Write an explanatory account of the sequence of activities involved in GIS related work.

The following sequences of the activities are involved in GIS related work:

1. Spatial data input: These could be summarised into the following two categories:

(a) Acquiring digital data site from a data supplies. The present day data supplies make the digital data readily available which range from small scale maps to the large scale maps.

(b) Creating digital data: Manual input of data to a GIS involves four main stages:

• Entering the spatial data.

• Entering the attribute data.

• Spatial and attribute data verification and editing.

The manual data input methods depend on whether the data base has a vector typology or grid cell structure.

2. Entering the attribute data: Attribute data defines the properties of a spatial entity that need to be handled in the GIS but which are not spatial.

3. Data verification and editing: The spatial data captured into a GIS require verification for the error identification and corrections so as to ensure the data accuracy.

4. Linkages: GIS typically links different data sets. Suppose we want to know the mortality rate due to malnutrition among children under ten years of age in any state, we must first combine or link the two. In one number of children of this age group and another contains the mortality rate from malnutrition.