Lesson Notes By Weeks and Term - Senior Secondary 1

TERM – 1^ST TERM

WEEK TEN

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Geography

Topic: BASIC CONCEPT OF GEOGRAPHIC INFORMATION SYSTEM (GIS)

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Establish the relationship between GIS and geographic data.
2. Mention with examples the methods of representing features in GIS.
3. Explain the sources of geographic data in GIS (maps, fieldwork).
4. Explain geo-referencing and its importance.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

BASIC CONCEPT OF GEOGRAPHIC INFORMATION SYSTEM (GIS)

GIS stands for Geographic Information System. It's a system designed to capture, store, analyze, and manage spatial or geographic data. GIS allows users to visualize, interpret, and understand data in the context of maps, making it valuable for various fields like urban planning, environmental science, and resource management.

In general, GIS describes any information system that integrates, stores, edits, analyzes, shares, and displays geographic information. GIS applications are tools that allow users to create interactive queries (user-created searches), analyze spatial information, edit data in maps, and present the results of all these operations. Geographic information science is the science underlying geographic concepts, applications, and systems.

Relationship between GIS and Geographic data

GIS and geographic data have a symbiotic relationship. GIS relies on geographic data, which includes information about the physical location and attributes of features on the Earth's surface. This data can range from simple coordinates to complex information like land use patterns, population demographics, or environmental characteristics.

GIS organizes, analyzes, and presents this geographic data in a spatial context. By integrating various types of geographic data, GIS enables users to make informed decisions, solve problems, and gain insights into spatial relationships. In essence, geographic data is the foundation upon which GIS operates, providing the essential information needed for mapping and analysis.

Methods of representing features in GIS

GIS represents features using various methods, including:

1. Vector Data: Vector data represents spatial information using points, lines, and polygons. Points denote specific locations, lines represent linear features like roads or rivers, and polygons outline areas such as parcels or administrative boundaries. Each element in vector data has associated attribute information, forming a comprehensive dataset for mapping and analysis.

   - Points: Represented by a single pair of coordinates (e.g., a city on a map).

   - Lines: Represent linear features (e.g., roads, rivers).

   - Polygons: Represent enclosed areas (e.g., countries, land parcels).

2. Raster Data: Raster data consists of a grid of cells, where each cell contains a value representing a specific attribute. Unlike vector data, which uses points, lines, and polygons, raster data is structured as a regular grid of pixels. Common examples include satellite imagery, elevation models, and land cover classifications. Raster data is suitable for continuous phenomena and provides a detailed representation of spatial variations across a landscape.
3. Networks: Networks typically refer to network data models used for representing and analyzing connectivity among spatial features, like roads, utility networks, or transportation systems. These models capture relationships between network elements, such as intersections and connectivity rules, enabling route analysis, network tracing, and other spatial analyses related to connectivity and flow.
4. Image Data: Image data usually involves raster data that represents spatial information through pixel values. This could include satellite imagery, aerial photographs, or other types of visual data. Each pixel in the image has a value corresponding to a certain attribute, such as color intensity or spectral information. Image data is valuable in GIS for tasks like land cover classification, change detection, and visual interpretation of geographic features.
5. 3D Models: In GIS, 3D models are representations of geographic features with elevation or height information, adding a third dimension to the traditional 2D spatial data. These models enable a more realistic depiction of the terrain, buildings, or other objects in the geographic space. 3D GIS is valuable for applications such as urban planning, environmental modeling, and simulations, providing a more comprehensive view of the landscape by incorporating elevation or elevation changes.

Sources of Data in GIS

Geographic Information Systems (GIS) rely on various sources of geographic data:

1. Maps: Digital and paper maps provide foundational spatial information, ranging from topographic maps to thematic maps depicting specific features like land use or population density.
2. Satellite Imagery and Aerial Photography: Remote sensing technologies capture high-resolution images from space or aircraft, offering detailed visual data for mapping and analysis.
3. Global Positioning System (GPS): GPS technology allows accurate location data collection in the field, contributing to the creation of spatial datasets and updating existing ones.
4. Field Surveys and Ground Truthing: On-site data collection through field surveys and ground truthing ensures accuracy by validating information obtained from other sources.
5. Census Data: Population and demographic data collected through national censuses provide essential information for various spatial analyses and mapping applications.
6. Remote Sensing Sensors: Specialized sensors, such as LiDAR (Light Detection and Ranging), collect three-dimensional data, enabling detailed mapping of terrain and vegetation.

Geo-referencing 

This is the process of associating a spatial location, typically expressed in coordinates (latitude and longitude), with data or imagery. This alignment allows geographic information to be accurately positioned within a specific coordinate system, enabling meaningful spatial analysis and integration within Geographic Information Systems (GIS). The importance of geo-referencing lies in several key aspects:

1. Spatial Accuracy: Geo-referencing ensures that geographic data accurately represents its real-world location, enhancing the reliability of analyses and decision-making.
2. Data Integration: By aligning various datasets to a common spatial reference system, geo-referencing facilitates the integration of diverse information sources, such as maps, satellite imagery, and survey data, within a cohesive framework.
3. Overlay Analysis: Geo-referenced data can be overlaid and compared, allowing analysts to identify spatial relationships, patterns, and correlations. This is crucial for tasks like land-use planning, environmental onitoring, and infrastructure development.
4. Navigation and Routing: Geo-referencing is fundamental to navigation systems, ensuring accurate positioning for applications like GPS-based navigation, location-based services, and routing algorithms.
5. Emergency Response: In times of disasters or emergencies, geo-referencing aids in quickly locating affected areas, coordinating rescue efforts, and managing resources efficiently.
6. Map Production: Geo-referencing is essential for creating accurate maps. It ensures that features on maps align with their true geographic positions, providing reliable reference points for map users.
7. Urban Planning: Geo-referencing is crucial for urban planners to analyze and visualize spatial patterns, assess infrastructure needs, and make informed decisions about city development.

EVALUATION: 1. Discuss the relationship between GIS and geographic data.

2. Identify 3 ways of representing features in GIS.
3. Identify 4 sources of Data in GIS.
4. What is geo-referencing? Give two importance of geo-referencing.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively