest
Light Green – Grassland
Brown – Uncultivated land
Red – Built-up areas
Blue – Water features
Black – Railway lines
The Survey of India uses standard conventional signs to represent features like roads, rivers, railways, wells, temples, boundaries, forests, etc.

Key Points: Study and Interpretation of Some Selected Topographical Maps

Scale & Area: Survey of India sheets; Hisar (plain), Mirzapur (plain + plateau).
Relief: Hisar – flat plain; Mirzapur – Ganga Plain & Vindhyan Plateau.
Drainage: Hisar – no river, canals important; Mirzapur – River Ganga main river.
Vegetation: Hisar – very little (semi-arid); Mirzapur – farming plain, forested plateau.
Settlements: Hisar – rural compact villages; Mirzapur – irregular villages, few towns.
Transport: Hisar – few roads, no railway; Mirzapur – roads + railway + ferry.
Occupation: Mainly agriculture in both areas.

Key Points: Geographical Study and Interpretation of Topographical Sheet No.53H/3

Introduction: Published by Survey of India; scale 1:50,000; covers Delhi and Gurgaon districts.
Relief: Two regions – hilly area (200–300 m) and plain area (about 200 m); hills have steep slopes.
Drainage: No major river; small seasonal streams like Mehandwari Nadi; presence of tanks (Johars).
Vegetation & Climate: No thick forests; shrubs in hills; plains used for farming; semi-arid climate.
Settlements: Gurgaon is the main town; most settlements are rural and compact; hills are sparsely populated.
Transport & Communication: One railway line connects Gurgaon with Delhi; good network of metalled roads; post and telephone services present.
Irrigation & Occupation: Wells and tube-wells are main irrigation sources; agriculture is main occupation; some industries (e.g., Maruti factory).

Key Points: Nature of Occupation

Agriculture: Main occupation in the fertile Ganga plain due to good irrigation.
Lumbering: Done in forest areas of the plateau region.
Cattle & Sheep Rearing: Practised in grass-covered plateau areas.
Quarrying: Found in five places; people work in stone quarries.
Industries: Some industries present, like cotton mill (Mirzapur) and carpet factory (Khamaria).

Key Points: Means of Transport

Railways: Two railway lines – Northern Railway (main line) and North-East Railway (branch line).
Major Stations: Important stations are Mirzapur and Vindhyachal.
Metalled Roads: Mirzapur is the main road centre; important roads connect Lalganj, Robertsganj, Chunar, Jaunpur and Allahabad.
Unmetalled Roads: Kachcha roads connect smaller villages to main towns.
Water Transport: River Ganga is used for boat transport and has ferry crossings.