Define GIS. Describe benefits of GIS. What is remote sensing?

How remote Explain about the functional

A Geographic Information System (GIS) is sensing works? components of GIS.
a computer-based system that facilitates the Remote sensing is the science and Functional components:
phases of data entry, data analysis and data technology of collecting information Hardware – Computers, servers, GPS
presentation especially in cases when we are about objects or areas on Earth without devices, and other equipment used to run
dealing with georeferenced data. being in direct contact with them. GIS software and collect data.
Benefits of GIS: Remote sensing works in four main steps: Software – GIS programs that allow
1 Cost savings resulting from greater Energy Source (Sun or Sensor) data input, storage, analysis,
efficiency The Sun sends electromagnetic radiation visualization, and mapping (e.g.,
2 Better decisions making (light, heat, etc.) to Earth. ArcGIS, QGIS).
3 Improved Communication Some sensors (like radar) create their own Data – The core of GIS; includes spatial
4 Better geographic information signals. data (location, coordinates, shapes) and
recordkeeping Interaction with Earth’s Surface attribute data (descriptive information
5 Managing geographically. The energy hits the Earth's surface (land, about features).
…………………………………… water, vegetation, buildings). People / Users – Skilled personnel who
Explain elements of map. Some of it is reflected, absorbed, or operate GIS, analyze data, and make
Scale: transmitted. decisions based on GIS outputs.
Shows the ratio between distances on the Sensors Capture Energy Methods / Procedures – Techniques,
map and actual distances on the ground Satellites, aircraft, or drones have sensors workflows, and rules for collecting,
(e.g., 1 cm = 10 km). (cameras, scanners, radar). processing, analyzing, and presenting
Direction: These sensors record the reflected or geographic data efficiently.
Indicates directions (North, South, East, emitted energy. …………………………………………
West). Data Transmission & Processing Describe the characteristics of good
Legend: The recorded signals are sent to ground database design.
Explains the symbols, colors, and patterns stations. Data Integrity – Ensures that the
used on the map Computers process the raw data into database stores accurate, consistent, and
Title: images, maps, or measurements. reliable data, maintaining correctness
Tells what the map is about (e.g., "Political Scientists interpret the data for across all operations and preventing
Map of Nepal"). applications (like weather forecasting, errors from updates or deletions.
Symbols: agriculture, disaster management, etc.). Normalization – Organizes data
Represent real-world features (e.g., …………………………………… efficiently by removing redundancy and
mountains, rivers, roads, cities). What is digital terrain model? dividing it into related tables, which
…………………………………… Describe its application. reduces storage use and prevents
Discuss the principles and techniques A Digital Terrain Model (DTM) is a 3D anomalies.
involved in vector-based spatial analysis. representation of the bare ground surface Scalability – The design allows the
Principles Techniques of the Earth without objects like trees, database to grow in data volume and
buildings, or other structures. user load without losing performance or
Geometry-Based Buffering – It shows the elevation (height) values of speed.
Analysis – Uses Creating zones the Earth’s surface at different points. A Flexibility – A good database can adapt
shape, location, and around features DTM is usually created from remote to new requirements, making it easier to
spatial relationships (e.g., rivers, roads) sensing data (like LiDAR, modify, expand, or update as needs
Topology – photogrammetry, radar, or satellite change.
Overlay – images).
Maintains spatial Security – Protects sensitive information
Combining layers Application of DTM
relationships like using access controls, authentication,
to derive new Topographic Mapping
adjacency and and backups, ensuring only authorized
information Used to prepare contour maps and
connectivity users can modify or view data.
elevation profiles of an area. Efficiency – Optimizes the structure for
Attribute Integration Network Analysis
Civil Engineering & Construction quick storage, retrieval, and querying,
– Analyzes spatial – Shortest path,
Helps in planning roads, railways, dams, even when dealing with large or
features with their optimal routes,
canals, and tunnels by analyzing slopes complex datasets.
non-spatial attributes service areas
and elevations. Simplicity – Maintains a clear and
Overlay Analysis – Spatial Querying – Hydrology & Water Resource logical structure, making it easier for
Examines Selecting features Management developers and administrators to
relationships between based on location Used in flood modeling, watershed understand, manage, and maintain.
multiple layers or attributes analysis, drainage mapping, and river Data Consistency – Ensures uniformity
Network Analysis – Point-in-Polygon basin management. across the system, preventing conflicting
Studies connected Analysis – Urban & Regional Planning or contradictory information and
features such as roads Identifying points Supports land use planning, site maintaining reliability.
or pipelines inside polygons selection, and infrastructure
development.
Telecommunication
Helps in radio tower placement by
analyzing line-of-sight and signal
coverage.
Short Note: Define raster and vector data. Differentiate Explain spatial database design with
a) Map Layers between their properties with advantages example.
Map layers are the building blocks of and disadvantages. A spatial database design is the process
digital maps in a GIS. Each layer Raster Data: A type of spatial data of creating a database that can store,
represents a specific type of information represented as a grid of cells or pixels, where manage, and analyze spatial (location-
such as roads, rivers, land use, each cell stores a value showing information based) data along with traditional
vegetation, or elevation. By stacking like elevation, temperature, or imagery. attribute data. Unlike normal databases
multiple layers, a user can analyze the Vector Data: A type of spatial data that only handle text or numbers, spatial
relationships between different represented using points, lines, and polygons databases also handle geographic
geographic features. For example, in to define discrete features such as roads, objects like points, lines, and polygons,
Google Maps, you can view separate rivers, cities, and land boundaries. as well as their relationships (distance,
layers like traffic, satellite imagery, or Raster Data Vector Data area, overlap, connectivity).
terrain. Layers can be turned on or off as Steps in spatial database design:
needed, making them flexible and Represents data as Requirement Analysis – Identify what
Represents data as a
powerful tools for visualization and points, lines, and spatial and non-spatial data are needed.
grid of cells or pixels
analysis. polygons Conceptual Design – Create an Entity-
b) Map Projection Best for continuous Relationship (ER) model including
Best for discrete
A map projection is the method used to data (e.g., elevation, spatial entities.
data (e.g., roads,
represent the curved, three-dimensional temperature, satellite Logical Design – Define spatial data
boundaries, cities)
surface of the Earth on a flat, two- images) types (point, line, polygon) and
dimensional map. Since the Earth is File size is usually relationships.
spherical, this transformation always File size is smaller Physical Design – Implement tables,
large due to pixel
introduces some distortion in terms of and more compact indexes, and storage using a spatial
storage
shape, area, distance, or direction. DBMS (e.g., PostgreSQL with
Different projections are used for Provides high PostGIS, Oracle Spatial).
Accuracy depends on
different purposes: for example, the accuracy for shapes ……………………………………
resolution of pixels
Mercator projection is widely used for and boundaries Describe the role of GIS in
navigation because it preserves Easy to overlay and Easy to update, developing country like Nepal.
direction, while conic and azimuthal analyze continuous edit, and analyze GIS plays an important role in
projections are useful for regional or surfaces discrete features developing countries like Nepal by
polar mapping. The choice of projection Boundaries are less Boundaries are helping in planning, decision-making,
depends on the purpose of the map and precise (stair-step sharp and well- and resource management. It supports
the accuracy required. effect) defined sustainable development through
c) Geodatabase accurate mapping, monitoring, and
A geodatabase is a specialized database Suitable for analysis of natural and social resources.
Suitable for remote
designed to store, organize, and manage mapping, planning, GIS is useful in disaster management,
sensing and surface
geographic data along with related and network urban planning, agriculture, forestry,
modelling
attribute information. It can handle both analysis transportation, and health services,
vector data (points, lines, and polygons) ………………………………………… where reliable spatial data improves
and raster data (grids, images, and Explain different types of map projections. efficiency and reduces costs.
surfaces). Geodatabases are essential in Cylindrical Projection: In this projection, the Example Application:
GIS applications because they allow Earth’s surface is projected onto a cylinder In Nepal, GIS has been used in disaster
efficient storage, easy retrieval, and (e.g., Mercator). It preserves angles and management, especially for earthquake
advanced spatial analysis of large shapes, making it good for navigation, but and landslide risk mapping. By
datasets. They support data integration distorts area near the poles and is unsuitable analyzing terrain data and settlement
and sharing, making them widely used for global maps. patterns, authorities can identify high-
in fields such as urban planning, Conic Projection: The Earth is projected onto risk zones, plan safer infrastructure, and
environmental management, a cone (e.g., Albers Conic). It is ideal for mid- prepare effective emergency response
transportation, and resource monitoring. latitude regions with minimal distortion in strategies.
d) Spatial Database: smaller areas, but distortion increases away
A spatial database is a specialized from standard parallels, making it unsuitable
database designed to store, manage, and for world maps.
analyze spatial (geographic) data along Azimuthal (Planar) Projection: The surface
with their attributes. It supports vector is projected onto a flat plane, usually at a point
data (points, lines, polygons) and raster (e.g., Polar Projection). It preserves directions
data (grids, images), allowing efficient and distances from the center, useful for polar
queries, analysis, and mapping. Spatial mapping, but distortion grows toward the
databases are essential for GIS edges and is not ideal for large regions.
applications in urban planning, disaster Mathematical/Other Projections: These use
management, transportation, and formulas to flatten the Earth (e.g., Mollweide,
environmental monitoring. Robinson). They balance distortions of area,
shape, and distance for thematic maps, but
some distortion always remains and they are
not precise for navigation or engineering.
Explain functions and applications of What is GPS? Explain components of Describe the role of GIS in agriculture
GIS. GPS. for developing country like Nepal.
Functions: GPS (Global Positioning System) is a Soil and Land Analysis – Helps identify
Data Capture – Collecting spatial data satellite-based navigation system that soil types and land suitability for different
from maps, GPS, satellites, surveys, etc. provides location (latitude, longitude, crops.
Data Storage & Management – altitude) and time information anywhere Crop Monitoring – Tracks crop growth,
Organizing spatial and attribute data in on Earth, 24/7, under all weather health, and productivity using spatial data.
databases. conditions. It is widely used in Irrigation Planning – Assists in
Data Analysis – Performing spatial navigation, mapping, surveying, and designing efficient irrigation systems
queries, overlays, buffering, and tracking. based on terrain and water resources.
modeling. Components of GPS Pest and Disease Management – Maps
Visualization & Mapping – Displaying Space Segment – A constellation of at affected areas to plan targeted
data as maps, 3D models, or charts. least 24 satellites orbiting the Earth that interventions.
Data Sharing – Distributing maps and transmit signals. Yield Prediction – Analyzes
information for decision-making. Control Segment – Ground stations that environmental and climatic data to
Applications: monitor satellites, update their positions, estimate crop yields.
Urban Planning – Designing roads, and ensure signal accuracy. Resource Management – Optimizes use
utilities, and land use. User Segment – GPS receivers used by of fertilizers, water, and land for
Disaster Management – Earthquake, people to receive satellite signals and sustainable farming.
flood, and landslide risk mapping. calculate precise positions. ………………………………………
Agriculture – Crop monitoring, soil ………………………………………… Short Note:
analysis, irrigation planning. ………………………………. Map Feature:
Transportation – Route planning, traffic Explain the benefits of a geodetic Map features are the individual elements
management, logistics. datum based on ITRF? represented on a map to show real-world
Forestry & Environment – Global Accuracy – ITRF provides highly objects or phenomena. They can be points
Deforestation monitoring, wildlife habitat precise coordinates that are standardized (e.g., wells, schools), lines (e.g., rivers,
mapping. across the world, allowing users in any roads), or polygons (e.g., lakes, land
Health Services – Tracking disease country to reference the same spatial parcels). Features are usually linked with
outbreaks and planning health facilities. locations with minimal errors. attributes that provide additional
…………………………………….…… Consistency – By providing a uniform information, such as names, population, or
…………………………….… reference system, ITRF ensures that area. Map features form the foundation of
Define map projection. Describe the maps, surveys, and GIS datasets from GIS analysis and help users visualize
techniques used for map projection different regions or time periods can be spatial relationships.
A map projection is a method of integrated and compared reliably. Surface Modelling:
representing the curved, three- Accounts for Earth Movements – ITRF Surface modeling is the process of
dimensional surface of the Earth onto a considers tectonic plate movements and representing the continuous variation of a
flat, two-dimensional map. Since the other crustal deformations, making it geographic phenomenon over a region,
Earth is spherical, some distortion in suitable for long-term monitoring and such as elevation, temperature, or rainfall.
shape, area, distance, or direction is minimizing positional errors due to It uses techniques like raster grids, contour
unavoidable in any projection. Earth's dynamic changes. lines, or triangulated irregular networks
Techniques of Map Projection Supports GPS and Navigation – Since (TIN) to create a 3D or 2D model of the
Cylindrical Projection – The Earth’s GPS satellites are referenced to ITRF, surface. Surface modeling is widely used in
surface is projected onto a cylinder. using it as a datum ensures accurate topography, flood analysis, watershed
Conic Projection – The Earth’s surface is positioning for navigation, surveying, and management, and terrain visualization.
projected onto a cone. location-based services. Future of GIS
Azimuthal (Planar) Projection – The Scientific & Planning Applications – The future of GIS is rapidly evolving with
Earth’s surface is projected onto a flat ITRF-based geodetic data is essential for advances in technology, making it more
plane. applications like infrastructure intelligent, real-time, and accessible.
Mathematical/Conventional Projection development, disaster risk assessment, Integration with AI and machine learning
– Uses formulas instead of physical environmental monitoring, and will enhance predictive analysis, while IoT
shapes. geophysical research, where precise and GPS will enable live monitoring of
spatial information is critical. traffic, weather, and resources. Cloud-
based GIS will allow easy data sharing and
collaboration, and mobile GIS will expand
location-based services. Additionally, big
data analytics, 3D/4D modeling, and real-
time visualization will make GIS an
indispensable tool for urban planning,
disaster management, environmental
monitoring, and decision-making
worldwide.
Explain the term “Data is fuel to GIS”. Define Geodatabase. Briefly describe Explain the role of remote sensing in GIS
What are the types and sources of the steps for geodatabase design. data capturing.
geographic data? Describe different A geodatabase is a specialized database Data Acquisition – Remote sensing
data capturing methods. designed to store, manage, and analyze provides up-to-date spatial data from
spatial data along with associated satellites and aerial imagery.
The phrase means that GIS cannot attribute information. It supports both Large-Area Coverage – Captures data
function without data, just like a vehicle vector data and raster data enabling over large and inaccessible regions
cannot run without fuel. Spatial and efficient storage, retrieval, and analysis in efficiently.
attribute data form the foundation for GIS GIS applications. Multispectral Information – Collects
analysis, mapping, and decision-making. Steps for Geodatabase Design data in different spectral bands to analyze
Without accurate and sufficient data, GIS Requirement Analysis – Identify the vegetation, water, soil, and land use.
tools cannot produce meaningful results. types of spatial and attribute data needed Time-Series Analysis – Enables
Types of Geographic Data and the objectives of the GIS application. monitoring of changes over time (e.g.,
Spatial Data – Represents the location Conceptual Design – Create a model deforestation, urban growth).
and shape of geographic features. showing entities, relationships, and Integration with GIS – Remote sensing
Vector Data: Points, lines, polygons (e.g., spatial features. data can be processed and imported into
roads, rivers, land parcels). Logical Design – Define data structures, GIS for mapping, analysis, and decision-
Raster Data: Grid or pixel-based data spatial data types, topology rules, and making.
(e.g., satellite images, elevation, relationships. …………………………………………
temperature). Physical Design – Implement the
Attribute Data – Descriptive information database in a GIS system (e.g., ArcGIS Maps GPS
about spatial features (e.g., population of geodatabase, PostgreSQL/ PostGIS),
a city, type of soil, building height). including tables, feature classes, and Traditional source Satellite-based
Sources of Geographic Data indexes. of spatial data, system providing
Maps – Topographic, thematic, or Data Entry and Validation – Populate showing features precise location
cadastral maps. the geodatabase with spatial and attribute like roads, rivers, coordinates (latitude,
Remote Sensing – Satellite imagery and data and ensure accuracy and consistency. and boundaries longitude, altitude)
aerial photographs. …………………………………….. Provides general
Provides real-time,
GPS Surveys – Ground-based position What is hydrology modeling? Explain and static
dynamic, and highly
data using GPS devices. the role of GIS to solve the challenges information, often
accurate positional
Census and Field Surveys – in hydrology. in paper or digital
data
Demographic, environmental, and socio- Hydrology modeling is the process of form
economic data. simulating the movement, distribution, Ideal for precise
Existing Databases – Government and and quality of water in rivers, lakes, Good for large-
navigation,
institutional GIS datasets. watersheds, and groundwater systems. It scale planning and
surveying, and field
Data Capturing Methods helps predict floods, droughts, water reference
data collection
Digitization – Converting paper maps availability, and watershed behavior
into digital GIS data using scanners and using mathematical and computer-based May have errors
High accuracy with
digitizing tablets. models. due to outdated
minimal human error
Surveying / GPS Measurement – Role of GIS in Hydrology information or
if properly used
Collecting accurate location data with Watershed Delineation – Identifies scale limitations
total stations, GPS receivers, or drones. catchment areas and drainage networks. Enables tracking
Limited ability to
Remote Sensing – Using satellite or Flood Risk Assessment – Maps flood- changes over time
capture temporal
aerial images to extract spatial prone zones using elevation and rainfall with repeated
changes
information. data. measurements
Existing Data Import – Using pre- Water Resource Management – Data extraction Data is already in
existing digital maps, databases, or open- Analyzes River flow, groundwater may require digital format and
source GIS data. recharge, and reservoir planning. digitization for ready for GIS
Field Observation – Collecting attribute Soil and Land Use Analysis – Evaluates GIS use integration
and spatial data manually in the field. runoff, erosion, and sediment transport.
Decision Support – Helps planners and
authorities make informed choices for
irrigation, disaster management, and
environmental protection.