The Purpose of Geographic Information Systems (GIS)

GIS serves as a versatile tool to solve spatial problems, analyze geographic data, and support informed decision-making across diverse domains. Below are key purposes of GIS explained in detail:

1. Data Integration and Management

Purpose: To combine, organize, and manage spatial and non-spatial data from various sources.
GIS allows users to integrate data such as maps, satellite imagery, field surveys, and statistical records into a unified system.
This creates a comprehensive database that can be efficiently accessed, updated, and analyzed for various applications.

2. Spatial Analysis and Pattern Recognition

Purpose: To analyze spatial relationships, identify patterns, and understand trends.
GIS facilitates advanced spatial analyses, such as proximity, overlay, and clustering.
For example, it can identify the spread of diseases, monitor land use changes, or determine the shortest route between two points.

3. Visualization of Geographic Information

Purpose: To create maps and visual models that communicate complex spatial data effectively.
GIS transforms raw data into visual formats such as thematic maps, 3D models, and interactive dashboards.
These visualizations make it easier for users to understand geographic phenomena and communicate findings to stakeholders.

4. Decision-Making Support

Purpose: To provide insights that help in making informed decisions.
GIS supports decision-making in urban planning, disaster management, environmental conservation, transportation, and more.
For instance, GIS helps planners identify the best location for a new hospital by analyzing population density, accessibility, and existing facilities.

5. Monitoring and Management of Resources

Purpose: To monitor, manage, and conserve natural and human-made resources.
GIS is used to track deforestation, water resource distribution, and urban development.
It aids in ensuring sustainable use of resources by providing data-driven solutions to resource-related challenges.

6. Disaster Management and Risk Assessment

Purpose: To prepare for, respond to, and mitigate the impacts of disasters.
GIS helps identify vulnerable areas, plan evacuation routes, and allocate emergency resources efficiently.
It is widely used in flood mapping, earthquake risk assessment, and wildfire tracking.

7. Understanding Environmental Change

Purpose: To study and mitigate the effects of environmental changes.
GIS is critical in analyzing climate change impacts, monitoring biodiversity, and managing ecosystems.
It helps identify areas at risk of desertification, sea-level rise, or habitat loss.

8. Urban Planning and Infrastructure Development

Purpose: To plan and optimize urban growth and infrastructure.
GIS supports zoning, land-use planning, and transportation network design.
It enables planners to evaluate population trends and infrastructure demands for future development.

9. Public Health and Epidemiology

Purpose: To track diseases, manage healthcare resources, and ensure equitable service delivery.
GIS is used to map disease outbreaks, analyze healthcare access, and allocate medical resources effectively.
For example, during pandemics, GIS helps visualize hotspots and plan vaccination drives.

10. Historical and Cultural Preservation

Purpose: To document, study, and preserve historical and cultural landmarks.
GIS is used to map archaeological sites, monitor heritage preservation, and analyze spatial patterns of cultural significance.

11. Business and Market Analysis

Purpose: To support businesses in market analysis, customer targeting, and logistics planning.
GIS helps companies identify optimal locations for new stores, analyze market trends, and plan efficient delivery routes.

12. Education and Research

Purpose: To aid in academic and scientific studies involving spatial data.
GIS is used in fields such as geography, geology, ecology, and environmental science for data collection, analysis, and visualization.

Calicut University fyugp

Second semester notes

Comments

Accuracy Assessment

Accuracy assessment is the process of checking how correct your classified satellite image is . 👉 After supervised classification, the satellite image is divided into classes like: Water Forest Agriculture Built-up land Barren land But classification is done using computer algorithms, so some areas may be wrongly classified . 👉 Accuracy assessment helps to answer this question: ✔ "How much of my classified map is correct compared to real ground conditions?" Goal The main goal is to: Measure reliability of classified maps Identify classification errors Improve classification results Provide scientific validity to research 👉 Without accuracy assessment, a classified map is not considered scientifically reliable . Reference Data (Ground Truth Data) Reference data is real-world information used to check classification accuracy. It can be collected from: ✔ Field survey using GPS ✔ High-resolution satellite images (Google Earth etc.) ✔ Existing maps or survey reports 🧭 Exampl...

History of GIS

1. 1832 - Early Spatial Analysis in Epidemiology: - Charles Picquet creates a map in Paris detailing cholera deaths per 1,000 inhabitants. - Utilizes halftone color gradients for visual representation. 2. 1854 - John Snow's Cholera Outbreak Analysis: - Epidemiologist John Snow identifies cholera outbreak source in London using spatial analysis. - Maps casualties' residences and nearby water sources to pinpoint the outbreak's origin. 3. Early 20th Century - Photozincography and Layered Mapping: - Photozincography development allows maps to be split into layers for vegetation, water, etc. - Introduction of layers, later a key feature in GIS, for separate printing plates. 4. Mid-20th Century - Computer Facilitation of Cartography: - Waldo Tobler's 1959 publication details using computers for cartography. - Computer hardware development, driven by nuclear weapon research, leads to broader mapping applications by early 1960s. 5. 1960 - Canada Geograph...

Development and scope of Environmental Geography and Recent concepts in environmental Geography

Environmental Geography studies the relationship between humans and nature in a spatial (place-based) way. It combines Physical Geography (natural processes) and Human Geography (human activities). A. Early Stage 🔹 Environmental Determinism Concept: Nature controls human life. Meaning: Climate, landforms, and soil decide how people live. Example: People in deserts (like Sahara Desert) live differently from people in fertile river valleys. 🔹 Possibilism Concept: Humans can modify nature. Meaning: Environment gives options, but humans make choices. Example: In dry areas like Rajasthan, people use irrigation to grow crops. 👉 In this stage, geography was mostly descriptive (explaining what exists). B. Evolution Stage (Mid-20th Century) Environmental problems increased due to: Industrialization Urbanization Deforestation Pollution Geographers started studying: Environmental degradation Resource management Human impact on ecosystems The field became analytical and problem-solving...

Change Detection

Change detection is the process of finding differences on the Earth's surface over time by comparing satellite images of the same area taken on different dates . After supervised classification , two classified maps (e.g., Year-1 and Year-2) are compared to identify land use / land cover changes . Goal To detect where , what , and how much change has occurred To monitor urban growth, deforestation, floods, agriculture, etc. Basic Concept Forest → Forest = No change Forest → Urban = Change detected Key Terminologies Multi-temporal images : Images of the same area at different times Post-classification comparison : Comparing two classified maps Change matrix : Table showing class-to-class change Change / No-change : Whether land cover remains same or different Main Methods Post-classification comparison – Most common and easy Image differencing – Subtract pixel values Image ratioing – Divide pixel values Deep learning methods – Advanced AI-based detection Examples Agricult...

Supervised Classification

Image Classification in Remote Sensing Image classification in remote sensing involves categorizing pixels in an image into thematic classes to produce a map. This process is essential for land use and land cover mapping, environmental studies, and resource management. The two primary methods for classification are Supervised and Unsupervised Classification . Here's a breakdown of these methods and the key stages of image classification. 1. Types of Classification Supervised Classification In supervised classification, the analyst manually defines classes of interest (known as information classes ), such as "water," "urban," or "vegetation," and identifies training areas —sections of the image that are representative of these classes. Using these training areas, the algorithm learns the spectral characteristics of each class and applies them to classify the entire image. When to Use Supervised Classification: - You have prior knowledge about the c...

Vineesh V, Geography

Search This Blog