Laboratory Exercise 6
 
 

Selecting Records in a Table


Background

This laboratory consists of exercises from Chapter 14 of the lab text, Getting to Know ArcView GIS, with the data obtained from the accompanying CD-ROM (exercises 14a,b,c).

ArcView is a powerful desktop geographic information system (GIS) made by Environmental Systems Research Institute (ESRI). With ArcView, you can load any data that's linked to geographic locations and display it graphically as maps, charts and tables. You can also edit the data , change the way it's displayed, append additional data, create some of your own, perform queries to answer specific questions, or meet certain criteria, and analyze information statistically as well as spatially. Results can be shown as quality graphic presentations to print out or display your screen.

In this exercise, you will learn to access information of features from the database, called the attribute table. You will learn to select records with the select tool and the Query Builder. With the Query Builder, you write a statement, called a query, specifying and attribute and a value. ArcView then selects all the features that match your query. You will learn how to get statistics on the records selected by the Query Builder, and summarize the theme attribute tables to find out how many records share each of the values in a specified field (column). You will also learn how to merge several features and their records into one.

The exercise begins with rainfall data for Marsabit (Kenya) and a contour n]map of the rainfall amounts in mm. The table also contains areas of the polygon records, and a description of the rainfall amounts as dry, medium or wet. The first part of the exercise involves sorting the records for rainfall amounts <300 mm, and studying the statistics of those records. You also learn to summarize the number of records of a certain attribute value. Finally, we will learn the merging techniques to produce a contour map with only three contour values - wet, medium, dry.

Procedure

With the supervision of your instructor, or lab coordinator, use the Getting to Know ArcView GIS CD-ROM to carry out the directions of exercises 14 a,b,c. The path to the exercises may vary from PC to PC, so check with the lab instructor or lab coordinate.

Report Format

Name:

Email:
 

Q1. In the attributes of rainfall table, for the polygon with an area of 20.7208 sq km, what is the rainfall?

Q2. A contour map is

Q3. You can sort in order or order.

Q4. A summary table has at least columns (fields).

Q5. The fields referred to in 3 above list:

Q6. A merge is defined as:


 
 
 


 

If this form, for some reason, does not work, submit your Word- formatted answers by way of e-mail to:

gatemail@mail.hartford.edu