Basics of Geographic Information System (GIS)

The book focuses on the basics of GIS without which the core understanding about GIS is not possible. It helps the reader how to carefully analyse and decide about placing a real world entity either as a raster or as a vector (point, line or polygon). The book discusses the projection system which helps the reader to understand the pros and cons associated in data conversion from a 3D environment to a 2D environment and how the authenticity of the data is hampered. The reader get an understanding about the characteristic features of an ideal data to attain a quality output and points to be considered while collecting data, reasons or sources causing the inaccuracy of data with special reference to the vector data.

In GIS topology and associated errors is the biggest challenge the text explains the ways and means to fix them. Further, the text explains non topological editing and juggling the data to create a new data set from the existing data, the way to deal with the bulky data in small segments which are presented as a single file with no ambiguities related to feature geometry and the mechanism to produce smooth looking features that looks visually more appealing along with the bulky data compression with almost zero compromise over data quality.

The reader gets the understanding of data retrieval through query which is factor of data structuring in the database management system which is the base for setting up a vector data model.

The most important functionality of an efficient GIS model is presenting the data as a map (cartography) such that even a layman can understand it with least training; this aim is achieved by discussing map making and its important elements along with the different types of maps with significant applications which is possible through data manipulation which is usually addressed as data classification in more refined terms.

The book helps the reader to understand the benefits of data exploration in GIS over statistics. Reading a tabulated or document data seems to be less interpretable and requires a sincere attention this issue can be resolved by representing the data in a pictorial manner which provides at a glance view and easy understanding of any analysis. Reading this chapter one will get to know the application of data analysis and statics analysis in GIS environment that help in understanding the trends and changes in a geographical vicinity along with this reader will also get to know about the different types of queries that can be performed to analyse the data as per different user requirements.

The content focuses on vector data analysis and simple operations such as buffering, geometry of the entities and associated buffer, variations in buffering, applications of buffering, basic operations of vector data analysis such as overlay operation, its important factors and methods; distance analysis and its applications; pattern analysis and its interpretation; and hot spot determination. Further the content also discusses simple feature manipulation operations such as dissolve, clip, append, select, eliminate, update, erase and split. These geospatial analytical operations help the user in planning projects, exploration projects and many other studies that would have been more expensive and time consuming with less productive results if directly performed in fields.

GIS offers a platform to study different contributing factors for a phenomenon and attain a solution to a problem by the compilation of the different contributing factors as per there degree of influence. Further the reader can study and understand complex phenomenon such as trend analysis, basics of hill shed, view shed and watershed analysis.

By the end of the book one gets the understanding about the step by step process of GIS data modelling, the process of data validation and what are the benefits of modelling? Ideally by the end of the chapter the reader will have through understanding of all the concepts of GIS data modelling such that one can handle complex problems with ease and produce the results that are easy to understand by a layman since the end products of a GIS models are simple charts, maps, database sheets or even the animated map and models that require lesser fine visualization skill and provides at a glance view of the complete analysis in a more interpretable manner.