NCERT Solutions For Class 12 Geography Part C Chapter 6 Spatial Information Technology
Q. Choose the right answer from the four alternatives given below :
(i) The spatial data are characterised by the following forms of appearance :
(ii) Which one of the following operations requires analysis module software?
(iii) Which one of the following is disadvantage of Raster data format ?
(iv) Which one of the following is an advantage of Vector data format ?
(v) Urban change detection is effectively undertaken in GIS core using:
Q. Answer the following questions in about 30 words :
(i) Differentiate between Raster and Vector data models.
|Raster data model||Raster data model Vector data model|
|1.||A graphic feature is a pattern of grids of squares.||Vector data represents the object as a set of lines drawn between specific points.|
|2.||Simple data structure.||Compact data structure.|
|3.||Easy and efficient overlaying.||Efficient for network analysis.|
|4.||Compatible with satellite imagery.||Efficient projection transformation.|
|5.||High spatial variability is efficiently represented.||Accurate map output|
(ii) What is an overlay analysis?
Ans. GIS is known for its overlay analysis operations. An essential analytical function is the integration of many layers of maps utilising overlay techniques. In other words, GIS allows overlaying two or more thematic layers of maps from the same region to create a new map layer, similar to sieve mapping, which involves tracing maps on a light table to compare them and create an output map.
(iii) What are the advantages of GIS over manualmethods?
Ans. Separate data storage and presentation are intrinsic advantages of GIS. It also helps to examine and show the data in a variety of ways. The following are some of the most significant benefits of GIS:
(iv) What are important components of GIS ?
Ans. The important components of a Geographical Information System include the following:
(v) What are different ways in which spatial data is built in GIS core?
Ans. The geographic database into a GIS is known as spatial data input. It may be made from a number of different sources. The following two categories can be used to summarise them:
(vi) What is Spatial Information Technology ?
Ans. It refers to the characteristics and phenomena that are dispersed throughout a geographically delimited region and hence have physical dimensions. In other words, Spatial Information Technology uses technical inputs to collect, store, retrieve, present, manipulate, manage, and analyse spatial data.
Q. Answer the following questions in about 125 words :
(i) Discuss raster and vector data formats. Give example.
|Raster data format||Vector data format|
|Meaning||Raster data format represents a graphic feature as a pattern of grids of squares.||Vector data represents the object as a set of lines drawn between specific points.|
|Suitability||The Raster file formats are most often used for the following activities: ||The Vector files are most often used for: |
|Advantage||Simple data structure; Easy and efficient overlaying; Compatible with satellite advantage imagery; High spatial variability is efficiently represented.||Compact data structure; Efficient for network analysis; Efficient projection transformation.|
(ii) Write an explanatory account of the sequence of activities involved in GIS related work.
Ans. In GIS-related activity, the following sequence of actions is involved: