Map Reading

UNIT: 8 Map Reading

Maps are the symbolic representations of an area, usually drawn on a flat surface. They present information about the world in a simple, visual way, teaching us about the world by showing the sizes and shapes of countries, locations of features, and distances between places.

Map

·         A map is a depiction or sketch of the earth’s surface or a portion of it rendered on a flat surface to scale

·         Maps provide a detailed depiction of a larger section of the globe

·         The plan is termed a map if the size of the graphical depiction on a horizontal plane is modest

·         For a small-scale reference, the map is created

·         Vertical distances like elevations are also indicated on a topographic map by contour lines

·         A map is created for big areas like the Map of the Region.

Types of Maps:

1.    On the basis of purpose:

a.     Topographical map

b.    Cadastral map

c.     Thematic map

d.    Navigational Chart/ Aeronautical chart

2.    On the basis of originality:

a.     Original map

b.    Derived map

3.    On the basis of scale:

a.     Large scale map

b.    Medium scale map

c.     Small scale map

Topographical map:

Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms. In context of Nepal topographical map of any part of Nepal is prepared by Survey Department.

A topographic map is a detailed representation of the Earth's surface, showing both natural and man-made features. They are essential tools for hikers, campers, geologists, engineers, and anyone else who needs to understand the lay of the land.

Cadastral map:

A cadastral map is a detailed map that shows the boundaries and ownership of specific pieces of land, also known as parcels. Cadastral system in Nepal is treated as part of the land administration process and does exist district-wise. In general, cadastral mapping, preparation of related document and the registration of the parcel are performed by the Goswara (survey party), Cadastral Survey Branch, Survey Department.

Thematic map:

Thematic maps are the maps which are dedicated to specific theme viz. settlements, climates, soil, transportation, education, population, land use, land cover etc.

Aeronautical chart:

An aeronautical chart is a specialized map designed to assist in the navigation of aircraft, similar to how nautical charts aid watercraft navigation and road maps help drivers. Aeronautical charts provide pilots with crucial information for safe and efficient flight.

Original map:

These are maps created from original research and fieldwork. They involve directly collecting data about a place, like its features, boundaries, or other relevant information. This data is then used to create a new map that has never existed before.

Derived map:

These are maps derived from existing maps. Cartographers (mapmakers) rely on information from previous maps and other sources to create these. They may combine information from multiple sources, change the scale or projection, or add new features to an existing map.

Large scale map: Medium scale map: Small scale map:

 Maps On the basis of map scales, maps can be classified into different classes. Although there are no fixed boundaries between these classes, in general maps can be divided into large-scale map (1:200,000 and larger), medium-scale map (smaller than 1:200,000 up to 1:1000,000) and small-scale map (smaller than 1000,000). 

This classification method varies in different countries according to the conventions. In Nepal, survey department has adopted the following system.

Large-scale map (1:10,000 and larger)

Medium-scale map (1:50,000 up to 1:25,000)

Small-scale map (1:500,000 to 1:100,000). 

 

Plans are more detailed drawings that focus on a smaller area, such as a building, a floor of a building, or a piece of land. Plans are often used to show the layout of a space, including the location of walls, doors, windows, and furniture. Plans may or may not be drawn to scale.

Plan

·         A plan, on a wide scale, is a depiction of a small territory

·         A plan gives little information on a specific local region

·         A plan is a graphical depiction, to some size, of features on, behind, or under the earth’s surface as projected on a horizontal plane

·         For a large-scale, a plan is created

·         Horizontal distances and directions are often depicted on a plan

·         A plan created is usually for a small area like a House plan, bridge plan, school plan

Difference between Map and Plan

Map	Plan
A map is a visual illustration of a region’s figurative representation highlighting associations between elements of that space such as regions, themes and objects.	Plans are a set of two-dimensional drawings or diagrams used to illustrate an object or place, or to communicate fabrication instructions or a building.
Maps can be represented as real, space, or imagined without regard to scale.	Plans are mainly for technical purposes such as engineering, architecture, or planning.
Maps contain a lot of information	In plans details are given in the form of symbols
It is used for representing larger areas like continents, countries and also for representing small areas like towns and small villages.	It is used for representing things that cannot be represented on a map. For example the length and breadth of a room cannot be shown in a map. For this purpose a plan is used.
A map is a representation or a drawing of the surface of the earth or a part of it drawn on a flat surface according to a scale.	On a broad scale, a plan is a drawing of a small region.

 

Importance of Plan & Maps

Maps & Plans are important for a variety of reasons as follows: 

1.    Maps Streamline Complex Data

Maps take complex data sets and show them in a visually appealing image that may be used to answer queries about your surroundings. 

2.    Maps are excellent resources

Most people understand how GPS works. It locates you and then tells it wherever you want to travel. GPS is great for taking you to your next destination, but it doesn’t tell you anything at all about the areas you’re traveling through. 

3.    Maps Aid in the Development of Life Skills in Children

Maps help youngsters visualize where items, locations, cities, and nations are in connection to one another, which promotes spatial thinking. 

4.    Maps Have the Potential to Save Your Life

Every year, millions of people visit nature reserves, forests, and wilderness regions. Alerts & mobile signals may not reach all of these regions, thus maps may be your sole source of information in an emergency.

5.    Maps serve as a blueprint for our history

Maps provide insight into how people perceived this environment at the period the map was made. 

Maps and Photograph

Photographs are realistic images of a place or object. They capture the details of a scene, including the colors, textures, and lighting. Photographs can be used to document a place, to tell a story, or to create a mood.

Maps and photographs can be used together to provide a more complete understanding of a place. For example, a map can show you the location of a city, while a photograph can give you a sense of what the city looks like.

Maps and photographs, while both visual representations, serve different purposes and have distinct characteristics. Here's a breakdown of the key differences:

S.N.		Maps	Photographs
1.	Purpose	Designed to convey spatial information and aid navigation. They show the relative locations of features like roads, buildings, bodies of water, etc.	Capture a realistic image of a specific scene or object. They provide a more detailed visual record but lack the broader spatial context of a map.
2.	Representation	Use symbols and abstractions to represent geographical features. Scale is crucial, ensuring that distances between places are accurately depicted.	Offer a more realistic portrayal of a scene, capturing details like colors, textures, and lighting. They don't typically have a scale, making it difficult to judge distances.
3.	Information	Focus on conveying essential information for navigating an area. They may include details like landmarks, elevation, and directions.	May contain a wider range of information depending on the photographer's intent. They can capture the mood, atmosphere, or specific details of a place.
4.	Accuracy	Strive for high accuracy in representing the spatial relationships between features. The scale ensures consistent representation of distances and areas.	Accurate in capturing the scene they depict, but may not be geographically accurate due to perspective and lens distortion.
5.	Applications	Used for navigation, route planning, understanding geographical relationships, and visualizing spatial data.	Used for documentation, capturing memories, appreciating aesthetics, and illustrating stories or concepts.

 

Map Reading:

Map reading is the skill of interpreting a map to understand the real world it represents. By understanding the symbols, scales, and other features of a map, you can: Find your location, Measure distances, understand your surroundings, plan a routes etc.

Map reading is the process of looking at the map to determine what is depicted and how the cartographer depicted it.

Map Components: (Map elements)

A=  MAP FACE/ MAP BODY

B=  NEAT LINE/ CLIPPING LINE

C=  FRAME LINE/ BOARDER LINE

D=  BOARDER AREA/ BOARDER INFORMATION

E=  MARGINAL AREA/MARGINAL INFORMATION /META DATA

 

 

MAP FACE/ MAP BODY:

It is part of the map where the ground details or the spatial distributions of the data are shown only. In this portion of the map details are shown by using different symbols. We can also say that the area between the neat line is known as the map face or map body or map interface.

 

NEAT LINE/ CLIPPING LINE:

The line surrounding the map face or map body is known as the neat line. It used to determine the area for the map interface. In some case grid line or graticule line uses as the neat line. It is also called as the clipping line

 

FRAME LINE/ BOARDER LINE:

Line drawn outer side of the neat line is known as the frame line. Frame line is drawn only in the topographical map, other map like cadastral map there is no frame line. It is also known as the boarder line.

 

BOARDER AREA/ BOARDER INFORMATION:

The area between frame line and neat line is known as the boarder area. And the information kept on it is known as the boarder information.

Information kept in boarder area is as listed below:

1.    Geographical coordinate

2.    Grid values

3.    Destination of the path

4.    Adjoining plane name

 

MARGINAL AREA/MARGINAL INFORMATION:

Area between the frame line and the paper edge is known as the marginal area and the information under it is known as the marginal information or Meta data.

Information kept in marginal area are listed below:

1.    Title name	2.    Series number
3.    Administrative index	4.    Contour interval
5.    Sheet number	6.    Sheet index
7.    Scale	8.    Location diagram
9.    Legend	10.           Datum information
11.         Pronunciation guide	12.           Sources

 

Map information:

There are many different types of maps that attempt to represent specific things. Maps can display political boundaries, population, physical features, natural resources, roads, climates, elevation (terrain), and economic activities.

 

Information in topographical map:

1.    Distance between two point

2.    Elevation of the point

3.    Bearing of the line

4.    Location of certain places

5.    Area of the certain features

6.    Coordinate of point

7.    Name of features and nature of topography

Information in cadastral map:

1.    Parcel number

2.    Area of parcel

3.    Number of parcel in sheet

4.    Distance between two point

Map setting:

Map is said to be set when the spatial features on the map are in a position relative to the actual feature on the surface of the ground. Map setting is checked by inspection of distance relative to the scale and inspection of the grid north towards magnetic north.

Position finding:

We can find our position on the map after map has been set and the area is mapped, and after that we can compare the details on the map with the key features in your surroundings, such as road, hills, tower etc.

In digital map also we can find the position of own:

Since you are currently in Shankharapur, Bagmati Province, Nepal, I can't assist with finding your location on a map. However, I can help you find Shankharapur on a map:

·         Open a web browser and go to your preferred map service.

·         Search for "Shankharapur, Nepal".

·         The map should zoom in on Shankharapur. You can then zoom in or out to get a better view of the surrounding area.

                                                    

Map interpretation:

Map interpretation is the process of extracting information and meaning from a map. It involves more than just looking at features like roads and mountains. Map interpretation involves the study of factor that explains the causal relationship among several features shown on the map.

Map update:

Maps are constantly evolving as the world around us changes. Keeping maps up-to-date is crucial for ensuring their accuracy and usefulness.

Here's a breakdown of the key principles behind map updates:

·         Accuracy and Completeness: The primary goal is to maintain the accuracy of the map data by reflecting real-world changes. This includes adding new features, modifying existing ones, and removing outdated information.

·         Timeliness: Updates should be done in a timely manner to ensure users have access to the most recent information. The frequency of updates depends on the map's purpose and the rate of change in the area it covers.

·         Data Source Integration: Reliable data sources are essential for effective updates. This can include aerial photography, satellite imagery, ground surveys, and user reports.

 

Methods for Map Updating

There are several methods used for updating maps, depending on the scale, resources, and type of changes involved:

·         Field Surveys: Ground-based surveys involve sending personnel to physically verify and collect data on changes. This method is highly accurate but can be time-consuming and expensive for large areas.

·         Aerial Photography and Remote Sensing: Modern technologies like satellite imagery and aerial photography provide a cost-effective way to capture large areas and identify changes in detail.

·         GPS and Lidar: Global Positioning Systems (GPS) and Light Detection and Ranging (LIDAR) can be used to collect highly precise data on features like road networks and elevation changes.

·         Crowdsourcing: Utilizing user-generated data is an emerging method. Users can report changes, like new businesses or road closures, through apps or online platforms. This approach requires data validation to ensure accuracy.

Who Updates Maps?

Ø Government Mapping Agencies: Many countries have dedicated government departments responsible for official map creation and updates.

Ø Commercial Mapping Companies: Companies like Google Maps and Apple Maps use various methods to update their maps frequently.

Ø Individuals and Organizations: Hikers and outdoor enthusiasts might update trail maps, while local businesses could report changes in their area.