Add Field, Source, Land Cover and Use, Classification Based

Doorsteptutor material for competitive exams is prepared by world's top subject experts: get questions, notes, tests, video lectures and more- for all subjects of your exam.

Add Field

Working with Vector layer in Arc GIS, “Add Field” is one important tool to create new field or column in the existing data to give it new information. The “Add Field” options has six different type of fields for different purpose, they are

Data Type and Applications
Data typeApplications
Short integerNumeric values without fractional values within specific range; coded values
Long integerNumeric values without fractional values within specific range
Float (single-precision floating-point number)Numeric values with fractional values within specific range
Double (double-precision floating-point number)Numeric values with fractional values within specific range
TextFor Alphabetical Characters
DateFor date and time

Source

webhelp. esri. com

Land Cover

Land cover denotes the physical cover on the earth surface which laid by earth itself after origin of life, like vegetation, water body, lakes, glaciers etc.

Land Use

  • Land use simply denotes the use or conversion of land cover by anthropogenic or human induced activities like agricultural land, Dam, settlement, transportation etc.
  • Now a day՚s LULC mapping with remote sensing data is most effective and applicable for showing the global changes in land surface from small scale to large scale.

There are various way of making LULC map like

  • Classification based
  • Digitization based

Classification Based

In GIS there are mainly two type of classification techniques,

  • Supervised Classification – This is used when the user is well known about the study area, so that he/she can define the samples.
  • Unsupervised Classification – This is used when the area of interest is unknown to the user and he/she can classify only on the basis of spectral signature.

Manishika