Geo 4427: GIS Design and Needs Assessment

the 1st step towards a GIS

Dr. Yihong Yuan

Department of Geography, Texas State University

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Sep 2nd 1st client visit

• 10-10:15am: City of Austin - Evaluation of ACT Tree Program, ELA 315

10:15-10:30am: City of San Marcos- Roman Lucio Park, ELA 31510:30-10:45am: City of San Marcos- Gary Sports Complex, ELA 315(15 mins break, room change)

• 11:00-11:15am: University Archives - Historic Maps, ELA 120 11:15-11:30am: Westcave - Bird Count Mapping, ELA 120

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GIS Development Cycle

• Requirement Analysis / needs assessment

• Conceptual Design / Logical Design (Flow map)

• Physical Design

• Implementation

• Pilot Study/Test/System Integration

Needs assessment report – pre-step and a major component of proposal writing.

Although…

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What does needs assessment do?

• To define the specific workings / tasks / functionsof the potential project and client;

• To determine their information needs(especially geographical information);

• To assess how GIS could be applied.

• What is expected from the project, a blueprint

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What is the rationale behind needs assessment?

Why needs assessment?• Cost of not planning?• Expectation management• Identify potential problems

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What is a hierarchical view of needs assessment?

Goal

Function

Data

Attribute

Adapted from Huxhold 1991, Introduction to Urban GIS 6

General strategic directions of the project, e.g., Reduce crimee.g. Resolve traffic issue on I-35

General strategic major activity that support the goals:

To reduce the crime…We need to

Various data or feature classes needed to conduct a certain function

- LandSat satellite image, background shapefiles

characteristics of the data…

e.g. location, condition, size, date, type

After a needs assessment, we should be able to identify -

• GIS Applications / Models to be developed• Population/Transportation/Energy…

• GIS functions required• Visualization...analysis…modeling…data collection

• Data needed in the GIS database

• Data maintenance procedures• Backup…backup…backup..

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Performing needs assessment is NOT as simple as making an inventory of maps and spatial data

Major activities during needs assessment:

• Interviewing• Individual, group, Telephone Conference, etc

•DocumentingA general introduction of Project goal

A list of GIS function that will be needed• Will be used to prepare the GIS specification

A list of Information product • To be generated

A master list of geographic data• Will be used to develop GIS data model

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Major categories of GIS functions

simple

complicated

• Browse a town map to see all schools;

• Generate a map showing locations of all schools;

• Display the locations of all elementary schools that also have pre-K program;

• Display the locations of all elementary schools that located in minority neighborhoods;

• What will be the effects for the current elementary school districts if a new school is built?

• Browse / data collection• Simple display (automated mapping)

• Query and display

• Map analysis

• Spatial modeling

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Example

• Project: Harry potter’s school (Hogwarts)

is interested in knowing the spatial distribution of all magic creatures, and identity how this distribution affect students’ safety

What questions you will ask to get the right information?

Major objective:

GIS functions:

Expected product:

Data:10

Name of Government

Geographic Information System

Requirements Analysis

GIS Application Description

Application Identification #:

Application Name:

Department:

Defined by:

Type of Application:

Display Display/Map Scale:

Query Query Key:

Query & Display Response Time:

Map Analysis Frequency:

Spatial Model

Data Required:

Features (entities): Attributes:

Prepared by: Approved by: Date:

Purpose and Description:

Different forms used for needs assessment

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Final products - Composing an information product description (IPD)

• Identify title that best describes information product - Write synopsis of information product needed

• IPD could be one or more of the following:• Map, tabular, text, image, 3D, schematic requirements

• List of something, e.g., perhaps a ranked list• Narrative of something, e.g., text requirement• Maps of feature classes, e.g., map requirement• Diagram/Table that shows the potential database design, e.g. schematic design requirement• ……

• Other elements as follows…

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Name of Government

Geographic Information System

Requirements Analysis

Map Display

Application Identification #:

Application Name:

Department:

Defined by:

Prepared by: Approved by: Date:

Graphical Output Sample: Screen: Hard Copy:

Symbols/Legend

Name of Government

Geographic Information System

Requirements Analysis

Table Display

Application Identification #:

Application Name:

Department:

Defined by:

Prepared by: Approved by: Date:

Report Layout/Format: Screen: Hard Copy:

HEADINGS

SUB-HEADINGS

SUB-TOTALS/TOTALS:

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Different forms used for needs assessment

The Master Data Listentity attributes Spatial

Object

Status

parcel Owner-name,

address, assessed –

value…

polygon available

Which data set is needed for meeting requirements of information structure?If you can, identify standard name for each data setIs the data set available?If data are not readily available, where are data? How can we obtain the data? 14

Functions and IPDs … we need Logical linkages

• Three types of logical linkages• Relationships between attributes and spatial objects (e.g. land parcel boundary and assessed

value)

• Relationships between features (e.g. house and parking space); referential keys should be established

• Relationships between maps/datasets (e.g. hazard zone and population) for spatial overlay where coordinate systems of two maps should be considered

• Determine the relationships required between the data elements (does an information product require the linkage between data elements?)• The easiest way is to draw a Flow map…

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Name of Government

Geographic Information System

Requirements Analysis

Data Flow Diagram

Application Identification #:

Application Name:

Department:

Defined by:

Prepared by: Approved by: Date:

Process Description: Data Flow Diagram or Flow Chart

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For today’s lab

• Project objective – we will talk more later

• Which GIS functionalities (i.e., operations) are invoked at each step to make the product? • Attribute query, data input/output, spatial query, display, edit, label,

symbolize, create list

• A master data list - whether they are available

• Create a flow chart

• All of these will be used later in your proposal…

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Questions?

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