TABLE OF CONTENTS
Question one
The
effectiveness an efficiency of GIS database depends on how it can perform
different functions, and give different scenarios or alternatives for reference
in planning and decision making. Briefly comment the statement.
Question two.
i.
Briefly describe the importance of
establishment of Information Need Assessment from different stakeholders in
order to structure and design GIS database.
ii.
Describe GIS data models and the
benefits of GIS.
iii.
Describe the factors which influence
establishment of GIS database in any organization.
iv.
Describe the steps procedure of applying
ODBC IN Database Management system.
Question three.
Briefly
describe derivative mapping, process simulation and modeling in GIS technology.
Question one.
The
effectiveness and efficient of GIS database depend on how it can perform
different functions and give different scenarios or alternatives for reference
in planning and decision making. Briefly comment the statement.
It is true that the effectiveness and efficient of GIS database depend
on how it can perform different functions and give different scenarios for
reference in planning and decision making as commented bellow;
It
offers a number of techniques for storing data and allows using the most
efficient one. This means that it support storage optimization.
It
allows imposing rules on the stored data, which will be automatically checked
after each update to the data. Meaning support data integrity.
It
also offers easy to use data manipulation languages, which allows performing
all sorts of data extraction and data updates. Meaning that it has a query
facility.
It
can be used by multiple users at the same time, this means that it allow
concurrent use.
GIS
database function provide quick and easy access to large volume of geographical
data, it allow the user to understand geographical in an easy manner without
having to go to large volume of confusing data and it help to visualize the
geography of a particular location.
Question two.
i). Briefly describe the importance
of Establishment of Information Need Assessment from different stakeholders in
order to structure and design GIS data base.
In
order to structure and design GIS database information need assessment from
different stakeholders in order to structure and design GIS data Base is very
important aspect as follows.
Information
need assessment helps to ensure sources of information, this will help to know
were to get reliable information for example form individuals, private sectors,
government institutions or research international agencies.
Helps
to ensure markets of information produced, this can be achieve through
assessing the demand of information, affordability, and identifying if people
are willing to pay for information.
Helps
to know the sources of data (major and minor sources of data), quality of
available data, types of data, uses of data (planning, reporting decision
making, and monitoring evaluation research), and reliability and accessibility
of data.
Helps
to identify the required resources such as hardware, software, tools, financial
resources, technical expertise, maintenance program, and working environment.
Finally
helps in maintaining security of data, updating procedures information
management personnel and information dissemination procedures and guidelines.
ii). Describe GIS Data Model and
Benefit of GIS.
A data model in geographic
information systems is a mathematical
construct for representing geographic objects or surfaces as data. For example,
the vector data model
represents geography as collections of points, lines, and polygons; the raster data model
represent geography as cell matrices that store numeric values; and the TIN data model represents geography as sets of contiguous, no
overlapping triangles.
The benefits of
GIS
a.
Cost
savings resulting from greater efficiency. These are associated either with carrying out
the mission (i.e., labor savings from automating or improving a workflow) or
improvements in the mission itself.
b.
Better
decision making. This typically has to do with making better decisions about
location. Common examples include real estate site selection,
route/corridor selection, zoning, planning, conservation, natural resource
extraction
c.
Improved
communication. GIS-based maps and visualizations greatly assist in
understanding situations and story telling. They are a new language that
improves communication between different teams, departments, disciplines,
professional fields, organizations, and the public.
d.
Better
geographic information recordkeeping. Many organizations have a primary
responsibility of maintaining authoritative records about the status and change
of geography (geographic accounting).
- Improved allocation of resources and planning.
a)
The need to simple and became fully managed. GIS database enable easy management of
any organization.
b)
The need to have reliability and security. In any organization
confidentiality is required thus GIS can help to maintain security of
information.
c) The need to ensure partnerships and integrations.
GIS database technology can provide easy coordination among organizations hence
increase performance among them.
d)
The need of developing an institutional memory. GIS database helps to keep
records for future use.
e)
The need to improve Performance and
scalability.
f) The need to have more convenient
maintenance.
iv). Describe the steps procedure of applying ODBC in Database
Management system.
Open Database Connectivity (ODBC) is a standard
that allows programs to read from almost all of the databases currently
available. Also, Open Database
Connectivity (ODBC) can be defined as Microsoft's strategic interface for
accessing data in a heterogeneous environment of relational and non- relational
database management systems. Based on the Call Level Interface specification of
the SQL Access Group, ODBC provides an open, vendor- neutral way of accessing
data stored in a variety of proprietary personal computer, minicomputer, and
mainframe databases. (Andrew, 2003).
The steps procedure for applying ODBC in Database management
system includes the following;
Step
1: Connect to the Data Source; the first step in any application is to connect to the data
source. This phase, including the functions it requires.
It deals with connecting to the data source is to
load the Driver Manager and allocate the environment handle with SQLAllocHandle.
Step 2: Initialize the Application, The second step is to
initialize the application; exactly what is done here varies with the
application. At this point, it is common to
use SQLGetInfo to
discover the capabilities of the driver.
Step 3: Build and Execute and SQL
Statement,
the methods used to perform this step are likely to vary tremendously. The
application might prompt the user to enter an SQL statement, build an SQL
statement based on user input, or use a hard-coded SQL statement.After the SQL statement is built and any parameters are bound,
the statement is executed with SQLExecDirect.
Step 4a: Fetch the Results, if the statement executed in "Step 3: Build and Execute an
SQL Statement" was a select statement
or a catalog function, the application first calls SQLNumResultCols to determine the number of columns in the
result set. This step is not necessary if the application already knows the
number of result set columns, such as when the SQL statement is hard-coded in a
vertical or custom application.
Step 4b: Fetch the Row Count, if the statement executed in Step 3: it deals with an update, delete,
or insert statement;
the application retrieves the count of affected rows with SQLRowCount. The application
now returns to step 3 to execute another statement in the same transaction or
proceeds to step 5 to commit or roll back the transaction.
Step 5: Commit the Transaction, The fifth step is to call SQLEndTran to commit or roll back the transaction. The
application performs this step only if it set the transaction commit mode to
manual-commit; if the transaction commit mode is auto-commit, which is the
default, the transaction is automatically committed when the statement is
executed.
Step 6: Disconnect from the Data Source, the final step is to
disconnect from the data source, as shown in the following illustration. First,
the application frees any statement handles by calling SQLFreeHandle.Next, the application
disconnects from the data source with SQLDisconnect and frees the connection handle with SQLFreeHandle
The basic application steps are shown in the following
illustration below;
Question Three.
Briefly describe derivative
mapping, process simulation and modeling in GIS technology.
Typically
the mapping process is made up of
the following phases of work, (Clarhe, 2003).
Planning,
a mapping project is usually initiated as a result of the user requirement,
study and analysis.
Cartographic
production phase, this phase starts with cartographic design which determines
what the end product will look like.
Product
delivery phase, this phase involves the storage and management of printed maps
and the establishment of map sales offices and other channels for distribution
to the user.
Data
acquisition phase, this phase of work includes the selection and establishment
of the geographical reference framework and the actual collection of geospatial
data by the methods of geodetion and land surveying, photogrammetric, and
remote sensing.
Generally,
the mapping process is always described as a cycle in the sense that after the
completion of the four phases of work described here, the mapping agency has
the obligation to maintain a map revision program.
GIS modeling
uses spatial data analysis techniques to produce models of spatial phenomena.
There are two main objectives in GIS modeling; to understand and to predict.
For understanding, generalization of spatial phenomena is made. (Yeung, 2007).
There
are six basics steps to follow in GIS modeling;
i.
Stating the problem or define the goals
of the model. This is analogous to defining a research problem. What are the
phenomena to be modeled?
ii.
Breaking down the problem into
components or elements and to define the properties of each element and the
interaction between the elements in the form of a conceptual diagram.
iii.
Searching for data
iv.
Deciding on one or more suitable spatial
analytical models to use
v.
Deciding on suitable GIS program (vector
or raster model) to use, and
vi.
Implementing the model in the GIS
environment and calibration of the model. The modeler needs data to run and
calibrate the model.
Process simulation is used for the design, development, analysis, and
optimization of technical processes such as: chemical plants, chemical processes,
environmental systems, power stations,
complex manufacturing operations, biological processes, and similar technical
functions. (Rhodes, 1996).
REFERENCES
Albert K.W.Yeung, (2007). Concepts and
Techniques of Geographic Information Systems. Pearson Prentice
Hall.
And
Media.
Keith C. Clarhe, (2003). Getting Started with
Geographic Information Systems. Pearson Education Ink
Rhodes C.L. (1996). “The
Process Simulation Revolution: Thermo physical Property Needs and Concerns”.
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