Manual to basic gis

Manual to Basic GIS – Sushmita Timilsina Page 1
Manual to
Basic GIS
Prepared by: Sushmita Timilsina

Contents:
1. Introduction
2. Playing with data
3. Projection system
4. Georeferencing
5. Data analysis
6. Importing and exporting data in and out of GIS
7. Data layout

INTRODUCTION
Arc GIS when installed it automatically the following with itself
1. Arc catalogue
2. Arc map
3. Arc Globe
4. Arc Scene
Component: 1. arc catalogue
a. Data loading and preview with their information about data and metadata
-Difference in vector and raster file
Data can be easily loaded onto the Arc Catalogue by browsing our
destination folder that contains our data. Data may be raster or vector.
The differences can be seen by previewing the graphics as well as the
properties of the data. The data can be viewed through Preview option
just above the file. The attributes information is also available. The
attributes can be spatial and other metadata information.
b. Creation of files(shape file, xml)
The databases and required files can be created in our destination folder.
To create File Geodatabase, personal geodatabase, shape file, xml, tables
etc. it is as simple as making a new folder. Just you need right click on
the free space and click on what you want to create.
For creating a shape file:
Right click on the free space inside the destination folder or in the
destination folder and choose New and select Shapefile. A new dialogue
box will pop up that contains the information to be filled up to create any
shape file.

You must give a name to the shape file. Choose the feature type you
want to make your shape file (point, line, polygon etc). Now provide the
Spatial reference System to the file through the click on Edit. You can
then select, import or create your new projection that is necessary for
our project. Selecting select you can select the predefined spatial
reference system necessary for your project. Selecting import you can
simply import the system that has already been used also you create your
own using create. Once you provide these information your shapefile is
now created.
2. Arc map
a. Create your own interface by adding, removing and managing the function
that is necessary for your analysis. You can add your necessary function by
customizing the extension of simply through right click on the top free space
and check in in the necessary functions.

3. Arc toolbox
Number of tool is present in Arc GIS inside Arc Toolbox that help in analysis.
There are many tools inside the toolset. Just go on browsing it and explore. You
can also create your own toolbox. To do so just right click on the free space and
select new to create new and select add to add existing toolbox.
Playing with data
Add your data using add button displayed as plus button found above in the
task bar. You can add raster, vector or database file in Arc map. The layer can
be displayed to see what it depicts. In order to change the appearances of the file
you add explore by right click on the layer. Now you see copy (copies the
layer), remove (removes the layer), open attribute table (opens the attribute
table), zoom to layer (zooms the layer to be wholly visualize within the layer),
selection (for selecting the feature or any criteria) data (with data you can
simply export a single layer from Arc GIS or make the layer permanent and also
view its metadata).
The main important and mostly used option in the right click is the Properties
option. When the properties is selected it opens a window like following.

Each tab is equally important in layer properties:
General: in general you can change the layer name, can make it visible, add
description and aslo manage scale range.
Source: you can see the extent of your data. The current data source of the layer
can be seen. Also if you want to change the spatial reference system you can do
it by selecting Set Data Source.
Selection: selection symbol to customize our selected features. You can change
the symbol or colour for your selection.
Display: this tab maintains the displaying information. Transparency can be
adjusted using this tab.
Symbology: this is the most used tab. You can give the symbol of your interest
for single and multiple features. On the left side, under Show: has Features that
contains single symbol inside which can be assigned to the layer. Similarly,
Categories contains unique values (you assign unique value and colour to
different feature of that layer) unique values, many field (you can assign unique
values to multiple field) match to symbol in a style (to match the symbol with
the predefined style in your directories). Under the Quantities you can find
Graduated colors (provides colour graduation to field using the value of the
field) Graduated symbols (provides the symbol graduation for the field with the
values) proportional symbols (it draws the quantities using symbol size to show
exact values). Under Charts you can draw pie chart, bar/column or stacked
chart for each feature. Under multiple attribute it contains Quantity by
category (useful to draw quantities for each category).
Fields: it displays the field of the layer. You can choose the field to be visible
and see, select or clear the layer’s fields.
Definition Query: this tab is to define the query. Query Builder can be used in
order to build query of our on using the functions defined.
Labels: this tab is used to label the features in the selected layer. The text
symbol, colour, size , scale range, placement properties and label style can be
managed in this tab.
Join & Relate: Join joins the two layers attribute table with a common field in
both the table. Relate associates the table /layer with one another.

HTML Popup: to show content for the selected layer.
Now explore the Attribute table. You see rows and column like in the simple
table. Rows are called tuples or record. Columns are called fields. Fields can
be added or deleted. The simple geometry can also be calculated and statistical
data can be observed. Once you select on any tuple the selection will also be in
the display. Explore option on the right-down side.
Projection
Projection is necessary to represent the data onto the screen. Distortion is
always likely to occur due to projection. Therefore it is crucial act to choose the
type of projection system.
UTM(Universal Traverse Mercator) is the universal projection system that takes
the origin to be the intersection between Greenwich meridian and equator. This
system divides the globe into zones from -180 to 180 each of 6 degree zones.
Nepal consists of two zones 44 and 45.
Nepal lies in the northern hemisphere. The department of survey of Nepal has
defined the MUTM(Modified Universal Traverse Mercator) for Nepal where
MUTM divides the zones of 3 degree each. Nepal consists of three zones 81,
84, 87.It is hence necessary to define the zone of any coordinates to prevent
dilemma.
Data frame properties can be used for viewing and assigning projection system.
Data frame properties is available in the View button of menu bar. Also
projection system can be viewed and set in source in properties with rt. Click in
the layer of our interest.
Also can be defined and transformation can be done if necessary

Geo-referencing
Data is always not provided like we want.. so we must create data
TIC_ID X(Easting/Longitude) Y(Northing/Latitude)
1 574000 3116000
2 577000 3116000
3 577000 3112000
4 574000 3112000
Aligning geographic data to a known coordinate system so it can be viewed,
queried, and analyzed with other geographic data is termed as Georeferencing.
Georeferencing may also involve shifting, rotating, scaling, skewing, and in
some cases warping, rubber sheeting, or orthorectifying the data.
Any image or orthophoto has no spatial reference so to do our analysis using the
existing image, first we need to georeference the image with the known
coordinates. It involves identifying the known points in the image and assigning
the points on the image and rectify it.

After assigning the points calculate RMS error.. if error is permissible rectify
the picture to image and provide its projection system. Also must define the
projection system to data frame and the raster layer. Now you can digitise
(points, line polygon) your data necessary after the creation of any shape file in
the same location using editor.
Data analysis
Spatial Analysis (extract, proximity, clip, intersect)
The Extract toolset contains tools used to select features and attributes in
a feature class or table based on an attribute query (SQL expression) or spatial
extraction. The new features and attributes are stored in a new feature class or
table.

Tool Description
Clip
Extracts those features or portions of features from an input
coverage that overlap with a clip coverage polygon. The Clip tool is
similar to the Intersect tool; however, the Clip tool does not transfer
any attributes from the clip coverage to the output.
Select
Extracts map features from the input coverage based on logical
expressions or applying the criteria contained in a selection file.
Split Clips portions of the input coverage into multiple coverages.

Proximity is another of the most basic GIS questions, such as:
 How close is this well to a landfill?
 Do any roads pass within 1000 meters of a stream?
 What is the distance between two locations?
 What is the nearest or farthest feature from something?
 What is the distance between each feature in a layer and the features in
another layer?
 What is the shortest street network route from some location to another?
Feature-based proximity tools
Feature-based proximity tools Raster-based distance tools
Create Thiessen Polygons creates polygon features that divide the available
space and allocate it to the nearest point feature. The result is similar to the
Euclidean Allocation tool for rasters. Thiessen polygons are sometimes used
instead of interpolation to generalize a set of sample measurements to the areas
closest to them. Thiessen polygons are sometimes also known as Proximal
polygons. They can be thought of as modeling the catchment area for the points,
as the area inside any given polygon is closer to that polygon's point than any
other.
Importing and exporting data in and out of GIS
Mainly used extension is kml that is used by google earth. Using data in ArcGIS
extracting from Google Earth:

Google earth is needed to be installed first into your computer.
Open Google Earth. Now move towards the area of your interest using zoom,
pam, rotator to the area of interest. Now create a new folder where you want
your data to be saved inside the My Places. When the folder is created now you
can start digitising by using add button. The button can be point, polygon or
line feature. When you are done with extracting your necessary feature, now we
move towards using it in the GIS and save it to our destination folder by right
clicking on the folder.
In order import the data directly into GIS you need check in the
interoperability option in extensions. Now you need to browse the data
interoperability tools in Arc Toolbox and select quick import and then you
import your data that you created in Arc GIS. It automatically supports the data
and if you check the spatial reference system, it gives the wgs84 of that of
Google Earth. Now you can move forward for your analysis.
Exporting data to Google Earth
Now when the data you have is necessary to be displayed in global scale, you
can export your layer. Before exporting your data you need to convert your data
to kml. Arc GIS provide tools to convert layer to kml. Automatically it
converts to the file that is easily accepted by Google Earth. When the data is
exported successfully you can easily open the file without opening Google
Earth. When you open your file it automatically opens the Google Earth to the
region that you exported from Arc GIS. Now you can visualise your data.
ENJOY!!

Creating a map layout
A page layout is a collection of map elements organized on a virtual page,
designed for map printing. Common map elements that are arranged in the
layout include one or more data frames (each containing an ordered set of map
layers), a scale bar, north arrow, map title, descriptive text, and a symbol
legend.
Below are the general steps for laying out a map in ArcMap:
1. Before starting in ArcMap, it's wise to design the arrangement of the
elements onto the map page and plan your layout.

2. Start by setting your layout's page size and dimensions. Create, edit, and
symbolize your data as appropriate in your data frame(s).
3. In layout view, click the Insert menu to add elements onto your layout. If
you have more than one data frame in your map, the elements you insert
will relate to the active data frame (to activate a data frame, right-click its
name and choose Activate).
4. When you add map elements (for example, a scale bar), the map reflects
your updates. You can select, reposition, and modify map elements. Right-
click a selected element to access its shortcut menu and set additional
options.
5. Add other text or graphics, such as notes, borders, and frames, using
the Draw toolbar. You can use guides, grids, and rulers to help you
precisely position elements on your page.

6. Print or publish your map. Under the file menu you have the options to
open the Page and Print Setup dialog box, Print Preview, Print the
page, or to Export Map.

Manual to basic gis

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