Briefly explain the concept of GIS. What are the various components of GIS?
How GIS can help for transport planning and traffic management.
GIS stands for Geographic Information System. It is a computer-based system that allows users
to collect, manage, analyze, and visualize spatial (geographic) data. GIS technology enables
users to explore and interpret data in order to make informed decisions related to a particular
location or region. GIS is used in a wide variety of fields including urban planning, natural
resource management, transportation, and public health, among others. The technology is
particularly useful for analyzing spatial patterns and relationships, and can help users to identify
trends and make predictions about future events.
The components of a GIS are;
•
•
•
•
•
Hardware: This includes the physical equipment used to run the GIS software, such as
computers, servers, and peripherals.
Software: This includes the GIS applications and tools used to collect, manage, analyze,
and visualize geographic data. Some popular GIS software includes ArcGIS, QGIS, and
GRASS GIS.
Data: This includes the geographic data used by the GIS, such as satellite imagery, digital
elevation models, and vector data (e.g. points, lines, and polygons).
People: This includes the individuals who use the GIS technology, including GIS analysts,
data scientists, and developers.
Procedures: This includes the workflows and processes used to manage and analyze
geographic data using GIS tools.
GIS can be a valuable tool for transport planning and traffic management in a number of
ways:
•
•
•
•
Spatial analysis: GIS can be used to analyze traffic flow patterns, identify bottlenecks,
and determine the best routes for vehicles. This can help to optimize transport networks
and reduce congestion.
Real-time data: GIS can be used to monitor traffic in real-time using sensors and
cameras, allowing transport authorities to respond quickly to incidents and manage
traffic flow more effectively.
Network optimization: GIS can be used to model different transport scenarios, allowing
planners to test the impact of changes to road networks, public transport systems, and
other transport infrastructure.
Public transport planning: GIS can be used to identify areas with high demand for public
transport, plan new routes, and optimize existing networks to improve accessibility and
reduce journey times.
•
•
Environmental impact assessment: GIS can be used to assess the environmental impact
of transport projects, such as new roads or public transport systems, by modeling noise
pollution and air quality.
Emergency response: GIS can be used to support emergency response by providing realtime data on traffic flow, road closures, and alternative routes.
“GIS is a multibillion dollar business”. Explain.
The use of GIS has been growing rapidly and will continue to do so for many years. It will
become so integrated into our lives that we won't be able to imagine how we lived without it. It
has been an amazing success story in marketing and will keep changing the way we do things.
GIS is indeed a multibillion-dollar business that is expected to continue growing in the coming
years. According to market research, the global GIS market size was valued at USD 7.5 billion in
2020 and is projected to reach USD 14.8 billion by 2025, growing at a compound annual growth
rate (CAGR) of 14.2% during the forecast period.
There are several factors driving the growth of the GIS market, including:
•
•
•
•
Increasing demand for location-based services: With the widespread adoption of
smartphones and other mobile devices, there has been a growing demand for locationbased services, such as mapping, navigation, and location-based marketing.
Advancements in GIS technology: There have been significant advancements in GIS
technology in recent years, including improvements in data capture, processing, and
visualization. These advancements have made GIS more accessible and easier to use,
which has helped to drive market growth.
Growing adoption across industries: GIS is now being used across a wide range of
industries, including agriculture, energy, transportation, and urban planning. As more
organizations realize the benefits of GIS, the market is expected to continue to grow.
Government initiatives: Governments around the world are investing in GIS
infrastructure to support various initiatives, such as smart cities, environmental
monitoring, and disaster management. These investments are driving market growth
and creating new opportunities for GIS vendors.
Define GIS as an Information System. How a country like Nepal can benefit from
GIS? Describe its application in Agriculture.
GIS, or Geographic Information System, is an information system that allows users to collect,
store, manage, analyze, and visualize data with a geographic component. GIS combines spatial
data, such as maps and satellite imagery, with non-spatial data, such as population and
economic statistics, to provide a more complete understanding of a particular phenomenon or
issue.
A country like Nepal can benefit from GIS in several ways. Some of the potential applications
of GIS in Nepal include:
•
•
•
•
Disaster management: Nepal is prone to natural disasters, such as earthquakes, floods,
and landslides. GIS can be used to create maps of disaster-prone areas, model the
impact of natural disasters, and support emergency response efforts.
Urban planning: Rapid urbanization and population growth have put pressure on
Nepal's cities and infrastructure. GIS can be used to create maps of urban areas, model
the impact of new development, and support more effective urban planning.
Natural resource management: Nepal has significant natural resources, including
forests, water, and minerals. GIS can be used to map and monitor these resources,
support sustainable management practices, and ensure equitable distribution of
benefits.
Agriculture: Agriculture is a significant sector of Nepal's economy, and GIS can be used
to support precision agriculture practices, including soil analysis, crop monitoring, and
yield forecasting.
The application of GIS in agriculture, some of the potential benefits are:
•
•
•
•
Precision agriculture: GIS can be used to map soil properties and moisture content,
which can help farmers optimize irrigation and fertilization practices, leading to higher
crop yields and reduced costs.
Crop monitoring: GIS can be used to monitor crop growth and health, helping farmers
identify potential issues early and take corrective action.
Yield forecasting: GIS can be used to model crop growth and yield potential, helping
farmers plan for harvest and make informed decisions about inputs and marketing.
Land use planning: GIS can be used to map and analyze land use patterns, helping
farmers make informed decisions about crop rotations and diversification.
Explain the various applications with suitable examples of GIS in Municipality.
Some of the applications of GIS in Municipality are;
•
•
•
Zoning and land use planning: GIS can be used to create maps that show current zoning
designations, land use patterns, and development potential. This information can be
used to guide land use decisions and identify areas for future development.
Infrastructure management: Municipalities are responsible for managing a range of
infrastructure assets, including roads, bridges, water supply systems, and sewage
treatment plants. GIS can be used to map and manage these assets, track maintenance
and repair activities, and plan for future upgrades or expansions.
Emergency management: In the event of a natural disaster or other emergency, GIS can
be used to create maps of affected areas, track the movement of emergency response
teams, and coordinate relief efforts.
•
•
•
•
Public safety: GIS can be used to map crime patterns, identify high-risk areas, and track
the deployment of police and other public safety personnel.
Environmental management: Municipalities are responsible for managing natural
resources and protecting the environment. GIS can be used to map wetlands, track
water quality, and monitor air pollution levels.
Transportation planning: GIS can be used to create maps of existing transportation
infrastructure, model traffic patterns, and plan for future transportation improvements,
such as new roads or public transit systems.
Property assessment and tax collection: GIS can be used to create maps of property
boundaries, assess property values, and collect property taxes.
Why do we need map in GIS? Explain the elements of MAP in brief.
Maps are an essential component of GIS because they provide a visual representation of spatial
data. GIS uses maps to help users understand the relationships and patterns within spatial data
and to make informed decisions based on that data.
Element of Map
Almost all maps have certain basic elements that provide critical information for effective use of
the map. These include the title, scale, legend, body of the map, north arrow, cartographer, neat
line, date of production, projection used, and information about sources. The placement and
style of depiction may vary based on the map's purpose and audience. While some elements
are found on almost all maps, others may depend on the context in which the map will be used.
•
•
•
Scale: The scale is the relationship between the distance on the map and the actual
distance on the ground. It helps users understand the size and relative location of
features on the map. For example, a scale of 1:10,000 means that 1 unit of distance on
the map represents 10,000 units of distance on the ground.
Explanation (Legend): The explanation or legend is a key that explains the meaning of
the symbols, colors, and patterns used on the map. It allows users to understand the
data represented and interpret the map accurately.
Direction: Direction refers to the orientation of the map and is typically indicated by a
north arrow. It helps users understand the direction of features on the map in relation to
the cardinal directions of north, south, east, and west.
What is projection? How it is different from MAP?
Projection refers to the process of creating a two-dimensional map of the earth's surface from a
three-dimensional globe. Since the earth is round and maps are flat, a projection is used to
show the curved surface of the earth on a flat map.
Projection
A mathematical method used to represent
the three-dimensional surface of the earth on
a two-dimensional map
Involves flattening the curved surface of the
earth onto a two-dimensional surface
Many different types of projections are
available, each with its own strengths and
weaknesses
Projections can affect the accuracy and
usefulness of a map
A projection is an essential part of creating a
map in GIS
Map
A visual representation of geographic data
A two-dimensional image of geographic
features, typically created using a projection
Maps can be created using various
projections, but also incorporate other
elements such as legend, scale, and labels
Maps can be customized and styled to convey
specific information or to suit the intended
audience
A map can be created without a projection,
but it may not be an accurate representation
of the earth's surface
Explain the techniques used to create a projection.
There are many techniques used to create a projection in GIS, but the basic idea is to transform
the three-dimensional surface of the earth into a two-dimensional plane. Here are some
common techniques used in projection creation:
•
•
•
Cylindrical projection: This technique involves wrapping a cylinder around the globe and
projecting the image of the earth onto the cylinder. The cylinder is then flattened out to
create a two-dimensional map. The most common example of a cylindrical projection is
the Mercator projection.
Conic projection: This technique involves wrapping a cone around a portion of the globe
and projecting the image onto the cone. The cone is then unrolled to create a twodimensional map. Conic projections are often used to represent regions that are taller
than they are wide, such as North and South America.
Planar projection: This technique involves projecting the image of the earth onto a flat
plane. This creates a two-dimensional map that is centered on a specific point on the
earth's surface. Planar projections are often used for maps that focus on a particular
region or city.
What are main sources of GIS Data? Explain the various methods of data capture
in GIS.
There are many sources of GIS data, including:
•
•
•
•
Remote sensing: This involves collecting data from satellites, aircraft, or drones that
capture images of the earth's surface. The data collected can include images, infrared
data, and radar data.
Surveying: This involves collecting data on the ground using tools such as GPS, total
stations, and surveying equipment.
Existing data sources: This includes data that has already been collected for other
purposes, such as census data, weather data, or geological data.
Crowd-sourcing: This involves collecting data from the public, often through mobile apps
or web-based platforms.
The various methods of data capture in GIS include:
•
•
•
•
•
•
•
GPS: This involves using GPS receivers to collect data on the ground, such as the location
of features or the elevation of terrain.
Aerial photography: This involves capturing images of the earth's surface from the air
using aircraft or drones.
Satellite imagery: This involves collecting data from satellites orbiting the earth that
capture images of the earth's surface.
Lidar: This involves using lasers to create high-resolution images of the earth's surface,
which can be used to create 3D models of terrain and other features.
Field surveys: This involves collecting data on the ground using tools such as GPS, total
stations, and surveying equipment.
Digitizing: This involves manually tracing features on a paper map and entering the data
into a GIS software.
Crowdsourcing: This involves collecting data from the public, often through mobile apps
or web-based platforms.
What do you mean by spatial data modelling? Explain spatial data types. What is
geocoding? Explain spatial analysis with example.
Spatial data modeling is the process of creating a representation of real-world objects, events,
or phenomena in a digital format that can be analyzed and manipulated in a GIS. It involves
organizing and structuring spatial data in a way that accurately reflects the spatial relationships
and characteristics of the objects or features being represented.
There are two main types of spatial data: vector and raster.
•
•
Vector data: Vector data represents geographic features as points, lines, and polygons.
Points are used to represent discrete features such as cities, while lines represent linear
features such as roads or rivers. Polygons are used to represent areas such as counties or
states. Vector data is stored as a series of coordinate pairs that define the location of
each feature. Vector data is useful for analyzing discrete features and their relationships
to other features in a GIS.
Raster data: Raster data represents geographic features as a grid of cells or pixels, with
each cell having a value representing a specific attribute. Raster data is commonly used
to represent continuous phenomena such as elevation, temperature, or rainfall. Raster
data is stored as a grid of values that cover a defined geographic area. Raster data is
useful for analyzing continuous phenomena across a large area.
Geocoding is the process of converting a textual address or place name into geographic
coordinates, such as latitude and longitude. This allows users to locate addresses on a map
and analyze associated spatial data. Geocoding is done by matching the textual address to a
database of known addresses and geographic coordinates, which can be collected from
sources like postal services, GPS devices, and satellite imagery. Overall, geocoding is a
valuable tool in fields like urban planning, transportation management, and marketing
analysis.
Spatial analysis is the process of examining spatial data using analytical methods and
techniques to extract meaningful insights and knowledge. It involves studying patterns and
relationships in geographic data to gain insights into various phenomena and processes that
occur in the real world. Spatial analysis can be performed using a variety of tools and
techniques such as statistical analysis, data visualization, and spatial modeling. It is widely
used in fields such as geography, urban planning, environmental science, public health, and
business.
For example, let's say a city wants to analyze the distribution of its parks and playgrounds to
ensure they are equitably distributed throughout the city. They can use spatial analysis tools
to map the locations of all parks and playgrounds, along with demographic data such as
population density, income levels, and age groups. By analyzing this data, they can identify
areas that are underserved and in need of additional parks and playgrounds.
What do you mean by coordinate system in GIS? Explain any four.
A coordinate system is a standardized method for assigning codes to locations so that
locations can be found using the codes alone. Standardized coordinate systems use absolute
locations.
There are several types of coordinate systems used in GIS, including:
•
•
•
•
Geographic coordinate system (GCS): A GCS is a system that uses latitude and
longitude to define the locations of features on the Earth's surface. It is based on a
three-dimensional model of the Earth, which is known as a geoid.
Projected coordinate system (PCS): A PCS is a system that uses Cartesian
coordinates to represent locations on a two-dimensional map. It is based on a
mathematical transformation of the GCS to a flat surface.
State Plane Coordinate System (SPCS): SPCS is a widely used system in the United
States that divides the country into 124 zones and uses a combination of Cartesian
and geographic coordinates to represent locations on a two-dimensional map.
Universal Transverse Mercator (UTM): UTM is a global system that divides the Earth
into 60 zones, each of which has a unique grid system for representing locations on a
two-dimensional map. It is widely used for navigation and military applications.
Explain GPS and remote sensing with example
GPS (Global Positioning System) and remote sensing are both technologies used in Geographic
Information Systems (GIS) to collect and analyze spatial data.
GPS is a satellite-based navigation system that provides location and time information in all
weather conditions, anywhere on or near the earth's surface. It uses a network of satellites and
receivers to triangulate a user's position on the earth's surface, and can be used to determine
the position of vehicles, people, and assets in real-time. For example, a GPS device in a car can
provide driving directions to a user, or a GPS-enabled smartphone can allow users to check in on
social media at a specific location.
Remote sensing involves collecting data about the earth's surface from a distance, usually from
satellites, aircraft, or drones. The data collected can be in the form of images or spectral data
that can be used to identify and analyze the properties of the earth's surface, such as land use,
vegetation, water resources, and temperature. For example, remote sensing can be used to
track the growth and health of crops over a large area, or to monitor changes in the
environment over time.
An example of how both GPS and remote sensing can be used together is in precision
agriculture. GPS can be used to determine the precise location of crops or agricultural
equipment, while remote sensing can provide data on soil moisture, crop health, and other
factors that affect crop yields. By combining these two technologies, farmers can optimize their
crop yields and reduce waste.
What do you mean by Digital Surface Model (DSM)? Explain its application with
example.
A Digital Surface Model (DSM) is a digital representation of the earth's surface, including both
natural and man-made features, such as buildings, vegetation, and terrain. It is a type of digital
elevation model (DEM) that represents the highest point on the earth's surface, including all
objects and features, like trees, buildings, and infrastructure. DSM is a useful tool for various
applications such as 3D modeling, urban planning, and flood modeling.
Applications of Digital Surface Model along with examples are described below:
•
•
•
•
Urban planning: DSMs can be used to create 3D models of cities and towns, which can
be used for urban planning, zoning, and design. For example, DSMs can help identify
areas at risk of flooding or landslides, determine the best locations for new buildings,
and assess the impact of proposed developments on the surrounding environment.
Environmental monitoring: DSMs can be used to monitor changes in the Earth's surface
over time, such as erosion, deforestation, and land use changes. For example, DSMs can
help identify areas at risk of soil erosion, track changes in wetlands and water bodies,
and monitor the impact of climate change on the landscape.
Agriculture: DSMs can be used to optimize crop management, including irrigation,
fertilization, and harvesting. For example, DSMs can help identify areas with the best soil
quality, monitor crop growth and health, and estimate crop yields.
Natural resource management: DSMs can be used to manage natural resources, such as
forests, water bodies, and wildlife habitats. For example, DSMs can help identify areas
with the highest biodiversity, monitor changes in forest cover and deforestation, and
track the movement of wildlife populations.
What are raster and vector data? Differentiate between their properties with
advantages and disadvantages.
Raster data refers to data that is represented as a grid of cells or pixels, where each cell or pixel
has a value that represents a specific attribute, such as elevation or temperature. Raster data is
commonly used for continuous data, such as satellite imagery, digital elevation models, and
weather data.
Vector data, on the other hand, represents features as points, lines, and polygons. Vector data
is commonly used for discrete data, such as roads, rivers, and administrative boundaries.
Here are some key differences between raster and vector data:
•
•
•
•
Representation: Raster data is represented as a grid of cells, while vector data is
represented as individual points, lines, and polygons.
Scale: Raster data is more suited for large-scale analysis, such as terrain analysis or land
use mapping, while vector data is more suited for small-scale analysis, such as street
mapping or parcel identification.
Accuracy: Vector data is generally more accurate than raster data, as it represents
features more precisely. Vector data is preferred for accurate mapping of features like
roads, buildings, and land parcels, while raster data is better suited for modeling
continuous phenomena like temperature, rainfall, or elevation.
Data size: Raster data can be very large in size, as each pixel has a value, while vector
data is generally smaller in size, as it only stores the coordinates of the features. This
means that raster data requires more storage space and processing power than vector
data.
Advantages of Raster Data:
•
•
•
Suitable for continuous data analysis.
Can be used for large-scale analysis.
Can be easily processed using mathematical operations such as interpolation and
convolution.
Disadvantages of Raster Data:
•
•
•
Can be computationally intensive for large datasets.
Lower accuracy than vector data.
Data size can be very large, which can be challenging to manage.
Advantages of vector data:
•
•
•
More accurate than raster data.
Suitable for small-scale analysis.
Smaller data size than raster data.
Disadvantages of Vector Data:
•
•
•
Cannot represent continuous data as well as raster data.
Processing can be complex, especially for complex topologies.
Difficult to overlay multiple layers due to differences in topology.
Describe wireframe modelling and surface modelling with their advantages and
disadvantages.
In wire frame modelling, a geometric model of an object is created by using the two
dimensional geometric entities such as: points, straight lines, curves, polygons, circles etc.
Wireframe modeling is a technique where a geometric model of an object is created using twodimensional geometric entities such as points, straight lines, curves, polygons, circles, etc. These
entities are connected to form a network of lines and edges, which represent the outer
boundaries and internal structure of the 3D object. Wireframe models are typically used as a
starting point for creating more complex 3D models.
Advantages of Wireframe Modeling:
•
•
•
Easy to create and modify
Requires less computer memory and processing power compared to other 3D modeling
techniques
Suitable for creating simple shapes and objects
Disadvantages of Wireframe Modeling:
•
•
•
Limited ability to represent complex objects and shapes with smooth surfaces
Lack of realism in the final output
Difficult to visualize the final product without additional software or rendering tools
Surface modeling is a technique where a 3D object is created by defining the surfaces of the
object. The surfaces are defined using mathematical equations, and the object is created by
combining multiple surfaces together. Surface modeling is suitable for creating objects with
smooth, continuous surfaces, such as car bodies, airplane fuselages, and product designs.
Advantages of Surface Modeling:
•
•
•
Ability to create complex shapes and objects with smooth surfaces
Realistic representation of the final product
Can be used for rapid prototyping and design iteration
Disadvantages of Surface Modeling:
•
•
•
Requires more computer memory and processing power compared to wireframe
modeling
Can be difficult to create and modify for beginners
Can result in more complex models, which can be challenging to manage and work with
How can we use hydrologic modelling for the simplification of the real world
system (surface water, soil water, wetland, ground water)? Explain.
Hydrologic modeling is a technique used to simplify and represent complex real-world
hydrologic systems, such as surface water, soil water, wetlands, and groundwater, using
mathematical models. These models can be used to simulate the behavior and interactions of
different components of the hydrologic system and to predict the impact of different scenarios
or changes to the system.
Hydrologic modeling can be used for simplification of the real-world system in the following
ways:
•
•
•
•
•
Simplification of system components: Hydrologic modeling can help to simplify the
complex interactions and relationships between different components of the hydrologic
system. By breaking down the system into its component parts, such as surface water,
soil water, wetlands, and groundwater, and modeling their behavior separately, we can
gain a better understanding of the system as a whole.
Identification of key variables: Hydrologic modeling can help to identify the key
variables and parameters that influence the behavior of the hydrologic system. By
focusing on these key variables, we can simplify the modeling process and reduce the
complexity of the system.
Prediction of system behavior: Hydrologic modeling can be used to predict the behavior
of the hydrologic system under different scenarios, such as changes in precipitation, land
use, or climate. These predictions can help to simplify the understanding of the system
and highlight the most important factors that influence its behavior.
Prediction of system behavior: Hydrologic modeling can be used to predict the behavior
of the hydrologic system under different scenarios, such as changes in precipitation, land
use, or climate. These predictions can help to simplify the understanding of the system
and highlight the most important factors that influence its behavior.
Optimization of system management: Hydrologic modeling can be used to optimize the
management of the hydrologic system. By simulating different management scenarios,
such as water conservation, flood control, or groundwater recharge, we can identify the
most effective strategies for managing the system.