MEV 019: Unit 06 - Geospatial Tools
6.1 Introduction
Geospatial tools play a transformative role in
modern environmental science. These tools involve technologies that collect,
analyze, and interpret spatial data to better understand and manage the Earth's
surface and its dynamic changes. Whether it's tracking deforestation, assessing
flood risk, or mapping biodiversity, geospatial technologies like Remote
Sensing, GIS, and GNSS provide critical insights for research and
policy-making.
6.2 Objectives
After studying this unit, learners will be able
to:
- Understand the basic principles and components of geospatial tools.
- Differentiate among Remote Sensing, GIS, and GNSS technologies.
- Explore the various environmental applications of geospatial
technologies.
- Identify sources and types of geospatial data.
- Recognize the importance of geospatial analysis in climate and
ecosystem studies.
6.3 Basic Concepts
6.3.1 Remote Sensing
Remote Sensing (RS) is the science of obtaining
information about objects or areas from a distance, typically from aircraft or
satellites. It involves capturing electromagnetic radiation reflected or
emitted from the Earth's surface.
Key Features:
- Sensors can be active (RADAR, LiDAR) or passive (optical, thermal).
- Data is collected in various spectral bands (visible, infrared,
microwave).
- Applications include vegetation analysis, land use mapping, and
disaster monitoring.
6.3.2 Geographic Information
System (GIS)
GIS is a computer-based system
used to capture, store, analyze, manage, and visualize spatial or geographic
data.
Components of GIS:
- Hardware: Computers, GPS units, servers.
- Software: Tools like ArcGIS, QGIS.
- Data: Spatial (maps, shapefiles) and attribute data (tabular).
- People and Procedures: Analysts, scientists,
workflows.
Functions:
- Overlay analysis
- Spatial queries
- Buffering
- Network and terrain analysis
6.3.3 Global Navigation
Satellite System (GNSS)
GNSS refers to satellite systems
that provide geolocation and time information anywhere on Earth. GPS (USA),
GLONASS (Russia), Galileo (EU), and NavIC (India) are key GNSS systems.
Applications in Environmental Science:
- Field data collection
- Real-time tracking of environmental phenomena
- Precision mapping of habitats, pollution sources, or disaster zones
6.4 Applications of Geospatial
Technologies
6.4.1 Natural Resources
Management
Geospatial tools help monitor and manage
forests, water bodies, minerals, and agricultural lands.
Examples:
- Forest cover change detection
- Watershed delineation and water quality assessment
- Land degradation and soil erosion mapping
6.4.2 Mapping and Monitoring
Urban Environment
Urbanization can be tracked and assessed using
satellite imagery and GIS.
Key Applications:
- Land use and land cover (LULC) mapping
- Urban sprawl analysis
- Infrastructure planning and zoning
- Pollution hotspot detection (air, water, noise)
6.4.3 Terrestrial and Aquatic
Ecosystems Related Studies
Geospatial tools support biodiversity
conservation and ecosystem health assessments.
Examples:
- Wildlife habitat mapping and corridor design
- Wetland inventory and monitoring
- Coral reef and mangrove monitoring
6.4.4 Climate Related Studies
Climate models and environmental indicators are
often spatially analyzed using GIS and RS.
Key Uses:
- Temperature and precipitation mapping
- Drought and flood modeling
- Sea level rise impact analysis
- Climate vulnerability and risk mapping
6.5 Geospatial Data and their
Sources
Geospatial data can be derived from various
primary and secondary sources.
Types of Data:
- Raster data: Pixel-based (e.g., satellite images, aerial photographs)
- Vector data: Point, line, and polygon features (e.g., rivers, roads,
administrative boundaries)
Sources:
- Remote Sensing Satellites: Landsat, Sentinel, IRS,
MODIS
- Survey and Field Instruments: GNSS/GPS devices
- Public Data Repositories: Bhuvan (ISRO), USGS
EarthExplorer, Copernicus Open Access Hub
- Crowdsourced Platforms: OpenStreetMap, citizen
science apps
6.6 Let Us Sum Up
Geospatial tools have become indispensable in
environmental research and management. Remote sensing allows for large-scale
observation, GIS provides analytical capabilities, and GNSS ensures spatial
accuracy in field data. Together, they support applications ranging from
resource management to urban planning and climate resilience.
6.7 Key Words
- Remote Sensing (RS): Technique for observing
Earth from a distance.
- Geographic Information System (GIS): System for managing
spatial data and performing geographic analyses.
- Global Navigation Satellite System (GNSS):
Satellite systems used for positioning and navigation.
- Raster Data: Grid-based data, typically from images or scans.
- Vector Data: Geographic data represented as points, lines, and polygons.
- Overlay Analysis: GIS technique to
analyze spatial relationships by layering datasets.
- LULC: Land Use and Land Cover.
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